HEMODYNAMIC RESPONSES AFTER LARYNGEAL MASK AIRWAY OR ENDOTRACHEAL TUBE PLACEMENT IN SHORT ELECTIVE SURGERY: A PROSPECTIVE COMPARATIVE STUDY

Background: Endotracheal tube (ETT) placement may provoke transient cardiovascular stimulation, whereas a laryngeal mask airway (LMA) avoids tracheal passage. Published comparisons remain procedure specific, and the magnitude of any immediate hemodynamic difference under routine anesthesia is uncertain. 
Methods: This prospective, non-blinded two-group comparative study reanalysed complete individual-level data from 56 low-risk adults undergoing short elective surgery (LMA, n=26; ETT, n=30). Heart rate, systolic and diastolic blood pressure, and peripheral oxygen saturation were recorded before induction, after induction, immediately after airway placement, and at 3 and 5 minutes. The primary analytic contrast was the change from post-induction to immediate post-insertion. Change-score comparisons, participant fixed-effects trajectory models, and baseline-adjusted sensitivity models were used. 
Results: The groups differed in sex distribution and in pre-induction heart rate and systolic blood pressure. From post-induction to immediate post-insertion, the LMA−ETT difference in change was −0.88 beats/min for heart rate (95% confidence interval [CI], −2.81 to 1.06; P=0.366), 2.98 mmHg for systolic blood pressure (95% CI, 0.31 to 5.65; P=0.030), and 1.01 mmHg for diastolic blood pressure (95% CI, −1.31 to 3.33; P=0.385). The systolic finding reflected a greater decrease in the ETT group. Serial device-by-time interactions were not significant for heart rate (P=0.055), systolic blood pressure (P=0.115), diastolic blood pressure (P=0.694), or oxygen saturation (P=0.312). At 0 minutes, adjusted ETT−LMA differences were not significant for heart rate (2.13 beats/min; 95% CI, −0.19 to 4.44), systolic blood pressure (−1.04 mmHg; 95% CI, −4.70 to 2.61), or diastolic blood pressure (−0.53 mmHg; 95% CI, −2.86 to 1.80). 
Conclusions: In this cohort, both devices-maintained oxygenation and no statistically significant adjusted immediate hemodynamic advantage of LMA over ETT was demonstrated. The results support a claim of superior peri-insertion hemodynamic stability with LMA in this setting.