Gastrointestinal system & gastrointestinal emergencies Flashcards
What are the general causes of abdominal pain?
Distension of organ or organ capsule
Ischaemia
Traction
Inflammation due to underlying disease
Not treating issues relating to the abdomen can lead to?
Necrosis of tissue and loss of function of the abdominal organs and may result in SIRS, sepsis and MODS
What is a predisposed condition often found in young GSD that have pancreatic exocrine insufficiency?
mesenteric volvulus
A patient with both an increase in PCV and TP is likely to be what?
Dehydrated
A normal or increased PCV with a normal to low TP indicates?
Protein loss from the vasculature, acute abdomen, peritonitis, HGE.
A parallel decrease in PCV and TP indicates?
Haemorrhage (initially PCV may be normal or elevated and TP normal or reduced due to splenic contraction)
Which of PCV and TP is a more sensitive indicator of acute blood loss?
TP
Why may a patient have high glucose associated with an acute condition of the abdomen?
Diabetes, transient diabetes associated with pancreatitis, stress
Why may a patient have a low glucose associated with an acute condition of the abdomen
sepsis (not generally extremely low), hypoadrenocorticism
Loss of kidney detail, ‘streaky’ appearance or distension in the retroperitoneal area may indicate?
A space occupying lesion
Gas in the peritoneum on lateral or horizontal beam radiograph may indicate
GI perforation
Ruptured urinary bladder
Extension of a pneumomediastinum
Segmental gas or fluid distension in the small intestines is suggestive of
Gastrointestinal obstruction
Normal diameter of the small intestine
Dogs: 2-3X width a rib or no more than the width of an intercostal space
Cats: <2X the height of the central portion of L4 or 12mm
* all areas of the small intestine should be the same diameter
Modified transudate
Cells 300-5500/uL, protein 3-5g/dL, ND neutrophils, mesothelial cells, lymphocytes, RBC, macrophages
Congestion, RHSHF, liver disease, heartworm, neoplasia
Exudate
Cloudy or blood, protein >3g/dL, cells >5000-7000/uL, likely neutrophils +++, +- bacteria
Haemorrhage, septic peritonitis
Pathophysiology of pancreatitis
(diagram in notebook)
Common lab findings with pancreatitis
Increased liver enzymes + Tbil
Increased triglycerides, cholesterol etc
Neutrophilic leukocytes is or neutropaenia (often with left shift)
Increase/positive cPLI
Hypoalbuminaemia
+- anaemia and thrombocytopaenia
Low electrolytes
Elevated coags
Haemoconcentration
Ultrasound findings of patients with pancreatitis
Enlarged hypoechoic pancreas
Dilated pancreatic duct
Free fluid (often inflammatory)
Hepatobiliary dz
Thromboses/organ infarcts
+- masses
Biochemical marker for pancreatitis
CRP best we have so far
Treatment of pancreatitis
Early enteral feeding
Pain relief (opiates and lidocaine +- ketamine)
AM therapy if severe or concerns for bacteria
Eliminate underlying cause
Aggressive fluid resuscitation, consider colloids
Management of underlying illnesses
+- oxygen therapy
+- FFP (a-macroglobulins)
Frequent blood testing (pcv/ts, VBG, lytes, lactate, albumin, renal function, coags, glucose)
Intensive patient monitoring
Supplement electrolytes as needed (avoid Ca unless titanic otherwise promote ROS and free rads)
+- LD dopamine for haemodynamic support and may reduce microvascular permeability
Other supportive therapies
Why is early nutrition a must in pancreatitis
Those with SAP are in a catabolic state
Improves mucosal structure and function
Reduces chances of bacterial translocation
* if ileus or vomiting trickle feeds preferred
* supplement with glutamine
* watch for refereeing syndrome
Acute cholecystitis
Shetland sheepdogs and cocker spaniels are over represented
It is not always accompanied with inflammation
Bacterial (bacteria, parasites) or obstructive (mucocele, infarction) in nature
Signs of acute cholecystitis
Anorexia
Vomiting and diarrhoea
Abdominal pain
Increased ++ liver and biliary enzymes
Abnormal appearance of GB on imaging
Bacterial cholecystitis
Often caused by bacteria such as E. coli, clostridium, enterococcus, bacteroides and may be due to reflux of duodenal fluid or through portal system.
- Gas within the gall bladder indicates a gas forming bacteria present such as E. Coli or clostridium
Overall survival with either medical management or pref surgery = 61-82%
Obstructive cholecystitis
EHBO results in the dilation of the gall bladder and cystic duct within 24h but IH bile ducts within 5-7 days. Changes in liver and biliary enzymes will be apparent which may indicate hepatocyte necrosis, cholangitis and periportal fibrosis. +- choleliths
Choleliths
Most often an incidental finding and not always associated with cholecystitis
Occur due to mucin production and reduced GB motility producing either calcium carbonate or bilirubin pigment liths.
Surgery is generally required and carries a survival of about 78% in cats but only 41% in dogs
Gall bladder mucocele
Exclusive to dogs
Occurs when there is thick, mucin-laden bile within the gall bladder and ducts causing an obstruction to bile flow which leads to ischaemic necrosis of the GB wall and likely to rupture without intervention. Can attempt to medically manage however most of the time require surgery to avoid rupture and consequences of rupture
‘Kiwi fruit’ appearance
Medical management of GB mucocele
UDCA: immunomodulatory, increases GB motility, decreases mucin secretion
Levothyroxine
sAME: glutathione precursor and antioxidant
Amoxicillin
Omega FA
Hepatitis
Inflammatory cell infiltrate within hepatic parenchyma with cholangiohepatitis referring to the involvement of the intrahepatc bile ducts. There are many causes for hepatitis including: idiopathic (CCH, idiopathic feline hepatitis), viral (infectious CH, FIP), bacterial (leptospirosis, bartonellosis, septicaemia) or drugs/toxins
Mechanisms of hepatocellular injury
Hypoxia
Lipid perioxidation
Endogenous or intracellular toxins
Intracellular co-factor depletion
Cholestatic injury
Hepatocyte membrane injury
Hypoxic injury to hepatocytes
Cytokines & organelle injury > ATP depletion > free radical and oxidative injury
Toxin injury to hepatocytes
I.e. bile acid retention
Nuclei acid binding > impaired protein synthesis
Inflammation
TNF-a expression
Neutrophilic v. Lymphocytic idiopathic feline cholangitis complex
In both hepatic and biliary enzymes may or may not be increased
Mixed inflammatory infiltrates are seen in lymphocytic compared to neutrophilic
Treatment of neutrophilic involves antimicrobials whereas lymphocytic involved immunosuppressive therapy
IBD and pancreatitis may be associated with both
Hepatic tissue biopsies differentiate
Both are likely due to ascending bacterial infection from the GIT
Canine chronic hepatitis (CCH)
Idiopathic
Progressive, necroinflammatory disease likely with some immune-mediated process
Histopathologic assessment of liver tissue: lymphocytic, plasma cystic and may also be neutrophilic; apoptosis/necrosis, signs of regeneration with fibrosis
Treated with immunosuppressive therapy: UDCA, glucocorticoids, metronidazole, azathioprine, cyclosporine and +- copper chelation
Copper in CCH
These patients seem to have elevated levels of copper and unsure if primary copper storage disorder or if due to inability of diseased liver to excrete. In any situation chelation with d-penicillamine or trietine may be indicated
Leptospirosis and hepatitis
L. icterohaemmorhagiae or L. Pomona likely to induce hepatitis
May not test positive for first 2 weeks; infection may span 2-6 weeks
Usually induces ARF but hepatitis seen in 20-35% of cases
Treatment with doxycycline 5mg/kg q12
Bartonellosis and hepatitis
Likely henselae or clarridgeiae varieties and confirmed with PCR
Treatment with azithromycin (or: doxy, enro, rifampin)
Liver failure
Occurs when there is severe hepatocyte injury or dysfunction that leads to severe metabolic dysfunction, hepatic encephalopathy and coagulopathy.
Liver failure induces…
Coagulopathy
GI ulceration
Bacterial sepsis
Cardiopulmonary dysfunction
Ascites
CNS signs
How much of the liver can regenerate within a few weeks?
<75%
Acute v. Chronic liver failure
Acute liver failure likely to appear as hepatocellular necrosis as a primary lesion whereas chronic will have this as well as fibrosis, inflammation and hyperplasia of ductular structures.
Common clinical signs of hepatic failure
Hepatic encephalopathy (CNS abnormalities)
Hypotension
Lactic acidosis
Electrolyte abnormalities
Coagulopathy
Hypoglycaemia
Azotaemia
PU/PD (decreased ADH response, urea processing failure)
Icterus
GI signs
Consequences of hepatic failure
Higher risk of infection
Systemic hypotension
Portal hypertension
Pulmonary infiltrates
Renal dysfunction
Acid-base abnormalities
Haematology findings in patients with hepatic failure
Target cells
Acanthocytes
Anicytosis
Anaemia; nonregenrative indicates chronic where regenerative may be more acute process
Leukocytes is or leukopaenia
Biochemistry findings in hepatic failure
Increased liver enzymes
Increased TBil
Low cholesterol
Hypoalbuminaemia
Hypoglycaemia
Low BUN
ALT & AST
Found in cytosol of hepatocytes and leak when hepatocyte cell membrane disrupted (ALT shorter HL and therefore more specific for acute hepatic failure)
ALP
Found on the membranes of hepatocytes and biliary epithelial cells increasing in cholestatic disease
GGT
Specific for cholestatic disease
Albumin in liver failure
Altered albumin synthesis not detected until >66-80% of liver function lost and is a hallmark of chronic liver disease due to it having a long half life of 8 days. It is 25% of all proteins synthesised in the liver
How much cholesterol is synthesised in the liver
50%
When does hypoglycaemia occur in liver disease
When only 30% of liver function is present
UA findings in hepatic failure
Ammonium biurate crystals
Urate crystals
Bilirubinaemia
Treatment options for liver failure
Treat underlying disorder
Liver protectants
Routine supportive care
Treatment of HE
Treatment of coagulopathy
Seizure control (avoid benzodiazepines)
Vitamin E
Milk thistle
L-carnitine
Vitamin B complex
Gastroenteritis
Inflammation of the stomach and digestive tract
Stomach layers
Glandular; parietal cells (H secretion), chief cells (pepsinogen), mucosal (bicarbonate)
Mucosal; protects from effects of acids
Muscle: grinds, moves food
Small intestine areas and functions
- Duodenum
- Jejunum
- Ileum
Functions to breakdown/grind and absorb food/nutrients
Contains enterocytes, villi, microfilm etc
Infectious gastroenteritis pathogens
Clostridium
CPV-2
Campylobacter
Salmonella
Helicobacter
E. Coli
Cryptosporidia
Toxocaria
Trichuris (whip worm)
Hook worm
Urcinaria
Trichomonas
Histoplasmosis
HGE
Acute onset of haemorrhagic diarrhoea that is likely an immune response to bacteria, bacterial endotoxin or dietary ingredients. It is associated with a PCV >60%, vomiting, haemorrhagic diarrhoea, anorexia, depression.
Why do we quickly want to correct fluids in gastroenteritis
The GIT is a shock organ particularly in dogs and therefore poor perfusion to the gut worsens inflammation, promotes bacterial translocation and also promotes sepsis, and DIC.
Protein losing enteropathy (PLE)
Broad classification that indicates that there is massive plasma protein loss from the GIT. It causes disruption to the GI barrier and normal enterocyte function as well as deranged permeability of the tight junctions. This results in loss of albumin and antithrombin which leads to decreased oncotic pressure, pro inflammatory response and thromboembolism
Diagnostics and treatment of gastroenteritis
Faecal testing, systemic evaluation, determine underlying cause, imaging, albumin therapy, electrolyte and fluid therapy, radiographs, ultrasound, biopsies, nutritional support, try to avoid antibiotics, consider gastroprotectants.
Megaoesophagus
Congenital or acquired
Distension of vagus afferent system innervating the oesophagi is ineffective
Diagnosed either with plain radiographs or contrast radiographs
Treatment of megaoesophagus
Prokinetics
H-H2 blocker
PPI
Pyridostigmine
Prednisone
Mycophenylate
Azathioprine
Small, frequent meals from a height
Consider feeding tubes
Gastric empting disorders
Due to mechanical obstruction or defective propulsion and associated with chronic intermittent vomiting, gastric distension and weight loss. It is confirmed with a barium study and treated with small, frequent meals and prokinetics
Transit disorders
Include ileus, enteritis, nematode infestation, sclerosis, radiation eneteritis.
Can be a result of bacteria, bacterial endotoxin, surgery etc
Before beginning prokinetic therapy must rule out a mechanical obstruction