Dexmedetomidine for Attenuation of Pressor Response

Various drugs include local anesthetics, beta-blockers, calcium channel blockers, and narcotic analgesics have been tried to blunt the laryngoscopy and intubation response, with varied success. Dexmedetomidine is a potent and highly selective alpha-2 receptor agonist with sympatholytic, sedative, amnestic, and analgesic properties. Its various effects have led to its increasing use for reducing anesthetic and analgesic requirements in the perioperative period. It inhibits sympathetic activity thus terminating the pain signals and thereby blunts the pressor response associated with laryngoscopy and endotracheal intubation. Electrical cardiometry is recently introduced for assessment of many cardiovascular variables and continuously applicable method of cardiac output (CO), stroke volume (SV), and other hemodynamic parameters monitoring. Its use is growing because it is non-invasive, shows reliability in CO measurements and can be used as a continuous bedside monitor Although different doses of dexmedetomidine (0.5- 2.0 μg/kg) have been used in various studies which suggested its efficacy in blunting the hemodynamic pressor response , However, no studies to the best of our knowledge had incorporated CO monitoring for detection of minimal hemodynamic changes during laryngoscopy and endotracheal intubation which can be best achieved by using Cardiometry monitor.

In this study, we will compare two doses of dexmedetomidine for prophylaxis against pressor response of ETI using cardiometry.

Inclusion criteria

1 - ASA physical status 1-2. 2. Age 18- 60 years old of both sexes. 3. Patients undergoing elective surgery under general anesthesia and tracheal intubation.

Exclusion criteria

• Age < 18 years and ≥ 60 years
• Pregnancy
• Emergency surgery or full stomach
• Renal or Hepatic patients
• Patients with suspected difficult airway {e.g., high neck circumference, high body mass index (above 30 kg/m2), airway masses, mouth scars, neck scars, limited neck extension or history of snoring.
• Total duration of laryngoscopy will be noted and in cases where duration exceeded 15 sec the case will be excluded from the study.
• Any patient on regular intake of beta blockers or calcium channel blockers
• Patients with any known hypersensitivity or contraindication to dexmedetomidine,
• Patients with significant neurological, psychiatric, or neuromuscular disorders.