Video Versus Direct Laryngoscopy and The Hemodynamic Response and Myocardial Workload During Tracheal Intubation Under Standardized Anesthetic Induction: A Randomized Trial

Abstract

Background. Tracheal intubation triggers a sympathoadrenal reflex that raises heart rate and blood pressure. Whether video laryngoscopy (VL) reduces this response is debated.

Objective. To compare GlideScope VL with Macintosh direct laryngoscopy (DL) for the hemodynamic response and rate pressure product (RPP) under standardized induction.

Methods. In this single-blind randomized trial, 40 adults (ASA I–II) received VL (n = 20) or DL (n = 20). Induction was fentanyl 2 mcg/kg, propofol 2 mg/kg, atracurium 0.5 mg/kg, and 1.5% sevoflurane, with laryngoscopy 3 minutes after the relaxant. Heart rate (HR), systolic (SBP) and mean arterial pressure (MAP) were recorded at baseline (T0) and 1 (T1), 2 (T2), and 5 (T5) minutes after intubation.

Results. HR was lower with VL at T1 (75.45 ± 11.23 vs. 90.15 ± 15.22 bpm, p = 0.001) and T2 (74.15 ± 10.80 vs. 89.85 ± 14.50 bpm, p < 0.001). MAP showed a Time × Group interaction (p < 0.001) and was lower with VL at T1 (96.30 ± 7.80 vs. 108.40 ± 9.60 mmHg, p < 0.001). SBP at T1 did not differ significantly (p = 0.052). RPP was lower with VL at T1 (8,952 ± 1,480 vs. 11,453 ± 2,210) and T2 (8,649 ± 1,390 vs. 11,213 ± 2,150 bpm·mmHg; both p < 0.001). First-pass success was 100% vs. 90% (p = 0.487).

Conclusion. In young ASA I–II patients, VL was associated with lower HR, MAP, and RPP 1–2 minutes after intubation than DL; SBP and first-pass success did not differ significantly.