Abstract / Summary
Introduction: Laryngoscopy and intubation provoke sympathetic tachycardia and hypertension. These transient changes may precipitate adverse effects in patients with undiagnosed co-morbidities. Magnesium sulphate and dexmedetomidine attenuate this response, but direct comparisons at clinical doses remain limited. Aim: To compare magnesium sulphate 30 mg/kg and dexmedetomidine 1 μg/kg for attenuating cardiovascular responses to laryngoscopy and endotracheal intubation. Materials and Methods: This double-blind, randomised clinical trial was conducted at Shija Hospitals and Research Institute, Imphal, Manipur, India from May 2021 to May 2022. A total of 80 adults with American Society of Anaesthesiologists physical status (ASA PS) I or II were randomly allocated equally to receive intravenous magnesium sulphate (30 mg/kg) or dexmedetomidine (1 μg/kg), infused over 10 minutes, beginning 15 minutes before intubation. The parameters assessed included demographic characteristics, haemodynamic variables including Heart Rate (HR), Systolic Blood Pressure (SBP), Diastolic Blood Pressure (DBP) and Mean Arterial Pressure (MAP), recorded at baseline, after drug infusion, after induction and at 1, 5, 10 and 15 minutes after intubation, and postoperative adverse events categorical variables were analysed using the Chi-square test, while quantitative variables were compared using Student’s t-test. The p-value <0.05 was considered statistically significant. Results: The two groups were comparable at baseline. The mean age was 34.80±10.16 years in Group A and 38.55±10.77 years in Group B (p-value =0.113). Group A included 19 males and 21 females, compared with 18 males and 22 females in Group B. The distribution of ASA PS was also similar between groups, with 29 and 31 patients classified as ASA PS I and 11 and nine patients as ASA PS II in Groups A and B, respectively. HR was lower with dexmedetomidine at all postinduction time points at T2 (p-value=0.004), T3 (p-value=0.036), T4 (p-value=0.043), T5 (p-value=0.002). At 15 minutes, Group A versus Group B values were: HR, 78.70±16.50 versus 68.83±11.37 beats/min (p-value=0.003); SBP, 116.15±13.77 versus 114.05±17.61 mmHg (p-value=0.550); DBP, 72.50±14.60 versus 72.65±13.55 mmHg (p-value=0.962); and MAP, 87.20±19.67 versus 86.48±14.00 mmHg (p-value=0.851). No clinically significant bradycardia, hypotension or postoperative adverse effects occurred. Conclusion: Both drugs effectively attenuated the haemodynamic response to intubation. Dexmedetomidine provided better control of HR than magnesium sulphate. Blood Pressure (BP) responses were comparable between the two groups. Neither drug caused clinically significant adverse effects.