Neuromuscular Blocking Agent during Targeted Temperature Management for Out-of-Hospital Cardiac Arrest Patients: A Multicenter Prospective Observational Study (SOS-KANTO 2017 study)

Abstract

Abstract Background Neuromuscular blocking agents (NMBAs) can control shivering during targeted temperature management (TTM) of patients with cardiac arrest. However, the effectiveness of NMBA use during TTM on neurologic outcomes remains unclear. We aimed to evaluate the association between NMBA use during TTM and favorable neurologic outcomes after out-of-hospital cardiac arrest (OHCA). Methods This was a multicenter prospective observational cohort study of OHCA patients from 2019 to 2021 (SOS-KANTO 2017 Study database). A total of forty-two emergency hospitals participated in this study. The study included adult OHCA patients who received TTM after hospitalization and excluded patients with missing data on NMBA use. After multiple imputations for missing data, we conducted overlap weight based on propensity-score analyses to compare outcomes between those with and without NMBA use during TTM. A favorable neurological outcome was defined as a cerebral performance category of 1 or 2 at discharge. Subgroup analyses were conducted according to initial monitored rhythm, findings of brain computed tomography (hypoxic encephalopathy and reduced gray-to-white-matter ratio), and each targeted temperature. Results Of the 516 eligible patients, 337 received NMBAs during TTM. The propensity score analysis showed a higher proportion of favorable neurologic outcomes in the NMBA group than in the non-NMBA group (32.7% vs. 20.9%; risk difference (RD), 11.8%; 95% confidence interval (CI), 1.2–22.3%). Subgroup analyses showed higher proportions of favorable neurologic outcome in the NMBA users among those with initial shockable rhythm (46.2% vs. 26.6%; RD, 19.6%; 95% CI, 3.5–35.6%), no hypoxic encephalopathy (48.3% vs. 27.9%; RD, 20.4%; 95% CI, 6.1–34.7%), and no reduced gray-to-white-matter ratio (36.2% vs. 20.5%; RD, 15.7%; 95% CI, 3.9–27.5%). Conclusions The use of NMBAs during TTM was significantly associated with favorable neurologic outcomes at hospital discharge for OHCA patients. NMBAs may have benefits in selected populations of patients with initial shockable rhythm and no poor prognostic computed tomography findings.