The effect of Ketamine and dexamethasone on frequency and intensity of Fentanyl-induced cough

Abstract

Background: Intravenous (IV) administration of fentanyl during induction of general anesthesia often elicits cough, with frequency of 18 to 80. Therefore, in this study, we aimed to compare the effects of ketamine and dexamethasone on decreasing cough in patients undergoing general anesthesia with fentanyl. Methods: During a double-blind randomized clinical trial study, 99 patients aged 18-64 years with class I and II based on the scale of American Society of Anesthesiologists (ASA) who were undergoing general anesthesia with fentanyl were investigated. Patients were randomly divided equally into 3 groups receiving ketamine (0.5 mg/kg), dexamethasone (0.1 mg/kg), and placebo (5 ml normal saline). All drugs were administered 1 minute before administration of 2.5 μg/kg fentanyl. Vital signs, and frequency and intensity of cough were measured and recorded. Statistical analysis was performed using one-way ANOVA and Kruskal-Wallis tests. Findings: The frequency of cough was significantly lower in the ketamine group (81.8) compared with dexamethasone (90.9) and placebo (93.1) groups (P = 0.03). The intensity of cough was significantly lower in the ketamine group (mild: 18.2; moderate: 78.8; severe: 3.0) compared with placebo group (mild: 9.1, moderate: 72.7; severe: 18.2) (P = 0.04). Furthermore, there were significant differences between the three groups in variations of systolic blood pressure, diastolic blood pressure, and heart rate (P < 0.05 for all). Conclusion: Administration of low-dose ketamine can effectively reduce frequency and intensity of fentanyl-induced cough during anesthesia in patients undergoing general anesthesia. © 2018, Isfahan University of Medical Sciences(IUMS). All rights reserved.