The effects of propofol, ketamine and combination of them in prevention of coughing and laryngospasm in patients awakening from general anesthesia: A randomized, placebo-controlled, double blind clinical trial

Background: Coughing and laryngospasm are undesirable outcomes occurring during emergence from general anesthesia. We compared the effect of small doses of propofol, ketamine and a combination of them on the occurrence and severity of coughing and laryngospasm in patients awakening from general anesthesia.Materials and Methods: 160 patients who were scheduled to undergo operations under general anesthesia were randomly assigned to one of the following groups, 40 in each group: propofol group (0.25 mg/kg intravenous (IV) propofol), ketamine group (0.25 mg/kg IV ketamine), combination group (0.25 mg/kg IV propofol, and 0.25 mg/kg IV ketamine) and control (0.1 ml/kg IV saline). Drugs were administered before extubation at previously defined time. Presence and severity of coughing and laryngospasm were recorded within twominutes after extubation.Results: The presence of coughing in the combination group (27.5%) was less than that in other groups; also it was less frequent in the propofol group (57.5%) than the control (82.5%) (all P < 0.05). But the incidence did not differ between the propofol and the ketamine (70%) group; nor did it differ between the ketamine and control groups (P = 0.356 and P = 0.121, respectively). The cases with severe coughing (grade 3) in the combination group (none) were significantly less than in the propofol (four) and the control groups (seven) (P = 0.040 and P = 0.006 respectively). There was no significant difference between the groups in frequency of laryngospasm.Conclusion: Administration of propofol or combination of propofol and ketamine decreases the incidence of post extubation coughing. This combination can also decrease severe cases