Smallies 9 Flashcards
What is the evaluation of clear fluid from a diagnostic peritoneal lavage?
No obvious injury/peritoneal disease
What is the evaluation of opaque and bloody fluid from a diagnostic peritoneal lavage?
Haemorrhage
What is the evaluation of fluid that gets darker with each attempt when performing a diagnostic peritoneal lavage?
Continued haemorrhage
What is the evaluation of turbid/cloudy fluid from a diagnostic peritoneal lavage?
Peritonitis
What is the evaluation of bluish/greenish fluid from a diagnostic peritoneal lavage?
Bile leakage or upper GI leak
What is the evaluation of finding fluid with a PCV of <2% from a diagnostic peritoneal lavage?
mild haemorrhage
What is the evaluation of finding fluid with a PCV of 3-10% from a diagnostic peritoneal lavage?
moderate haemorrhage
What is the evaluation of finding fluid with a PCV of >10% from a diagnostic peritoneal lavage?
severe haemorrhage
What is the evaluation of finding fluid with white cells >1000x10^9 from a diagnostic peritoneal lavage?
mild peritoneal irritation
What is the evaluation of finding fluid with white cells >2000x10^9 from a diagnostic peritoneal lavage?
marked peritoneal irritation
What is the evaluation of finding fluid with more amylase than serum from a diagnostic peritoneal lavage?
Pancreatitis, trauma, small bowel leak
What is the evaluation of finding fluid with more ALK phosphatase than serum from a diagnostic peritoneal lavage?
Trauma, ischaemia, leakage
What is the evaluation of finding bilirubin in the fluid from a diagnostic peritoneal lavage?
Leak from biliary tract/bowel
What is the evaluation of finding fluid with more creatinine than serum from a diagnostic peritoneal lavage?
Uroabdomen
What is the evaluation of finding fluid with neutrophilia (toxic neutrophils) from a diagnostic peritoneal lavage?
suppurative peritonitis
What is the evaluation of finding fluid with plant material from a diagnostic peritoneal lavage?
GI leak
What is the evaluation of finding neoplastic cells in the fluid from a diagnostic peritoneal lavage?
neoplasia
What is the evaluation of finding fluid with more triglycerides than serum from a diagnostic peritoneal lavage?
chyloabdomen
What is GVD?
Gastric dilatation volvulus, also known as gastric dilation, twisted stomach, or gastric torsion, is a medical condition that affects dogs in which the stomach becomes overstretched and rotated by excessive gas content
What are the mortality rates with surgery for a GDV patient?
10-18%
List extrinsic risk factors of GDV
Diet Post prandial exercise Pre-prandial exercise Single daily feeding Hospitalisation – increased stress
List intrinsic factors of GDV
Breed (deep-chested) Body size Thoracoabdominal dimensions Gastric volume Gastric position Gastric ligament laxity (hepatoduodenal and hepatogastric) Eructation control Pyloric canal function A parent (1st degree relative) who has experienced a GDV – don’t breed from dogs who have had a GDV Temperament and “happiness”
List breeds predisposed to GDV
Great Dane, St Bernard, Weimaraner, Irish Setter, Gordon Setter, Standard Poodle, Basset Hound, Doberman Pinscher, Old English Sheepdog, German Shorthaired Pointer
What is the aetiology of GDV?
Multifactorial Aerophagia leading to gastric dilation Abnormal oesophageal motility Dysphagia Gas or fluid accumulate in stomach and the normal means of relief (vomiting, regurgitation, pyloric function) have become inoperative
Is clockwise or anti-clockwise rotation more common with GDV cases? And what is the maximum rotation for each way?
Clockwise; most common, max rotation of 270-360 degrees
Anti-clockwise; rare, max rotation of 90 degrees
Describe the roation in GDV
Generally (in GDV) the stomach rotates in a clockwise manner when viewed from the surgeon’s perspective (dog on its back, clinician at dog’s side facing cranially (rotation can be 90-360 degrees).
Gastric dilatation usually precedes volvulus; twisting occurs passively due to the alteration of anatomical relationships by the progressively ballooning stomach. As the stomach dilates, it pushes dorsal and the pylorus becomes ventralised. Once it has twisted it is not likely to untwist. When the stomach twists, it rotates into the omental bursa.
What will you typically see when you open up a dog with GDV?
You will see a single layer of omentum overlying the stomach when you open the dog up
What are the resultant pathophysiological events of a GDV?
Hypovolaemia Endotoxaemia Hypoxia Cardiac dysfunction Gastric ischaemia and mucosal necrosis Splenic ischaemia/infarction
What is the pathophysiology of local events at the stomach with a GDV case?
Gastric wall blood supply disrupted – avascular necrosis and infarction most likely on the greater curvature of the stomach (Leads to rupture and peritonitis)
As the greater curvature of the stomach is displaced the gastric branches of the splenic artery can avulse
Haemorrhage and ischaemia result
Perfusion pressure falls
Mechanical obstruction to vessels (caudal vena cava and portal vein)
Thrombi (due to clotting) can develop if the blood flow slows down
Gastric necrosis (most commonly greater curvature)
What is the pathophysiology of local events at the spleen with a GDV case?
Displaced as greater curvature of the stomach moves
Venous congestion due to compromised venous drainage
Splenic artery avulsions can occur
Infarction (arterial supply decreased due to congestion downstream)
Splenic torsion
Splenomegaly due to congestion can occur
What are the pathophysiological systemic consequences in a GDV case?
Blood flow obstruction e.g. caudal vena cava and hepatic portal vein
Venous return decreased and cardiac output falls
Heart rate increases
o Myocardial oxygen demand increases
o Myocardial oxygen delivery is falling
Poor perfusion and stasis
Arrhythmias
Ischaemic reperfusion injury (IRI)
Gastric perforation – adversely affects prognosis (PTS/death likely)
Septic peritonitis
Post-operative disseminatied intravascular coagulation (DIC)
Post-operative Systemic Inflammatory Response Syndrome (SIRS)
What are the presenting signs of a GDV case?
Progressively expanding and tympanic abdomen – care with giant breeds, the ribs cover the stomach
Dog depressed, may be recumbent
In ‘shock’, CRT prolonged, pale
Tachycardia, poor pulses, tachypnoea
Dog exhibiting signs of pain
May shown signs of non-productive retching/vomiting (if they can produce vomit this does not mean they don’t have a torsion)
Restless
What should be included in the diagnostic work up of a GDV case?
Clinical signs Assess severity of shock Electrolytes Acid/base status Electrocardiogram Radiography
What are the therapeutic goals of GDV?
Restore and support the circulation
Provide oxygen to help the oxygen demand on the heart and to the periphery
Decompress the stomach
Work out if it is GD or GDV? Not always clear cut, even with radiography
Surgical planning to untwist the stomach
Prophylactic gastropexy – prevent it happening again (may not be performed at the same time as the fixative surgery)
What does the initial management of GDV consist of?
First priority is to treat shock Fluid therapy Decompression ECG – treat dysrhythmia? IV corticosteroids – may or may not be beneficial but won’t do any harm as a single injection
What do we what to measure in the blood of a GDV patient?
PCV and TS
Electrolytes
Lactate
Venous blood gases
What are we looking for in the venous blood gases of a GDV patient?
Metabolic acidosis, tissue hypoperfusion, anaerobic metabolism and lactate accumulation
What type of fluids are suitable for a GDV case?
A balanced eletrolyte solution e.g. Hartmanns (first choice) or 0.9% NaCl
What rate should we give crystalloids to a GDV patient?
Shock dose (90ml/kg) give a proportion
E.g. 20-25ml/kg over first 10-15 mins
Repeat as necessary (up to 90ml/kg
What can you use as a last resort in a GDV case (aka the dog is dying in front of your eyes)?
Give hypertonic saline (7.2%) (1ml/kg/min)
What analgesia is indicated in a GDV case?
A pure mu agonist opioid is indicated o Methadone (Comfortan) is licensed for dogs and cats o So is fentanyl (Fentadon) (licensed, shorter acting, more potent, less available)
Should you use NSAIDs in a GDV patient?
Avoid if possible
Is an ECG indicated with a GDV patient?
If available, perform an ECG:
• The magnitude of the arrhythmias can be assessed
• Correcting hypoperfusion, pain and electrolyte abnormalities commonly resolves the arrhythmias
When should you treat arrhythmias in a GDV patient?
Avoid the temptation to treat unless
o Arrhythmia is sustained, paroxysmal or polymorphic ventricular tachycardia (> 150 bpm)
o Pre-existing cardiac disease
Why do you get secondary arrhythmias in a GDV patient?
As a result of acid base abnormalities, electrolyte disturbances, haemostatic abnormalities and/or reperfusion injury
What is the initial managment of a GDV patient once it is stablised?
Orogastric tube – put vet wrap into mouth of dog to hold the jaw open and pass the gastric tube through
Percutaneous trocar
Gastrotomy
Describe the process of passing a stomach tube?
Pre-measure large stomach tube and mark (holes +++)
Sedate with care (opioid or opioid + benzodiazepine) but often not required
Insert bandage roll (e.g. Vetrap) into dog’s mouth and pass lubricated tube through the lumen
If tube will not advance, do not force it – a change in position might help it pass
Lavage and drain, if possible
What should you do if a tube cannot be passed in a GDV patient?
Perform a percutaneous gastrocentesis
What should you use for a percutaneous gastrocentesis?
Large bore needle/trocar or OTN catheter (14-16 G)
Where should you perform a percutaneous gastrocentesis?
Place on most distended side caudal to last rib
Right side is often preferable to help avoid the spleen – but anywhere you can percuss the stomach is suitable
When should you radiograph a GDV patient?
Once decompression has been achieved and the dog is stabilised
Do you always need to radiograph a GDV patient?
No - can go straight to surgery if the diagnosis is obvious and the treatment won’t change depending on the image
What is the aim of surgery in GDV patients?
Correct gastric malposition
Assess and treat ischaemic injury
Prevent recurrence
What should you do if you find necrotic tissue when you open a GDV dog?
Can invaginate the necrotic part of the tissue and stitch together the healthy part of the tissue
Invagination is not commonly done, more likely to do a gastrectomy to remove the necrotic tissue
How can you prevent recurrence with GDV?
Tube gastropexy Incisional gastropexy Circumcostal gastropexy Belt loop gastropexy Incorporating gastropexy Laparoscopic gastropexy
What types of gastropexy are most commonly performed?
Incisional gastropexy
Belt loop gastropexy
What is the advantage of a tube gastropexy?
The theoretical advantage is that you have a tube in the stomach so if you get another dilation in the post-operative period you can drain the gas.
Briefly explain what is done in a belt-loop gastropexy
Raise seromuscular flap off the greater curvature, pass through gap made in transversalis muscle and suture back in place.
Use stay suture attached to apex of the flap to pass through loop made through muscle in abdominal wall. Use long lasting, monofilament e.g. PSD. Seromuscular layer and seromuscular layer of flap - no penetration of stomach lumen
Briefly explain what is done in an incisional gastropexy?
On the pyloric antrum make a linear incision (can be transverse) through seromuscular layer. Make a similar linear incision on the abdominal wall and stitch them together.
Incision made through serosal layer, 8-10cm long, partial thickness (seromuscular incision, only down to submucosa), then touch to abdominal wall to get idea of where stomach needs to sit. Often need assistant to evert lateral wall to get at this easily. Make incision through serosa and underlying transversalis on body wall (single incision). Stitch one side of abdominal wall incision to one side of stomach incision. Do the far side first to make it easier to suture back up. Use monofilament long lasting polydiaxonone eg. PDS
Briefly explain what is meant by an incorporating gastropexy?
When you exit the ex-lap to put the stomach back in its usual position, incorporate part of the stomach wall into the linear alba as you close it
What are the post-operative complications of a GDV case?
Death Shock Dysrhythmias - 40% of dogs Anaemia Hypokalaemia
How do you treat post-op dysrhythmias in GDV patients?
Lidnocaine/procainamide
What should GDV patients be fed post-op?
Low fat, semi-liquid, low protein diet
What should you tell the owner after a GDV case?
Feed a few small meals per day (better than one or two larger meals)
Avoid stress around the time of feeding
Restrict exercise both before and after feeding
Do not use an elevated food bowl (may encourage aerophagia) – conflicting studies
Do not breed from dogs with a 1st degree relative with a history of GDV
Consider prophylactic gastropexy (?)
Why is small bowel torsion rare?
Mechanisms in place to prevent this. Fixed points in abdomen prevent twisting and things getting stuck
What is the prognosis of small bowel torsion and why?
Poor
May get torsion around the mesentery, animal will nearly always die. By the time it presents, bowel will be ischaemic and dead
What breed is most likely to get small bowel torsion?
GSD
What are the ideal suture materials for closure of the stomach, and how long does it last?
Polyglyconate - 21 days
Polydioxanone - 28 days
Glycomer 631 - 18 days
What are the ideal suture materials for closure of the urinary bladder, and how long does it last?
Glycomer 631- 18 days Polyglytone 6211 - 10 days Poliglecaprone 25 - 14 days Polyglyconate - 21 days Polydioxanone - 28 days
What are the ideal suture material for closure of the linea alba, and how long does it last?
Polyglyconate - 21 days
Polydioxanone - 28 days
What are the ideal suture materials for surgery of the pancreas, and how long does it last?
Polypropylene - permanent
Polyglyconate - 21 days
Polydioxanone - 28 days
What are the ideal suture materials for surgery of the gall bladder, and how long does it last?
Glycomer 631 - 18 days
Polyglyconate - 21 days
Polydioxanone - 28 days
What are the advantages of balfour abdominal retractors?
Three-point retractor – stable once placed
Can be used as a two-point or three-point retractor
Many versions come with a locking nut to prevent the retractor closing once placed
What are the disadvantages of balfour abdominal retractors?
Large – may not fit in practice autoclave
Expensive
Cannot be used on small patients
How are abdominal retractors classified?
Hand-held
Self-retaining
Two-point, three-point or circular
How do gosset retractors stay open?
Self-retaining
Remain open due to friction
What is the main disadvantage of gosset retractors?
Often close inappropriately
What is the main disadvatage of langenbeck retractors?
Require a surgical assisstant to hold them
What would be a good antibiotic to use for use in a clean/contaminated small bowel enterectomy surgery in small animals?
Cephalosporin 1st/2nd/3rd gen e.g. Cefuroxime 20mg/kg Iv
Clavulanate amoxicillin 20 mg/kg IV
When would be the best time for antibiotics to be administered peri-operatively?
IV every 60-90 min dependent on surgery
Duration of therapy
o Contaminated: 24h
o Dirty: therapeutic - 5d?
What safety precautions should be taken when using surgical swabs during open abdominal surgery?
Count the swabs prior to performing the procedure
Count the swabs prior to closure of the linea alba
Do not disposed of the swabs until the swab count is correct and the operation is finished
What are common foreign bodies in dogs?
Bones, Rawhide, Toys and balls, Fish hooks, Clothing
What are common foreign bodies in cats?
Needles, String, Toys, Hair
What are clinical signs of foreign bodies?
Retching Regurgitation (food & water) Vomiting Ptyalism Anorexia Restlessness Cervical pain
What investigations should be included when working up a foreign body case?
High index of suspicion from clinical history Plain radiography (in most instances the foreign body will be radio dense or the ingestion was witnessed) Endoscopy
Give examples of foreign bodies which appear radiolucent on radiography?
Rawhides and furballs
Should you perform constrast radiography in a suspect foreign body case?
Avoid if possible - risk of perforation
If you have to perform a contrast radiograph on a suspect FB case what should you use?
If you need to give one, select a water-soluble iodine agent suitable for swallowing
Why should you avoid using barium as a contrast agent in a suspected FB case?
Don’t give barium due to the potential risk of oesophageal perforation as the contrast agent will irritate the mediastinum or cause aspiration pneumonia
What is the treatment for FB?
Emergency surgical removal
How are oesophageal FBs usually treated?
Endoscopic retrieval
How should you treat the 10% of oesophageal FBs than cannot be removed orally?
Push them into the stomach - often digested and removal not needed
What is the blood supply to the spleen?
Blood supply runs down the hilus
Main splenic artery and vein, and an anastomotic supply to the greater curvature of the stomach via short gastric arteries, and left gastroepiploeic arteries
Also has an anastomotic arterial supply from the greater curvature of the stomach
What is the most common reason for a spenectomy?
Mass
How do you prevent bleeding in an emergency splenectomy?
In an emergency situation, can perform mass ligation technique - ligate splenic artery, then mass ligation of 3 bites of suture around mesentery and remove en mass
What is a problem of mass ligation of spenic vasculature?
Will also remove some blood supply to the stomach, but no real issues in the dog as stomach has lots of blood supply
How do you perform a spenectomy in a non-emergency case?
If not emergency, the slower closure of all vessels around the edge better as this will maintain blood supply to the liver better
Describe the blood supply to the stomach
There is a blood supply down the great (left and right gastroepiploic) and lesser (right and left gastric) curvature of the stomach
What is the risk with gastric perforation?
Gastric acid contamination is a bigger worry than bacterial contamination
Why would a gastrotomy be indicated?
The creation of an artificial external opening into the stomach for nutritional support or gastric decompression
