LAUSR

INTRODUCTION: Gastrointestinal (GI) dysfunction is prevalent in critically ill patients with coronavirus disease 2019 (COVID-19) Inadequate nutrition in critically ill patients has been associated with increased morbidity and mortality The acetaminophen absorption test (AAT) has been previously described as a direct method for assessment of GI function This study seeks to determine whether the AAT can be used to assess gastrointestinal function in critically ill COVID-19 patients, compared with traditional measures of GI function METHODS: This retrospective observational study was performed in three ICUs The study cohort consisted of critically ill adult COVID-19 positive patients who were receiving enteral nutrition via nasogastric tube (NGT) and had received the AAT to assess absorption The AAT was performed by administration of 950-1000 mg of acetaminophen liquid suspension through the NGT, which was then clamped for 1 hour The times of administration were recorded and blood samples were ordered to be drawn 90 minutes following acetaminophen administration Acetaminophen plasma levels were then measured via laboratory evaluation The test was considered positive for absorption if the plasma acetaminophen concentration was greater than or equal to 5 mcg/mL at 90 minutes following administration RESULTS: Among the study cohort 55% (11/20) 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 hours 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=0 03), tolerated tube feed rates were higher (40 vs 10 mL/hr;p=0 01) and there was a trend towards lower gastric residual volumes (45 vs 830 mL p=0 11) CONCLUSIONS: 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 order to optimize nutritional status in this patient population