Comparison of the effect of three different sub-dissociative doses of ketamine on the quality of sedation in flexible fiber optic bronchoscopy

Abstract

Abstract Background: Reducing the patient's anxiety and stress is necessary to facilitate fiberoptic (flexible) bronchoscopy. This study was conducted with the aim of comparing the effect of three sub anesthetic doses of ketamine on the quality of sedation in bronchoscopy. Methods: This clinical trial study was conducted from November 2020 until May 2021 in Al-Zahra (S) and Khorshid hospitals in Isfahan, 90 patients who were candidates for flexible fiberoptic bronchoscopy (FFB) was randomly entered into the study in three groups of 30 people. In the first group (k1) Ketamine 0.2mg/kg, in the second group (K2) Ketamine 0.4mg/kg and in the third group (k3) Ketamine 0.5mg/kg intravenously (IV) Prescribed. In all patients, propofol was administered through a pump syringe containing 15 ml of propofol. First, a bolus dose of 0.4 mg/kg was injected, and then the infusion of propofol continued at a rate of 50-100 µg/kg/min through bronchoscopy. After reaching level 4 of sedation based on the Ramsey sedation criteria, bronchoscopy was started. The quality of sedation and its duration, the duration of bronchoscopy, the satisfaction of the patient and the bronchoscopist were evaluated and recorded. Data analysis was done using SPSS version 23 software (USA, NY, Armonk, SPSS IBM) and Mann-Whitney-U tests, student t-test, chi-square and analysis of variance with repeated observations. Results: In terms of demographic variables including age ((P=0.56)), gender ((P=0.22)) and ASA class ((P=0.69)) there were no significant differences between the three groups. The average score of sedation and duration of sedation in k3 group is more than K2 in both. It was more than k1 (P>0.001). The level of satisfaction of treating doctor (P=0.78) and patient (P=0.019) in k3 group was higher than other groups. The dose of propofol received in k3 group was lower than K2 and in both groups it was lower than k1 (P>0.001). Changes in systolic, diastolic and average blood pressure were not significantly different between the three groups (p>0.05). Discussion: Sedation regimens using ketamine appear to be appropriate for adult FFB. Increasing the sub-anesthetic dose of ketamine from 0.2 mg/kg to 0.5 mg/kg in combination with propofol is associated with an increase in Ramsey's sedation score, an increase in patient and physician satisfaction, and a decrease in propofol consumption. For fiberoptic (flexible) bronchoscopy in adults, a dose of 0.5 mg/kg may be preferable to other doses. The aforementioned trial has been duly registered with the Clinical Trials Registration Center of Iran under the identification number IRCT20180416039326N17, with the registration date being the 10/12/2020