Intravenous hypertonic saline to reduce intraocular pressure: the effect of splitting the bolus

Abstract

To compare intraocular pressure (IOP) and pain after a single versus split bolus of intravenous hypertonic saline (IVHTS). In a prospective, randomized, interventional trial, we enrolled patients with an IOP of 22-34 mmHg. Twenty patients in Group 1 received IVHTS as a single bolus of 1 mmol/kg 23.4% sodium chloride, and 13 patients in Group 2 received two boli of 0.5 mmol/kg separated by 10 min. They graded pain at the infusion site. We measured IOP, heart rate and blood pressure before and 10 and 20 min after IVHTS. Eighteen patients (90%) in Group 1 felt pain (median, 6.5; range, 0-10). In Group 2, 11 patients (85%) felt pain after the first bolus (median, 6.0; range, 0-8) and 12 (92%) after the second one (median, 8; range, 0-10). We found no difference in pain grade between the groups after their first bolus (p = 0.33) or between the first bolus of Group 1 and the second bolus of Group 2 (p = 0.47). The median IOP reduction in Group 1 was 6.5 mmHg (range, 2-16) at 10 min and 7.0 mmHg (range, 4-16) at 20 min (p < 0.001 for both). In Group 2, the corresponding reductions after the second bolus were 9.0 mmHg (range, 4-10; p = 0.002) and 8.0 mmHg (range, 6-11; p = 0.002). The IOP reduction at 10 and 20 min was comparable between groups (p = 0.094 and p = 0.41, respectively). Splitting the bolus did not reduce pain associated with IVHTS. Single bolus is consequently recommended.