Vol. 6, Issue 5, Part G (2020)

Abstract
Background: Dexmedetomidine is a highly selective α2 adrenergic agonist and used as adjuvant in anaesthesia to reduce the intra-operative anaesthetic and analgesic requirement. It regulates the autonomic and cardiovascular systems by acting on blood vessels and inhibiting norepinephrine release at sympathetic terminals, thereby attenuating the heart rate and blood pressure responses to intra-operative stressful events of anaesthesia. It effectively minimises the surgical blood loss and improves the surgical field visibility. Its haemodynamic effects are predictable and dose-dependent. Objectives: To observe any inadvertent adverse effects associated with the intravenous administration of dexmedetomidine as an anaesthetic adjuvant. Methods: Sixty adult patients in two groups aged 18-58 years, weighing 45-80 kg, of either sex belonging to ASA classification 1 and 2 posted for middle ear surgeries at our institute. Results: Majority of our patients in Group A i.e. 11 (33.3%) and Group B i.e. 9 (33.3%) were 50-59 years of age. The mean age in Group A patients was 40.7+11.84 years and in Group B it was 42.7+10.33 years. Mean heart rate in Group A was 89.30 and in Group B it was 88.19. Mean SBP was 130.45 and 129.19 in Group A and Group B. Mean DBP was 85.61 in Group A and 84.22 in Group B. Mean MAP was 100.56 and 99.21 in Group A and Group B. Mean SpO₂ was 97.61 and 97.48 in Group A and Group B. Mean duration of surgery was 131.5 minutes and 129.8 minutes in Group A and Group B. When heart rate was compared at different time intervals, the overall time interval was 71.14 in Group A and 83.07 in Group B. When systolic blood pressure (SBP) was compared at different time intervals, the overall time interval was 100.49 in Group A and 119.27 in Group B. When diastolic blood pressure (DBP) was compared at different time intervals, the overall time interval was 65.74 in Group A and 77.06 in Group B. When mean arterial pressure (MAP) was compared at different time intervals, the overall time interval was 77.32 in Group A and 91.06 in Group B. Conclusion: They concluded that dexmedetomidine infusion can be safely used to decrease intra-op bleeding for better visualization during middle ear microsurgery.