558: RISK OF H2RA VERSUS PPI FOR DEVELOPING ICU DELIRIUM IN MECHANICALLY VENTILATED OLDER ADULTS

Abstract

Introduction: Histamine 2-receptor antagonists (H2RA) and proton pump inhibitors (PPI), two acid suppressing drugs, are commonly prescribed for stress ulcer prophylaxis (SUP) in the intensive care unit (ICU). Although both exhibit equivalent effectiveness, recent data suggests a higher risk for ICU delirium with H2RA when compared to PPI. Methods: This was a single-center, retrospective, observational cohort. Mechanically ventilated ≥65 years old patients admitted to a Medical ICU between January 2020 and December 2021 were included if they received at least one dose of H2RA or PPI. Patients were excluded if they received both H2RA and PPI or had a positive Confusion Assessment Method (CAM-ICU) within 24 hours prior to the administration of the drug. Descriptive statistics were used for frequency, median, and mean. Associations between characteristics and the SUP were measured using chi-square, Fisher’s exact, and Wilcoxon rank-sum or t-test. The primary objective was to compare the rate of ICU delirium (≥1 day positive CAM-ICU) in mechanically ventilated older patients receiving H2RA vs. PPI for SUP. Secondary objectives were to compare the percentage of ICU days in delirium and compare the rate of ICU delirium stratified by age (65-75 years old and >75 years old). Results: We screened 236 patients and identified 60 patients for inclusion; 35.0% were female and 70.0% were 65 to 75 years old. Fifty-five percent of patients received H2RA and 45% received PPI. The incidence of delirium in groups was similar; 69.7% (23) for H2RA vs. 63.0% (17) for PPI (p=NS). The percentage of ICU days in delirium was also similar; 37.5% for H2RA vs. 28.2% for PPI (p=NS). Analysis stratified by age also did not show statistical differences between SUP therapies and incidence of delirium or percentage of ICU days in delirium. The relative risk in advanced elderly ICU patients was numerically higher with H2RA (28% greater risk in patients >75 years old vs. 2% greater risk in patients 65-75 years old). Conclusions: We found no association between choice of SUP and risk for ICU delirium development in mechanically ventilated older Medical ICU patients. Larger epidemiologic studies are needed to elucidate whether there is potentially a differential risk between H2RA and PPI in the advanced elderly population.