Association between known or strongly suspected malignant hyperthermia susceptibility and postoperative outcomes: an observational population-based study

摘要

PurposeWhether current standards of care management for malignant hyperthermia (MH)-susceptible patients result in acceptable postoperative clinical outcomes at a population level is not known. Our objective was to determine if patients with susceptibility to MH experienced similar outcomes as patients without MH susceptibility after surgery under general anesthesia.MethodsThis was a retrospective, population-based cohort study from 1 April 2009 until 31 March 2016 in the Canadian province of Ontario. Participants were adults who underwent common in- or outpatient surgeries under general anesthesia. The exposure studied was either known or strongly suspected MH susceptibility as determined by usage of a specific physician billing code. The primary outcome was a composite of all-cause death, hospital readmission, or major postoperative complications, all within 30 postoperative days. Separate analyses were employed, based on whether a patient had in- or outpatient surgery. Inverse probability of exposure weighting based on the propensity score was used to estimate adjusted exposure effects.ResultsThe cohort included 957,876 patients (583,254 in- and 374,622 outpatients). There were 2,900 (0.3) patients with a known or strong suspicion of MH susceptibility. For inpatients, the primary outcome occurred in 146,192 (25.1) of the non-MH-susceptible group and in 337 (20.1) of the MH-susceptible group (unadjusted risk difference RD, -5.0; 95 confidence interval CI, -6.9 to -3.1; P < 0.001). In outpatients, the primary outcome occurred in 9,146 (2.4) of the non-MH-susceptible group and in 32 (2.6) of the MH-susceptible group (RD, 0.2; 95 CI, -0.7 to 1.1; P = 0.72). After adjustment, MH susceptibility was not associated with the primary outcome in either the inpatients (adjusted risk difference aRD, 1.2; 95 CI, -1.3 to 3.6; P = 0.35) or outpatients (aRD, -0.1; 95 CI -1.0 to 0.9; P = 0.90).ConclusionsAmong adults in Ontario who underwent common surgeries under general anesthesia from 2009 to 2016, known or strongly suspected MH was not associated with a higher risk of adverse postoperative outcomes. These findings support the current standard of care management for MH-susceptible patients.