We certainly have no argument with the position of Drs. Messent and Lim that when serious doubt exists about one’s ability to secure a patent airway, the administration of neuromuscular blocking agents is contraindicated. As our data 1
make clear, even after doses of succinylcholine as low as 0.40 mg/kg, significant recovery (at the adductor pollicis) may on occasion not begin until 6–7 min have elapsed. Nonetheless, we feel compelled to point out that even experienced anesthetists may misjudge the ease of tracheal intubation. In these circumstances, the shorter the period of “cannot intubate, cannot ventilate” is, the better.
Forty years ago, when the senior author was a resident, a common intubation sequence consisted of little more than 4 mg/kg thiopental and 0.60 mg/kg succinylcholine. In that era, this protocol produced some fairly “ugly” intubations. Four decades later, after an induction consisting of propofol and a short-acting opioid, the same dose of succinylcholine produces highly satisfactory conditions for tracheal intubation in the majority of patients. For routine nonemergent intubations, we rarely exceed this dose. Nevertheless, as we pointed out in our conclusion, when complete neuromuscular block is critical, doses of succinylcholine as high as 1.0–1.5 mg/kg may be still be appropriate.
We would also like to thank Dr. Kron for his kind remarks. However, we think that the efficacy of the slow administration of succinylcholine as a means of reducing the magnitude of fasciculations and the incidence of postoperative myalgia is controversial. Certainly, this stratagem has been offered by several authors. 2,3
On the other hand, there is equally convincing data to suggest that this technique is not efficacious. 4,5
We would suggest that the hypothesis that small initial doses of succinylcholine produce a “self-taming” effect remains unproven.
Aaron F. Kopman M.D.
Bledi Zhaku B.A.
Kane S.Lai M.D.
1. Kopman AF, Zhaku B, Lai KS: The ‘intubating dose‘ of succinylcholine: The effect of decreasing doses on recovery time. Anesthesiology 2003; 99:1050–4
2. Baraka, A: “Self taming” of succinylcholine-induced fasciculations. Anesthesiology 1977; 46:292–3
3. Strom J, Jansen EC: Pain-reducing effect of self-taming suxamethonium. Acta Anaesthesiol Scand 1984; 28:40–3
4. Pace NL: Prevention of succinylcholine myalgias: A meta-analysis. Anesth Analg 1990; 70:477–83
5. Wilson DB, Dundee JW: Failure of divided doses of succinylcholine to reduce the incidence of muscle pains. Anesthesiology 1980; 52:272–5
© 2004 American Society of Anesthesiologists, Inc.