Abstract
Purpose :
To investigate the effects in intraocular pressure (IOP) measurements in non glaucomatous pediatric patients undergoing general anesthesia with sevoflurane (SVF) versus nitrous oxide (NO).
Methods :
Patients between 1 and 12 years old undergoing general anesthesia for strabismus surgery were enrolled. Patients with contraindications for nitrous oxide induction, glaucoma, previous ocular surgeries or obstructive sleep apnea were excluded. All subjects received preoperative oral midazolam 30 minutes before induction of general anesthesia. Patients were randomized to two groups: group 1 (SVF) and group 2 (NO). Tetracaine 0.25 % was placed in the right eye and 3 IOP measurements at 30 second intervals were taken using a tonopen. The nitrous oxide group received sevoflurane and underwent a second set of 3 IOP measurements. The rates of change in IOP from induction to subsequent measurements were calculated and compared between groups.
Results :
A total of 45 patients were included and randomized (25 in group 1 (SVF) and 20 in group 2 (NO)).
There were no statistical significant differences between group SVF and group NO in age (85.41±41.30 and 64.82±32.65 months, p=0.08), weight (46.81 ± 31.72 and 41.32 ± 32.61 Kg, p=0.59) and height (38.87 ± 27.74 and 41.33 ± 20.35, p=0.75). Eleven (44%) and 12 (60%) were females in group SVF and NO respectively (p=0.29).
The mean IOP in the SVF group at 30 seconds post-induction did not differ from the mean IOP of the NO group (14.8 ± 3.12 mmHg and 15.17 ± 2.28 mmHg respectively, p=0.68). The IOP measurements at 60 seconds did not differ between SVF and NO (13.92 ± 2.68 mmHg and 14.67 ± 2.89, p=0.39). In the NO group, after introduction of SVF in the same patients, there were no differences in IOP at 30 seconds with NO and SVF (15.17 ± 2.82 mmHg and 14.17 ± 2.91 mmHg, p=0.21) and at 60 seconds with NO and SVF (14.94 ± 2.72 and 14.76 ± 3.05, p=0.82).
There were no differences between the rates of change in IOP from induction to 30 seconds (-0.02 ± 0.21 for SVF and 0.07 ± 0.22 for NO, p=018), from induction to 60 seconds (-0.08 ± 0.19 for SVF and 0.02 ± 0.18 for NO, p=0.09) and from 30 to 60 seconds (-0.04 ± 0.17 for SVF and -0.03 ± 0.15, p=0.85).
Conclusions :
IOP measurements under sevoflurane and under nitrous oxide are similar in a non glaucomatous pediatric population.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.