New RCT – Remifentanil vs. Neuromuscular Blockers for RSI First-Pass Success
February 23, 2023
Written by Alex Clark
Spoon Feed
This randomized, non-inferiority trial found that remifentanil plus hypnotics were inferior to neuromuscular blocking agents plus hypnotics for rapid sequence intubation (RSI) of patients at risk of aspiration in the operating room setting.
Why does this matter?
In patients at risk of aspiration, RSI with a combination of a sedative/hypnotic agent and paralytic is standard of care. However, no studies to date effectively challenge this practice. Adverse effects of neuromuscular blockers include metabolic derangements and prolonged paralysis with awareness. These are real considerations in the current climate of prolonged ED boarding. Are rapid-onset opioids, such as remifentanil, a safe and effective alternative to paralytics?
Remi on the block…
This multicenter, parallel-group, open-label, randomized non-inferiority clinical trial included 1,150 patients at-risk for aspiration (pre-op fasting < 6 hours, bowel obstruction or ileus, recent emesis, or past medical history such as gastroparesis) and requiring RSI in the operating room. Outcomes were compared between patients who were randomized to either receive 3-4 µg/kg remifentanil or 1 mg/kg succinylcholine or rocuronium after administering a hypnotic (propofol in >98%). The primary outcome was successful tracheal intubation on the first attempt without major complications such as aspiration, hypoxemia, or hemodynamic instability, and the non-inferiority margin was set at -7%. The authors also included various secondary outcomes including time to intubation, rescue therapies for difficult intubation, and several others.
They found first pass success without major complication in 66.1% of patients in the remifentanil group and 71.6% in the neuromuscular blocker group: adjusted difference –6.1% (95%CI –11.6% to –0.5%, P = 0.37 for noninferiority), which means remifentanil was inferior*. Importantly, the subgroup analyses between both video and direct laryngoscopy, as well as digestive occlusion (i.e. ileus, bowel obstruction) versus other risk factors, each demonstrated a similar trend for inferiority of remifentanil, without intergroup statistically significant differences. Overall, remifentanil is not ready for prime time, particularly for ED-specific RSI. Although the authors leave the door open to future investigations, I will proceed with a sedative and paralytic during my next RSI.
Source
Effect of Remifentanil vs Neuromuscular Blockers During Rapid Sequence Intubation on Successful Intubation Without Major Complications Among Patients at Risk of Aspiration: A Randomized Clinical Trial. JAMA. 2023 Jan 3;329(1):28-38. doi: 10.1001/jama.2022.23550.
*Nerd’s Corner: Non-inferiority trials are tricky to interpret. They established up front that if the lower 95%CI was greater than (more positive than) –7%, this would indicate non-inferiority. But this is just the opinion of the authors. Do you think 7% is the right number? Reasonable people could disagree. But it was –11.6%, which means it was not non-inferior. That alone doesn’t mean it is inferior. However, since the upper 95%CI was also negative (–0.5%), this showed it was, in fact, inferior. In other words, use a neuromuscular blocker – as if we didn’t already know that. ~Clay Smith