Does Nitrous Oxide Affect the Corneal Endothelium? Prospective Randomized Study in Pediatric Patients

Abstract

In this study, we aimed to evaluate the mean changes in the corneal endothelial cells and pachymetry values of patients who underwent general anesthesia with sevoflurane with N2O or O2. Materials and Methods: Forty eyes of 40 patients who had extraocular surgery under general anesthesia were included in this prospective study. The patients were divided into two groups as the O2 and N2O groups, for which %50 O2 (total flow rate; 2 L/min in O2-air mixture) and %50 O2 (total flow rate; 2 L/min in O2-N2O mixture) were used, respectively. The duration of the surgery was recorded. The CD (cell density), CV (cell variation), Hex (hexagonality rate) and pachymetric specular microscopy results were evaluated before surgery, and at the first and fourth weeks after surgery. Results: The surgical duration and demographic data of the groups were similar, and there was no statistically significant difference between the two groups. The value of CV was 26±2 cell/mm2 for the O2 group and 30 cell/mm2 for the N2O group at the first week. There was a statistically significant increase in the N2O group values, compared to the preoperative values (p=0.008). The Hex value was 52±10% for the O2 group and 62±11% for the N2O group at the first postoperative week, and there was a statistically significant increase in the N2O group values in comparison to the preoperative values (p=0.007). There was no significant difference between the two groups in terms of CD, CV, Hex, and pachymetry at other times. Discussion and Conclusion: Statistically significant change was observed at the first postoperative week in the corneal variation and hexagonality rate values of the pediatric patients who underwent general anesthesia with nitrous oxide. More studies need to be done for further assessments.