Discontinuation, restart and survival associated with neuromuscular blocking agent use for hypoxemia in critically Ill patients: a multi-database retrospective cohort study

Abstract Background The utilization of neuromuscular blocking agents (NMBAs) in hypoxemic critically ill patients varies, and real-world patterns of NMBA discontinuation and subsequent restart remain insufficiently described. This study aimed to evaluate patterns of NMBAs utilization and explore associations with subsequent NMBA restart and ICU mortality. Methods A retrospective cohort study was conducted using an integrated intensive care database (MIMIC-III / IV, eICU, HiRID, AmsterdamUMCdb, and our institution). Mechanically ventilated patients with PaO 2 /FiO 2 (P/F) ratio < 200 who received NMBAs for > 24 h were included to analyze NMBA discontinuation ( n = 829). For those who discontinued NMBA during ICU stay ( n = 737), NMBA restart and ICU mortality were also evaluated. Results Prolonged NMBA use exceeding 48 h occurred in 332 of 829 patients (40.0%), with substantial inter-dataset variability. Younger age, higher body mass index, later NMBA initiation and lower respiratory system compliance were associated with longer NMBA duration. Among the 737 patients who discontinued NMBA during the ICU stay, 291 (39.4%) required NMBA restart and 260 (35.3%) died in the ICU. Although NMBA duration was significantly associated with subsequent NMBA restart (Odds Ratio=1.006, CI 1.003–1.009, p < 0.001), it was not associated with ICU mortality (Odds Ratio=1.002, CI 0.999–1.005, p = 0.250). Conclusion NMBA practices varied widely, and prolonged administration was common, with a high rate of restart following discontinuation. NMBA duration was associated with subsequent NMBA restart but not with ICU mortality. These findings highlight the need for further studies to identify clinical factors associated with NMBA discontinuation and restart and to better understand the clinical significance of these observed patterns in hypoxemic respiratory failure.