The usual dose of succinylcholine for tracheal intubation is 1.0 mg/kg. If the patient is not ventilated by face mask after administration of the succinylcholine (1.0 mg/kg), the patient may experience significant hemoglobin desaturation. The purpose of the present study was to evaluate an appropriate dose of succinylcholine for tracheal intubation in Korean.

Sixty patients scheduled for elective surgery were randomly divided into three groups; group I (succinylcholine 0.3 mg/kg, n = 20), group II (succinylcholine 0.6 mg/kg, n = 20), group III (succinylcholine 1.0 mg/kg, n = 20). All patients were not premedicated. After loss of consciousness, the patients received succinylcholine 0.3, 0.6, 1.0 mg/kg, respectively. The contraction responses of the adductor pollices muscle were monitored by using TOF. Tracheal intubation was accomplished as the height of T₁ was inhibited maximally. Then, intubation scores were recorded. The recovery times from neuromuscular blockade in groups II and III were also measured.

The acceptable conditions for tracheal intubation were 30%, 100%, and 100%, respectively in groups I, II, and III. The onset time was 80.4 ± 15.5 sec, 69.6 ± 13.1 sec, and 56.1 ± 9.3 sec, respectively. The recovery time (T₁ = 90%) was 446.0 ± 86.2 sec, 694.0 ± 84.7 sec, respectively in groups II and III. The onset time was the fastest in group III. But the recovery time in group III was slower than in group II.

We concluded that 0.6 mg/kg of succinylcholine is an appropriate dose for tracheal intubation in Korean except for rapid sequence intubation.