Background. The stress response to laryngoscopy and intubation causes an undesirable increase in heart rate, blood pressure, and intraocular pressure. This study was designed to compare the effect of two doses of gabapentin on the stress response to laryngoscopy and intubation. Patients and Methods. (ASA I and II) 60 patients, aged from 18 to 60 years undergoing elective eye surgery requiring endotracheal intubation, were randomly allocated into 3 groups, 20 patients each. 2 hours before the surgery, group I received oral placebo, and groups II and III received oral gabapentin 800？mg and 1200？mg, respectively. Heart rate (HR), mean arterial pressure (MAP), and intraocular pressure (IOP) were measured before and after induction of anesthesia, immediately after, 5 minutes, and 10 minutes after intubation. Results. Gabapentin 1200？mg prevented the increase in HR, MAP, and IOP, secondary to laryngoscopy and intubation, and kept them below the baseline till 10 minutes after intubation ( ), while with gabapentin 800？mg, the increase in HR, MAP, and IOP was nonsignificant ( ) and returned to levels below the baseline at 5 and 10 minutes after intubation. Conclusion. Preoperative gabapentin 1200？mg effectively prevented the stress response to laryngoscopy and intubation; meanwhile, gabapentin 800？mg only prevented significant stress response. 1. Introduction Laryngoscopy and endotracheal intubation can evoke a transient but marked response manifested as hemodynamic changes such as hypertension, tachycardia, even dysrhythmias, and an increase in intraocular pressure [1, 2]. The hemodynamic responses to laryngoscopy and intubation can be tolerated by a normal subject but they may be dangerous increasing the morbidity and mortality in patients with hypertension and ischemic heart disease [3]. The control of intraocular pressure (IOP) is of prime importance in eye surgery especially in penetrating eye injury and glaucoma surgery [4]. Many pharmacologic agents have been proposed to attenuate the stress response to laryngoscopy and intubation such as systemic and local lidocaine, B blockers, calcium channel blockers, vasodilators, and opioids [5–7]. In the past few years gabapentin has been used in anesthetic practice as an analgesic in the perioperative setting and has been noticed to provide hemodynamic stability, so some studies have been conducted to test the effect of gabapentin by different doses on the stress response to laryngoscopy and intubation and yielded different results [8, 9]. This study was designed as a prospective randomized double-blinded
References
[1]
A. L. Kovac, “Controlling the hemodynamic response to laryngoscopy and endotracheal intubation,” Journal of Clinical Anesthesia, vol. 8, no. 1, pp. 63–79, 1996.
[2]
R. Robinson, M. White, P. McCann, J. Magner, and P. Eustace, “Effect of anaesthesia on intraocular blood flow,” British Journal of Ophthalmology, vol. 75, no. 2, pp. 92–93, 1991.
[3]
U. Bafna, V. K. Goyal, and A. Garg, “A comparison of different doses of gabapentin to attenuate the haemodynamic response to laryngoscopy and tracheal intubation in normotensive patients,” Journal of Anaesthesiology Clinical Pharmacology, vol. 27, no. 1, pp. 43–46, 2011.
[4]
A. A. Zimmerman, K. J. Funk, and J. L. Tidwell, “Propofol and alfentanil prevent the increase in intraocular pressure caused by succinylcholine and endotracheal intubation during a rapid sequence induction of anesthesia,” Anesthesia and Analgesia, vol. 83, no. 4, pp. 814–817, 1996.
[5]
M. Vucevic, G. M. Purdy, and F. R. Ellis, “Esmolol hydrochloride for management of the cardiovascular stress responses to laryngoscopy and tracheal intubation,” British Journal of Anaesthesia, vol. 68, no. 5, pp. 529–530, 1992.
[6]
A. M. Maguire, N. Kumar, J. L. Parker, D. J. Rowbotham, and J. P. Thompson, “Comparison of effects of remifentanil and alfentanil on cardiovascular response to tracheal intubation in hypertensive patients,” British Journal of Anaesthesia, vol. 86, no. 1, pp. 90–93, 2001.
[7]
A. Fassoulaki and P. Kaniaris, “Intranasal administration of nitroglycerine attenuates the pressor response to laryngoscopy and intubation of the trachea,” British Journal of Anaesthesia, vol. 55, no. 1, pp. 49–52, 1983.
[8]
V. K. F. Kong and M. G. Irwin, “Gabapentin: a multimodal perioperative drug?” British Journal of Anaesthesia, vol. 99, no. 6, pp. 775–786, 2007.
[9]
A. Fassoulaki, A. Melemeni, A. Paraskeva, and G. Petropoulos, “Gabapentin attenuates the pressor response to direct laryngoscopy and tracheal intubation,” British Journal of Anaesthesia, vol. 96, no. 6, pp. 769–773, 2006.
[10]
A. P. Hall, J. P. Thompson, N. A. P. Leslie, A. J. Fox, N. Kumar, and D. J. Rowbotham, “Comparison of different doses of remifentanil on the cardiovascular response to laryngoscopy and tracheal intubation,” British Journal of Anaesthesia, vol. 84, no. 1, pp. 100–102, 2000.
[11]
A. J. Cunningham and P. Barry, “Intraocular pressure-physiology and implications for anaesthetic management,” Canadian Anaesthetists Society Journal, vol. 33, no. 2, pp. 195–208, 1986.
[12]
F. N. Kaya, B. Yavascaoglu, M. Baykara, G. T. Altun, N. Gülhan, and F. Ata, “Effect of oral gabapentin on the intraocular pressure and haemodynamic responses induced by tracheal intubation,” Acta Anaesthesiologica Scandinavica, vol. 52, no. 8, pp. 1076–1080, 2008.
[13]
A. Turan, B. Karamanlio？lu, D. Memi？, P. Usar, Z. Pamuk？u, and M. Türe, “The analgesic effects of gabapentin after total abdominal hysterectomy,” Anesthesia and Analgesia, vol. 98, no. 5, pp. 1370–1373, 2004.
[14]
E. M. Tiippana, K. Hamunen, V. K. Kontinen, and E. Kalso, “Do surgical patients benefit from perioperative gabapentin/pregabalin? A systematic review of efficacy and safety,” Anesthesia and Analgesia, vol. 104, no. 6, pp. 1545–1556, 2007.
[15]
D. Memis, A. Turan, B. Karamanlioglu, S. Seker, and M. Ture, “Gabapentin reduces cardiovascular responses to laryngoscopy and tracheal intubation,” European Journal of Anaesthesiology, vol. 23, no. 8, pp. 686–690, 2006.
[16]
U. Bafna, V. K. Goyal, and A. Garg, “A comparison of different doses of gabapentin to attenuate the haemodynamic response to laryngoscopy and tracheal intubation in normotensive patients,” Journal of Anaesthesiology Clinical Pharmacology, vol. 27, no. 1, pp. 43–46, 2011.
[17]
K. Fink, D. J. Dooley, W. P. Meder et al., “Inhibition of neuronal Ca2+ influx by gabapentin and pregabalin in the human neocortex,” Neuropharmacology, vol. 42, no. 2, pp. 229–236, 2002.
[18]
C. Sarantopoulos, B. McCallum, W. M. Kwok, and Q. Hogan, “Gabapentin decreases membrane calcium currents in injured as well as in control mammalian primary afferent neurons,” Regional Anesthesia and Pain Medicine, vol. 27, no. 1, pp. 47–57, 2002.
[19]
M. H. Yoon and J. I. Choi, “Hemodynamic effects of gabapentin in rats,” Journal of Korean Medical Science, vol. 18, no. 4, pp. 478–482, 2003.
