An examination of gastrointestinal absorption using the acetaminophen absorption test in critically ill patients with COVID‐19: A retrospective cohort study

Objective Gastrointestinal (GI) dysfunction is prevalent in critically ill patients with coronavirus disease 2019 (COVID‐19). The acetaminophen absorption test (AAT) has been previously described as a direct method for assessment of GI function. Our study determines whether the AAT can be used to assess GI function in critically ill COVID‐19 patients, compared with traditional measures of GI function. Design Retrospective observational study of critically ill patients with COVID‐19. Setting Three intensive care units at a tertiary care academic medical center. Patients Twenty critically ill patients with COVID‐19. Interventions The results of AAT and traditional measures for assessing GI function were collected and compared. Measurements and Main Results Among the study cohort, 55% (11 of 20) of patients had evidence of malabsorption by AAT. Interestingly, all patients with evidence of malabsorption by AAT had clinical evidence of bowel function, as indicated by stool output and low gastric residuals during the prior 24 h. When comparing patients with a detectable acetaminophen level (positive AAT) with those who had undetectable acetaminophen levels (negative AAT), radiologic evidence of ileus was less frequent (20 vs 88%; P = .03), tolerated tube‐feed rates were higher (40 vs 10 ml/h; P =.01), and there was a trend toward lower gastric residual volumes (45 vs 830 ml; P =.11). Conclusion Malabsorption can occur in critically ill patients with COVID‐19 despite commonly used clinical indicators of tube‐feeding tolerance. The AAT provides a simple, rapid, and cost‐effective mechanism by which enteral function can be efficiently assessed in COVID‐19 patients.