Effect of Magnesium Sulphate on Perioperative Hemodynamic Responses in Hypertensive Patients Undergoing Laparoscopic Cholecystectomy. A Randomized Controlled Double Blinded Trial

Abstract Background: Orotracheal intubation is one of the most invasive perioperative stimuli. Orotracheal intubation is associated with stimulation of somatic and visceral nociceptive afferents of the epiglottis, hypopharynx, peritracheal area, and vocal cords, which augment sympathetic activity. Transient tachycardia and hypertension are common cardiovascular responses to laryngoscopy and intubation. These transient hemodynamic changes are probably of no consequence in healthy individuals, but they may be dangerous in those with hypertension as they may lead to myocardial ischemia, arrhythmias, and intracranial hemorrhage Therefore, attenuation of cardiovascular response following tracheal intubation is of particular importance in hypertensive patients, whom are more susceptible to exaggerated cardio-vascular response to laryngoscopy and tracheal intubation than normotensive patients. Aim of Study: The present study was designed to study the effects of pre-induction intravenous Magnesium Sulphate on hemodynamic responses to laryngoscopy, post-intubation, during pneumoperitoneum and in post-operative period in hypertensive patients undergoing laparoscopic cholecystecto-my. Patients and Methods: After approval of the institutional research board and getting informed written consent from the patients, this double blind randomized prospective study was conducted at the gastro-intestinal surgery center in June 2019 Patients were prepared according to ASA fasting guidelines. The day before operation, all patients were subjected to preoperative history taking, physical examination and basal laboratory investigation. Complete blood count, coagulation profile, renal and liver function test. In addition, the instruction have been given to the patient and the paramedical stuff that all antihypertensive drugs must continues till the surgery time except for ACE/ARBS must be stopped the day before surgery. Upon arrival to the pre-operative holding area, a peripheral intravenous 18-20-gauge cannula was inserted; monitor was attached to the patients and hemodynamic parameters like heart rate, noninvasive blood pressure, oxygen saturation and ECG were recorded. Patients were randomly allocated into two groups using computer-generated randomization and closed envelops. Study medications were prepared by an anesthesiologist who was blinded to the computer-generated randomization schedule. Patients received one of these below mentioned solution as a bolus intravenously in the pre-operative period. (Group I, n=40): Received Magnesium Sulphate 20mg/kg in 250ml of isotonic 0.9% sodium chloride solution intrave-nously over 15 to 20 minutes in the preoperative room imme-diately before induction of anesthesia. (Group II, N=40): Same volume of isotonic 0.9% sodium chloride solution intravenously over 15 to 20 minutes in the preoperative room just before induction of anesthesia. Results: There were statistically significant difference between magnesium group and control group as regarded the hemodynamic responses to intubation and surgical stimulation during laparoscopic cholecystectomy in hypertensive patients. Conclusion: Administration of magnesium sulphate im-mediately pre-operative can attenuate the hemodynamic response in hypertensive patient undergoing laparoscopic cholecystectomy.