Rocuronium versus succinylcholine for rapid sequence induction intubation.

BACKGROUND: Patients requiring emergent endotracheal intubation often require a rapid sequence induction intubation (RSI) technique to protect against gastric aspiration, to facilitate intubation, or to protect against increased intracranial pressure. Succinylcholine is the most common muscle relaxant used because it has a fast onset and a short duration. Unfortunately it can have serious side effects as a result of it's membrane depolarizing effect and release of potassium. Rocuronium has been suggested to create intubating conditions similar to succinylcholine. Previous studies have been underpowered to determine equivalence and there has been no previous meta-analysis performed.
OBJECTIVES: To determine if rocuronium creates comparable intubating conditions to succinylcholine during RSI intubation. Comparisons were made with succinylcholine based on the dose of rocuronium, use of a narcotic, emergent versus elective intubation, age group and the induction agent used. The primary outcome was excellent intubation conditions. A secondary outcome of clinically acceptable conditions was also performed. These were all dichotomous outcomes using cutpoints from a four point scale by Goldberg to evaluate intubation conditions. SEARCH STRATEGY: We searched MEDLINE (1966-March 2000), EMBASE (1988-March 2000) and the Cochrane Central Register of Controlled Trials (CENRAL) (March 2000) for randomized controlled trials (RCT) or controlled clinical trials (CCT) relating to the use of rocuronium and succinylcholine. Foreign language journals were included. References of identified studies were hand-searched for citations missed by the electronic searches. SELECTION CRITERIA: All trials meeting the inclusion criteria (comparison of rocuronium and succinylcholine, one of study's main outcomes was scoring of intubation conditions) were included. DATA COLLECTION AND ANALYSIS: Data were extracted and methodological quality was assessed independently by two reviewers for allocation concealment. The outcomes were combined using MetaView 4.1 with risk differences for all categories and RR for the excellent outcomes with a random effects model. MAIN
RESULTS: 40 studies were identified; 26 were combined for analysis. Overall, rocuronium was inferior to succinylcholine, with a RR=0.87 (95%CI = 0.81 to 0.94) (N=1606). In the group that used propofol for induction of anaesthesia, the intubation conditions were similar, with a RR=0.96 (95%CI = 0.87 to 1.06) (N=640). No major adverse events were reported. REVIEWER'S
CONCLUSIONS: Succinylcholine created superior intubation conditions to rocuronium when comparing excellent intubation conditions. Using the less stringent outcome, clinically acceptable intubation conditions, the two agents were not statistically different. Intubation conditions were not statistically different between succinylcholine and rocuronium when propofol was used.