Decision making regarding GI disease

Question 1

What are the critical questions when deciding to refer a colic case?

Answer 1

What is the severity of the condition?
Is referral indicated?
Is surgery indicated?
What is the prognosis?

Question 2

During what timeframe do you need to make the decision: to cut or not to cut?

Answer 2

Rapidly- the earlier the better
- ideally within the first 10-30 min of your evaluation
- subsequent evaluation and monitoring may lead to a change in the plan (always be open to changing plans)
- additional diagnostic information can be useful but is not always required to formulate an appropriate plan

Question 3

T/F: a definitive diagnosis is always required in order to make a decision regarding surgical colic

Answer 3

False- it is not always available and is not required
- often GI surgery is a diagnostic as much as a therapeutic (and its not always therapeutic)

Question 4

What are the most critical history questions in colic cases?

Answer 4

signalment, history of previous colic, duration of signs, severity of signs, changes in signs over time, response to treatment prior to referral

Question 5

What types of colics are more likely in mare vs stallion? What about older horses?

Answer 5

Mare: uterine artery rupture, uterine torsion
Stallion: testicular torsion, inguinal hernia

Old horses- strangulating lipomas, epiploic entrapments

Question 6

How can breed impact differentials in colic cases?

Answer 6

Ponies: at decreased odds of colon displacements, as well as increased odds of strangulation of the small intestines by lipomas
Miniature types: decreased odds of strangulating small intestinal lesions
Drafts: increased odds of cecal conditions

Question 7

T/F: longer duration of signs is usually associated with a better outcome

Answer 7

True- usually less severe
- however, if it’s a short duration and you catch earlier you can have an improved outcome
-but if its severe and acute, often there’s a worsened outcome

Question 8

While severity of signs is usually associated with a worse prognosis, what are some confounding factors?

Answer 8

-with severe strangulation, minimal signs may be present and interpretation can be clouded by severe obtundation
-also with ruptures, signs of pain often subside (though all these horses have to be euthanized)

Question 9

T/F: Increasing pain level means the lesion is more likely to be surgical. Decreasing pain levels are always associated with a better prognosis

Answer 9

False- both increasing and decreasing pain levels can be associated with worsening of the lesion

Question 10

What is tachycardia, MM color, CRT associated with in terms of colic?

Answer 10

Tachycardia- mediated by hypotension and/or pain
MM color- related to peripheral vascular tone and blood pressure
CRT- indicator of perfusion

*if one is abnormal, others are more likely to be as well. Abnormalities may be associated with SIRS unrelated to GI pathology

Question 11

T/F: An increasing HR is associated with decreased survival especially in conjunction with abnormal mucous membranes

Answer 11

True
-but there is poor sensitivity and specificity (just associated with severity of systemic illness)

Question 12

Why is abdominal distension poorly sensitive?

Answer 12

-the absence of visible distension does not rule out internal distension/displacement
-test is inherently subjective

Question 13

If borborygmi is absence, what may this indicate?

Answer 13

You are much more likely to be dealing with a surgical lesion (OR 11.97)

Question 14

Describe the diagnostic value of nasogastric reflux

Answer 14

• it is nonspecific and reflux presence may be a result of either a functional or mechanical obstruction
  -reflux volume >5 correlates with worsening severity of lesion
  -copious reflux may suggest proximal jejunitis, or anterior enteritis

Question 15

If a horse presents with a high HR and is actively painful, what is the first thing you should do?

Answer 15

Pass a tube to prevent stomach rupture!

Question 16

What signs in addition to reflux can help you determine i the reflux is due to enteritis or is surgical?

Answer 16

Fever- more likely enteritis
- although owner has often already treated with banamine

*best indicator is relief after tube is passed- if horse is no longer actively painful more likely to be enteritis

Question 17

T/F: unless alternative diagnosis is available (impaction), most horses that respond poorly to analgesics are surgical candidates

Answer 17

True

Question 18

What are the advantages and disadvantages of abdominocentesis?

Answer 18

Advantages: easily performed, abnormal findings are typically significant
Disadvantages: complete analysis may not be possible or timely, poor sensitivity and specificity

Question 19

What should you evaluate peritoneal for?

Answer 19

Appearance, TP, nucleated cell count, cytology, lactate

Question 20

What does normal peritoneal fluid look like?

Answer 20

Light yellow and clear
-discoloration (red brown or green) is a bad sign (most diagnostic) as well as increased turbidity (which may be due to cells, protein, GI contents or fat)

Question 21

Which is more helpful prognostically: normal or abnormal color of abdominal tap?

Answer 21

Abnormal- much more likely to be surgical
-however a horse with normal fluid still may be surgical

Question 22

T/F: total protein is a very useful factor in determining whether surgery is indicated

Answer 22

False- low sensitivity, fair specificity
- normal values range widely

Question 23

Is NCC of peritoneal fluid diagnostically useful?

Answer 23

Not really
- looking at color is much more predictive for whether a horse needs surgery

DONT WAIT FOR RESULTS THAT WONT AFFECT DECISION MAKING

Question 24

Is lactate levels diagnostically useful?

Answer 24

YES
- elevated concentration is strongly correlated with need for surgical intervention

Question 25

What is the HCT level useful for?

Answer 25

prognosis, but not surgical decision making

Question 26

What can hyperglycemia tell you in colic cases?

Answer 26

Prognosis
- hyperglycemia is associated with non-survival (>350=unlikely to survive)

Question 27

Can azotemia and hypoproteinemia help you? What about lactate?

Answer 27

Not really, they are very non-specific

Lactate is useful as a marker of disease severity and prognosis

Question 28

When is abdominal ultrasonography of greatest use?

Answer 28

As an adjunctive tool to rectal palpation
-sometimes useful for identification of abdominocentesis sites (not necessary, but helpful)

Question 29

When can radiographs be helpful in colic cases?

Answer 29

They have low sensitivity and specificity but can be of diagnostic use in cases of diaphragmatic hernias, enterolithiasis, or sand colic
-in foals can diagnose small or large intestinal distention