INTRODUCTION

Laryngoscopic response is characterised by a sudden surge in mean arterial pressure (MAP) and heart rate (HR), arising 30 seconds following direct laryngoscopy and intubation and approaches baseline in 10 minutes Various pharmacological agents are used to attenuate this noxious response with varied success.

Dexmedetomidine is a highly selective alpha-2 adrenergic agonist having sympatholytic, sedative, hypnotic and analgesic properties. Lignocaine is an amide synthetic local anaesthetic and used commonly for decreasing airway reflexes, bronchial hyperactivity and suppress the laryngoscopic response by inhibiting sensory C fibres of the airway Administration of drugs via nebulisation route provides greater surface area for absorption and better safety profile.

AIM AND OBJECTIVE

Aim: To explore two effective nebulisation regimens to attenuate laryngoscopic response

Objective: To compare heart rate and mean arterial blood pressure after nebulisation with dexmedetomidine or lignocaine post laryngoscopy

MATERIALS AND METHODS

MATERIALS

1. Study Design: Prospective randomised double-blind study
2. Study population: All ASA-PS: I, II patients posted for elective surgery under general anaesthesia
3. Study duration: 1 year
4. Sample size: N = 65 per group 
5. Parameters to be studied:
1. Heart Rate (HR)
2. Mean Arterial Pressure (MAP)
6. Inclusion criteria:
1. Patients aged between 18-60 years of either sex scheduled to undergo surgery under general anaesthesia
2. American Society of Anaesthesiologists- Physical Status-1, 2 (ASA-PS-1, 2) patient
3. Modified Mallampati grade 1 and 2
4. Patients weighing between 45 kg and 75 kg
7. Exclusion criteria:
1. Patient refusal
2. Patients with bleeding disorder
3. Patients with known history of allergy, hypersensitivity
4. Unanticipated difficult intubation (Laryngoscopy time >15 seconds)
5. Patients with psychiatric disease
6. Pregnant lady
8. Study Group: Patients will be randomly assigned by computer generated number to one of the two groups- Group A and Group B
9. Randomisation: Randomisation will be done by Sequentially numbered, opaque, sealed envelope (SNOSE) method
10. Blinding: A two-operator technique will be used to maintain blinding.
1. The principal investigator will record all the hemodynamic variables
2. An anaesthesiologist, who is not involved in the study, will administer the nebulised drugs to the patient in the absence of principal investigator

Methods

Group A will be nebulised with Dexmedetomidine (1.5 μg/kg) dissolved in sterile water to make 5 ml and similarly Group B patients will be nebulised with Lignocaine (4.5 mg/kg) diluted with sterile water 30 minutes prior to induction of anaesthesia. All the vital parameters (HR, MAP and SPO2) will be recorded immediately after laryngoscopy and intubation (T0). The patient will be left undisturbed for 10 minutes; HR, MAP and SPO2 will be recorded for every 2 minutes post laryngoscopy till 10 minutes (T2, T4, T6, T8, T10). Rescue medication used will be Inj. Propofol integrated dose if rise in MAP>20% of baseline