Hepatic Failure/GI/Endocrine Emergencies
Sham feeding
Sham feeding is the process of eliciting the release of hormonal and neuronal GI activity without
regular feeding. One way by which this mechanism can occur is through the chewing of gum.
In a small randomized study of 19 patients, chewing gum three times a day reduced time to first
flatus (2.1 days vs. 3.2 days, p<0.01) and time to first defecation (3.1 days vs. 5.8 days, p<0.01)
compared with control.
Pharmacologic therapy
Opioid-sparing analgesia
NSAIDs have two potential effects on resolving POI: sparing opioids through their analgesic
effects and reducing the production of inflammatory mediators (e.g., prostaglandin). Adding
an NSAID to opioid therapy reduces the need for opioids by 20%–30%.
ii.
A randomized, double-blind study of morphine patient-controlled analgesia with or without
ketorolac showed decreased morphine use and earlier first bowel movements (1.5 days vs. 1.7
days, p<0.05) in the patients who received the additional ketorolac compared with those who
did not.
iii.
Use should be carefully assessed so that the benefit outweighs the risk of postoperative bleeding
caused by platelet inhibition together with the potential increased risk of anastomotic leak and
wound dehiscence.
Prokinetics and laxatives
Erythromycin
| (a) | Erythromycin is a macrolide antibiotic that has prokinetic activity as a motilin receptor |
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agonist. Motilin induces gastric contractions and migrating motor complex.
| (b) | In randomized controlled trials, erythromycin does not appear beneficial for POI |
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resolution.
ii.
Metoclopramide. No studies of POI have shown a benefit; however, the antiemetic activity of
metoclopramide may be beneficial as an adjunctive therapy for patients with POI.
iii.
Laxatives
| (a) | Laxatives should play an important role in the management of POI because of their |
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stimulatory action in the GI tract; however, data are limited on the use of laxatives.
| (b) | Most of the data regarding the use of laxatives for POI support the use of bisacodyl |
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suppositories (e.g., 10 mg rectally daily), which have reduced time to return of normal
bowel function and some evidence of reduced hospital length of stay.
iv.
Gastrografin
| (a) | Gastrografin is an oral contrast agent with theoretical benefit in POI because it is hypertonic |
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and reduces gut wall edema by drawing fluid into the gut lumen and promoting peristalsis.
| (b) | In a randomized controlled trial of 80 patients with prolonged POI, gastrografin did not |
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significantly reduce the mean duration of POI compared with placebo (83.7 vs. 101.3
hours, p=0.19).
Peripherally acting mu-opioid receptor antagonists
Alvimopan (Entereg)
| (a) | Alvimopan has 200-fold selectivity for the peripheral opioid receptors and has poor |
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absorption from the GI tract when administered orally (bioavailability about 6%),
decreasing the likelihood of systemic absorption and penetration across the blood-brain
barrier.