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Nishika Patel
Critical care pharmacist with a fondness for cats, wine, and all things vintage. Also an insta-nerd who likes to teach ICU tidbits on her IG page @dr.scriptsndrips.
The Pre-brief
Today we’ll be discussing the management of 3 gastrointestinal hiccups (pun intended) commonly dealt with in the ICU:
- Gastroparesis
- Constipation
- Functional ileus
Due diligence must be taken to ensure that the diagnosis is correct before pharmacological treatment is started. A physical exam and/or imaging may be necessary to exclude the presence of a mechanical obstruction that requires surgical management.
Additional info:
- Unfortunately, there is not much literature to support the use of peripherally acting μ-opioid receptor antagonists (PAMORAs) for opioid-induced constipation or functional ileus in critically ill patients. The recent MOTION trial (2020) evaluated methylnaltrexone vs placebo for opioid-induced constipation in critically ill patients and found no significant difference in time to rescue-free laxation between groups (p=0.22). They also found a marked difference in mortality between groups with 10 deaths in the methylnaltrexone group vs 2 deaths in the placebo group (p=0.007).
- Several small studies have evaluated the effectiveness of PO naloxone for opioid-induced constipation and these have yielded mixed results. Despite extensive first-pass metabolism in the liver, the potential for opiate reversal after oral administration remains a concern.
The Debrief
- Gastroparesis, constipation, and functional ileus are 3 gastrointestinal issues that are commonly encountered in the ICU.
- The mechanical obstruction which would necessitate surgical intervention should be ruled out before initiating pharmacological treatment.
- While limited literature exists in critically ill patients, current data suggest that the use of PAMORAs for opioid-induced constipation, specifically methylnaltrexone, may increase the risk of mortality.
References
- Ladopoulos T, Giannaki M, Alexopoulou C, et al. Gastrointestinal Dysmotility in Critically Ill Patients. Ann Gastroenterol. 2018; 31(3): 273-281.
- Camilleri M, Parkman H, Shafi M, et al. Clinical Guideline: Management of Gastroparesis. Am J Gastroenterol. 2013 Jan; 108(1): 18-38.
- Lexi-Drugs. Lexicomp. Wolters Kluwer Health, Inc. Riverwoods, IL. Available at: http://online.lexi.com.
- Vincent J, Preiser J. Getting Critical About Constipation. Pract Gastroenterol. 2015 Aug; 144.
- Vilz T, Stoffels B, Strassburg C, et al. Ileus in Adults. Dtsch Arztebl Int. 2017; 114: 508-18.
- Camilleri M, Lembo A, Katzka D. Opioids in Gastroenterology: Treating Adverse Effects and Creating Therapeutic Benefits. Clin Gastroenterol Hepatol. 2017 Sep; 15(9): 1338-1349.
- Patel P, Brett S, O’Callaghan D, et al. Methylnaltrexone for the Treatment of Opioid-Induced Constipation and Gastrointestinal Stasis in Intensive Care Patients. Intensive Care Med. (2020) 46: 747-755.
