DEXMEDETOMIDINE: AS NOVEL PREMEDICATION

Laryngoscopy and tracheal intubation causes intense autonomic reflex responses such as tachycardia, hypertension and a rise in intraocular pressure (IOP). Rise in IOP is further compounded by the use of succinylcholine. Various drugs used to attenuate the rise in IOP are pre- treatment with non-depolarizing muscle relaxant, lignocaine, narcotics, nifedipine and nitroglycerine, but none is found to abolish it completely. To obtain haemodynamic response lignicaine, opiods, nitroprusside, nitroglycerine, vearpamil, nifedipine, esmolol, clonidine etc. have been used. AIMS AND OBJECTIVES: We investigated whether dexmedetomidine an α2 agonist could attenuate the rise in IOP after succinylcholine and intubation. Simultaneously, its effect on attenuation of haemodynamic response (Heart rate and MAP) to laryngoscopy and intubation was also evaluated. MATERIALS AND METHODS: Eighty patients without pre-existing eye disease undergoing general anesthesia was randomly premedicated by iv dexmedetomidine 0.6µg or saline. Heart rate (HR), mean arterial pressure (MAP), IOP (using Schioetz tonometer) was measured before, after the premedication, after thiopental, after succinylcholine, immediately after intubation and then every minute for 3 minutes. Statistical Analysis: descriptive and inferential statics using chi-square test, z- test and Wilcoxon sign rank test was done. Software used in the analysis was SPSS 17.0 version and Graph Pad Prism 5.0. Data was reported as mean value ± SD & p-value < 0.05 was considered as level of significance. RESULTS: Succinylcholine and intubation increased IOP in both the groups. However, in the dexmedetomidine group, it was not significantly different from baseline values (z value=0. 93, p=0. 358) and was significantly lower than in the control group (z =6. 644, p=0. 000). After intubation the MAP in the control group (z=17. 4, p=0. 000) was higher than that in the dexmedetomidine group (z=8, p=0. 000) and exceeded the baseline value (p<0.05). The heart rate also showed a less fluctuation in the dexmedetomidine group than in the control group. (z=7. 73, p<0.05 after succinylcholine and z=9. 22, p<0.05 after intubation) CONCLUSION: IV dexmedetomidine 0.6µg premedication is advantageous as it is found to be effective in reducing the rise in IOP. It is also beneficial in attenuating the haemodynamic response of succinylcholine, laryngoscopy and intubation to prevent its consequences.

[1]  H. Türe,et al.  Dexmedetomidine as an adjunct to anesthetic induction to attenuate hemodynamic response to endotracheal intubation in patients undergoing fast-track CABG. , 2010, Annals of cardiac anaesthesia.

[2]  J. Alqahtani,et al.  Effect of dexmedetomidine premedication on the intraocular pressure changes after succinylcholine and intubation. , 2008, British journal of anaesthesia.

[3]  M. Klimek,et al.  Reversal of rocuronium-induced (1.2 mg kg-1) profound neuromuscular block by accidental high dose of sugammadex (40 mg kg-1). , 2007, British journal of anaesthesia.

[4]  S. Wong,et al.  Dexmedetomidine infusion as a supplement to isoflurane anaesthesia for vitreoretinal surgery. , 2007, British journal of anaesthesia.

[5]  J. Dasta,et al.  Dexmedetomidine: An Updated Review , 2007, The Annals of pharmacotherapy.

[6]  E. Chidiac,et al.  Succinylcholine and the open eye. , 2006, Ophthalmology clinics of North America.

[7]  S. Gayer.  Rethinking anaesthesia strategies for patients with traumatic eye injuries: Alternatives to general anaesthesia , 2006 .

[8]  M. Yildiz,et al.  Effect of Dexmedetomidine on Haemodynamic Responses to Laryngoscopy and Intubation , 2006, Drugs in R&D.

[9]  G. Alessio,et al.  Combined topical anesthesia and sedation for open-globe injuries in selected patients. , 2003, Ophthalmology.

[10]  G. Katsikis,et al.  Sufentanil or clonidine for blunting the increase in intraocular pressure during rapid-sequence induction , 2002, European journal of anaesthesiology.

[11]  P. Talke,et al.  The Hemodynamic and Adrenergic Effects of Perioperative Dexmedetomidine Infusion after Vascular Surgery , 2000 .

[12]  S. de Lange,et al.  Effects of a single pre‐operative dexmedetomidine dose on isoflurane requirements and peri‐operative haemodynamic stability , 1997, Anaesthesia.

[13]  H. Scheinin,et al.  Dexmedetomidine as intramuscular premedication for day‐case cataract surgery , 1994, Anaesthesia.

[14]  H. Scheinin,et al.  Dexmedetomidine as intramuscular premedication in outpatient cataract surgery , 1993, Anaesthesia.

[15]  E. Martin,et al.  Oral clonidine premedication prevents the rise in intraocular pressure following succinylcholine administration. , 1993, German journal of ophthalmology.

[16]  M. Scheinin,et al.  Dexmedetomidine reduces intraocular pressure, intubation responses and anaesthetic requirements in patients undergoing ophthalmic surgery. , 1992, British journal of anaesthesia.

[17]  A. Urtti,et al.  Dexmedetomidine-induced ocular hypotension in rabbits with normal or elevated intraocular pressures. , 1992, Investigative ophthalmology & visual science.

[18]  S. Bose,et al.  Oral clonidine premedication for elderly patients undergoing intraocular surgery * , 1992, Acta anaesthesiologica Scandinavica.

[19]  M. Scheinin,et al.  Dexmedetomidine attenuates sympathoadrenal responses to tracheal intubation and reduces the need for thiopentone and peroperative fentanyl. , 1992, British journal of anaesthesia.

[20]  L. Quintin,et al.  Anesthesia for Ophthalmic Surgery in the Elderly: The Effects of Clonidine on Intraocular Pressure, Perioperative Hemodynamics, and Anesthetic Requirement , 1988, Anesthesiology.

[21]  J. H. Cook.  The effect of suxamethonium on intraocular pressure , 1981, Anaesthesia.

[22]  K. Barnett,et al.  Anæsthesia and intraocular pressure , 1966 .

[23]  K. Barnett,et al.  Anaesthesia and intraocular pressure. , 1966, Anaesthesia.