A PROSPECTIVE RANDOMIZED STUDY COMPARING THE HEMODYNAMIC RESPONSE TO INTUBATION USING C-MAC VIDEO LARYNGOSCOPE VERSUS MACINTOSH LARYNGOSCOPE IN PATIENTS POSTED FOR ELECTIVE SURGERY UNDER GENERAL ANESTHESIA

Abstract

Background: Laryngoscopy and tracheal intubation are often associated with tachycardia, hypertension and, arrhythmia. The major stimuli to cardiovascular change during laryngoscopy and tracheal intubation are the forces exerted by the laryngoscope blade on the base of the tongue while lifting the epiglottis. Direct laryngoscopy remains the gold standard technique as an effective means to securing the airway. Video laryngoscopes have quickly gained popularity as an intubation device in a variety of clinical scenarios and settings, as well as in the hands of airway experts and non-experts. Video laryngoscopy utilizes video camera technology to visualize airway structures and facilitate endotracheal intubation. C-MAC Video laryngoscope blade is similar to the Macintosh, with the additional advantage of a video camera. The distal end of the blade incorporates a small digital camera and a high-power light-emitting diode. The video laryngoscopes are found to be associated with lesser hemodynamic response to laryngoscopy and intubation. Objectives: The main aim of our study is to compare the hemodynamic response to intubation using C-MAC video laryngoscope and Macintosh laryngoscope. The primary objectives of the study are to assess and compare the hemodynamic parameters such as Heart rate (HR), Systolic blood pressure (SBP), Diastolic blood pressure (DBP) using C-MAC video laryngoscope and Macintosh laryngoscope. The secondary objectives of the study are to compare the intubation time, the number of attempts, glottis view and, airway morbidity using CMAC video laryngoscope and Macintosh laryngoscope. Methodology: A prospective randomized, comparative study with a total of 66 American Society of Anaesthesiologists Physical Status (ASA PS) 1 patients of age group between 20 and 50 years was divided into two groups C(C-MAC) and M(Macintosh). Group allocation was achieved by a computer-generated randomization list. Patients were wheeled into the operation theatre on the day of surgery and connected to a multi-para monitor with Electrocardiogram (ECG), non 1 invasive blood pressure (NIBP), Oxygen saturation (SPO2) and, End-tidal carbon dioxide (ETCO2) and, all baseline parameters of HR, SBP, DBP were recorded. Laryngoscopy was performed with C-MAC video laryngoscope in group C and with Macintosh laryngoscope in group M. The HR, SBP, DBP and SPO2 were recorded at the time of introduction of laryngoscope (T0), one minute after intubation (T1), three minutes after intubation (T2), five minutes after intubation (T3). The time taken for intubation was recorded as the time between the introduction of the laryngoscope blade between the canines and the appearance of the first ETCO2 trace in the monitor. The laryngoscope view is graded according to the Cormack Lehane grading. Any injury to the oral mucosa or the tooth will be noted after securing the airway. Data were analyzed using the chi-square test and student t-test. Results: The mean Heart Rate at 1 minute, 3 minutes, 5 minutes after intubation were 77.2±7.9 beats/min, 75.9±7.2 beats/min, 73.5±8.3 beats/min in the C-MAC group and 95±11.3 beats/min, 89.4±10.9 beats/min, 81±10.5 beats/min in the Macintosh group respectively. The mean systolic blood pressure at 1 min,3 mins,5 mins after intubation were 120±9.3 mm Hg,113.2±6 mm Hg, 113.2±8 mm Hg in the C-MAC group and 130.5±15.6 mm Hg, 128.5±13.2 mm Hg, 125.9± 6.8 mm Hg in Macintosh group respectively. The diastolic blood pressure at 1 min, 3 mins, 5 mins after intubation were 72.2±6.3 mm Hg, 72.7±7.8 mm Hg, 70.6±8.2 mm Hg in the C-MAC group and 96.2±9.1 mm Hg,93.2±8.5 mm Hg, 91.9±9.5 mm Hg in the Macintosh group respectively. There was a statistically significant difference with a lesser increase in HR, SBP and DBP in patients intubated with C-MAC video laryngoscope. The Cormack-Lehane grading 1 was observed in 32 patients and grade 2 was observed in 1 patient in the C-MAC group and grade 1 was observed in 21 patients and grade 2 was observed in 12 patients in the Macintosh group. This conveys that the C-MAC group showed a better glottic view when compared to the Macintosh group. The mean time taken for intubation was 20.3±3.6 seconds in the C-MAC group compared to 31.2±6.0 seconds in the Macintosh group. The first attempt success rate was 100 percent in both the C-MAC group and the Macintosh group. Mucosal trauma was recorded in one participant in the Macintosh group and none in the CMAC group. Conclusion: CMAC video laryngoscope provoked or elicited lesser hemodynamic response after intubation like lesser increase in HR, the lesser elevation of SBP, DBP and also better CL grading, lesser intubation time and lesser incidence of trauma in comparison to Macintosh laryngoscope.