Evaluation of Succinylcholine Dosing for RSI Procedures Within Different Weight Groups

Introduction: Rapid sequence intubation (RSI) is a procedure often done in the emergency department (ED) to secure the airway in patients in respiratory failure. It is a process done by administering sedative and neuromuscular blocking agents, in rapid succession to allow for endotracheal intubation. Succinylcholine is a common paralytic agent used in RSI due to its quick onset and short duration. Common dosing for succinylcholine ranges from 1-1.5 mg/kg based on total body weight (TBW) with a maximum of 150mg, but larger doses have been evaluated in specific comorbidities. Many studies suggest that optimal dosing is not achieved in obesity due to dosing maximums and may lead to suboptimal intubation conditions. The objective of this study was to evaluate appropriate succinylcholine dosing for RSI within different weight groups.


Methods: Adult patients who were intubated by an ED provider with succinylcholine in the ED from January 2023 to December 2024 were evaluated for inclusion within this study. Subjects were divided by body mass index (BMI) scores into >30kg/m2 or < 30kg/m2. The primary outcome of this study was to measure the number of patients who received appropriate succinylcholine dosing based on TBW in RSI (within 10% of recommended dose, 1-2mg/kg). A retrospective chart review was conducted to obtain patient BMI, succinylcholine dose in mg/kg, hypotension and/or bradycardia after administration of succinylcholine, and first pass success.


Results: 167 patients were included with 101 patients in the BMI < 30kg/m2 group and 66 patients in the BMI >30kg/m2 group. There was no difference found between BMI groups with regard to appropriate dosing of succinylcholine (p = 0.560). Upon review of patients who received inappropriate doses, patients with a BMI < 30kg/m2 were more likely to be overdosed and those with a BMI >30kg/m2 were more likely to be underdosed (p < 0.001). First pass success was similar between the two groups (p=0.64). Hypotension was the most experienced adverse effect; however, it was similar between the two groups (p=0.61).


Conclusions: There was no difference observed in appropriateness of succinylcholine dosing during RSI in patients with BMI >30kg/m2 or BMI < 30kg/m2. Adverse effects related to succinylcholine were similar between BMI groups.