Relationship between the Change of PTC and the Response of Endotracheal Intubation after Vecuronium Induction

Kim, Jin Soo; Lee, Kyoung Woo; Kim, Soon Im; Kim, Sun Chong; Kim, Sung Yell

Abstract

The relationship between the post-tetanic count(PTC) and the response of tracheal intubation after vecuronium-induced neuromuscular blockade was studied in 99 cases who were ASA 1 or 2 adult patients. All patients were premedicated with glycopyrrolate 0.2mg and hydroxizine 1 mg/kg IM 1 hour before induetion, and were inducted with pentothal sodium Smg/kg and O2- N2O(50%) enflurane(2%). The patients were randomly divided to two groups according to dose of vecuronium applied after inducion ; 0.08 mg/kg(n=54) group and 0.12 mg/kg(n=45) group. Neuromuscular blockade was monitored by stimulation of the ulnar nerve at the wrist with single twitch using INNERVATOR(Fisher and Paykel Co.). Post tetanic count(PTC) was counted at different times, i.e., 0, 10, 20, 25, 30 and 35 seconds, 9 persons respectively at each time, after disappearance of single twitch. Tracheal intubation was performed immediately after counting of PTC. The response of tracheal intubation was appreciated based on vocal cord reflex, coughing or barking and patient movement. The time from administration of vecuronium to disappearance of single twitch was 167.8+/-23.4 seconds in 0.08mg/kg group and 163.7+/-51.1 seconds in 0.12mg/kg group and there was no statistical difference. After complete disappearance of single twitch, the PTC was zero at 35 seconds in 0.08 mg/kg group and at 25 seconds in 0. 12 mg/kg group. While the PTC was lowering, the lower intubation condition score should be expected, but the 0 of PTC did not coin-cided with the 0 of intubation condition score. However, the 0 of PTC did not always indicated that response to tracheal intubation could be disappear completely. Profound neuromuscular blockade did not reduce the hemodynamic responses to tracheal intubation.