A prospective randomised study comparing intravenous magnesium sulphate and sublingual nitroglycerine spray in attenuating haemodynamic responses to laryngoscopy and intubation

Deepti M. Kotwani, Manish B. Kotwani, Amit Hiwarkar


Background: Laryngoscopy and tracheal Intubation are invariably associated with certain stress responses due to the sympatho-adrenal stimulation. These cardiovascular and neurohumoral alterations may directly affect the physiology and increase the risk. So far, various drugs have been tried but none has been considered ideal for blunting this presser response. We therefore, planned this comparative study to evaluate and compare the efficacy of intravenous magnesium sulphate (30 mg/kg) versus sublingual nitroglycerine spray (0.4 mg/spray) in attenuating the presser response to Laryngoscopy and Tracheal Intubation.

Methods: Fifty patients, aged 15–50 years, scheduled for elective surgery under general anaesthesia, were randomly assigned to one of the two groups of 25 each, Group A (magnesium group) and Group B (nitroglycerine group). Study drug was given 90-120 seconds before tracheal intubation. Heart rate, Systolic blood pressure and Rate pressure product were recorded at different intervals after administering the study drug till 3 minutes after intubation.

Results: Mean heart rate was significantly higher from the baseline at all times after administering the study drug in both the groups. Increase in systolic blood pressure as a presser response was limited to 7.25% in Group A and 5.83% in Group B from the baseline after tracheal intubation. There was relative hypotension after administration of the study drug in both the groups.

Conclusions: Intravenous magnesium or sublingual nitroglycerine pre-treatment is found to be effective in attenuating the presser response to laryngoscopy and intubation. These drugs may lead to rise in HR but it is transient and dose dependent. However, both the drugs can significantly control the hypertensive response after laryngoscopy and intubation.



Laryngoscopy, Intubation, Magnesium sulphate, Nitroglycerine spray

Full Text:



Singh M. Stress Response and Anaesthesia altering the peri and postoperative management. Indian J Anaesth. 2003;47(6):427-34.

Derbyshire DR, Smith G. Sympathoadrenal responses to anaesthesia and surgery. Br J Anaesth. 1984;56(7):725-39.

Bruder N, Ortega D Granthil C. Consequences and prevention methods of hemodynamic changes during laryngoscopy and intubation. Ann Fr Anaesth Reanim. 1992;11(1):57-71.

Randell T. Haemodynamic responses to intubation: what more do we have to know? Acta Anaesthesiol Scand. 2004;48(4):393-5.

Velickovic I, Yan J, Gross JA. Modifying the neuroendocrine stress response. Seminars in Anaesthesia, Perioperative Med Pain. 2002;21(1):16-25.

Fox EJ, Sklar GS, Hill CH, Villanueva R, King BD. Complications related to the pressor response to endotracheal intubation. Anesthesiology. 1977;47(6):524-5.

Mitra S. Blunting of haemodynamic responses to laryngoscopy and intubation- A review of methods. Indian J Anaesth. 1998;42:14-9.

Takita K, Morimoto Y, Kemmotsu O. Tracheal lidocaine attenuates the cardiovascular response to endotracheal intubation. Can J Anaesth. 2001;48(8):732–6.

VandenBerg AA, Halliday EM, Soomro NA, Rasheed A, Baloch M. Reducing cardiovascular responses to laryngoscopy and tracheal intubation: A comparison of equipotent doses of tramadol, nalbuphine and pethidine, with placebo. Middle East J Anaesthesiol. 2004;17:1023-36.

Kovac AL. Controlling the hemodynamic response to Laryngoscopy and Endotracheal Intubation. J Clin Anesth. 1996;8(1):63-79.

Kay B, Healy TE, Bolder PM; Blocking the circulatory responses to tracheal intubation. A comparison of fentanyl and nalbuphine. Anaesthesia; 1985;40(10):960-3.

Sugiura S, Seki S, Hidaka K, Masuoka M, Tsuchida H. The hemodynamic effects of landiolol, an ultra-short-acting β1-selectiveblocker on endotracheal intubation in patients with and without hypertension. Anesth. Analg 2007;104(1):124-9.

Coleman AJ, Jordan C; Cardiovascular responses to anesthesia. Influence of beta-adrenoreceptor blockade with metoprolol. Anaesthesia. 1980;35(10):972-8.

Davies MJ, Cronin KD, Cowie RW; The prevention of hypertension at intubation. A controlled study of intravenous hydralazine on patients undergoing intracranial surgery. Anaesthesia. 1981;36(2):147-51.

Hasegawa J, Mitsuhata H, Matsumoto S, Enzan K. Attenuation of cardiovascular response to laryngoscopy and tracheal intubation with bolus injection of diltiazem. Masui. 1992;41:356 - 62.

Montazeri M, Falah M. Dose-response study: MGSO4 in cardiovascular responses after laryngoscopy & endotracheal intubation. Canadian J Anesthesia. 2005;52(1):129.

Delhumeau A, Granry JC, Monrigal J-P, Costerousse F. Therapeutic use of magnesium in anaesthesia and intensive care (French). Ann Fr Anesth Réanim. 1995;14:406–16.

Sanders GT, Huijgen HJ, Sanders R. Magnesium in disease: a review with special emphasis on the serum ionized magnesium. Clin Chem Lab Med. 1999;37:1011–33.

Crowther C. Magnesium sulphate versus diazepam in the management of eclampsia: a randomized controlled trial. Br J Obstet Gynaecol. 1990;97:110–7.

Reinhart RA. Clinical correlates of the molecular and cellular actions of magnesium on the cardiovascular system. Am Heart J. 1991;121:1513–21.

Vigorito C, Giordano A, Ferraro P, Acanfora D, De Caprio L, Naddeo C, et al. Hemodynamic effects of magnesium sulfate on the normal human heart. Am J Cardiol. 1991;67:1435–7.

James MFM, Beer RE, Esser JD. Intravenous magnesium sulfate inhibits catecholamine release associated with tracheal intubation. Anesth Analg. 1989;68:772–6.

Ashton WB, James MFM, Janicki P, Uys PC. Attenuation of the pressor response to tracheal intubation by magnesium sulphate with and without alfentanil in hypertensive proteinuric patients undergoing caesarean section. Br J Anaesth. 1991;67:741–7.

Puri GD, Marudhachalam KS, Chari P, Suri RK; The effect of magnesium sulphate on hemodynamics and its efficacy in attenuating the response to endotracheal intubation in patients with coronary artery disease. Anesth Analg. 1998;87:808–11.

Montazeri M, Falah M. Dose-response study: MGSO4 in cardiovascular responses after laryngoscopy & endotracheal intubation. Canadian J Anesthesia. 2005;52(1):129.

Atlee JL, Dhamee MS, Olund TL, George V. Use of Esmolol, Nicardipine, or Their Combination to Blunt hemodyanamic Changes After Laryngoscopy and Tracheal Intubation. Anesth Analg. 2000;90:280-5.

Kumari I, Naithani U, Dadheech VK, Pradeep DS, Meena K, Verma D. Attenuation of pressor response following intubation: Efficacy of nitro-glycerine lingual spray. J Anaesthesiol Clin Pharmacol. 2016;32(1):69-73.

Singh AV, Singh S. A Study of Pressor Response to Laryngoscopy and Intubation and Its Attenuation by Nitroglycerine. IJAR. 2015;1(12):683-7.

Channaiah VB, Kurek NS, Moses R, Sathees B. Chandra. Attenuation of Hemodynamic Response to Laryngoscopy and Endotracheal Intubation with pre-induction Fentanyl ersus Combination of IV Fentanyl and Sub Lingual Nitroglycerin Spray. Med Arch. 2014;68(5):339–44.