If roc was THE drug for RSI, we wouldn't use sux at all because of the potential complications that go along with it. There's a reason it hasn't gone away, and that is speed of onset. There IS a difference.
Except that difference is not statistically significant and arguably not clinically significant either.
Pantawala, AE et al (2011) Comparison of succinylcholine and rocuronium for first-attempt intubation success in the emergency department. Acad Emerg Med.
Perry JJ et al (2008) Rocuronium versus succinylcholine for rapid sequence induction intubation. Cochrane Database of Systematic Reviews
Mallon, W. et al. (2009) Rocuronium vs. succinylcholine in the emergency department: A critical appraisal J Emerg Med.
The other big drawback of roc, and will be until sugammadex is widely available in the US, is that once it's in, you can't reverse it immediately, so if you can't intubate your patient and can't ventilate them, you're screwed. That's why sux is still the drug of choice for potential difficult intubations as well (my definition of difficult
). If you can't intubate and can't ventilate, your patient will be breathing again in a couple minutes.
That is the same rationale that the above two reviews use to come to the conclusion that sux is the superior drug despite the lack of difference in intubating conditions.
However there are a couple of problems with that philosophy.
First of all, it isn't true. Critical desaturation will occur prior to sux wearing off even in healthy patients. In unhealthy patients (i.e. the ones we are intubating, not the ones in the OR for an elective procedure) that is even more so the case. Sux will actually hasten desaturation, presumably through increased O2 consumption due to fasciculations. Rocuronium on the other hand prolongs the period of safe apnoea you have, allowing more time for intubation attempts or alternative airways to be used.
Tang, L. et al (2011) Desaturation following rapid sequence induction using succinylcholine vs. rocuronium in overweight patients. Acta Anaesthesiol Scand.
Heier, T et al (2001) Hemoglobin desaturation after succinylcholine-induced apnea: a study of the recovery of spontaneous ventilation in healthy volunteers. Anesthesiology.
Benumof JL et al (1997) Critical hemoglobin desaturation will occur before return to an unparalyzed state following 1 mg/kg intravenous succinylcholine. Anesthesiology
Naquib, M et al (2005) Succinylcholine dosage and apnea-induced hemoglobin desaturation in patients. Anesthesiology
Taha, SK et al (2010) Effect of suxamethonium vs rocuronium on onset of oxygen desaturation during apnoea following rapid sequence induction. Anaesthesia
The other major issue I have with that approach for in-field RSI is: If you are about to RSI a patient, and your back up plan if you can't intubate is to just let them breath up on their own, why are you trying to RSI them in the first place?