Comparison of Dexmedetomidine and Midazolam as Co-induction Agents to Propofol for Proseal Laryngeal Mask Airway Insertion: A Randomised Control Trial

Introduction: The Laryngeal Mask Airway (LMA) is a supraglottic device designed to secure the airway during minor to moderate surgical procedures. Second-generation LMAs, such as the ProSeal LMA (PLMA), offer enhanced safety features, including a gastric drain to reduce the risk of aspiration. Optimal insertion conditions depend on effective sedation with agents like propofol and adjuvants such as dexmedetomidine, which provide stable haemodynamics and suppress airway reflexes. Aim: To compare dexmedetomidine and midazolam as coinduction agents with propofol for ProSeal laryngeal mask airway (PLMA) insertion, assessed using the Muzi scoring system. Materials and Methods: This prospective, randomised controlled trial was conducted at the Department of Anaesthesiology, ACS Medical College, Chennai, India, over a period of 16 months and included 60 patients scheduled for elective surgeries under general anaesthesia. Patients were randomly assigned to Group I (n=30) - dexmedetomidine (0.5 mcg/kg) with propofol (2.5 mg/ kg), or Group II (n=30) - midazolam (0.04 mg/kg) with propofol (2.5 mg/kg). PLMA insertion conditions, insertion time, first-attempt success rate, and haemodynamic stability were compared between the two groups using the t-test and Chi-square test. Results: There were no significant differences in age, gender, height, or weight between the groups. Group I demonstrated significantly better PLMA insertion conditions, including a higher first-attempt success rate (93.3% vs. 70%, p=0.019) and shorter insertion time (18.30±4.39 seconds vs. 21.27±6.21 seconds, p=0.04). Haemodynamic stability was superior in Group I, with lower heart rates (75.07±10.40 vs. 81.13±11.98 bpm, p=0.04) and lower systolic mean arterial pressures (115.67±5.70 vs. 119.93±5.69 mmHg, p=0.005 at 5 min; 117.20±4.69 vs. 121.07±4.83 mmHg, p=0.003 at 10 min). The requirement for additional propofol doses was lower in Group I (3.3% vs. 20%). The incidence of complications, such as sore throat (3.3% in Group I vs. 10% in Group II) and patient movement, was minimal in both groups, with no significant differences. Conclusion: Dexmedetomidine, as a co-induction agent with propofol, significantly improves PLMA insertion conditions, reduces the need for additional propofol, and provides superior haemodynamic stability, suggesting it is a more effective adjunct for PLMA insertion than midazolam.