The Influence of Two Different Doses of Magnesium Sulfate on Intraocular Pressure Variations after Injection of Succinylcholine and Endotracheal Intubation: A Prospective, Randomized, Parallel Three-Arm, Double-blind, Placebo-controlled Clinical Trial.

BACKGROUND

The use of succinylcholine for rapid sequence induction in patients with open globe injuries may be detrimental to the eye.

AIM: The aim of this study is to determine if the premedication with magnesium sulfate (MgSO4) could attenuate the increase in intraocular pressure (IOP) associated with succinylcholine injection and intubation.

SETTING

Operation theaters in a tertiary care University Hospital between December 2014 and July 215.

DESIGN

This was a prospective, randomized, parallel three-arm, double-blind, placebo-controlled clinical trial.

PARTICIPANTS

One hundred and thirteen patients' physical status ASA Classes I and II underwent elective cataract surgery under general anesthesia.

PATIENTS AND

METHODS

These patients allocated into three groups: Group C (control group) received 100 ml normal saline, Group M1 received 30 mg/kg MgSO4 in 100 ml normal saline, and Group M2 received 50 mg/kg MgSO4 in 100 ml normal saline. IOP, mean arterial pressure (MAP), and heart rate (HR) reported at 5-time points related to study drug administration. In addition, any adverse effects related to MgSO4 were recorded. Intragroup and between-groups differences were examined by analysis of variance test.

RESULTS

We noticed a significant decrease in IOP in M1 (n = 38) and M2 (n = 37) groups as compared with C group (n = 38) after study drugs infusion, 2 and 5 min after intubation, P < 0.001. While the difference between M1 and M2 groups was insignificant, P = 0.296 and P = 0.647, respectively. There was a significant decrease in MAP and HR in M1 and M2 groups as compared with C group 2 and 5 min after intubation, P = 0.01. While the difference between M1 and M2 groups was insignificant, P = 1.

CONCLUSION

MgSO4 30 mg/kg as well as 50 mg/kg effectively prevented the rise in IOP, MAP, and HR associated with rapid sequence induction by succinylcholine and endotracheal intubation.