Rocuronium vs. Succinylcholine: Which Is Best?
By Robert Finn
Elsevier Global Medical News
SAN FRANCISCO - In the battle of the paralytics, the established champion apparently beats the young upstart, at least according to Dr. William K. Mallon.
At a conference on emergency medicine sponsored by Stanford University, Dr. Mallon found more reasons to prefer succinylcholine over rocuronium for rapid sequence intubation.
But he made the point that the stakes are high no matter which paralytic agent you choose. "If you're going to use paralytics, you'd better have everything at your disposal to make sure that there's an airway at the other end," said Dr. Mallon of Los Angeles County USC Medical Center. "I always tell our residents that you have no business calling for paralytics without a knife in your pocket."
A head-to-head comparison (see table) makes it clear that a patient receiving high-dose rocuronium takes about 90 seconds to be ready for intubation, compared with 30-60 seconds for succinylcholine. Is that small difference really clinically significant, especially when the rule of thumb is that a preoxygenated patient will take more than 8 minutes to desaturate?
Unfortunately, that rule of thumb only works for the ideal patient. It doesn't work for a trauma patient who may have pulmonary contusions or hemothorax and pneumothorax. A patient like that can desaturate in 90 seconds or less.
If the time that the paralysis begins is important, so is its duration. Succinylcholine paralysis lasts 8-15 minutes, compared with 45-60 minutes for rocuronium. And that difference will be very significant if the patient has blunt head trauma. Neurosurgeons can get testy if they have to wait an hour to examine someone who may have a subdural hematoma, Dr. Mallon cautioned.
Dr. Mallon also finds it useful to compare the lists of contraindications for the two agents. You shouldn't use succinylcholine in patients with severe hyperkalemia, with a catheter for peritoneal dialysis, with late burn or crush injuries, or with denervation syndromes in which atrophy is evident.
You shouldn't use rocuronium in patients with blunt head trauma or those who might have a difficult airway. You also shouldn't use it in crashing asthmatics or with uncooperative hypoxia of any kind.
Dr. Mallon noted that the succinylcholine contraindications tended to be rare and identifiable, whereas the rocuronium contraindications tend to be more common and unpredictable. This is another reason to prefer succinylcholine.
Whichever paralytic you choose, Dr. Mallon said there is good reason to use doses at the higher end of the scale - 1.0-1.2 mg/kg for rocuronium and 1.5-2.0 mg/kg for succinylcholine. These doses give faster onset of activity and less postfasciculation myalgia and pain.