Influence of Different Doses of Ketamine on Intubating Conditions during a Rapid Sequence Induction and Intubation Model.

OBJECTIVE: This prospective, randomized, double-blinded study aimed to compare the effects of three different doses of ketamine or lidocaine on intubating conditions and haemodynamics in a rapid-sequence induction model with 3 mg kg(-1) propofol and 0.6 mg kg(-1) rocuronium.

METHODS: A total of 128 ASA I-III patients who were scheduled for elective surgery were randomized in the following five groups: Group 1 (n=24), 1 mg kg(-1) lidocaine+3 mg kg(-1) propofol+0.6 mg kg(-1) rocuronium; Group 2 (n=23), 0.1 mg kg(-1) ketamine+3 mg kg(-1) propofol+0.6 mg kg(-1) rocuronium; Group 3 (n=29), 0.3 mg kg(-1) ketamine+3 mg kg(-1) propofol+0.6 mg kg(-1) rocuronium; Group 4 (n=26), 0.5 mg kg(-1) ketamine+3 mg kg(-1) propofol+0.6 mg kg(-1) rocuronium and Group 5 (n=26), 3 mg kg(-1) propofol+0.6 mg kg(-1) rocuronium+saline as placebo. After preoxygenation, induction was performed with the assigned combination, and intubation was initiated after 60 s. The time to intubation, intubation score (Viby-Mogensen score) and haemodynamic data were recorded. Postoperative hoarseness, sore throat and hallucination incidences were followed up.

RESULTS: Demographic, time to intubation and haemodynamic data were comparable among groups. Group 4 [13.5 (4-14)] revealed a higher intubation score then groups 1, 2 and 5 [12 (3-14), 11 (2-14) and 9.5 (0-13) and p=0.026, p=0.001 and p=0.000001, respectively]. Groups 3 [13 (4-14)] and 4 [13.5 (4-14)] had similar intubation scores. Side effects were comparable among all groups.

CONCLUSION: The combination of 0.5 mg kg(-1) ketamine and 0.6 mg kg(-1) rocuronium along with propofol improves intubation conditions in a stimulated rapid-sequence induction model.