U4 O1 - Gastrointestinal and Medical Abdominal Emergencies Flashcards

Question

What 3 body systems can be the cause of regurgitation?

Answer 1

oesophageal/pharyngeal disease neuromuscular disease endocrine

Answer 2

``` Megaoesophagus oesophagitis obstruction - foreign body stricture mass vascular ring anomaly hiatus hernia gasto-oesophageal intususseption ```

Answer 3

``` Myasthenia gravis Tetanus Botulism dysautonomia polyneuropathy ```

Answer 4

hypothyroidism | hypoadrenocorticism

Answer 5

There may also be coughing, weakness, fever and respiratory signs, secondary to concurrent aspiration pneumonia. Animals with regurgitation will be predisposed to developing aspiration pneumonia since they are unable to protect their airway.

Answer 6

A patient with generalised neuromuscular disease may also have exercise intolerance/collapse

Answer 7

A cat with feline dysautonomia (Key-Gaskell syndrome) will have additional clinical signs associated with this condition e.g. mydriasis, constipation. A presumptive diagnosis of feline dysautonomia is often made based on clinical signs. However to obtain a definitive diagnosis tissue samples are required. Cats that are severely affected carry a grave prognosis.

Answer 8

A minimum database of haematology (PCV, blood smear etc.), biochemistry and urinalysis is advised (Garosi, 2013). Bloodwork may reveal abnormalities consistent with an underlying disease process (e.g. ↑ K and ↓ Na with hypoadrenocorticism); or aspiration pneumonia (neutrophilia with left shift). A patient with a pyloric outflow obstruction, for example, may have regurgitation alongside vomiting due to mechanical obstruction of food outflow. However, the blood results for this patient may show a hypochloraemic, hypokalaemic metabolic alkalosis caused by vomiting of stomach origin.

Answer 9

Thoracic radiography is of great value in animals with regurgitation if it can be performed without risk to the patient. It can confirm the presence and extent of a megaoesophagus; and the presence and location of radiopaque foreign bodies. Depending on the underlying cause of the regurgitation, signs of aspiration pneumonia and pneumomediastinum may also be apparent. When trying to confirm the presence of megaoesophagus, radiography should ideally be performed in the conscious patient, as general anaesthesia can lead to radiographic signs of megaoesophagus associated with muscle relaxation and the agents used

Answer 10

The patient should be positioned carefully for a lateral view, with the head elevated, ideally, by using a tilted table. If the patient starts to regurgitate it should be moved immediately to sternal recumbency to reduce the chance of aspiration occurring. A positive contrast study e.g. barium meal may be required to confirm the cause of the regurgitation. N.B. Barium sulphate should NOT be administered if there is any possibility of an alimentary perforation and it should only be administered to a conscious patient. Great care MUST be taken to prevent regurgitation and aspiration following the administration of barium sulphate

Answer 11

a regurgitating patient is a higher risk of aspiration pneumonia. Therefore, if radiography cannot be performed in the conscious patient, a rapid sequence general anaesthetic induction and intubation is a safer option than sedation and leaving the patient with an unprotected airway. The RVN should ensure that suction is available, the animal is induced in sternal recumbency and the airway is secured as quickly as possible. Careful monitoring throughout the procedure and into recovery is vital. Ultrasound examination can also provide diagnostic information e.g. presence of an oesophageal mass. It is non-invasive and does not require sedation or anaesthesia. However, identifying abnormalities of the oesophagus may be challenging- therefore a combination of diagnostics is normally indicated. POCUS can also highlight areas of pulmonary consolidation which may be indicative of aspiration pneumonia. Further investigation might involve specific tests such as ‘a thyroid panel’ or an ACTH stimulation test may be performed; identifying antibodies to acetylcholine (Ach) receptor sites will aid a diagnosis of myasthenia gravis (Garosi, 2013). Advanced diagnostics such as oesophagoscopy and fluoroscopy may also be performed

Answer 12

Treatment will be focused on the underlying cause (e.g. removal of the foreign body, treatment for hypoadrenocorticism etc.). Nursing care is extremely important for animals with megaoesophagus- ensuring adequate nutrition and preventing comorbidities developing such as aspiration pneumonia. Megaoesophagus is discussed in more detail later in this outcome (4.1.7). Regular ongoing assessments are indicated even once the underlying cause has been identified and resolved as patients may develop aspiration pneumonia after this point.

Answer 13

Vomiting is not a diagnosis but a clinical sign- there are lots of different causes. Whilst chronic vomiting is common, emergency presentations are often due to acute onset vomiting with large volumes of fluid lost or vomiting of blood, for example. Depending on the underlying cause, acute or chronic diarrhoea may also be present. The patient may have mild clinical signs and a self-limiting condition. However, a patient with excessive vomiting can present with hypovolaemia and electrolyte derangements due to excess fluid loss. Vomiting is often associated with an underlying problem e.g. intestinal foreign body/ pancreatitis and may be an early sign of a severe underlying problem (e.g. septic peritonitis). The presence of blood in vomit is usually a serious finding – depending on the underlying cause it may be fresh blood (haematemesis) or digested blood (melaena). Small flecks of blood may sometimes be present in a patient with acute vomiting due to damage to the gastric mucosa

Answer 14

The vomiting may be of gastro-intestinal tract (GIT) origin e.g. gastritis, foreign body etc. - most cases are dietary in origin e.g. scavenging. Vomiting, however, can also be associated many other infectious and non-infectious conditions - • Neurological disease e.g. vestibular syndrome • Liver disease • Renal disease • Endocrine disease e.g. hypoadrenocorticism, diabetic ketoacidosis (DKA) • Pancreatic disease • Toxicity • Infectious e.g. Parvo virus, Salmonella, Campylobacter etc. • Neoplastic • Pericardial effusion (vomiting may occur 24-48 hours before acute cardiovascular signs • Coagulopathy e.g. haematemesis, melaena

Answer 15

The signalment and history are important in helping to identify the likely cause of vomiting and provide appropriate treatment e.g. a young dog which scavenges has increased likelihood of foreign body; an unvaccinated, young dog may have parvoviral enteritis; an old cat with weight loss, PUPD and halitosis is more likely to have chronic renal failure. It is useful to try and identify the time course, the frequency of vomiting and the nature of the vomitus as this can indicate a possible cause/ level of seriousness in some cases.

Answer 16

The colour of the vomit can suggest which part of the GIT it could have arisen from and can, sometimes, indicate the seriousness of the problem e.g. ➢ clear – could be swallowed saliva ➢ yellow - could be bile that has refluxed into the stomach ➢ green- could be undigested bile that has built up in the upper duodenum due to an intestinal obstruction or ileus ➢ brown (with foul, fetid smell) – could be from small intestine secondary to complete intestinal obstruction ➢ red – fresh blood in vomit ➢ coffee grounds – altered blood in vomit

Answer 17

➢ clear – could be swallowed saliva

Answer 18

➢ yellow - could be bile that has refluxed into the stomach

Answer 19

➢ green- could be undigested bile that has built up in the upper duodenum due to an intestinal obstruction or ileus

Answer 20

➢ brown (with foul, fetid smell) – could be from small intestine secondary to complete intestinal obstruction

Answer 21

➢ red – fresh blood in vomit

Answer 22

➢ coffee grounds – altered blood in vomit

Answer 23

The cardiovascular system should be thoroughly assessed to determine if there is any compromise (i.e. decreased perfusion which may be caused by hypovolaemia or distributive shock). A patient with acute vomiting can lose a large volume of fluid and electrolytes over a short time course. The respiratory rate and pattern might be abnormal secondary to acid-base derangements e.g. acidosis. As well as assessing whether the patient is hypovolaemic, it is important to assess the hydration status- IVFT will be required for hypovolaemic and dehydrated patients. The patient’s position and abdominal musculature may suggest abdominal pain e.g. praying position/ guarded abdomen. Not only will signs of abdominal pain influence the treatment plan on welfare grounds e.g. analgesia, but the underlying cause will also need to be identified as pain may be associated with a ‘surgical abdomen’ e.g. perforation.

Answer 24

A metabolic acidosis may be present due to loss of fluid from the vomiting - with the progressive dehydration, resultant hypovolaemia and anaerobic respiration, lactic acid is produced. Alternatively, however, a hypochloraemic metabolic alkalosis may develop secondary to a high gastrointestinal obstruction, due to loss of chloride in the vomitus. Appropriate fluid resuscitation will depend on the electrolyte/metabolic derangements that are present - hence the importance of being able to accurately identify these

Answer 25

An emergency database (EDB = MDB +Extended DB) should ideally be obtained in all cardiovascularly unstable animals that present with vomiting. The EDB should identify any immediate life-threatening problems such as hypoglycaemia, azotaemia and electrolyte abnormalities

Answer 26

Lactated ringer’s solution (LRS) is usually the fluid of choice for most patients that are vomiting - metabolism of the lactate to bicarbonate helps in the correction of a metabolic acidosis. However, in the patient with an upper GI obstruction and consequent hypochloraemia, 0.9% saline is indicated. Whilst the RVN is not responsible for the choice of fluids, it is important to understand when each type could be used and any potential side effects they may have.

Answer 27

Faecal analysis can be useful in patients with diarrhoea. There are commercial test kits for detection of parvovirus antigen. It is important to note that whilst the majorityof patients who present with parvoviral enteritis will be unvaccinated and under 6 months old, it can be seen in older animals and should not be ruled out in a patient showing compatible clinical signs until testing has been carried out. In the case of a vaccinated animal showing clinical signs of parvovirus, a polymerase chain reaction (PCR) test may be needed to confirm the diagnosis. Whilst it will take longer to obtain a PCR result, prompt and aggressive intervention and treatment should be provided for the patient suspected of having parvoviral enteritis. Microscopic examination of stained faecal smears may show large Gram-positive rods suggestive of Clostridia species or Gram-negative ones typical of Campylobacter species. Faecal examination for evidence of endoparasites can also be performed - this may be an issue in particularly in young animals. Microbial culture and sensitivity tests may be performed.

Answer 28

Haematology may show a leucocytosis and neutrophilia associated with infection but in animals with viral conditions there may be leucopaenia e.g. young animals with parvoviral enteritis. A blood smear can be performed to evaluate the need for antibiotics in a patient with acute GI signs, such as vomiting and diarrhoea. Historically patients with acute haemorrhagic diarrhoea, for example, would receive empirical antibiotic treatment. However, as discussed by Hall (2018), in most acute onset cases antibiotics are not indicated unless there is evidence of SIRS/sepsis (pyrexia, increased WBC). Probiotics may be indicated in this situation.

Answer 29

Biochemistry may reveal pre-renal azotaemia in a hypovolaemic patient or those with severe dehydration; hypoglycaemia and hypoalbuminaemia may also be significant findings. In addition, it may help to identify other diseases (e.g. hyperglycaemia and ketonaemia in diabetic ketoacidosis; increased ALKP and cholesterol in pancreatitis)

Answer 30

Abdominal radiography can help to determine- • the presence of foreign material e.g. intestinal or gastric foreign body • the presence of a complete or partial obstruction e.g. ileus • the presence of free abdominal gas or an effusion • the size, shape, opacity and position of abdominal structures e.g. gastric dilation/volvulus • the presence of an abdominal mass

Answer 31

Diagnostic imaging, including abdominal radiography and abdominal ultrasound, is usually essential in this situation. Whilst endoscopy can be performed in a vomiting patient for examination +/- biopsy, this is less likely in the emergency patient unless for retrieval of an oesophageal/ gastric foreign body patient for examination +/- biopsy, this is less likely in the emergency patient unless for retrieval of an oesophageal/ gastric foreign body

Answer 32

Radiographic abdominal contrast is generally poor compared to other areas of the body. Many patient factors (e.g. thin, very young) and pathological conditions (e.g. abdominal fluid, emaciation) can be associated with further loss of abdominal contrast

Answer 33

Sometimes, serial radiography and monitoring of gas patterns may be indicated. If the patient has free abdominal gas (pneumoperitoneum), this indicates rupture of the GI tract or a penetrating abdominal wound- both would be considered a surgical emergency

Answer 34

Abdominal ultrasound is an extremely useful diagnostic aid especially in the acute abdominal presentation- prompt identification of any abdominal effusion is the initial aim. Even small volume effusions can be readily identified in most cases. A focussed assessment with sonography for trauma (FAST)/ point of care ultrasound examination (POCUS) should be performed (Powell, 2015). POCUS is invaluable in identifying the presence of free fluid within the abdomen- however it is also very useful for identifying ileus, a fluid filled stomach and other conditions present in the acute abdomen. RVNs with suitable training can carry out POCUS examination and report the findings to the VS -this would not be termed as making a diagnosis in the same way that reporting an ECG abnormality would not be making a diagnosis.

Answer 35

POCUS technique With the patient in left lateral recumbency, four areas are examined, in two planes: • Subxiphoid (looking for fluid around the liver) • Midline over the caudal abdomen/bladder • Gravity dependent (left if patient in left lateral recumbency) flank • Gravity independent (right if patient in left lateral recumbency) flank

Answer 36

It may be that no free fluid found on initial ultrasound examination in a hypovolaemic patient – however once the patient is fluid resuscitated it might start to gather. Therefore, for some patients, repeating the POCUS/ FAST scan, an hour or two after fluids have been started, is important in the identification of free abdominal fluid

Answer 37

To avoid splenic injury, abdominocentesis is usually performed standing or in left lateral recumbency. However, in a patient with a large volume abdominal effusion it may be more comfortable for the procedure to be carried out in sternal or standing position.

Answer 38

• All the equipment should be gathered initially including plain tubes (biochemistry, culture and sensitivity), EDTA tubes (cytology) and microscope slides for microscopy. • To avoid splenic injury, abdominocentesis is usually performed standing or in left lateral recumbency. However, in a patient with a large volume abdominal effusion it may be more comfortable for the procedure to be carried out in a sternal or standing position. • Hair should be clipped over the area and the skin aseptically prepared. • Either a single or a four quadrant abdominocentesis is performed. If a single insertion point is planned, this is usually slightly to the side and caudal to the umbilicus, unless ultrasound examination has demonstrated fluid in a particular location. Four quadrant abdominocentesis splits the abdomen into four quadrants either side of the lineal alba (right cranial, left cranial, left caudal and right caudal). Abdominocentesis is performed in each of these locations. • Using an aseptic technique, a 1 to 1.5-inch hypodermic needle is introduced into the abdomen, ideally under ultrasound guidance. o Abdominocentesis can be performed using either an open or closed technique. Regardless of the method used, an aseptic technique is indicated due to the risk of introducing pathogens into the body cavity. o The closed technique involves attachment of a syringe to the needle prior to insertion and fluid is collected by aspiration of the syringe. This prevents air and bacteria from entering the abdomen. Air would lead to the appearance of pneumoperitoneum radiographically which might cause diagnostic confusion. The disadvantage of this technique, however, is the potential occlusion of the needle bevel by omentum during suction. o The open technique relies on passive gravitational flow of fluid from the abdomen, rather than syringe aspiration. It may be used more commonly in patients that have small volumes of effusion. There is, however, the inherent risk of air and bacteria being introduced- increasing the risk of infection, causing a pneumoperitoneum and potentially complicating any subsequent radiographic interpretation. A needle or IV catheter is inserted, aseptically, in the most gravity-dependent portion of the abdomen and fluid allowed to flow by gravity.

Answer 39

Abdominocentesis can be performed using either an open or closed technique. Regardless of the method used, an aseptic technique is indicated due to the risk of introducing pathogens into the body cavity.

Answer 40

The closed technique involves attachment of a syringe to the needle prior to insertion and fluid is collected by aspiration of the syringe. This prevents air and bacteria from entering the abdomen. Air would lead to the appearance of pneumoperitoneum radiographically which might cause diagnostic confusion. The disadvantage of this technique, however, is the potential occlusion of the needle bevel by omentum during suction.

Answer 41

The open technique relies on passive gravitational flow of fluid from the abdomen, rather than syringe aspiration. It may be used more commonly in patients that have small volumes of effusion. There is, however, the inherent risk of air and bacteria being introduced- increasing the risk of infection, causing a pneumoperitoneum and potentially complicating any subsequent radiographic interpretation. A needle or IV catheter is inserted, aseptically, in the most gravity-dependent portion of the abdomen and fluid allowed to flow by gravity.

Answer 42

one of the most important aspects of analysing free peritoneal fluid is to identify a patient that needs prompt surgical intervention

Answer 43

Gross examination, cytology, haematology, total protein and biochemistry can all be performed

Answer 44

Gross examination of free peritoneal fluid can yield some important information- blood that does not clot suggests haemoabdomen; plant/food material in peritoneal fluid is indicative of rupture/ perforation of the GIT.

Answer 45

The following are potential causes of free peritoneal fluid- septic peritonitis, non-septic peritonitis, haemoabdomen, uroabdomen, pancreatitis, bile peritonitis, chylous effusion and neoplasia.

Answer 46

Cytological analysis is highly suggestive of septic peritonitis if there are– ➢ many leucocytes ➢ intracellular (phagocytosed) or extracellular bacteria ➢ toxic/degenerate changes in the neutrophils the presence of toxic changes in neutrophils indicates an inflammatory response is taking place in the patient. When there is a sudden demand for increased numbers of neutrophils in the circulation, many of those that are developing in the bone marrow are forced to mature more rapidly than normal. N.B. in this situation there are also likely to be increased numbers of band (immature) neutrophils seen. The toxic changes that might be present on a smear are not caused by bacterial damage but reflect unequal maturation of the nucleus and cytoplasm of the neutrophil.

Answer 47

Toxic changes that can be seen include- ➢ blue granules/ foamy appearance of the cytoplasm ➢ swelling of the nucleus ➢ Dohle bodies (light blue-grey, oval, inclusions in the peripheral cytoplasm)

Answer 48

Based on its composition, free peritoneal fluid can be classified as a transudate, modified transudate or exudates

Answer 49

Protein Transudate <25g/l Modified transudate >25g/l Exudate >30g/l

Answer 50

Nucleated cells Transudate <1 x 109/l Modified transudate <7x 109/l Exudate >7 x 109/l

Answer 51

Appearance Transudate Clear, colourless Modified transudate Cloudy Exudate Thick, purulent, white, cream, yellow etc.

Answer 52

Description Transudate low cellularity and a low protein content Modified transudate Intermediate between transudate and exudate. Exudate High cell count and high protein count

Answer 53

Cause(s) Transudate Decreased plasma oncotic pressure/increased hydrostatic pressure e.g. congestive cardiac failure Modified transudate Decreased plasma oncotic pressure/ increased hydrostatic pressure; disruption to endothelium; strangulation May be transition stage transudate and exudate as condition develops e.g. uroabdomen progressing to septic peritonitis Exudate Associated with an inflammatory process. May be associated with bacteria (septic) or sterile (non-septic)

Answer 54

It is also possible to measure the peritoneal fluid concentrations of glucose, lactate, potassium, creatinine, lipase, amylase, ammonia and bilirubin. It is not possible to give normal reference ranges for these in peritoneal fluid - the concentration will depend on the underlying cause of the peritonitis (e.g. potential dilution effect).

Answer 55

A peritoneal glucose concentration lower than blood glucose is likely in septic peritonitis as the bacteria present use glucose for energy

Answer 56

A peritoneal lactate concentration higher than blood lactate is likely in septic peritonitis

Answer 57

Peritoneal glucose level 1.1mmol/L lower than that obtained from a plasma sample; and peritoneal lactate level 2mmol/L greater than that obtained from a plasma sample have been quoted as diagnostic for septic peritonitis in animals. However, assessment of lactate and glucose levels are considered less accurate in feline patients

Answer 58

A peritoneal potassium or creatinine concentration higher than blood concentrations is suggestive of uroperitoneum. ‘An abdominal fluid creatinine concentration to peripheral blood creatinine concentration ratio of > 2:1 was predictive of uroabdomen in dogs (specificity 100%, sensitivity 86%). An abdominal fluid potassium concentration to peripheral blood potassium concentration of > 1.4:1 is also predictive of uroabdomen in dogs (specificity 100%, sensitivity 100%). All dogs with uroabdomen had an abdominal fluid creatinine concentration that was at least 4 times normal peripheral blood levels’

Answer 59

Bilirubin is not normally present in peritoneal fluid – identification of bilirubin in peritoneal fluid would suggest damage to the gall bladder.

Answer 60

Diagnostic peritoneal lavage (DPL) If fluid is not located during abdominocentesis, in a patient with a history and clinical findings suggestive of free abdominal fluid, DPL may be performed. However, DPL is less likely to be required if ultrasound guided abdominocentesis can be performed. DPL is like abdominocentesis but fluid is first introduced into the abdomen. It is left for a short time before being withdrawn and put into plain and EDTA tubes for cytological, biochemical and haematological analysis. Introducing fluid during DPL increases the chance of collecting free peritoneal fluid, especially if these is only a small volume present. Commercial DPL kits are available which use the Seldinger technique. Alternatively, DPL can be performed using an over the needle cannula. Some advocate fenestrating the IV cannula to increase the chance of obtaining fluid; however, this would need to be performed carefully to ensure fragments of the catheter are not lost within the abdomen. The urinary bladder is emptied and the ventral abdomen is aseptically prepared. Local anaesthetic may be administered prior to introducing a peritoneal dialysis catheter, or an over the needle 2 inch (5cm) 18-gauge cannula through the abdominal wall, 2cm caudal to the umbilicus. 10-20ml/kg of warmed sterile saline (0.9 %) or lactated ringers is instilled into the abdominal cavity. The patient’s abdomen is massaged or the patient is gently rolled. The patient should be observed closely for any signs of discomfort or respiratory distress. Increasing intra-abdominal pressure may worsen respiratory function, as well as cause significant discomfort to the patient. If the patient is already painful then analgesia should be given prior to carrying out the procedure. After a few minutes the fluid is withdrawn. In general, very little fluid is recovered but it is usually enough to allow a smear to be made to aid diagnosis.

Answer 61

Amylase, lipase and cPLI levels in peritoneal fluid can be assayed and aid in the diagnosis of pancreatitis

Answer 62

Diagnostic peritoneal lavage should not be performed if the patient has respiratory distress - the fluid may put pressure on the diaphragm and cause further breathing difficulties. DPL should also be avoided where there is major organ enlargement due to the risk of puncturing the organ during the procedure. Mazzaferro (no date) describes diagnostic peritoneal lavage.

Answer 63

If enough fluid is obtained, biochemical and haematological analysis can be performed in addition to cytological analysis of a smear. This, however, would be qualitative rather than quantitative due to dilution effect i.e. creatinine might be present but the actual amount cannot be accurately quantified as it has been diluted.

Answer 64

Generally, the patient will have a metabolic acidosis caused by hypoperfusion-induced hyperlactataemia and, often, loss of bicarbonate. The isotonic crystalloid solution, lactated ringers, is appropriate in this situation. The patient may, however, have hypochloraemic metabolic alkalosis due to acute, prepyloric vomiting (i.e. stomach origin). In this situation, ringer’s solution or 0.9% NaCl may be preferred. 0.9 % NaCl will provide enough chloride to correct the metabolic alkalosis.

Answer 65

Hypokalaemia can arise secondary to increased potassium loss and decreased intake. There are many causes of hypokalaemia, but it can be associated with both vomiting and diarrhoea, especially chronic diarrhoea. Clinical signs of hypokalaemia may not be apparent until the potassium levels are very low. If hypokalaemia is present, potassium supplementation is indicated. It is important to calculate the amount of potassium that is required to avoid over/under supplementation. Potassium is added to the IV fluids, as outlined in the table. It is essential that the bag of fluids is appropriately identified to show that potassium has been added – the flow rate must not be altered significantly. Regular agitation of the bag is needed to ensure distribution of the potassium salts throughout the infusion. Ongoing assessment of potassium levels should be made every 4-6 hour (Odunayo, 2014). It should also be noted that in many patients, due to administering IV fluid therapy, potassium dilution can occur. Therefore, even if the potassium level is normal on presentation it may subsequently become depleted.

Answer 66

Serum potassium Potassium chloride to be added (mmol/litre fluids) >5.5 Do not add 4.1-5.4 20 3.1-4 30 2.6-3 40 2-2.5 60 <2 80

Answer 67

Regular patient monitoring should be performed especially of perfusion parameters. Mucous membrane colour and CRT should be assessed. Central and peripheral pulses should be assessed for strength and quality. The heart should be auscultated at the same time enabling the identification of arrhythmias or a pulse deficit. Blood pressure monitoring should ideally be performed. If available a multi-parameter monitor can be used. This means ECG and non-invasive blood pressure is monitored on a continued basis. While this can be invaluable in critically ill patients, ‘hands on’ monitoring remains vital where appropriate

Answer 68

The patient should produce 1-2 ml/kg/hr.

Answer 69

Urine output should also be monitored every 60 minutes to assess the effectiveness of IVFT. The patient should produce 1-2 ml/kg/hr. In patients that are dehydrated on presentation, urine output may be low initially. Ongoing monitoring can include assessment of fluid ‘ins and outs’, patient’s weight (which should increase as hydration improve), PCV and total solids assessment and serial POCUS assessment of the bladder size.

Answer 70

Blood lactate levels should be monitored, where possible, throughout treatment to assess the efficacy of perfusion

Answer 71

Normal levels for plasma lactate are <2.5mmol/L.

Answer 72

In many acute presentations, treatment is usually symptomatic – symptomatic treatment is likely to involve case-specific combinations of intravenous fluid therapy, analgesia, gastrointestinal drug therapy and dietary management.

Answer 73

IVFT- Crystalloid fluids (usually isotonic) are indicated in a patient with hypovolemia +/- dehydration associated with vomiting/diarrhoea. Relatively low volumes of hypertonic saline (HTS) can be administered to a patient needing rapid, fluid resuscitation e.g. GDV patient. Synthetic colloids may be considered if the patient is hypoalbuminaemic e.g. sepsis. However, as previously outlined, there is debate over the use of synthetic colloids in companion animals. A large volume of fresh frozen plasma (FFP) would be needed to significantly increase plasma albumin levels in a patient with hypoalbuminaemia - making this an uneconomical and impractical option. FFP would, however, be appropriate if the patient had a coagulopathy

Answer 74

Multimodal analgesia is most likely to be effective in a patient with abdominal pain.

Answer 75

Full mu agonist opioids (e.g. morphine/ methadone) are likely to be required for a patient with abdominal pain. Fentanyl could be administered as a constant rate infusion (CRI). In a mild case, a partial agonist (e.g. buprenorphine) may be administered instead but it is essential that the patient’s level of pain is assessed very carefully. If in doubt it should be assumed that the patient is experiencing a high level of pain. However, Bradbrook (2016) advocates the use of buprenorphine in a cat with abdominal pain as full mu agonists can cause excess sedation. ➢ Lidocaine has anti-inflammatory effects and can be used alone or in combination with other drugs as a CRI (e.g. morphine, lidocaine and ketamine) to decrease the amount and frequency of full mu agonist administration. N.B. full mu agonist opioids can cause nausea. However, lidocaine can also cause nausea and is cardiotoxic if overdosed. ➢ Other local anaesthetic techniques may be employed e.g. epidural. ➢ Ketamine could be administered as a CRI alone with an opioid (morphine) +/- lidocaine to provide multimodal analgesia. ➢ Whilst non-steroidal anti-inflammatory agents have very good anti-inflammatory and moderate analgesic properties, they are not suitable in a hypovolaemic/ hypotensive patient or when gastric ulceration is suspected. ➢ In some situations, paracetamol may be used alongside other analgesia in a dog (not a cat) ➢ Gabapentin may be used for adjunctive analgesia in a cat. It is known to provide visceral analgesia for people although there is currently no evidence of this in cats

Answer 76

``` Full mu agonist opioids (e.g. morphine/ methadone) are likely to be required for a patient with abdominal pain. Fentanyl could be administered as a constant rate infusion (CRI). ```

Answer 77

Lidocaine has anti-inflammatory effects and can be used alone or in combination with other drugs as a CRI (e.g. morphine, lidocaine and ketamine) to decrease the amount and frequency of full mu agonist administration.

Answer 78

``` Depending on the patient’s status and the actual/ potential diagnosis, symptomatic gastrointestinal drug therapy may include some of the following - o antiemetics o antinausea agents o antispasmodics o gastrointestinal protectants/ anti-diarrhoeals o antacids o histamine (H2) antagonists o proton pump inhibitors (PPIs) o prostaglandin E1 analogue ```

Answer 79

Maropitant blocks receptors in the vomiting centre in the medulla and can be used as an antiemetic and antinausea agent. It modulates the inflammatory response and may provide some visceral analgesia

Answer 80

Metoclopramide is an antiemetic with upper GI prokinetic activity which may be used in dogs and cats. it stimulates peristalsis and works centrally and peripherally to decrease vomiting. N.B. Generally, it is advised that an antiemetic is only administered once a surgical cause of vomiting e.g. foreign body has been ruled out.

Answer 81

Sucralfate is a gastro-intestinal protectant which combines with exudates in the upper GI tract and creates a barrier over areas of mucosal damage e.g. gastric ulcers

Answer 82

Kaolin is an adsorbent antidiarrhoeal agent.

Answer 83

Antacids (combination of aluminium hydroxide, calcium carbonate and magnesium hydroxide) decrease pepsin activity and stimulate local prostaglandin synthesis.

Answer 84

H2 receptor antagonists, such as ranitidine and famotidine, block histamine induced gastric acid secretion by parietal cells. Ranitidine also has some prokinetic activity

Answer 85

Protein pump inhibitors (PPIs) e.g. omeprazole, are potent agents which bind to parietal cells and prevent acid being secreted into the stomach.

Answer 86

Misoprostol inhibits gastric acid secretion and increases bicarbonate and mucous secretion and can be used in the management of gastric ulceration (e.g. NSAID related)

Answer 87

Ondansetron is a serotonin (5-HT2) receptor antagonist. It is considered as effective as maropitant at preventing peripherally induced vomiting. It is, however, less effective at preventing centrally induced vomiting. It can be helpful in patients with parvovirus or chemotherapy induced vomiting

Answer 88

A consensus opinion on the rational administration of GI protectants to dogs and cats (proton pump inhibitors (PPIs), H2 receptor antagonists, misoprostol and sucralfate) is presented in ACVIM’s consensus statement: Support for rational administration of gastrointestinal protectants to dogs and cats (Marks et al., 2018). Marks et al., 2018) explain that long-term use of PPIs in people and animals can be harmful, so care is advised if used in veterinary patients. In the absence of evidence to support their use, they also challenge the routine use of GI protectants for various conditions, including gastritis, pancreatitis, hepatic disease and renal disease in dogs and cats, unless there is evidence of/ high risk of ulceration or GI bleeding.

Answer 89

In-house cytology and gram staining may help to guide initial antibiotic choice.

Answer 90

Broad spectrum antibiotics e.g. amoxicillin/clavulanate (Augmentin™) or cerufoxime (ZinacefTM) are likely to be administered intravenously if there is active infection or risk of infection (e.g. septic peritonitis, parvoviral enteritis). In-house cytology and gram staining may help to guide initial antibiotic choice. If a patient has or is thought to have septic peritonitis, which can be rapidly life-threatening, antibiotic therapy will be required, as soon as possible, before results of culture and sensitivity are available. In this situation four-quadrant antibiotic therapy (Gram -ve; Gram +ve; aerobes; anaerobes) may be administered

Answer 91

In a patient with hypovolaemic shock around 70% of the blood supply is diverted away from the gastro-intestinal tract. Consequently, it not surprising or uncommon for a patient to subsequently develop diarrhoea, which can sometimes be severe.

Answer 92

Diarrhoea is extremely common in animals that are presented as an emergency. As is the case with vomiting, diarrhoea may be a minor, self-limiting problem (e.g. secondary to dietary indiscretion) or may occur in association with a major lifethreatening problem (e.g. acute pancreatitis).

Answer 93

As with vomiting, diarrhoea is often associated with gastrointestinal (GIT) disease. It can be caused by a variety of different conditions including: • parasites (e.g. helminths, protozoa) • viruses (e.g. canine parvovirus/ distemper virus) • bacteria (Clostridium, Salmonella) • dietary indiscretion • neoplasia • inflammatory bowel disease. It may also occur secondary to systemic disease particularly if it occurs concurrently with vomiting (e.g. azotaemia, pancreatitis, hepatic disease, diabetic ketoacidosis and hypoadrenocorticism).

Answer 94

based on the animal’s condition on presentation, a thorough history should be obtained e.g. when did it start, the frequency, diet and drink (including any recent changes), any other clinical signs, any other animals (or humans) affected, any medication being given etc. The worming and vaccination status should be clarified- for recently acquired puppies/kittens their origin should be confirmed e.g. breeder/ pet shop etc. It is helpful to try to differentiate small intestinal diarrhoea from large intestinal- important information can be gained by determining the nature (small volume versus large, mucoid, small drops blood etc.) of the diarrhoea, the frequency and presence of tenesmus. If the owner reports the presence of blood, it is important to try to identify the volume and nature e.g. fresh or altered.

Answer 95

Haemorrhagic gastroenteritis (HGE)/ now known as acute haemorrhagic diarrhoea syndrome (AHDS) can be a very serious presentation with rapid onset and deterioration due to loss of large volumes of fluids, proteins and electrolytes.

Answer 96

Appropriate consideration must be given to the potential for contagious, infectious, zoonotic conditions- the patient may require barrier nursing in isolation facilities (Sturgess, 2014). It should also be considered that even if the patient does not have a contagious or infectious condition, its immune system may be compromised N.B. neutrophilia is relatively common in these patients. As such reverse barrier nursing is commonly used to protect the patient from the veterinary team and other patients due to it being immunocompromised.

Answer 97

If the patient has acute colitis the main clinical sign is likely to be sudden onset diarrhoea with frequent attempts to defaecate, but only small amounts of faecal material are produced- this may also contain fresh blood and mucous

Answer 98

If the patient has diarrhoea secondary to a systemic disease or a gastrointestinal condition such as parvovirus enteritis or septic peritonitis then clinical signs may be more severe and include hypotension, dehydration and abdominal pain

Answer 99

Small intestinal diarrhoea tends to be associated with larger volumes but is less frequently produced. Small intestinal diarrhoea can arise due to osmosis, secretion, altered motility and altered permeability

Answer 100

Monitoring trends in the patient’s clinical signs is very important- patients can deteriorate very rapidly if they are losing large volumes of fluid.

Answer 101

The presence of large volumes of fresh blood indicates severe damage to the intestinal lining- not only is the patient at risk due to blood loss, it is at risk from bacterial translocation across the damaged intestine e.g. parvoviral enteritis.

Answer 102

some of the diagnostic tests may be performed. An EDB is indicated for a patient that is systemically unwell, particularly if there is evidence of cardiovascular compromise. If the patient only has diarrhoea and is otherwise well, fewer diagnostics will be indicated in an emergency setting. It is, however, important to inform the owner to closely monitor their animal until recovered, as they can decline rapidly if the diarrhoea persists/worsens.

Answer 103

Faecal analysis is useful to identify the presence of parasites / infection. Commercial tests can be used to aid a diagnosis of parvoviral enteritis.

Answer 104

Hyperkalaemia, hyponatraemia with an abnormal Na: K ratio may be suggestive of hypoadrenocorticism if compatible with clinical signs e.g. waxing and waning illness and inappropriate bradycardia. Hypoadrenocorticism is known as the great pretender- clinical signs are often nonspecific; waxing and waning illness and clinical signs are common.

Answer 105

Pre-renal azotaemia will arise due to hypovolaemia and severe dehydration.

Answer 106

Hyperglycaemia, ketonaemia, glucosuria and ketonuria are suggestive of diabetic ketoacidosis

Answer 107

A very low cortisol level in a sick patient, with compatible signs, is highly suggestive of hypoadrenocorticism Remember a sick patient is a stressed patient. The adrenal glands should respond and produce increased levels of cortisol under these circumstances. This is not infallible, however, as the patient could potentially have critical illness related corticosteroid insufficiency (CIRCI) where the illness has been prolonged

Answer 108

Dynamic, function tests e.g. ACTH stimulation test may be needed to confirm hypoadrenocorticism in a patient with an Addisonian crisis. However in an emergency situation, a basal cortisol may be assessed in- house.

Answer 109

Animals with chronic diarrhoea can develop hypokalaemia.

Answer 110

``` Diagnostic imaging (ultrasound, radiography) may be performed. In patients with diarrhoea alone and no systemic signs, radiography is often non-diagnostic. Endoscopy/colonoscopy may be required but is unlikely to be performed during the initial emergency presentation in most cases ```

Answer 111

Many cases of diarrhoea are self-limiting meaning it is not in the patient’s best interests to be investigated, medicated and hospitalised e.g. patients with acute colitis are not routinely hospitalised. Stress can affect GIT function and motility. As with vomiting patients, the treatment tends to be a combination of fluid replacement, drugs and dietary management in most cases. Combinations of motility modifiers, antacids, mucosal protectants and adsorbents etc. may be administered depending on the clinical presentation.

Answer 112

Again, the importance of early enteral nutrition is recognised- prescription formulations/diets may be indicated. Otherwise the patient should be fed a bland, easily digestible, high biological value protein and low-fat diet. Both pre and probiotics may be used in the management of diarrhoea (Sturgess, 2015) in an attempt to alter the bacterial flora and improve intestinal function. Chandler (2017) discusses the use and latest research on probiotics.

Answer 113

The use of antibiotics is dependent on the clinical situation- inappropriate usage may promote bacterial resistance, as well as altering the patient’s own flora and potentially causing diarrhoea. Systemic antibiosis is indicated where the patient has or is at risk of sepsis/ septic shock; the patient is immunocompromised e.g. parvoviral enteritis or there is evidence of serious intestinal damage e.g. HGE/AHDS. Anthelminthics e.g. fenbendazole or antibiotics e.g. metronidazole may be prescribed for patients with giardiasis. Gentle exercise helps to promote normal gastrointestinal tract motility.

Answer 114

In patients that are systemically unwell, therapy and nursing care will be focused on treatment of the underlying condition and not the diarrhoea specifically e.g. aggressive IVFT in HGE/ AHDS (Mitchell, 2015). These cases will require intensive nursing – despite this some patients will die. Patients with gastrointestinal clinical signs, especially if severe, will often become very depressed and it is important to provide appropriate stimulation, interaction and environmental enrichment. Barrier nursing will often be required. Gentle exercise helps to promote normal gastrointestinal tract motility as well as maintaining patient hygiene and promoting wellbeing

Answer 115

Melaena is the presence of digested/ ‘altered’ blood in faeces. The colour and consistency are due to oxidation and bacterial degradation of haemoglobin. It appears tar-like and is consistent with gastrointestinal haemorrhage. As it takes several hours for the haemoglobin to be altered, melaena is usually associated with haemorrhage of the upper GIT or swallowed blood.

Answer 116

The colour and consistency are due to oxidation and bacterial degradation of haemoglobin. It appears tar-like and is consistent with gastrointestinal haemorrhage

Answer 117

melaena is usually associated with haemorrhage of the upper GIT or swallowed blood.

Answer 118

Haematochezia is the presence of red blood in faeces - this is usually of colonic origin e.g. colitis, rectal polyp, neoplasia etc.

Answer 119

Haematemesis (vomiting blood) may be present concurrently- depending on how long the blood is in the stomach it may look like ‘coffee grounds’ or it may be fresh, red blood

Answer 120

A patient with epistaxis, for example, may swallow excessive volumes of blood. If this is vomited up soon after it will look fresh and red. However, if remains in the GI tract and is digested the patient may have melaena instead.

Answer 121

There are two main causes of melaena- ➢ Bleeding, secondary to disruption of the normal intestinal tract, from ulceration or neoplasia ➢ Thrombocytopaenia.

Answer 122

GIT ulceration may develop secondary to NSAID/steroid administration (particularly if given concurrently or receiving non-selective COX inhibitors), azotaemia e.g. chronic renal failure or GIT tumours. A paraneoplastic effect of mast cell tumours is release of histamine which can cause increased gastric acid secretion, predisposing to GIT ulceration.

Answer 123

Thrombocytopaenia, severe enough to cause gastrointestinal haemorrhage, is likely to be due to immune-mediated thrombocytopaenia.

Answer 124

Evidence of bleeding elsewhere may be present if there is thrombocytopaenia e.g. petechiation, ecchymotic haemorrhages, epistaxis and/or haematuria.

Answer 125

Faeces will be black and tarry - they may have normal consistency or be soft. Occasionally there may be black, tar-like diarrhoea.

Answer 126

Blood may be seen in vomit (haematemesis) or ‘coffee granules’ if there is gastric ulceration

Answer 127

If thrombocytopenia is suspected and the patient has not yet had a diagnostic workup then careful handling and choice of venepuncture sites is vital until the platelet count or dysfunction can be confirmed.

Answer 128

Blood loss into the intestines may be severe with thrombocytopaenia, ulceration and intestinal neoplasia. If large volumes of blood are lost into the GIT, the patient may develop hypovolaemic shock. Clinical signs such as pallor, prolonged CRT, tachycardia and weak/ absent peripheral pulses will be evident if there is a large bleed. N.B. the clinical signs of hypovolaemia will often be apparent before there is evidence of blood in faeces as the transit time can be prolonged. This means GI haemorrhage could be the reason for a patient presenting in a hypovolaemic state even though there are no clinical signs attributable to GI bleeding.

Answer 129

A platelet count should be performed, especially if there is evidence of bleeding elsewhere- for accuracy, a manual count from a blood smear is preferred as automated analysers can be very inaccurate when measuring platelet counts. PCV and TP should also be checked. The animal may be very anaemic and hypoproteinaemic, if intestinal blood-loss is severe or chronic (Hackner (a) n.d.). Renal values should be checked if there is suspicion of GIT ulceration. BUN will be markedly elevated if there is gastrointestinal haemorrhage (due to the ‘digestion’ of blood which has a high protein content); the creatinine, however, is likely to be normal (unless there is also pre-renal azotaemia due to hypovolaemia). If renal failure is the cause of the gastric ulceration, the animal will have azotaemia, however.

Answer 130

If the animal is thrombocytopaenic then additional diagnostic imaging and investigation should be performed to determine if there is an underlying cause. Abdominal ultrasound may reveal a gastrointestinal mass- although GI ulceration is rarely identified on ultrasound unless the ulcer has perforated and there is free peritoneal fluid associated with secondary septic peritonitis. Endoscopy may identify gastric or proximal duodenal lesions and these can be biopsied.

Answer 131

Medication that the patient is currently receiving will need to be reviewed (e.g. NSAIDs /or steroid therapy) if there is suspicion of ulceration/neoplasia – however this would be the decision of the veterinary surgeon. Gastroprotectants (e.g. proton pump inhibitors, H2 blockers, sucralfate) are likely to be administered. If immune-mediated thrombocytopaenia is diagnosed, immunosuppressant therapy will be instigated e.g. corticosteroids +/- cyclosporine.

Answer 132

Close monitoring of these patients is essential. Acute and severe haemorrhage can occur - a patient can become unstable and severely hypovolaemic very quickly. Close attention should be paid to perfusion parameters (heart rate, mucous membrane colour, capillary refill time, pulse quality, urine output and lactate). Blood pressure should be monitored to promptly recognise hypotension. PCV/TP should be measured frequently if bleeding is on-going. If the cause of the GIT haemorrhage is thrombocytopaenia, regular manual platelet counts should be performed – review the technique for performing a manual platelet count. Blood should be collected from a peripheral vein and pressure applied for five minutes after sampling. Care should be taken when handling patients with thrombocytopaenia as they can bleed readily. The priority is to correct hypovolaemia with intravenous fluids (usually isotonic crystalloids in the first instance). Packed red blood cells or whole blood may be necessary to correct severe anaemia.

Answer 133

Conditions of the oesophagus typically cause regurgitation (see 4.1.3 above) although owners will commonly report ‘vomiting’. It is essential therefore that the veterinary team make this distinction- a thorough history and close patient observation are important.

Answer 134

Two main causes of oesophageal obstruction are encountered- either a physical obstruction due to a foreign body (e.g. bone, ball, fishhook, apple core, rawhide chew etc.) or narrowing of the oesophagus i.e. a stricture.

Answer 135

In both cases the normal passage of food and fluid down the oesophagus will be affected. Most foreign bodies cause a partial obstruction- complete obstruction of the oesophagus ‘choke’ is less common in small animals than large animals but is very distressing. Pressure necrosis of the oesophagus can occur if a large object is lodged. This may lead to perforation and some necrosis of the oesophageal tissues.

Answer 136

Pressure necrosis of the oesophagus can occur if a large object is lodged. This may lead to perforation and some necrosis of the oesophageal tissues.

Answer 137

Pressure necrosis of the oesophagus can occur if a large object is lodged. This may lead to perforation and some necrosis of the oesophageal tissues. Oesophageal perforation is a potential complication of a sharp foreign body e.g. a bone, fishhook or stick. Perforation of the cervical oesophagus can lead to localised infection and cellulitis; perforation of the thoracic oesophagus can lead to serious conditions e.g. pneumomediastinum, pneumothorax or pyothorax. A thoracic oesophageal foreign body will often lodge at the heart base.

Answer 138

``` The presenting signs depend on how long the foreign body has been present, the degree of obstruction and the location of the obstruction. Some animals are presented very quickly as the owner has observed the ingestion e.g. fishhook. The greater the degree of obstruction the more dramatic the clinical signs will be. A foreign body is most likely to lodge where the oesophagus is more narrow- thoracic inlet and the cardiac sphincter (Buckley and Rozanski, 2018). Clinical signs can include- 1. regurgitation 2. retching 3. pawing at mouth 4. distress 5. pain 6. drooling saliva 7. repeated swallowing movements 8. unwilling to move 9. lethargy/ depression 10. inappetence/ anorexia 11. cervical swelling 12. respiratory distress (if a large upper cervical oesophageal foreign body is pressing on the trachea/ larynx; or if pyothorax or pneumothorax has developed secondary to oesophageal perforation). ```

Answer 139

Pyrexia may be present in a patient with oesophageal necrosis or oesophageal perforation, secondary to an oesophageal foreign body

Answer 140

Rapid, shallow respiration (suggestive of pleural space disease) may be present if the patient has developed pyothorax, pleural effusion or pneumothorax secondary to perforation of the intrathoracic oesophagus (Buckley and Rozanski, 2018). It is also important to note any abnormal respiratory noises on auscultation e.g. crackles which might suggest aspiration. There may be evidence of swelling and cellulitis if there is perforation of the cervical oesophagus.

Answer 141

In some cases, the owner may be able to provide information that will aid with the diagnosis i.e. feeding bones or observing their dog swallowing a ball. Physical examination may detect some foreign bodies as they may be palpable within the cervical region. However thoracic foreign bodies are often only detectable using radiography or endoscopy. Lateral thoracic and cervical radiographs may show radio-opaque foreign bodies clearly- some foreign bodies, however, are not visible. If there is any suggestion of perforation, then barium sulphate should NOT be used for a positive contrast study. If a contrast study is required then a water-soluble, iodine-based agent should be used. POCUS may be performed if there is suspicion of pleural space disease. If available, computed tomography may be performed.

Answer 142

If there is any suggestion of perforation, then barium sulphate should NOT be used for a positive contrast study. If a contrast study is required then a water-soluble, iodine-based agent should be used.

Answer 143

If the patient is in distress, analgesia or sedation, early in the investigation, may be required. However, both excess salivation and the inability to swallow may increase the likelihood of the sedated patient aspirating saliva/regurgitated material. This should be considered with the patient positioned appropriately and monitored very closely. It might be decided to anaesthetise the patient as soon as possible in order to secure an airway with a cuffed endotracheal tube, thus decreasing the chance of aspiration. Many oesophageal foreign bodies lodge at the level of the heart base- this can lead to vagal stimulation and bradycardia. If this occurs, atropine sulphate or glycopyrrolate may be administered- whilst this may reduce the volume of saliva, the saliva may become more viscous. However, whilst anticholinergic administration should manage the bradycardia, it will not resolve the underlying issue. The focus, therefore, is on identifying and resolving that issue. Prior to administration of an anticholinergic in this situation, the patient’s cardiovascular function and perfusion parameters should be assessed to see if the bradycardia is actually affecting these. It is important to remember that proarrhythmia can be caused by administration antiarrhythmic drug.

Answer 144

All foreign bodies need to be retrieved under general anaesthesia. Many can be removed using endoscopy or under fluoroscopy (White, 2014). Although many foreign bodies may be removed per os, on occasion they will be lodged further down the oesophagus/ in the stomach. From here they may be removed surgically by gastrotomy or, if appropriate, left to be digested e.g. chicken bones. Following endoscopic retrieval of an oesophageal foreign body, the oesophagus will be examined endoscopically to evaluate whether there is damage caused by the obstruction. If oesophagitis is not anticipated and managed at this stage, the patient may subsequently develop an oesophageal stricture. It is also important to assess the presence of an oesophageal tear/perforation. An oesophageal foreign body that cannot be retrieved endoscopically may be removed surgically via an oesophagotomy. Surgical exploration is also indicated if there is radiographic evidence of oesophageal perforation. If the foreign body is lodged in the intrathoracic oesophagus this will necessitate thoracotomy. Once the oesophageal foreign body has been removed a gastrostomy tube may be placed to provide nutrition to the patient and allow the oesophagus to repair. However, after uncomplicated retrieval of an oesophageal foreign body the patient is usually allowed access to small meals of soft food or slurry, after 12-24 hours. Following removal of the foreign body, several medications may be prescribed to manage oesophagitis/ oesophageal ulceration e.g. H2 antagonists, sucralfate suspension and proton pump inhibitors.

Answer 145

If perforation has occurred, there may be a septic exudate within the mediastinum or pleural space- pyothorax. A thoracotomy will be required to manage the septic focus and repair the oesophagus. Chest drains may be placed. The patient will need to be monitored and nursed intensively as with any septic patient. Broad-spectrum antibiosis, intravenous fluid therapy, nutritional support, analgesia and close monitoring of perfusion parameters will be required

Answer 146

Megaoesophagus is dilation of the oesophagus due to weakness of the oesophageal musculature (rather than dilation from oesophageal obstruction). Being a chronic condition, it is not usually a reason for an emergency presentation condition unless the patient has developed secondary aspiration pneumonia.

Answer 147

Megaoesophagus may be congenital or acquired. Congenital megaoesophagus can affect some Siamese cats; it is also recognised in German Shepherd Dogs, Great Danes, Labrador Retrievers, Irish Setters and Newfoundlands. Acquired may be develop in association with hypoadrenocorticism, lead intoxication and myasthenia gravis

Answer 148

Congenital megaoesophagus can affect some Siamese cats;

Answer 149

German Shepherd Dogs, Great Danes, Labrador Retrievers, Irish Setters and Newfoundlands

Answer 150

Regurgitation is the most common clinical sign although owners may report this as vomiting (see 4.1.3 above). There may also be coughing, weakness, fever and respiratory signs secondary to concurrent aspiration pneumonia. Dogs with regurgitation will be predisposed to the development of aspiration pneumonia since they are unable to protect their airway.

Answer 151

As discussed previously, thoracic radiography is essential in a patient with regurgitation as it will confirm the presence of a megaoesophagus, if present. As general anaesthesia can lead to megaoesophagus, radiography should be performed on the conscious patient. Contrast radiography may be required- a barium meal (barium sulphate mixed with food) is a very effective way of confirming the presence and extent of a megaoesophagus. Great care should be taken to prevent aspiration during this procedure. Barium sulphate should not be administered if there is any chance of perforation. Bloodwork may reveal abnormalities consistent with an underlying disease process (e.g. hypoadrenocorticism) or aspiration pneumonia (neutrophilia with left shift). Specific laboratory tests such as a thyroid panel, ACTH stimulation test and acetylcholine (Ach) receptor antibody test (myasthenia gravis) may also be performed.

Answer 152

Nursing of an uncomplicated case includes: • feed little and often • feed high calorie diet (lower volume required) • feed the animal from an upright position • maintain the upright position for at least 10 minutes following the feed- a bailey chair may be used (criticalcare dvm, 2015) • there is no correct food consistency- some patients manage better with a liquid, ‘gruel’ consistency. Many animals will be very tolerant of the feeding of wet-food formed into ‘meat balls’. • limit activity after feeding • if the clinical signs are severe, or the patient has surgery for a stricture, a gastrostomy tube (e.g. peg tube) may be placed. this will need to be managed appropriately.

Answer 153

The nursing team should be aware of potential complications especially the risk of developing aspiration pneumonia

Answer 154

Signs would include tachypnoea, respiratory distress, pyrexia, lethargy and possibly a soft cough. A patient with aspiration pneumonia will need intensive nursing and frequent monitoring. Oxygen therapy may be required. In addition, nutritional and fluid management will be needed. Patients with aspiration pneumonia are often depressed, so should benefit both medically and psychologically from appropriate physiotherapy and environmental enrichment.

Answer 155

After eating, a patient with megaoesophagus should be positioned upright for a period of time to prevent regurgitation and facilitate passage of food down the oesophagus to the stomach. This can be done by physically holding the patient upright, encouraging them to place the front paws on a table or step to hold themselves upright or using a Bailey chair. Gentle coupage may be indicated and regular movement with slow, short walks will be of benefit. However, care must be taken not to exceed the patient’s oxygen requirement if aspiration has occurred.

Answer 156

Pancreatitis is a, usually, non-infectious, inflammatory condition of the pancreas that can affect dogs and cats. It can be acute or chronic- animals with chronic pancreatitis may have acute exacerbations of the condition. Following an initial insult, the pancreas starts to release digestive enzymes into its own parenchyma and the surrounding abdominal organs. Trypsin is activated initially, and this leads to activation of the other digestive enzymes (amylase and lipase) a patient can present with signs caused by acute hepatic/ biliary disease of various causes- infectious e.g. leptospirosis, toxic or obstructive. The presenting signs, clinical findings and initial management of the patient are often similar to that of a patient with acute pancreatitis so will not be discussed further. N.B. if there is serious liver damage leading to liver failure, the patient may also have signs of coagulopathy. Acute liver cell necrosis is a relatively common result of ingested toxins A patient may present as an emergency with neurological signs - hepatic encephalopathy caused by elevated blood ammonia due to chronic liver failure (cirrhosis) or a portosystemic shunt. Treatment of acute hepatic/ biliary disease is generally symptomatic initially e.g. IVFT, GI protectants, analgesia, nutritional support etc.

Answer 157

Clinical signs may vary from mild and self-limiting to severe and life-threatening. Clinical signs arise due to autodigestion of the pancreas by pancreatic enzymes released as a result of the inflammatory process

Answer 158

Miniature Schnauzers appear to be frequently affected but other breeds are also commonly represented- Labradors, Miniature Poodles and Yorkshire Terriers (WikiVet,

Answer 159

Other risk factors include hyperlipidaemia (e.g. following a high-fat meal), scavenging, hypercalcaemia, medications (e.g. azathioprine, corticosteroids and potassium bromide), trauma and hypoperfusion

Answer 160

Following an initial insult, the pancreas starts to release digestive enzymes into its own parenchyma and the surrounding abdominal organs. Trypsin is activated initially, and this leads to activation of the other digestive enzymes (amylase and lipase)

Answer 161

These active enzymes cause tissue damage and necrosis. This leads to an intensely painful inflammatory reaction with pancreatic oedema. In the acute form, this can lead quickly to peritonitis and hypovolaemic shock. In serious cases, SIRS, DIC and MODs may ensue

Answer 162

In the chronic form, a similar process occurs but it is less dramatic. Longer term, there may be so much destruction of the pancreas that the patient may have issues relating to decreased exocrine +/- endocrine function e.g. exocrine pancreatic insufficiency due to lack of trypsin, lipase and amylase; or diabetes mellitus due to lack of insulin. Most emergency presentations, however, are likely to be due to acute rather than chronic pancreatitis.

Answer 163

In cats, pancreatitis can be part of a syndrome called triaditis. Triaditis is the combination of inflammatory bowel disease, inflammatory liver disease and pancreatitis (Buckley and Rozanski, 2018). However, triaditis is generally chronic rather than acute - however a cat may present due to an acute flare-up or deterioration.

Answer 164

These are not condition specific (e.g. in dogs the signs may be like those of other ‘acute abdominal’ emergencies e.g. intestinal obstruction). Cats with pancreatitis often present with vague, non-specific clinical signs. The patient with acute pancreatitis may present with several clinical signs which can include (Idexx, 2014) - 1. acute vomiting (more common in dogs than cats) 2. diarrhoea (especially cats) 3. cranial abdominal pain (more common in dogs than cats) 4. palpable abdominal mass (especially cats) 5. pyrexia (dogs) / hypothermia (cats) 6. lethargy, dullness 7. anorexia 8. tachypnoea 9. icterus (especially cats) secondary to obstruction of the bile duct 10. signs consistent with hypovolaemic shock +/- SIRS 11. signs consistent with DIC/ MODS/ sepsis/septic shock If this is an acute flare-up of chronic pancreatitis, the patient may have additional clinical signs associated with chronic pancreatitis/ pancreatic malfunction e.g. diabetes mellitus due to lack of insulin. As triaditis/ pancreatitis in cats is generally a chronic condition, the patient may have a chronic, relapsing history of vomiting, diarrhoea and inappetence/ anorexia.

Answer 165

The major body systems should be examined initially. There may be signs of hypovolaemic shock e.g. tachycardia, weak pulses, prolonged CRT, hypotension, decreased mentation, decreased urine output, increased lactate etc. It is important to note any clinical signs that might be suggestive of SIRS, DIC or septic shock. Acute pancreatitis is usually very painful, so it is important to fully assess the patient for signs of acute pain noting demeanour, position, breathing etc. Changes in behaviour (e.g. aggression, vocalisation, lethargy and restlessness); changes in posture, position or movement (e.g. praying position, hunched, reluctance to move, constant shifting position etc.) and physiological changes (e.g. tachypnoea, pyrexia, tachycardia etc.) may all suggest pain. Physical examination will often reveal a tense, guarded abdomen which is particularly sensitive cranially.

Answer 166

An emergency database (MDB/ EDB) should ideally be obtained- PCV, TS, glucose, BUN, electrolytes +/- lactate. Additionally, serum biochemistry and haematology should be performed.

Answer 167

The patient will often have anormal blood glucose- either hyperglycaemia or hypoglycaemia; hypocalcaemia; pre-renal azotaemia; increased liver enzymes, amylase, lipase, cholesterol and bilirubin. Lipase and amylase are not specific markers for pancreatitis i.e. they may be elevated in conditions other than pancreatitis; some patients may have pancreatitis and yet have normal levels of amylase and lipase. Canine and feline pancreas specific lipase assays are helpful in diagnosing the disease in both cats and dogs: ‘Trypsin-like immunoreactivity (TLI) and pancreatic lipase immunoreactivity (PLI) tests are both pancreas-specific tests and are used in the diagnosis of pancreatitis’ (Liss, 2014). TLI is useful in diagnosing exocrine pancreatic sufficiency (EPI) but is not sensitive for acute pancreatitis. Canine (c) or Feline (f) PLI is useful in trying to establish a diagnosis of acute pancreatitis: commercial SNAP tests can demonstrate the presence of increased c/f PLI. For accuracy, further laboratory confirmation of increased c/f PLI based on a SNAP test result is recommended (Liss, 2014). Affected patients are likely to have elevated levels of C-reactive protein (CRP) - one of the acute-phase proteins produced by the liver when there is an acute inflammatory response. It should be noted that a patient with an intestinal foreign body may also have an increased snap PLI, especially a dog. The presence of a foreign body should be ruled out prior to administration of an anti-emetic which could mask deterioration and lead to poorer patient outcomes.

Answer 168

Haematology This may show an inflammatory leucogram- leucocytosis with neutrophilia and left shift. Haemoconcentration is likely if the patient is dehydrated with increased PCV and TS. There may be anaemia and thrombocytopaenia if DIC is present

Answer 169

Radiography This is useful for ruling out an intestinal obstruction- there are no radiographic signs that confirm pancreatitis but there may be a localised ground glass appearance secondary to pancreatic oedema +/- localised peritonitis. Localised, duodenal ileus may also be seen.

Answer 170

Ultrasound This can be very useful although the changes associated with pancreatitis are subtle-there may be evidence of inflammation and small pockets of fluid around the pancreas, suggestive of early localised peritonitis. The pancreas may also appear enlarged and more heterogeneous than normal. POCUS/ FAST ultrasound examination will help to rule out free abdominal fluid.

Answer 171

Abdominocentesis If performed, this should be ultrasound guided as there is usually only a small volume, localised effusion. This approach should allow sampling of any fluid around the pancreas, whilst avoiding further damage to the pancreas. If the patient has pancreatitis, the sample will probably have an elevated white cell count with toxic neutrophils but no evidence of bacteria (see 4.1.4.3). If bacteria ARE present, especially if intracellular, this confirms the presence of a septic abdomen and the patient will need immediate abdominal surgery

Answer 172

Exploratory laparotomy | This may be required to make a definitive diagnosis or to treat a pancreatic abscess which is occasionally present.

Answer 173

Monitoring The level of nursing care provided to patients with pancreatitis is very important to their recovery and well-being. Following Kirby’s Rule of 20 is an effective way of ensuring nothing is overlooked (Gray, 2017). Regular monitoring of the patient is very important noting any trends which could indicate deterioration/ improvement in condition. Regular cardiovascular assessment e.g. heart rate, mucous membrane colour, CRT, central and peripheral pulse quality (femoral/ dorsal metatarsal artery) should be performed to evaluate perfusion status and identify arrhythmias which may be caused by electrolyte abnormalities. Blood pressure monitoring, whether invasive or non-invasive, should be performed to ascertain whether IVFT is achieving the desired results. Ongoing hypotension in a patient that is being fluid resuscitated is a serious finding and can suggest that SIRS/sepsis may be present. Monitoring of blood lactate, glucose and coagulation can be helpful in assessing perfusion status and early identification of SIRS/sepsis. Regular pain assessment is very important. The patient should be monitored closely for signs of deterioration or complications e.g. SIRS, MODS, DIC - prompt recognition of patient deterioration is essential.

Answer 174

Fluid therapy The patient may have hypovolaemia +/- dehydration. If the patient has perfusion deficits, then bolus crystalloid therapy will be required initially. More aggressive fluid therapy is indicated where signs of shock (especially septic shock) are present- treatment is outlined in Unit 1 Outcome 2. In a very serious case, with DIC, a fresh, frozen plasma (FFP) transfusion may be administered. (Liss, 2014). Additional treatment is symptomatic. Hypoperfusion of the pancreas occurs during hypovolaemia (alongside other organs and tissues) so correction of this will improve perfusion of the pancreas itself.

Answer 175

Analgesia is essential- although the treatment regime will depend on whether the patient has acute or chronic pancreatitis Multimodal analgesia, which targets the pain pathway in different ways, should provide the patient with enhanced analgesia. Full mu opioid agonists e.g. methadone, fentanyl, morphine are preferred for the patient with acute pancreatitis, as they provide superior analgesia to partial agonists e.g. buprenorphine. They can be titrated to effect and administered alone or in combination with other drugs as a continuous rate infusion (CRI) e.g. fentanyl or morphine, lidocaine and ketamine (MLK) combined therapy.

Answer 176

A potential problem of full mu opioids is that they can induce nausea – administration of maropitant can help to prevent this; they can also cause excessive sedation in some cats where buprenorphine may be preferred. The patient should be weaned off the full mu opioid as soon as its condition warrants

Answer 177

Local anaesthetic (e.g. lidocaine) can provide analgesia by various routes e.g. nerve block, intra-abdominal/ intra-thoracic infiltration, lumbo-sacral epidural or, possibly, thoracic epidural in dogs. It can be administered as a CRI alone or in combination with other drugs. Lidocaine has an anti-inflammatory effect – acting both peripherally and centrally so can be very effective for inflammatory conditions such as pancreatitis

Answer 178

Some sources discuss using plasma to provide oncotic support and to neutralize pancreatic enzymes in patients with pancreatitis.– There is little evidence to support the routine use of plasma in these patients; however it may be indicated for those patients who develop signs compatible with SIRS(

Answer 179

NSAIDs are unlikely to be indicated in a patient with acute pancreatitis due to the associated risks of gastric ulceration and renal damage in a hypovolaemic patient. However, NSAIDs can be helpful in patient with chronic pancreatitis due to their anti-inflammatory effect

Answer 180

GI protectants are often administered to patients with pancreatitis – e.g. H2 receptor antagonists (ranitidine/famotidine) or PPIs (e.g. omeprazole), which are considered more effective by some (Liss, 2014). However as previously discussed in 4.1.4.4 the routine use of these drugs has recently been challenged by Marks et al

Answer 181

Metoclopramide may be administered for its pro-kinetic and anti-emetic effects

Answer 182

Antibiotics are not usually indicated in a patient with pancreatitis as the cause is not infectious. They may be required, however, in the hypotensive patient with septic shock, or very severe cases of pancreatitis if there is accompanying small intestinal injury, making bacterial translocation more likely

Answer 183

The guidance regarding the nutritional management of pancreatitis has altered recently- historically no food was given until the patient had stopped vomiting. Recent studies have suggested that it is beneficial to continue to feed these patients- ‘The premise for early feeding is to improve the health of the intestinal tract, as unhealthy enterocytes are thought to perpetuate systemic inflammation’ . The ability to do this does depend on the frequency of vomiting; however, the use of antiemetic/antinausea drugs should minimise vomiting and allow for early enteral nutrition. In cats, early feeding is advised as they are prone to developing hepatic lipidosis in association with starvation. Feeding tubes may be required in cats and dogs to ensure adequate provision of nutrients- naso-oesophageal, naso-gastric, oesophagostomy or gastrostomy tubes can be used successfully in most cases, although some patients will require jejunostomy tubes (Liss, 2014). The formulation should have a low-fat content to minimise the chance of recurrent episodes. If enteral nutrition cannot be provided, then total parenteral nutrition (TPN) would be the alternative approach

Answer 184

Canine Parvoviral Enteritis (PVE) | Canine parvovirus is a cause of severe, life-threatening, haemorrhagic gastroenteritis.

Answer 185

Any susceptible animal can be affected e.g. those that do not have passive or acquired immunity. This can be due to: • Failure of transfer of maternal antibodies • Early decline of maternal antibodies • Early vaccination in presence of maternal antibodies • Failure to vaccinate

Answer 186

It is most likely to affect young dogs from 2-8 months and unvaccinated adults.

Answer 187

Anecdotally, some breeds (often ‘black and tan’) appear to be more susceptible; or show more severe signs if affected e.g. Dobermann, Rottweiler, although any susceptible dog can be affected

Answer 188

Parvovirus is extremely resistant to environmental destruction (including most disinfectants), thus it can survive for many months in the environment (longer if frozen over winter months)

Answer 189

Transmission can be from dog to dog but also via fomites. Some geographical areas have higher viral loads than others. Recently, the increase in poor breeding practices and ease of obtaining a puppy (online ordering etc.) has resulted in more cases and outbreaks unrelated to that geographical area.

Answer 190

The severity of the clinical signs is dependent on the virus strain and susceptibility of the patient.

Answer 191

The virus destroys rapidly dividing cells e.g. crypt cells of the villous epithelium of the small intestine and cells of the bone marrow. Damage to the intestine results in gastroenteritis and bacterial translocation; damage to the bone marrow causes neutropaenia especially, although also lymphopaenia. Consequently, affected dogs develop severe gastroenteritis which results in significant fluid loss through vomiting and, often haemorrhagic, diarrhoea. This leads to dehydration and, usually rapidly developing, hypovolaemic shock. As these patients are usually young, hypoglycaemia is likely to be present alongside other serious electrolyte and acid base derangements. Close monitoring for this will be required. The severe GIT damage may lead to systemic inflammatory response syndrome (SIRS)/ DIC and MODs. The bacterial translocation and immunosuppression can result in sepsis and septic shock. There is usually concurrent infection with endoparasites and often giardia +/- coccidia which can make the clinical signs even worse. An affected patient may also develop an intussusception, so any worsening of clinical signs indicates the need for a further thorough assessment.

Answer 192

Clinical signs develop 3-14 days following exposure (usually 6-10 days).

Answer 193

The main clinical signs are – anorexia, depression, vomiting and profuse haemorrhagic diarrhoea. Owners typically notice sudden onset and progressive lethargy, anorexia and vomiting; diarrhoea (often haemorrhagic) usually develops within 48 hours of the presenting signs. Affected dogs are very dull/ lethargic and often have signs of hypovolaemia/hypoperfusion (tachycardia, pale mucous membranes, weak pulses, prolonged CRT etc.) and dehydration. They may be pyrexic initially (up to 40.5˚C/ 105˚F), however if they are severely hypovolaemic/have hypovolaemic shock, they are more likely to be hypothermic. They usually have a painful abdomen and even gentle abdominal palpation may induce vomiting or regurgitation. Severely affected puppies may be collapsed and hypothermic with hypovolaemic shock; or they might have signs of sepsis/ septic shock (hypotension, tachycardia, brick red mucous membranes etc.). DIC and MODs may develop. Affected patients often lose significant volumes of plasma proteins into the lumen of the intestine (Judge, 2015) leading to hypoproteinaemia, hypoalbuminaemia and, sometimes abnormalities of coagulation. Further complications may arise secondary to the parvoviral enteritis, including aspiration pneumonia and intussusception.

Answer 194

The signalment, history and presentation are highly suggestive of PVE. The decision as to what diagnostics are performed may be influenced by financial considerations. Ultimately aggressive intervention is needed for any patient presenting with the clinical signs of PVE. Whilst additional diagnostics are very beneficial to guide treatment, concerns over the cost of treatment for these patients are common. Often the patient has only been in the owner’s possession for a short period of time. Ideally, at minimum, blood glucose, PCV/total solids and a blood smear are evaluated. As these patients are often below six months of age the normal reference range for PCV is ~ 25-35%. A higher PCV alongside increased total solids would indicate dehydration.

Answer 195

Haematology will often demonstrate leucopaenia and lymphopaenia, as often occurs in the early stages of viral infections. A blood-smear is likely to demonstrate neutropenia. Ideally, manual platelet counts should be performed and clotting function assessed on an on-going basis, especially in seriously ill patients.

Answer 196

Blood-gas analysis is likely to reveal a metabolic acidosis secondary to elevated lactate levels (from hypoperfusion) and loss of bicarbonate ions in diarrhoea. Electrolyte assessment is likely to reveal hypokalaemia.

Answer 197

The correct answer is: Passing fresh blood in faeces

Answer 198

The correct answer is: There may be perforation of the oesophagus

Answer 199

The correct answer is: 10-20 ml/kg

Answer 200

The correct answer is: Hyperadrenocorticism

Answer 201

``` Monitor of perfusion parameters Pain assessment/ demeanour Blood gases Acid / base balance Blood pressure Blood lactate Coagulation times PCV/TP ECG Urine output Others ```

Answer 202

The correct answer is: <2.5mmol/L

Answer 203

The correct answer is: Anticoagulant, rodenticide intoxication

Answer 204

The correct answer is: Increased levels of ions and fluids passed from the cells lining the intestine into the lumen

Answer 205

The correct answer is: Transudate

Answer 206

The correct answer is: Hypokalaemia

Answer 207

The correct answer is: A patient with hypovolaemic shock is likely to be hypothermic

Answer 208

The correct answer is: 12 months

Answer 209

The correct answer is: Maropitant

Answer 210

The correct answer is: receive enteral nutrition as soon as possible

Answer 211

Pre-renal azotaemia, as a result of decreased perfusion, may be apparent on serum biochemistry. As puppies are often, both, hypoglycaemic and hypoproteinaemic frequent monitoring of blood glucose is necessary. Judge (2015) explains that, in patients with severe illness, hypoproteinaemia and hypoalbuminaemia are negative prognostic indicators

Answer 212

Urinalysis is generally unremarkable- it is likely to be concentrated, confirming pre-renal azotaemia

Answer 213

This test has good sensitivity and specificity although a false-positive result may occur, however, if the patient received an attenuated, live parvovirus vaccine in the preceding 5-15 days.

Answer 214

The treatment is largely supportive- prompt treatment of hypovolaemia/hypovolaemic or septic shock; correct dehydration; prevention/treatment of infection; analgesia; nutritional support and intensive barrier nursing care The mainstay of treatment is: • Isotonic, crystalloid fluid therapy • Analgesia • GI drugs e.g. anti-emetics/ antinausea, gastroprotectants, antacids, H2 receptor antagonists, ondansetron, PPIs etc. • Early enteral nutrition • +/- Antibiosis if the patient has sepsis • +/- Fresh frozen plasma (FFP) if DIC, hypoproteinaemia/ hypoalbuminaemia • +/- Frozen plasma (FP) if hypoproteinaemia/ hypoalbuminaemia • +/- Vasopressor therapy if septic shock e.g. dopamine

Answer 215

Where signs of shock are present, aggressive fluid resuscitation is indicated; if septic shock is present, additional vasopressor therapy may be required. Incremental IV boluses of isotonic crystalloids are recommended until signs of shock have improved. Synthetic colloid therapy remains controversial in this situation, as discussed previously- if available some clinicians will administer synthetic colloid boluses.

Answer 216

Frozen plasma (FP) may be administered - if a patient is hypoproteinaemic or hypoalbuminaemic (decreased total solids (TS)/ total protein (TP)) this could in theory be helpful, although as previously discussed large volumes would be required to increase albumin levels significantly. Anecdotally, it is considered that frozen/ fresh frozen plasma, may transfer passive immunity to affected patients. The patient outcome is thought to be more likely to be successful if frozen/ fresh frozen plasma administered. If the patient develops DIC, either fresh frozen plasma (FFP) or a whole blood transfusion may be administered. If the patient is septic, vasoactive drugs, such as dopamine, might be used to improve perfusion.

Answer 217

VOLUME OF FLUIDS = MAINTENANCE + FLUID DEFICIT/ REHYDRATION + ON-GOING LOSSES

Answer 218

MAINTENANCE fluid requirements are ~ 40-60 ml/kg/24 hours (depending on the size of the patient) ❖ Alternative calculations for maintenance fluid requirements are- * (30xBW) + 70ml (animals 2-30Kg in some texts) or * 70 x BW 0.75 (animals of any weight)

Answer 219

FLUID DEFICIT/ REHYDRATION volume (mL) = % dehydration x body weight x 10

Answer 220

ON-GOING LOSSES ~ 4 ml/kg/episode of vomit/diarrhoea

Answer 221

Once normovolaemia has been achieved, the first half of the calculated fluid volume deficit should generally be given rapidly e.g. over the first 6-8 hours and the rest over the next 16-18 hours. However, the patient MUST be frequently reassessed and fluid requirements adjusted accordingly. The patient should be monitored closely for signs of hypoperfusion and also volume overload.

Answer 222

If the patient is hypoglycaemic, 50% dextrose may be added to the bag of IV fluids to make a 2.5% or 5% solution.

Answer 223

However, if the dextrose concentration is 5% or more it should not be given through a peripheral catheter as it is irritant and could cause thrombophlebitis

Answer 224

Whilst antibiosis is not indicated for a viral infection, antibiotics will often be required due to the high likelihood of secondary infection and immunosuppression. In all but very mild cases, they should be administered intravenously. Amoxycillin/clavulanic acid or 2nd/3rd generation cephalosporins are generally considered suitable starting antibiotics- if the dog is neutropaenic a fluoroquinolone or aminoglycoside may be added to provide more comprehensive cover. N.B. Fluoroquinolones are contraindicated in young growing animals as they can cause damage to growth plates; and aminoglycosides should NOT be used in dehydrated or hypovolaemic animals as they are nephrotoxic.

Answer 225

Fluoroquinolones are contraindicated in young growing animals as they can cause damage to growth plates;

Answer 226

aminoglycosides should NOT be used in dehydrated or hypovolaemic animals as they are nephrotoxic

Answer 227

``` Analgesia Appropriate analgesia (e.g. opioids) should be administered as required. Patients should be appropriately and regularly assessed for pain. NSAIDs are not appropriate in these patients due to the gastrointestinal damage and hypoperfusion. ```

Answer 228

Nutrition Whilst the patient will usually be nil by mouth initially, when acutely vomiting, early enteral nutrition has been shown to be beneficial in dogs with parvoviral enteritis. Judge (2015) discusses the use of micro-enteral nutrition initially in these patients. Micro-enteral nutrition allows delivery of glucose, electrolytes and amino acids directly to the intestinal cells which helps to maintain the health of the intestinal mucosa, reduces atrophy of intestinal lumen cells and improves the rate of recovery from diarrhoea. Yagi (2016) advocates introducing enteral nutrition once the perfusion deficits have been corrected with IV fluid resuscitation – when the GIT should be adequately perfused again.

Answer 229

reasons for introducing early enteral feeding to these patients- ➢ fasting causes increased peristalsis which is painful ➢ feeding makes them feel nauseous for a shorter time ➢ feeding limits bacterial proliferation and translocation ➢ supports intestinal function and structure ➢ reduces inflammation ➢ provides nutrition directly to enterocytes

Answer 230

If a patient will not eat voluntarily/ eat enough voluntarily, early placement of a feeding tube should be considered to implement early enteral nutrition. A naso-gastric or naso-oesophageal tube is suitable initially as these can be placed quickly and are suitable for short-term hospitalisation.

Answer 231

There is a theoretical increased risk of reflux of gastric contents into the oesophagus if a naso-gastric tube is placed- this could result in oesophagitis and stricture formation

Answer 232

there is less chance of the naso-gastric tube moving and ending up in the wrong position following placement. Additionally, a naso-gastric tube enables gastric motility to be assessed and gastric decompression/ siphoning to be performed. Gastric emptying is often delayed and the distended stomach can add to the patient’s discomfort - so siphoning some of the gastric contents from the stomach can help the patient feel more comfortable. It is also beneficial as removal of stagnant gastric fluid can reduce nausea. Gastric siphoning/decompression must, however, be performed carefully to limit the risk of the patient aspirating. Yagi (2016) cites a study which demonstrates there were no more complications with a naso-gastric tube than a naso-oesophageal tube and therefore advocates a naso-gastric tube in this situation

Answer 233

Administering the feed, using either of these tubes, must be done very carefully, however, due to the risk of aspiration (Boag, 2013). An appropriate diet for tube-feeding is high-protein, high-calorie (energy-dense) and low-fat diet. As with any patient that has had a period of starvation the daily RER should be introduced gradually- 25-30% day one etc. Tube feeding may be performed using a bolus or CRI technique. If a bolus technique is used, the volume must be little and often- a large volume could cause vomiting. Yagi (2016) states that the veterinary technician (nurse) should be an advocate for early enteral nutrition in patients with parvovirus and reminds us - “while patients do eat when they feel better, they also feel better when they eat.”

Answer 234

If the patient does not have an intestinal obstruction (e.g. intussusception), antiemetics such as maropitant or metoclopramide may be administered. They can help to decrease fluid loss through vomiting and make the patient feel more comfortable- anti-nausea effect and less vomiting. Nausea can make the patient more miserable and depressed. As maropitant also provides some visceral analgesia, it is likely to be of benefit. As ondansetron is effective at reducing peripherally induced vomiting, it may be useful in this patient

Answer 235

Sucralfate may be used to protect the intestine

Answer 236

PPIs (e.g. omeprazole) are considered more effective than H2 receptor antagonists at decreasing gastric acid secretion and may be administered if gastric ulceration or oesophagitis are thought to be present

Answer 237

Deworming It may be that a large endoparasite burden may be a complicating factor, so anthelminthic treatment of an affected puppy may be required

Answer 238

The level of nursing care provided to patients with parvovirus is a very significant contributing factor to their survival. Following Kirby’s Rule of 20 is an effective way of ensuring nothing is overlooked (Gray, 2017). The patient should be nursed in isolation with strict barrier nursing (Bevan, 2010). The virus is very hardy AND is extremely contagious to other dogs via the direct faecal-oral route or indirectly via fomites etc. Environmental management is very important in the management - contaminated areas should be thoroughly cleaned and any waste (e.g. newspaper, paper towels, personal protective equipment PPE) should be disposed of as hazardous waste (Parish, 2009). Disinfectants which have activity against parvovirus should be used at the correct dilution. These puppies require intensive nursing - under barrier nursing conditions. Patients with parvovirus need lots of nursing care- the time required for bathing/cleaning alone is significant. Depression is very common and can be a factor in delayed recovery. They can be exhausted due to frequent vomiting and interventions, so it is important they have adequate opportunity to rest. In terms of importance, the benefits of maintaining hygiene and providing TLC should not be underestimated. These are commonly young animals that have only been away from their mother and litter mates for a few days and have now been placed into another new environment. Compassionate nursing care is essential. Whilst they do need intensive care, medications, blood tests and interventions can be grouped together, for example, to ensure they are allowed sufficient time to rest.

Answer 239

Dogs with parvoviral enteritis should be very closely monitored as their condition can deteriorate very quickly. Assessment of perfusion parameters (heart rate, mucous membrane colour, CRT, pulse quality, mentation, urine output, lactate etc.) should be performed at least every 2-4 hours in the acutely presented animals. If the patient’s condition deteriorates then the frequency of monitoring/ assessment will need to be increased. Temperature should be monitored regularly as these dogs may be pyrexic but can also become hypo- and hyperthermic. Noting pyrexia is important in patient being treated for parvoviral enteritis as it could be an early indicator of sepsis. Pain scoring should be performed frequently using a validated pain scoring method. Regular blood pressure monitoring is important – ongoing hypotension in the face of effective fluid resuscitation could be indicative of sepsis. The patient must be carefully and regularly monitored to check for any signs of under or over infusion of IV fluids. Assessment of hydration status, urine output and fluid requirements should be performed frequently depending on on-going losses due to vomiting/diarrhoea. For example, some patients may need boluses of fluids after each episode of vomiting or diarrhoea; or in the sickest patients, fluid rates may need to be adjusted every hour. These are dynamic patients that require almost continuous re-assessment and re-evaluation. Regular bodyweight assessment every six hours is indicated and body condition scoring should be performed every twenty-four hours. As previously discussed, assisted tube feeding is important for patient recovery – and aspiration of gastric contents may be needed until normal gastric motility returns (Tabor, 2011). The volume of food and secretions remaining in the stomach (gastric residual volume) can be measured and used to evaluate the stomach’s motility. However, as well as the risk of aspiration, gastric decompression/ siphoning could possibly cause electrolyte (hypochloraemia) and metabolic issues especially due to the removal of hydrochloric acid from the stomach. Hydrochloric acid, normally, helps to prevent bacterial multiplication (overgrowth), so there is an increased risk of bacterial multiplication in the intestine if gastric siphoning decompression is performed. some dogs with parvoviral enteritis can develop a hypercoagulable state (prone to clotting) and thrombophlebitis is common. IV catheters should be checked and rebandaged at least once daily- however they should only be removed if there are complications e.g. evidence of thrombophlebitis. It is challenging but essential to keep catheters and associated bandages clean. General nursing care is very important- if the patient is recumbent it should be turned regularly, and care should be taken to prevent decubitus ulceration developing. Ideally, the patient should be supported in an upright position to decrease the risk of aspiration if it is still vomiting. Oral care is important- suctioning maybe helpful if the patient is vomiting or salivating in excess due to nausea. A foley catheter may be placed in the patient’s rectum and attached to a closed collecting system to minimise faecal contamination of skin (Gray, 2017). Regular bathing of the patient will be required otherwise but care must be taken to avoid skin irritation. If oxygen supplementation is required it must be done in a way that is best tolerated by the patient and only delivered for as long as is needed. It is important to observe for other complications e.g. signs of intussusception. It is important to maintain patient hygiene which can be challenging in the patient with parvovirus. There are several techniques that can be used depending on the patient and the severity and frequency of the diarrhoea they are producing. The tail of short-haired patients, tail can be wrapped in cohesive flexible bandage. This gives some protection to the tail area, if the perianal area is simple to clean and dry. Careful clipping of the hair away from the perineal area to allow easy access and visualisation of the skin, means low levels of soiling, urine scald and skin damage can be promptly identified. Barrier preparations ca also be applied which may maintain help to maintain skin health. Cleaning will still be required - however this helps to minimise the risk of damaging the skin integrity.

Answer 240

Regular monitoring of blood glucose, lactate and coagulation is useful- hyperlactaemia can indicate hypoperfusion. Hypoglycaemia is a common finding in patients with parvoviral enteritis but can also arise with sepsis. In the early stages of sepsis, a patient may be hypercoagulable with a tendency to develop microthrombi/ clots (Gray, 2017). However, as sepsis develops the patient may become hypocoagulable and have prolonged bleeding N.B. if there is any concern re the patient’s coagulation status, blood should be drawn from a peripheral vein.

Answer 241

the risk of aspiration, gastric decompression/ siphoning could possibly cause electrolyte (hypochloraemia) and metabolic issues especially due to the removal of hydrochloric acid from the stomach. Hydrochloric acid, normally, helps to prevent bacterial multiplication (overgrowth), so there is an increased risk of bacterial multiplication in the intestine if gastric siphoning decompression is performed. Yagi (2016) advises that some/ all the fluid removed during gastric decompression/siphoning could be gradually refed to the patient to limit this risk but states that the evidence to support this is mixed.

Answer 242

A faecal catheter can be considered in a collapsed patient, A soft foley catheter is placed into the rectum, the balloon is carefully inflated, and the catheter is attached to a closed collection set. This technique offers several advantages in terms of maintaining hygiene; and it also allows to monitor and calculate the volume of fluid lost. In some patients this can be very beneficial. This faecal catheter requires careful management. The balloon should be deflated every four hours and the catheter slightly repositioned to avoid rectal necrosis occurring. A foley catheter may be placed in the patient’s rectum and attached to a closed collecting system to minimise faecal contamination of skin (Gray, 2017). Regular bathing of the patient will be required otherwise but care must be taken to avoid skin irritation. If oxygen supplementation is required it must be done in a way that is best tolerated by the patient and only delivered for as long as is needed. It is important to observe for other complications e.g. signs of intussusception

Answer 243

The balloon should be deflated every four hours and the catheter slightly repositioned to avoid rectal necrosis occurring.

Answer 244

With appropriate and aggressive therapy many affected animals will recover. Without appropriate treatment, mortality rates are typically 100%.