Stellate ganglion blockade for treating refractory electrical storm: a historical cohort study; [Bloc du ganglion stellaire pour le traitement des tempêtes électriques réfractaires : une étude de cohorte historique]

Background: Stellate ganglion blockade (SGB) has been used to treat electrical storm (ES) refractory to antiarrhythmic therapy or to stabilize patients before more definitive intervention. Nevertheless, its efficacy is not well understood, with only a few case reports and retrospective case series in the literature. Methods: We conducted a historical cohort study on patients with drug-refractory ES who underwent ultrasound-guided unilateral SGB from 1 January 2010 until 19 July 2019 at two hospital sites. Stellate ganglion blockade was performed with variable combinations of bupivacaine, lidocaine, ropivacaine, and dexamethasone. We collected data on demographic and procedural characteristics, the number of arrhythmias and defibrillation episodes, antiarrhythmic and anticoagulant medication, left ventricular ejection fraction (EF), and respiratory support requirement. Results: We identified N = 13 patients; their mean (standard deviation [SD]) age was 64 (13) yr, and 10 (77%) were male. The baseline mean (SD) number of overall arrhythmia and defibrillation episodes per day were 9 (6) and 4 (3), respectively; the mean (SD) pre-SGB EF was 23 (7)%. Seven patients (54%) received dexamethasone in addition to local anesthetic for SGB. One patient experienced hypotension after SGB. Arrhythmias and defibrillation episodes significantly decreased at 24, 48, 72, and 96 hr after SGB; at 96 hr, 62% and 92% of patients had no VA and defibrillation episodes, respectively (P < 0.001 for all time points). Ejection fraction and the number of patients receiving antiarrhythmic medications or requiring respiratory support were unchanged. Conclusions: Unilateral SGB was associated with a reduction in arrhythmias and defibrillation episodes, but did not affect antiarrhythmic medication, respiratory support, or EF. Randomized controlled trials on larger cohorts are needed to confirm these findings. © 2021, Canadian Anesthesiologists' Society.