A Comparative study on the hemodynamic changes between King Vision Videolaryngoscope and Macintosh direct laryngoscope in orotracheal intubation under general anesthesia

Abstract

Background: Laryngoscopy and endotracheal intubation (EI) can cause an increase in heart rate (HR) and blood pressure, which may be harmful in vulnerable patients. Video laryngoscopes such as the King Vision videolaryngoscope (KVVL) may reduce this response compared with the Macintosh direct laryngoscope (MDL) because they require less airway manipulation. Aims and Objectives: The aim of the study was to compare the hemodynamic pressor response to laryngoscopy between KVVL and MDL in EI for elective surgeries. Materials and Methods: This prospective randomised controlled trial included 100 adult patients (American Society of Anesthesiologists [ASA] I/II, normal airways) undergoing elective surgery under general anesthesia. Participants were randomized into Group K (n=50) or Group D (n=50). Standard induction used thiopentone and succinylcholine. Hemodynamic parameters (HR, systolic blood pressure [SBP], diastolic blood pressure [DBP], mean arterial pressure [MAP], oxygen saturation [SpO2]) were recorded at baseline and 1, 3, 5, 7, and 9 min post-laryngoscopy. Intubation time and attempts were noted. Data were analysed using an independent t-test and Chi-square test (P<0.05). Results: Demographic characteristics were comparable (mean age ~37 years, ASA I 60% both groups). Both groups showed increases in HR (Group D: Baseline 87.04±11.41–100.42±13.47 bpm; Group K: 85.84±8.21–96.22±10.89 bpm), SBP, DBP, and MAP post-intubation, with no significant intergroup differences at any time point (all P>0.05). SpO2 remained stable (>98%). First-attempt success was 94% (Group D) versus 90% (Group K) (P=0.461). Intubation time was longer in Group K (49.04±11.25 s) than Group D (39.20±8.80 s) (P=0.001). Conclusion: KVVL and MDL produced similar changes in HR and blood pressure in patients with normal airways. KVVL did not reduce the pressor response but took longer for intubation. Both devices can be safely used for routine intubation.