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Three Part Question

In a [patient undergoing rapid sequence induction in the emergency department] are [rocuronium and suxamethonium similar] at providing [optimal intubating conditions]

Clinical Scenario

You are about to perform a rapid sequence intubation on a 26 year old man. You’ve heard rocuronium may provide similar intubating conditions to succinylcholine with fewer side effects, and wonder which should be your muscle relaxant of choice.

Search Strategy

Medline 1966 - 08/2011 using the pubmed interface
The Cochrane Library 16/08/2011
PubMED: rocuronium AND (succinyl* OR sux*) where doses of succinycholine and rocuroinum were at least 1mg/kg, Limits: Humans, Clinical Trial, Meta-Analysis, Randomized Controlled Trial, English
Cochrane: rocuronium AND (succinyl* OR sux*) where doses of succinycholine and rocuroinum were at least 1mg/kg

Search Outcome

94 papers found of which 87 irrelevant leaving 7 papers for analysis that included 1 cochrane review

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Larsen et al, 2005 USA	All patients (n=578) who underwent RSI over one year at a level 1 trauma centre emergency department. 138 received Rocuronium (average dose 1mg/kg) 382 received succinylcholine (average dose 1.7mg/kg)	Prospective cohort study	(1) Time to paralysis. (2) Intubating conditions scored on (a) body movement, (b) vocal cord position and movement and (c) overall operator satisfaction. (0=no paralysis / complete dissatisfaction, 10=full paralysis / complete satisfaction)	(1) Time to paralysis 5s quicker with succinylcholine vs rocuronium (p=0.04); [succinylcholine (mean) 39s (95% CI = 37 to 41s); rocuronium (mean) 44s (95% CI = 39 to 50s)]. (2) Similar intubating conditions; (a) body movement (both sux & roc (median) 10 (IQR 9-10). (b) vocal cords (sux vs roc (median) 10 (IQR9-10) vs 9 (IQR9-10)) (c) operator satisfaction (both sux vs roc (median) 10 (IQR 9-10	No randomisation or blinding. <40% had independently observed paralysis times. Only average doses given for muscle relaxants.
Mazurek et al, 1998 USA	26 Children aged 2-15yrs requiring RSI for emergency surgery. 13 received rocuronium 1.2mg/kg and 13 succinylcholine 1.5mg/kg.	Double blind RCT	(1) Time to apnoea (loss of respiratory effort). (2) Intubating conditions on attempt after 25s (scored on jaw relaxation, vocal cord position and movement, response to tube) (3) Time to intubate	No significant difference between succinylcholine or rocuronium groups: (1) Time to apnoea; (succinylcholine=22.3sec + SD 12.8 (range 12-62; roc=15.6sec + SD 7.4 (range 5-30); p=0.8). (2) Intubating conditions; (rocuronium vs succinylcholine; excellent 53% vs 77% p=0.41; acceptable 92% vs 92% [p=1.0]). (3) Time to intubate (sux=41.8sec +/- SD 2.9 (range 36-45) vs Roc 40.2sec +/- 4 (33-48); p=0.5)	Anaesthesia setting, not ED. Paediatric population. Small number cases. Unclear primary outcome.
McCourt et al, 1998 Finland / UK	279 adults ASA 1-4 requiring RSI for elective or emergency surgery. Received rocuronium (1m/kg) or succinylcholine (1mg/kg). (0.6mg/kg rocuronium also studied but results not reviewed here). Excluded if pregnant, obese, potential difficult airway, neuromuscular disease or drugs which could interfere, or anticipated airway difficulty.	Double blind RCT	Intubation conditions on attempt 50s post muscle relaxant using standardised scoring system	No significant difference between muscle relaxant in producing good or excellent intubating conditions at 60’s (96.3% & 96.7%). Excellent conditions more often with succinylcholine 80% vs roc 65% (p=0.05)	Not in ED setting
Patanwala et al, 2011 USA	327 adults requiring RSI at level 1 trauma centre who received etomidate with succinlycholine (113 patients) or rocuronium (214 patients). Excluded if incomplete documentation.	Retrospective evaluation (database of all ED intubations July 2007 to Oct 2008)	First-attempt intubation success.	Average dose succinylcholine 1.65mg/kg IQR 1.26-1.95mg/kg); roc 1.19mg/kg IQR 1-1.45mg/kg) Similar rate of first-attempt intubation success 72.6% (succinylcholine) vs. 72.9% (rocuronium), p = 1.00 Groups were well matched regarding demographics and intubation parameters.	Retrospective trial. Doesn’t state time to intubation.
Andrews et al, 1999 UK	293 adult patients ASA 1-4 requiring RSI for elective or emergency surgery. Received 1mg/kg rocuronium or 1mg/kg succinylcholine. (0.6mg/kg rocuronium also studied but not reviewed here). Excluded if obese, pregnant or breast feeding, anticipated difficult intubations	Double blind RCT	Intubation conditions on attempt 50s post muscle relaxant using standardised scoring system	Acceptable (good or excellent) intubating conditions commencing laryngoscopy at 50seconds; Roc 93.2%, Sux 97.1% (difference -3.9% CI-9.7-1.9%). Not considered clinically relevant from power of study. Excellent conditions present in 66% vs 74% roc vs sux respectively. CI not calculated.	Non ED setting
Magorian et al, 1993 Switzerland	20 adult patients ASA 1-3, MAL 1-2 requiring RSI. Received 1.2mg/kg rocuronium or succinylcholine 1mg/kg. (30 other patients with lower doses of rocuronium or vecuronium also studied but not reviewed here)	Double blind RCT	(1) Time to onset muscle relaxant (nerve stimulator on adductor pollicis). (2) Intubating conditions at 60seconds (jaw relaxation, vocal cord postion and movement, diaphragm movement)	(1) Time to onset; no significant difference (rocuronium = 55s (SD14 range 36-84) vs succinylcholine = 50s (SD17 range 24-84)). (2) Intubating conditions at 60s not significantly different (100% acceptable (excellent or good) in both groups). Excellent in 70% vs 80% rocuronium vs succinlycholine, significance unlikely given small numbers studied.	Unclear method of randomisation and degree of blinding. Rocuronium group more obese. Small study (10 patients in each group)
Perry et al, 2008 Canada	58 studies, 39 met inclusion criteria. Inclusion criteria required that (1) a score of intubation conditions was one of the main outcomes; (2) the study compared rocuronium and succinylcholine; and, (3) the dose of rocuronium was at least 0.6 mg/kg and succinylcholine at least 1 mg/kg	Cochrane review / metaanalysis	Primary outcome: excellent intubation conditions created during RSI Secondary outcome; clinically acceptable (excellent or good) intubation conditions	Subgroup analysis comparing different doses of rocuronium. No statistical differences for excellent or acceptable intubation conditions in the group that received 0.9-1.0 mg/kg of rocuronium or the group that received 1.2 mg/kg of rocuronium vs succinylcholine.

Comment(s)

There are currently two main choices of muscle relaxant for RSI in the emergency department (ED); succinylcholine and rocuronium bromide. The speed at which rocuronium produces paralysis is dose dependent; at 1.0 mg/kg or greater, excellent intubating conditions can be produced at 60 seconds or less. Studies were therefore identified that compared 1mg/kg (or higher) succinylcholine against 1mg/kg (or higher) rocuronium in the setting of rapid sequence intubation (RSI). Six studies met the criteria, three of which were in an ED setting. There was one Cochrane review comparing various doses of rocuronium against succinylcholine. The findings from both the Cochrane review and the individual studies showed no significant difference between 1–1.2 mg/kg rocuronium and 1 mg/kg (or higher) of succinylcholine at providing excellent or acceptable intubating conditions for rapid sequence induction. There was a trend towards succinylcholine more likely providing excellent intubating conditions more quickly than rocuronium in several of the studies but this does not appear clinically significant. Two studies were from an ED setting (both non RCT). Patanwala et al's retrospective evaluation of 1.2 mg/kg rocuronium versus succinylcholine in 327 patients found no significant difference in first time intubation success, although it did not record time to intubation. Lauren et al's retrospective cohort analysis of 578 patients found succinlycholine provided paralysis five seconds quicker than rocuronium at 1 mg/kg, but that intubating conditions were not significantly different. The Cochrane review overall found succinylcholine provided more optimal conditions when compared with rocuronium, but 24 of the 37 studies identified used doses of 0.6 mg/kg where a delay to optimal intubating would be expected. When using studies comparing succinylcholine with only the higher doses of rocuronium (1mg/kg or more) they concluded that there was no difference in producing ‘excellent or acceptable intubating conditions’. There are other factors that determine the choice of muscle relaxant for RSI in the ED beyond the timely production of intubating conditions. Succinylcholine has long been the preferred agent, but unlike rocuronium it has some rare but potentially life-threatening problems that include hyperkalaemia, malignant hyperthermia, bradycardia, masseter spasm and increased intracranial pressure. Succinylcholine has a much shorter duration of action, but this can make it more dangerous than rocuronium. Full reversal of succinylcholine to the point of spontaneous respiration takes 5–10 minutes. Most patients requiring RSI in the ED will become critically hypoxic long before this. Reliance upon the sux ‘wake and breathe safety net’ can be dangerous not least when it delays alternate moves to secure the airway. During the period of partial neuromuscular blockade a patient will begin moving and may vomit, compromising an already difficult intubation. Even when surviving to full neuromuscular reversal, urgent intubation will still be required for the majority of patients requiring RSI in the first place as the pre-existing condition remains. Repeat dosing of succinylcholine will carry a greater frequency of its rare life threatening side effects. The physician should carefully consider these factors in choosing a muscle relaxant for emergency department RSI.

Clinical Bottom Line

There is no significant difference to time to intubate, intubating conditions, or intubating success rate when using 1–1.2 mg/kg rocuronium versus 1 mg–1.5 mg/kg of succinylcholine during RSI in an ED setting.

Level of Evidence

Level 2 - Studies considered were neither 1 or 3.

References

1. Larsen PB, Hansen EG, Jacobsen LS et al. Intubation conditions after rocuronium or succinylcholine for rapid sequence induction with alfentanil and propofol in the emergency patient Eur J Anaesthesiol 2005 Oct;22(10):748-53
2. Mazurek AJ, Rae B, Hann S et al. Rocuronium versus succinylcholine: are they equally effective during rapid-sequence induction of anesthesia? Anesth Analg 1998 Dec;87(6):1259-62
3. McCourt KC, Salmela L, Mirakhur RK et al. Comparison of rocuronium and suxamethonium for use during rapid sequence induction of anaesthesia Anaesthesia 1998 Sep;53(9):867-71
4. Patanwala AE, Stahle SA, Sakles JC et al. Comparison of succinylcholine and rocuronium for first-attempt intubation success in the emergency department Acad Emerg Med 2011 Jan;18(1):10-4
5. Andrews JI, Kumar N, van den Brom RH et al. A large simple randomized trial of rocuronium versus succinylcholine in rapid-sequence induction of anaesthesia along with propofol Acta Anaesthesiol Scand 1999 Jan;43(1):4-8.
6. Magorian T, Flannery KB, Miller RD Comparison of rocuronium, succinylcholine, and vecuronium for rapid-sequence induction of anesthesia in adult patients Anesthesiology 1993 Nov;79(5):913-8
7. Perry JJ, Lee JS, Sillberg VA et al. Rocuronium versus succinylcholine for rapid sequence induction intubation Cochrane Database Syst Rev 2008;(2):CD002788.