(387) Practice Patterns of Gastric Residual Volume Measurement and Outcomes in Perioperative ICU Patients

Introduction: The 2016 ASPEN/SCCM Critical Care Guidelines recommend against routinely measuring gastric residual volumes (GRVs) in hospitalized patients receiving enteral nutrition (EN). Whether this recommendation is routinely implemented is unknown. We aimed to describe GRV monitoring patterns and associations with outcomes in a contemporary cohort of mechanically ventilated (MV) perioperative ICU patients.

Methods: Retrospective cohort study of adult patients who underwent non-emergency, non-GI tract, non-airway, non-prone procedures with anesthesia during ICU admission between June 1st 2016 and June 1st 2022 at a quaternary hospital. Patients received MV within 12 hours and EN within 48 hours prior to surgery. We identified percentage of admissions with routine GRV monitoring (mean ≥4 GRV recordings per day). Patients were stratified by preoperative elevated GRV (≥200mL, which triggers MD consultation per hospital policy) within 48 hours of surgery. We used a binary composite outcome of death or MV at postoperative day 28 in a zero-inflated multivariable negative binomial regression.

Results: There were 440 unique ICU admissions for 436 patients during the study period. Proportion of admissions with GRVs checked routinely per year were: 16/44 in 2016 (36.4%), 40/96 in 2017 (41.7%), 38/99 in 2018 (38.4%), 37/88 in 2019 (42.0%), 3/81 in 2020 (3.7%), 0/28 in 2021 (0%), and 0/4 in 2022 (0%). 42 (9.6%) patients had an elevated preoperative GRV. Compared to the low pre-op GRV group, ASA status, mean Charlson Comorbidity Index (CCI), and median duration of MV at time of index surgery were similar to the high pre-op GRV group (97.6% vs 97.9% with ASA III status or higher, CCI 1.1 vs 1.2, 7.0 vs 7.4 days). An elevated pre-op GRV was associated with an increased odds of mortality or MV at post-op day 28 (OR = 2.37, p=0.025).

Conclusions: Routine GRV monitoring in the ICU decreased from 2020 to 2022 in patients who underwent a procedure during their ICU admission, coinciding with the COVID-19 pandemic (2020) rather than the release of ASPEN/SCCM guidelines, suggesting either a delay or failure with guideline implementation. ICU patients with higher preoperative GRV are at higher risk of death or MV one month postoperatively although it is unclear whether they would benefit from routine GRV monitoring.