Comparison Between Video Laryngoscope and Direct Laryngoscope for Pressor Response in Adult Patients Undergoing...

This prospective randomized study was done to compare hemodynamic and intraocular pressure (IOP) responses to laryngoscopy and intubation with the use of the Macintosh direct laryngoscope (DL) (Medisearch Systems Pvt. Ltd., Jalandhar, India) and C-MAC video laryngoscope (VL) (C-MAC®, Karl Storz, Tuttlingen, Germany) in patients undergoing brain tumor excision surgery.

Sixty American Society of Anesthesiologists (ASA) grade I and II patients aged 18-65 years undergoing fronto-parietal brain tumor excision surgery were randomly allocated into two groups: group DL (intubation using Mcintosh DL) (n=30) and group VL (intubation with C-MAC® VL) (n=30). Baseline values of mean arterial pressure (MAP), systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), and IOP were recorded. The primary outcome was the percentage change in MAP. Secondary outcomes were percentage changes in HR, SBP, DBP, and IOP. Hemodynamic parameters were noted during laryngoscopy (T_L1, T_L2, T_L3) and every 30 seconds after intubation (T₁-T₁₀). IOP was measured every minute for five minutes post-intubation. Blood pressures were measured using invasive arterial blood pressure, and IOP was measured using Schiotz tonometry.

Categorical variables were presented in numbers and percentages, and continuous variables were presented as mean±SD and median. Normality of data was tested by the Kolmogorov-Smirnov test. The unpaired t-test/Mann-Whitney U test was used for comparing quantitative variables, and the chi-squared test/Fisher's exact test was used for qualitative variables. A p-value lower than 0.05 was considered statistically significant.

The percentage rise in MAP was significantly greater in the DL group as compared with the VL group at all time points during laryngoscopy: T_L1 (p=0.005), T_L2 (p=0.009), and T_L3 (p=0.04). The percentage rise in SBP was significantly higher in the DL group during laryngoscopy at time points T_L1 and T_L2. The percentage rise in DBP and HR was significantly higher in the DL group at all time points during laryngoscopy. The percentage rise in DBP was also higher at certain time points post-intubation (T₆, T₇, T₉, and T₁₀). The percentage rise in IOP was significantly higher in the DL group post-intubation at most time points.

In elective neurosurgical patients, the C-MAC VL resulted in a lower rise in hemodynamic parameters and IOP as compared to DL.