A comparative study of the effect of low-dose epinephrine and ketamine on rapid-sequence endotracheal intubation by the priming dose method of cisatracurium in patients under general anesthesia

Low‑dose ephedrine and ketamine may accelerate the onset time of action of neuromuscular blocking agents. We studied the effect of ephedrine and ketamine and cisatracurium priming on endotracheal intubation conditions and the onset time of action of cisatracurium.

The study was a double‑blind clinical trial performed on American Society of Anesthesiologists (ASA) class 1 and 2 patients, who were candidates for general anesthesia. In total, 120 patients were entered into the study and were divided into 4 groups, E, K, E + K, and N. The first group was given 70 mcg/kg ephedrine (E group), the second group was given 0.5 ml/kg ketamine (K group), the third group was given the same amount of ketamine plus ephedrine (E + K group), and the fourth group was given the same volume of normal saline (control group); a single dose of 0.1 mg/kg cisatracurium was given, and intubating conditions were evaluated at 60 seconds after cisatracurium administration.

The mean Cooper score based on the response to laryngoscopy, the position of the vocal cords, and the movement of the diaphragm of patients in the control group with a mean of 2.53 ± 1.07 was significantly lower than in the three groups of E, K, and E + K with the means of 4.47. 1.17, 4.53 ± 1.14, and 7.63 ± 1.42, respectively (P value < 0.001). In the (E + K) group, it was significantly higher than in the two other drugs alone (P value < 0.001). The two groups of E and K alone were not significantly different from each other (P value = 0.997). The means of hemodynamic parameters were not significantly different in any of the groups (P value > 0.05).

According to the results of the present study, the use of low‑dose ephedrine and ketamine alone can improve intubation conditions. In addition, the combined use of these drugs not only had any Positive effect on patients’ hemodynamic parameters but also greatly improved intubation conditions.