🧭 REBEL Rundown
🔑 Key Points
- 😴 Rocuronium was associated with delayed post-intubation sedation and analgesia compared with succinylcholine in adult ED patients induced with etomidate.
- ⏱️ The absolute median differences were small: 2 minutes to sedation and 3 minutes to analgesia, making the clinical significance uncertain.
- 🧠 The real concern is awareness during paralysis: rocuronium may outlast the induction agent, leaving patients awake but unable to move or communicate.
- ⚠️ This was a retrospective observational study, and the 9.1% higher in-hospital mortality in the rocuronium group suggests important unmeasured baseline differences.
- 🚨 Post-intubation sedation and analgesia should be planned before RSI, especially when using long-acting paralytics.
📝 Introduction
Rapid sequence intubation in the emergency department involves the use of an induction agent and neuromuscular blocker. Two commonly used neuromuscular blockers with differing durations are succinylcholine (5-10 minutes) and rocuronium (20-75 minutes). The most common induction agents (etomidate, ketamine, propofol) have relatively short half-lives. When a short-lived paralytic wears off, we can assess discomfort providing us with a visual cue for additional sedation and analgesia. If sedation ends prior to paralysis, patients may be conscious but paralyzed or in discomfort without the ability to express it – a situation that may occur with longer acting paralytics like rocuronium.
🧾 Paper
Hwang C, et al. Impact of paralytic choice on postintubation sedation and analgesia in the emergency department. Am J Health Syst Pharm. 2025;82(Supplement_3):S2929-S2936. PMID: 40037283
Previously Covered On REBEL
⚙️ What They Did
📈 Results:
💥 Critical Results
- Sedation timing: Median time to first sedative was 12 minutes with rocuronium vs 10 minutes with succinylcholine.
- Analgesia timing: Median time to first analgesic was 24 minutes with rocuronium vs 21 minutes with succinylcholine.
- Adjusted sedation outcome: Succinylcholine was associated with improved time to sedation: aHR 1.3; 95% CI 1.2–1.5.
- Adjusted analgesia outcome: Succinylcholine was associated with improved time to analgesia: aHR 1.4; 95% CI 1.1–1.6.
- Absolute mean difference: Rocuronium was associated with longer mean time to sedation by 7.9 minutes and longer mean time to analgesia by 12.8 minutes.
- Sedation/analgesia gap: Only 44.8% of patients received both sedation and analgesia during their ED stay.
- Hypotension effect: Post-RSI hypotension was associated with lower likelihood of receiving sedation: aHR 0.7; 95% CI 0.5–0.8.
- Pharmacist presence: ED pharmacist bedside presence was associated with improved sedation timing: aHR 1.1; 95% CI 1.0–1.3.
- Mortality imbalance: In-hospital mortality was higher in the rocuronium group: 20.1% vs 11.0%, suggesting important baseline differences between groups.
💪🏽 Strengths
- Clinically important question: This study addresses a real ED problem: care does not end when the tube passes through the cords. Post-intubation sedation and analgesia are part of airway management.
- Large sample size: More than 2,000 ED intubations were included, giving this study a larger cohort than many prior studies on post-intubation analgosedation.
- Multicenter ED cohort: The study included three urban tertiary care academic EDs, including two Level 1 trauma centers, capturing variation in ED airway practice.
- Relevant bedside comparison: Rocuronium and succinylcholine are the two most common paralytics used for RSI, making the comparison directly applicable to ED practice.
- Granular medication timing: The authors evaluated the timing of medication administration rather than simply reporting whether sedation or analgesia was eventually given.
- Appropriate time-to-event analysis: The authors used an adjusted Cox proportional hazards model, which fits the clinical question because the outcome is not just whether sedation or analgesia occurred, but when it occurred.
- Attempted adjustment for confounding: The analysis adjusted for paralytic choice, post-RSI hypotension, ED pharmacist presence, and practice site. This does not eliminate confounding, but it strengthens the analysis compared with a simple unadjusted comparison.
- Site-level stratification: The model was stratified by participating site, which is important because sedation practices, trauma volume, patient populations, and local RSI culture may differ across EDs.
- Practice-pattern detail: The authors reported which sedatives and analgesics were used, along with initial dosing. This helps clinicians compare the study sites’ practice patterns with their own.
- Pharmacist presence examined: The study evaluated ED pharmacist bedside presence, highlighting a potentially modifiable system factor associated with improved sedation timing.
- Biologic plausibility: The findings fit the pharmacology: etomidate wears off quickly, succinylcholine wears off relatively quickly, and rocuronium lasts much longer, creating a plausible pathway to awareness with paralysis.
- Consistent with prior literature: The findings align with prior studies associating rocuronium use with delayed or reduced post-intubation analgesia and sedation.
⚠️ Limitations
- Etomidate-only cohort: Only patients induced with etomidate were included, so findings may not apply to RSI with ketamine or propofol.
- Small absolute time difference: Although statistically significant, the median difference was only 2 minutes for sedation and 3 minutes for analgesia, making clinical significance unclear.
- Disease-centered outcome: Time to first sedative or analgesic is not patient-centered and does not tell us whether patients experienced awareness, pain, distress, or recall.
- No direct awareness assessment: Patients were not interviewed for recollection of awareness while paralyzed.
- Baseline imbalance: The rocuronium group had a 9.1% higher in-hospital mortality rate, suggesting important unmeasured baseline differences.
- Retrospective observational design: Paralytic choice was not randomized, creating risk of selection bias and confounding by indication.
- Residual confounding: Illness severity, trauma status, airway complexity, and contraindications to succinylcholine may have influenced paralytic choice.
- Mortality signal is not causal: Higher mortality in the rocuronium group should not be interpreted as rocuronium causing harm.
- No sedation-depth data: The study does not report RASS scores or whether adequate sedation was achieved.
- First dose only: Timing of the first dose does not address dose adequacy, repeat dosing, infusion titration, or ongoing comfort.
- EHR timing limitations: Medication administration times may reflect documentation timing rather than true bedside administration.
- Pharmacist presence misclassification: Bedside pharmacist presence was inferred from schedules, not directly confirmed.
- Limited generalizability: The study was performed in three EDs within one health system in one state.
- Different study periods by site: Practice patterns may have changed over time across the included EDs.
- COVID-era effects: Pandemic workflows, isolation precautions, and staffing strain may have affected post-intubation care.
- Missing data: Blood pressure and pre-RSI GCS data were incomplete, limiting adjustment for severity of illness.
- No protocolized sedation approach: Local clinician preference and workflow likely influenced medication timing.
🗣️ Discussion
Awareness During Paralysis Is the Core Concern
“Paralyzed, conscious, and intubated” is a frightening situation for any patient. Choice of paralytic may affect our ability to recognize this situation based on duration of effect. When paralysis wears off, patients may begin to move, cough, breathe asynchronously, grimace, or show other signs of discomfort. Those signs often become a visual cue for additional sedation or analgesia. If the induction agent wears off before paralysis resolves, the patient may be awake, uncomfortable, and unable to communicate.
Anticipate the need for post-intubation sedation and analgesia before RSI, rather than waiting for movement, ventilator dyssynchrony, or visible distress to trigger treatment. This matters most when using rocuronium because the patient may not be able to demonstrate distress after the induction agent has worn off.
Interpreting the Signal
The results were statistically significant, but the absolute median differences were small: 2 minutes for sedation and 3 minutes for analgesia. Although no patient wants to be paralyzed and conscious for any length of time, it is unclear whether these small median differences reflect clinically meaningful delays.
The authors report both median times and mean differences. The mean differences were larger than the median differences, suggesting skewed data and likely influential outliers. This may be where the clinical signal lives. The issue may not be that every rocuronium patient receives sedation a few minutes later. The issue may be that some rocuronium patients may experience much longer delays.
Rocuronium was also associated with higher in-hospital mortality, 20.1% vs 11.0%, a 9.1% absolute difference. Which suggests the presence of unmeasured baseline differences between groups. Clinicians may have selected rocuronium for older, sicker, more complex patients.
The Practical Takeaway Is Workflow, Not Paralytic Tribalism
One can read this study as support for succinylcholine over rocuronium. A better interpretation is that when using rocuronium, clinicians must be more deliberate about timely sedation and analgesia. This is not an argument to abandon rocuronium. Rocuronium remains an important RSI medication. The problem is using a long-acting paralytic without an equally deliberate plan for post-intubation comfort. The bottom line is simple: do not wait for the patient to move. Have sedation and analgesia ready, reassess early, support blood pressure when needed, and titrate to patient comfort and safety.
📘 Author's Conclusion
“Use of rocuronium for RSI was associated with reduced likelihood of timely post-RSI sedation and analgesia. Coupled with low initial sedation dosing, our findings suggest that patients intubated with rocuronium are at increased risk of being awake during paralysis.”
💬 Our Conclusion
In adult ED patients undergoing RSI, the use of rocuronium for neuromuscular blockade was associated with delayed time to sedation and analgesia compared to succinylcholine, a statistically significant difference of a few minutes, but the concern is clinically important because rocuronium may mask awareness long after the induction agent has worn off.
This study should not push clinicians to reflexively choose succinylcholine over rocuronium. It should push us to build better RSI workflows: post-intubation sedation and analgesia should be anticipated, ordered, prepared, and administered promptly, especially when using long-acting paralysis.
🚨 Clinical Bottom Line
Regardless of which paralytic is used, have sedation and analgesia ready before intubation.
📚 References
- Hwang C, Michaels B, Park K, et al. Impact of paralytic choice on postintubation sedation and analgesia in the emergency department. Am J Health Syst Pharm. 2025;82(Supplement_3):S2929-S2936. PMID: 40037283
Post Peer Reviewed By: Anand Swaminathan, MD, MPH (IG: @emswami), and Marco Propersi, DO (X: @Marco_Propersi)
👤 Meet the Authors
🔎 Your Deep-Dive Starts Here
REBEL Core Cast 112.0 – Awareness During Paralysis
Take Home Points: Dose your RSI meds correctly. Reach for post-intubation sedation at ...
The ED-AWARENESS Study: Awareness with Paralysis
‘He remembered waking up with someone pulling very hard on his injured leg, ...
