Ileus

Question 1

What is ileus?

Answer 1

Inhibition of bowel motility

Question 2

What are causes of ileus?

Answer 2

Post op ileus

Alteration of motility due to electrolyte or perfusion abnormalities

Mechanical obstruction with gas distention

Inflammation

Drug induced

Question 3

T/F: Post operative ileus in horse is frequently seen after manipulation of the SI

Answer 3

True

Question 4

What is a type of post op ileus that is particularity seen in cases with chronic or painful musculoskeletal disorders ?

Answer 4

Post-anesthesia cecal dysfunction

Question 5

Ileus can be a consequence of sustained intense exercise because of alterations in ???

Answer 5

Electrolytes — esp Ca and K

Question 6

What drugs are associated with ileus?

Answer 6

Atropine — generalized depressed motility

Alpha 2 agonsits (xylazine and detomidine) — especially depresses large colon motility

Question 7

How does peritoneal inflammation/irritation initiate ileus?

Answer 7

Neural reflexes

Efferent limb of sympathetic over flow activated by peritoneal fibers

Endotoxemia —sympathetic over-stimulation by alpha 2 receptors - mimicking efferent limb

Question 8

What is the treatment of ileus?

Answer 8

Gastric decompression

Fluid/electrolyte therapy
— maintain extracellular K, Ca, and Mg
—replace deficit plus ongoing losses/anticipated losses (including amount lost from gastric decompression)

Avoid drugs that reduce motility or propagate stasis 
Pain control 
Anti-inflammatories 
Antimicrobials 
Prokinetics

Question 9

What drugs do you avoid in ileus cases because they reduce motility ?

Answer 9

Anticholinergic — atropine
Opioid receptor agonists — morphine or meperidine

Butorphanol seems to have very little effect on motility

Question 10

What do you use for pain control in ileus?

Answer 10

A2 agonists

• xylazine
• detomidine

—use carefully - can result in generalized ileus

Question 11

What is your choice anti-inflammatory for ileus?

Answer 11

Flunixin — anti-inflammatory, analgesic, antiendotoxic

Question 12

When are antibiotics indicated in a case of ileus?

Answer 12

Is sepsis is suspected

If immune compromised

Question 13

What prokinetic drugs lack local anesthetic and anti-dysarrythmic actions?

Answer 13

Benzamides

• metoclopramide
• cisapride

Question 14

What is the MOA of metoclopramide ?

Answer 14

Dopamine receptor antagonist, weak alpha 2 antagonsit
Indirect stimulation of ACh from myenteric plexus

—> limited effect to gastric and duodenal portions of GIT

Question 15

What is the MOA of cisapride ?

Answer 15

Primary effect by stimulating release of ACh from myenteric plexus

Generalized increase in progressive motility

Mostly have effect in Large intestine

Question 16

What are two colonomimetic drugs?

Answer 16

Bethanocol

Neostigmien

Question 17

MOA of bethanecol?

Answer 17

Stimulates smooth muscle contraction by working on muscarinic receptors

Increases gastric contractions without increasing acidity

Question 18

When is bethanecol indicated for ileus treatment?

Answer 18

Non obstructive disorders of gastric emptying

Question 19

What is the MOA of neostimgmine?

Answer 19

Increase receptor level of ACh my inhibiting acetylcholinesterase

Question 20

What drug is used for its mimicking effect of endogenous hormone motilin?

Answer 20

Erythromycin

Acts within enteric nervous system to release motilin through cholinergic pathways

Question 21

Where does erythromycin have its motility effects?

Answer 21

SI
Cecum
Colonic

Question 22

When is lidocaine indicated for ileus cases?

Answer 22

Post op ileus and duodentitis-proximal jejunitis (DPJ) for treatment of reflux

Question 23

What are the beneficial effects of lidocaine in the treatment of ileus?

Answer 23

Suppression of afferent reflex pathway from peritoneum
Analgesic
Anti-inflammatory