Changes in intraocular pressure following administration of suxamethonium and endotracheal intubation: Influence of dexmedetomidine premedication

Abstract

Background:Use of suxamethonium is associated with an increase in intraocular pressure (IOP) and may be harmful for patients with penetrating eye injuries. The purpose of our study was to observe the efficacy of dexmedetomidine for prevention of rise in IOP associated with the administration of suxamethonium and endotracheal intubation.Methods:Sixty-six American Society of Anaesthesiologists I or II patients undergoing general anaesthesia for non-ophthalmic surgery were included in this randomized, prospective, clinical study. Patients were allocated into three groups to receive 0.4 μg/kg dexmedetomidine (group D4), 0.6 μg/kg dexmedetomidine (group D6) or normal saline (group C) over a period of 10 min before induction. IOP, heart rate and mean arterial pressure were recorded before and after the premedication, after induction, after suxamethonium injection and after endotracheal intubation.Results:Fall in IOP was observed following administration of dexmedetomidine. IOP increased in all three groups after suxamethonium injection and endotracheal intubation, but it never crossed the baseline value in group D4 as well as in group D6. Fall in mean arterial pressure was noticed after dexmedetomidine infusion, especially in the D6 group.Conclusion:Dexmedetomidine (0.6 μg/kg as well as 0.4 μg/kg body weight) effectively prevents rise of IOP associated with administration of suxamethonium and endotracheal intubation. However, dexmedetomidine 0.6 μg/kg may cause significant hypotension. Thus, dexmedetomidine 0.4 μg/kg may be preferred for prevention of rise in IOP.

Intravenous dexmedetomidine versus clonidine for prolongation of bupivacaine spinal anesthesia and analgesia: A randomized double-blind study

“…[1011121314] Dexmedetomidine is a highly selective α 2 -adrenoreceptor agonist with α 2 :α 1 binding ratio of 1620:1 compared to 220:1 for clonidine. [2021]…”

“…[8] Analgesic and sedative properties were found when intrathecal, epidural or intravenous dexmedetomidine was used as an adjuvant in previous studies. [91011121314] There is paucity of studies which have compared the dose equivalence of these two drugs, however various studies have established that the dose of clonidine is 1.5-2 times higher than the dose of dexmedetomidine. [15161718]…”

Efficacy of alpha 2 agonists in obtunding rise in intraocular pressure after succinylcholine and that following laryngoscopy and intubation

“…But dexmedetomidine 0.4 μg/kg was recommended for this purpose as this dose did not result in significant hypotension. [ 11 ] But another study has shown that even 0.6 μg/kg given IV over 10 min, 10 min before induction, effectively prevented the rise in IOP associated with suxamethonium, laryngoscopy, and intubation with stable hemodynamics. [ 12 ]…”

Effects of Systemic Administration of Dexmedetomidine on Intraocular Pressure and Ocular Perfusion Pressure during Laparoscopic Surgery in a Steep Trendelenburg Position: Prospective, Randomized, Double-Blinded Study

“…There have been few studies on attenuation of the increase in IOP and maintenance of OPP during surgery in a steep Trendelenburg position. Topical application of brimonidine, an α-2 agonist, before general anesthesia resulted in a slight decrease in the intraoperative time-weighted average IOP, by 4 mmHg, and a bolus injection of gabapentin or dexmedetomidine as a premedication before tracheal intubation alleviated the increase in IOP ( 5 6 7 ). The most important factor that causes increased IOP in a steep Trendelenburg position is increased episcleral venous pressure ( 8 ).…”