The main stimulus for cardiovascular changes during laryngoscopy and tracheal intubation is the force exerted by the laryngoscope blade on the root of the tongue when it lifts the epiglottis. These hemodynamic changes can be dangerous for debilitated patients, patients with ischemic heart disease, cerebrovascular disease, etc. and should be prevented. There is little information on the pharmacological approach, non-pharmacological approach (especially laryngoscope blade design) to the answer

After approval by an institutional ethical committee and written informed consent. This randomized study was performed at People's Hospital associated with People's College of Medical Sciences& Research Institute, Bhopal, during the period from JANUARY 2024 to MARCH 2024. 60 patients of ASA grade I and grade II aged 20-50 years ,of either sex ,scheduled for elective surgeries under general anaesthesia were included after obtaining informed written consent. Patients belonging to ASA 3 OR more than 3 , pregnant patients undergoing emergency surgery, obese individuals (body mass index > 30 kg/m2 )were excluded Group1:Patientsundergoing laryngoscopy with Macintosh blade Group 2: Patients undergoing laryngoscopy with McCOY blade

Methodology: One day before surgery,all patients received a pre-anesthetic evaluation by the anesthesiologist.The night before surgery, patients were kept nil per oral after 10:00 p.m. Upon arrival in the operation theatre, patients were connected to the intravenous line and intravenous fluids was started; monitors for electrocardiogram,pulse-oximeter, and non-invasive blood pressure (NIBP) was also connected and set at monitoring modeThe patients were premedicated with injection glycopyrrolate 0.004mg/kg, injection midazolam 0.03mg/kg, and injection fentanyl 2mcg/kg. The patient were preoxygenated with 100% oxygen using closed circuit with 10 litres of total gas flow . induced with 2 mg/kg of propofol After ventilation was confirmed, injection succinylcholine 1.5mg/kg was administered, and the patient was ventilated with 100% oxygen.The laryngoscopy and intubation was carried out by a single, trained anaesthesiologist.After visualization of the epiglottis, blade was inserted into vallecula and the laryngoscope was pulled forward and upward to expose the glottis. In group B, during laryngoscopy and intubation, McCoy laryngoscope blade was used. After visualization of the epiglottis, blade was inserted into vallecula and the laryngoscope was pulled forward and upward to expose the glottis.

In group B, during laryngoscopy and intubation, McCoy laryngoscope blade was used. The McCoy blade is a modification of the standard MacIntosh blade.Unlike MacIntosh, the tip of McCoy is hinged. When the McCoy blade is inserted into the vallecula, elevation of the tip with the levering action of the blade acts on the hyoepiglottic ligament and lifts the epiglotis out of view to expose more of the glottis.

Heart rate (HR), SBP, DBP, and MAP was recorded 30 s before induction, 30 s, 1, 2,3, 4, 5, and 10 min after laryngoscopy and tracheal intubation, by an independent observer the anaesthesia was maintained with 60%Nitrous oxide and 40%oxygen and isoflurane.

Statistical Analysis

Statistical analysis was performed using the Statistical Package for Social Sciences software (SPSS) version 22.0 IBM. P< 0.05 was considered statistically significant

HR, SBP, DBP, MAP

TABLE 1:

Two groups were compared posted for elective surgery requiring general anaesthesia HR rose significantly for 3 min following laryngoscopy in the Macintosh group and for 2 min in the McCoy group.The maximum rise in the HR compared to baseline seen was 18.7% in the Macintosh group compared to 7.7% in the McCoy group (P = 0.0001) The maximum change observed in SBP in the Macintosh group was 22.9% compared to 10.3% in the McCoy group (P = 0.0001). group the maximum change observed in the diastolic blood pressure in the Macintosh group was 27% compared to 15% in the McCoy group. (P = 0.0001)

Graph 1: showing comparison of mean heart rate in Group 1 and Group 2

Comparison of mean heart rate between Macintosh and McCoy Mean heart rate in Group 1 is 95.4 and Group 2 is 81.4which is statically significant.

Graph 2: Showing comparison of SPO2 in Group 1 and Group 2

Graph 3: showing comparison of SBP in Group 1 and Group 2

Comparison of SBP between Macintosh and McCoy blade SBP in Group 1 is 122.66 and diastolic blood pressure is 116.5 which indicates significant difference between the groups.

Graph 04 :Comparison of DBP in Group 1 and Group 2

Comparison of DBP between Macintosh and McCoy blade DBP in group 1 is 76 and group 2 is 71 which indicates significant difference between the groups.

Graph 05:Comparison of MAP in Group 1 and Group 2

Comparison of MAP between Macintosh and McCoy blade MAP in Group 1 in 84 and in Group 2 is 73 indicates significant difference between the groups.

Several methods have been used to blunt the cardiovascular response associated with laryngoscopy and tracheal intubation, with more focus on pharmacological methods as compared to non-pharmacological methods. Tewari et al. compared the two blades in 160 neurosurgical patients and showed that use of McCoy laryngoscope resulted in lesser change in HR and BP, compared to Macintosh blade when fentanyl was not used in obtundation of response.

The hemodynamic response in Macintosh group to laryngoscopy, shown by rise in HR ,SBP DBP and MAP in comparison to McCoy group.Thus, McCoy blade ( Flexitip blade ) , which is a modification of the Macintosh blade with its levering tipprovided better visualisation of larynx with less increase in hemodynamic response to laryngoscopy in comparison to MacIntosh blade

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