The effect of nitrous oxide on intra-ocular pressure in healthy adults.
Many anaesthetic agents affect intra-ocular pressure, yet little is known about nitrous oxide and intra-ocular pressure. This study assessed the effect of nitrous oxide on intra-ocular pressure in 20 healthy adult volunteers. The intra-ocular pressure was measured at baseline, while breathing a 70:30 mix of nitrous oxide and oxygen for 12 min, and then while breathing room air for 15 min. A linear mixed effects model was used to assess change in intra-ocular pressure over time. There was no significant difference in intra-ocular pressure between baseline and during or after nitrous oxide inhalation. Several differences in intra-ocular pressure were noted between internal time-points: pressure increased by 2.4 mmHg between 3 and 6 min of breathing nitrous oxide (p=0.01); it increased by 1.4 mmHg between 3 and 9 min of breathing nitrous oxide (p=0.046); and it decreased by 2.2 mmHg between 6 min of breathing nitrous oxide and 15 min of breathing room air (p=0.035). This study indicates that nitrous oxide inhalation does not significantly change intra-ocular pressure from baseline values in a population of healthy adults.
Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, USA. lalwanik@ohsu.edu
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D000293:Adolescent; D000328:Adult; D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects*; D008297:Male; D009609:Nitrous Oxide / Q000494:pharmacology*; D055815:Young Adult
D018685:Anesthetics, Inhalation; D009609:Nitrous Oxide