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

CONTEXT: Elevation of intraocular pressure (IOP) is an inherent and inadvertent association with the use of succinylcholine and alpha(2) agonists can be used to obtund this effect. AIMS: The study was aimed to assess the efficacy of intravenous dexmedetomidine and clonidine premedication in attenuating rise in IOP during laryngoscopy and intubation following administration of succinylcholine. SETTINGS AND DESIGN: This prospective, observational study was conducted in 40 patients aged 20–60 years undergoing non ophthalmic surgical procedures. SUBJECTS AND METHODS: For patients in Group D, dexmedetomidine 0.4 mcg/kg and in Group C clonidine 1 μg/kg over 10 min was administered before induction. All patients were induced with propofol. Laryngoscopy and intubation were performed 1 min after administration of succinylcholine 2 mg/kg. STATISTICAL ANALYSIS USED: Mann–Whitney, Chi-square and Wilcoxon tests. RESULTS: Mean baseline IOP of both groups were comparable (15.4 ± 2.6 vs. 14.7 ± 2.3). Following premedication and induction, IOP decreased in both groups and the reduction was significantly more in Group D. Following administration of succinylcholine and 1 min after intubation IOP raised and exceeded the baseline value in Group C (16.0 ± 1.6 and 18.6 ± 2.2). Though there was an increase in IOP in Group D (12.0 ± 1.9 and 14.0 ± 2.1), it did not reach up to baseline values. Then there was a gradual reduction in IOP in both groups at 3, 5, and 10 min and Group D continued to have a significantly low IOP than Group C up to 10 min. CONCLUSIONS: Dexmedetomidine 0.4 μg/kg resulted in a reduction of IOP and blunted the increase in IOP, which followed administration of succinylcholine, laryngoscopy, and intubation. Though clonidine 1 μg/kg reduced IOP, it did not prevent rise in IOP following succinylcholine, laryngoscopy, and intubation.