Ketamine-Dexmedetomidine Combination for Monitored Anaesthesia Care in Tympanoplasty Surgery: An Observational Study

Abstract

Introduction: Monitored Anaesthesia Care (MAC) has been widely used for patients undergoing middle ear surgeries. Previous studies have shown that the use of local anaesthesia has many advantages over general anaesthesia in performing ear surgeries. The use of Dexmedetomidine as a sole anaesthetic agent had many disadvantages owing to its insufficient sedative effect, increased recovery time and haemodynamic instability. Hence, using a combination of low dose ketamine with Dexmedetomidine can prove to be useful in middle ear surgeries. Aim: To evaluate the effects of Dexmedetomidine-Ketamine (DK) combination on the quality of sedation/analgesia and recovery profiles for MAC in tympanoplasty surgery. Materials and Methods: In this observational study, a total of 20 patients were included. All the demographic data- including, age, sex and American Society of Anesthesiologists (ASA) grade were recorded before the surgery. Before the surgery, all patients received 1 μg/kg dexmedetomidine over 15 minutes followed by infusion of 0.2-0.7 μg/kg/h to maintain 2 or 3 of modified observer’s assessment of analgesia and sedation score. Both the scores were checked every 10 minutes. Ketamine was infused at the rate of 10-15 mcg/kg/min, 10 minutes before the start of the procedure. The Heart Rate (HR), systolic and diastolic pressure, pain score and sedation score were monitored every 10 minutes until 120 minutes of the preoperative condition after the nerve block was used. Statistical analysis was performed using IBM SPSS Version 25.0 (IBM, New York, United States). Continuous data values were shown in the form of mean±standard deviation. To compare the mean difference between the groups, student’s t-test was used and p<0.05 was considered as statistically significant. Results: The mean age of the population was 39.45±12.66 years; among which 15 patients (75.0%) were females. Out of 20 patients, 12 (60.0%) were in the ASA-I and 8 (40.0%) were in the ASA-II grade. The result of the study showed not a single instance of complication. All the patients were haemodynamically stable and HR was also found to be constant in both pre and postoperative instances. The pain score was found to be around 2 even after 120 minutes after the surgery (2±0.93). No rescue analgesia was required in any of the patients and all the patients recovered within 3-5 minutes after the infusion was stopped. No postoperative nausea and vomiting instances were also reported. Conclusion: The present study showed that DK combination provides good haemodynamic stability, higher sedation score and lower pain score. In addition, this study also showed that for patients undergoing tympanoplasty surgery this is a safe and effective method of anaesthesia that provides good MAC.