CTRI

Endotracheal intubation is an important procedure practiced in the field of anesthesia. Laryngoscopy and endotracheal intubation increase the plasma concentration of catecholamines due to sympathetic stimulation which can result in tachycardia and hypertension in most of the individuals1 . Due to imbalance in oxygen demand and supply to the heart, this stress response can be detrimental to an extent leading to myocardial infarction, pulmonary oedema, arrhythmias, cerebrovascular accidents such as hemorrhage and other complications in susceptible patients. Various drug regimens and techniques have been used from time to time for attenuating the stress response to laryngoscopy and intubation, including opioids, barbiturates, benzodiazepines, beta blockers, calcium channel blockers, vasodilators, etc2 . Traditionally used drugs like lignocaine, fentanyl, esmolol etc. are either not fully effective or may results in considerable adverse effects3 . Dexmedetomidine and Fentanyl are studied and known to decrease the hemodynamic response during intubation in various doses. There have been little investigations in comparing the efficacy of Dexmedetomidine and Fentanyl in attenuating hemodynamic response during intubation and also different studies yielded conflicting results. So the current study may fill the lacunae in research to find out which one is best among these drugs in attenuating hemodynamic responses during laryngoscopy and intubation.

Procedure/ Technique After clinical approval of institutional ethical committee and taking informed and written consent, the sample size is calculated using COHENâ€™S â€“ D method. All patients selected based on the inclusion criteria under study will undergo preanesthetic evaluation including detailed history, clinical examination and appropriate investigations depending on age, sex and disease of the patient. Patients will be randomly grouped into three groups of 36 each. Group (D) will receive 0.5mcg/kg of Dexmedetomidine diluted to 10ml with normal saline, Group (F) will receive 2mcg/kg of Fentanyl diluted to 10ml with normal saline, and Group (M) will receive 30mg/kg of Magnesium sulfate diluted to 10ml with normal saline, over 10 minutes intravenously. All patients will be assessed serially for the following parameters like Heart Rate (HR), Systolic Blood Pressure (SBP), Diastolic Blood Pressure (DBP), Mean Arterial Pressure (MAP), Saturation of Peripheral Oxygen (SPO2) at 1, 3 and 5 minutes. After preoxygenation for 3 minutes, IV Propofol 2mg/kg is used as an induction agent and neuromuscular block is achieved with Vecuronium 0.1mg/kg. Oxygenation and depth of anesthesia were maintained by mask ventilation with 100% Oxygen and Isoflurane to maintain a minimum alveolar concentration of 1 through anesthesia work station. Intubation done and confirmation of its position done by auscultation and capnography. The patient is put on the volume control mode on a ventilator to maintain EtCO2 of 30-35 mmHg. At 1 min, 3 min, 5 min, 7 min and 10 min after laryngoscopy and intubation, hemodynamic parameters are recorded. Any fall in SBP to < 20% of basal levels is planned to treat with IV Mephentermine 3 to 6 mg and bradycardia with HR < 60 beats/min with IV atropine 0.6mg. No form of stimulus is given during this period. Analgesics such as Paracetamol, Pentazocine and Morphine are given to all three groups after 10min. The surgery commences after 10 min of intubation. Patients are extubated at the end of surgery. Sample size: Sample size for the study is determined by using COHENâ€™S â€“ D method for paired Comparison between Dexmedetomidine and Fentanyl in attenuation of Heart Rate during Laryngoscopy and Intubation before and after drug administration.