Comparison of two dosages of ketamine in preventing fentanyl-induced coughs in children

Background: Fentanyl is a short-acting drug used to induce anesthesia. Here, we aimed to compare the two doses of ketamine to prevent fentanyl-induced cough in children under general anesthesia. Materials and Methods: This is a randomized, clinical trial which was performed in 2019 in Imam Hossein Hospital in Isfahan, Iran. The study population consisted of children between 6 months and 2 years who were candidates for general anesthesia. Patients were randomized into three groups, each containing 31 patients. Groups 1 and 2 received 0.1 mg/kg and 0.2 mg/kg intravenous ketamine, respectively, 1 min before fentanyl injections. Group 3 received the same volumes of normal saline 0.9%. Patients were observed and evaluated for the incidence and intensity of coughs 1 min and 3 min after fentanyl injections. Results: We showed that the frequency of coughs 1 min after fentanyl injection was significantly lower in Group 2 compared to other groups (P < 0.001). Three min after fentanyl injection, the frequencies of coughs were significantly lower in Groups 1 and 2 compared to Group 3 (P < 0.001). We also showed that the intensity of coughs was significantly lower in Group 2 compared to other Groups 1 and 3 min after fentanyl injection (P < 0.001). Conclusion: The administration of 0.2 mg/kg ketamine is more effective than 0.1 mg/kg dosage in the prevention of fentanyl-induced cough. We also showed that this method could bring more stable hemodynamics and oxygenation saturation inpatients. The comparison of the two dosages was a novel issue in the recent literature.