Comparative analysis of LMA Blockbuster® clinical performance: Blind versus Miller laryngoscope-guided insertion in paediatric general anaesthesia - A double-blinded, randomised controlled trial

Background and Aims: The second-generation supraglottic airway device is conventionally inserted blindly, which might result in suboptimal placement. Limited literature exists on under-vision insertion techniques, particularly in paediatric patients. The primary objective of this study was to compare the oropharyngeal leak pressure (OPLP) between the blind insertion of the LMA Blockbuster (R) and the Miller laryngoscope-guided insertion in children. Secondary outcomes included the number of insertion attempts, haemodynamic disturbances, insertion time and airway complications. Methods: This randomised controlled trial study enroled 100 patients aged 1-4 years undergoing elective surgery. Patients were randomised into blind insertion (Group A) or Miller laryngoscope-guided insertion (Group B) of the LMA Blockbuster (R). The primary outcome measure was OPLP. Insertion time, haemodynamic changes and postoperative complications were also assessed. The Chi-square, Fisher's exact and t-test were applied appropriately, with the significance level set at P < 0.05. Results: Significantly higher mean OPLP was observed in Group B compared to Group A - 27.9 [standard deviation (SD): 1.58] cmH2O versus 25.94 (SD: 0.63) cmH2O [mean difference (MD): 1.96 (95% confidence interval {CI}: 1.48, 2.44; P < 0.001)]. Mean insertion time was longer in Group B, that is, 11.9 (SD: 1.91) s versus 8.7 (SD: 0.6) s [MD: 3.2 s; (95% CI: 2.63, 3.76; P < 0.001)]; however, the difference was not clinically relevant. First-attempt insertion, haemodynamic stability and postoperative complications were comparable (P > 0.05). Conclusion: Miller laryngoscope-guided under-vision insertion of LMA Blockbuster (R) improves alignment with epiglottic structures compared to blind insertion.