Use of Neuromuscular Blocking Agents in Mechanically Ventilated Patients with COVID-19: A Propensity Score Analysis

Background: Neuromuscular blocking agents (NMBA) have been previously used in patients with acute respiratory distress syndrome (ARDS). It is unknown if NMBA are useful in COVID-19 patients who require invasive mechanical ventilation (IMV). Methods: We investigated use of NMBA in COVID-19 patients on IMV from February 1 to November 24, 2020, in 147 hospitals across 6 continents, comprising the COVID-19 Critical Care Consortium. We performed propensity score (PS) matched Cox proportional hazards analysis to appraise the impact of NMBA use for ≥2 days, continuously or discontinuously (treatment), vs. no use of NMBA or only upon commencement of IMV (control) on 28-day intensive care unit (ICU) mortality. Findings: 1548 (72%) patients received any NMBA therapy; 1165 (54%) of patients were stratified in the treatment group, with a median (IQR) time from ICU admission to commencement of NMBA therapy of 0 (0-2) days. The median (IQR) duration of NMBA therapy was 3 (2-6) days (N=1548). Upon commencement of IMV, patients who received NMBA therapy had a lower mean (±SD) PaO2/FiO2 (139±75 vs 157±93; P<0.001). After PS matching, Cox proportional hazard model demonstrated that NMBA therapy was significantly associated with higher 28-day ICU mortality (adjusted HR 2.20, 95% CI 1.67, 2.89, P<0.001). Sensitivity analyses testing various NMBA therapeutic regimens confirmed similar associations with mortality. Interpretation: Use of NMBA is common in COVID-19 patients on IMV and associated with a 2.2-fold increase in risk of 28-day mortality. Until further randomised evidence is available, NMBA should be applied cautiously in routine clinical practice. Funding Statement: University of Queensland, Wesley Medical Research, The Prince Charles Hospital Foundation, The Health Research Board of Ireland; Biomedicine international training research programme for excellent clinician-scientists; European Union’s research and innovation programme (Horizon 2020); la Caixa Foundation. Finally, Carol Hodgson is funded by a National Health and Medical Research Council Grant. Declaration of Interests: Dr. Li Bassi received research support from Fisher & Paykel outside the submitted work. Dr. Dalton has consulting from Innovative ECMO Concepts, Abiomed and Instrumentation Labs , none which affect the current work. Dr. Brodie receives research support from ALung Technologies and he has been on the medical advisory boards for Baxter, Abiomed, Xenios and Hemovent. Dr. Fan reports personal fees from ALung Technologies, Baxter, Fresenius Medical Care, Getinge, and MC3Cardiopulmonary outside the submitted work. Dr. Laffey reports consulting fees from Baxter and Cala Medical, both outside the submitted work. Dr Nichol is supported by a health Research Board of Ireland award (CTN-2014-012). Dr. Fraser receives research support from Fisher & Paykel outside the submitted work. Remaining authors do not have any competing interest to declare. Ethics Approval Statement: Participating hospitals obtained local ethics committee approval and a waiver of informed consent was granted in all cases. De-identified patient data were collected and stored via the REDCap (Vanderbilt/NIH/NCATS UL1 TR000445 v.10.0.23) electronic data capture tool, hosted at the University of Oxford, United Kingdom and University of Queensland.