Effect of Wearing N95 Respirators vs. Triple Layer Surgical Masks on Peripheral Oxygen Saturation in Surgical Patients During the Peri-Operative Period: A Prospective Observational Study

Objectives During the COVID-19 pandemic, universal mask use became mandatory for surgical patients to reduce viral transmission. While N95 respirators offer superior filtration, concerns persist about their potential to impair oxygenation, including increased airflow resistance and rebreathing. In patients undergoing surgery under regional anaesthesia, who remain conscious and breathe spontaneously, any reduction in oxygen saturation may necessitate supplemental oxygen, thereby influencing perioperative safety and infection-control practices. Therefore, this study evaluated the effect of wearing N95 respirators versus triple-layer surgical masks on peripheral oxygen saturation (SpO₂) and the requirement for supplemental oxygen among patients undergoing elective surgery under regional anaesthesia. Material and Methods This prospective observational study included 100 ASA I-II patients undergoing elective surgery under regional anaesthesia. Patients were allocated to Group A (triple-layer surgical mask, n = 50) or Group B (N95 respirator, n = 50). Peripheral oxygen saturation was recorded preoperatively and at 30, 60, 90, and 120 min intraoperatively and postoperatively. Supplemental oxygen was planned if SpO₂ fell to <94%, in accordance with institutional protocol. Data were analysed using SPSS version 22, with p <0.05 considered statistically significant. Results Baseline demographic and clinical characteristics were comparable between groups ( p >0.05). Mean SpO₂ values declined mildly and progressively over time in both groups; however, no statistically significant intergroup differences were observed at any time point. Importantly, no patient in either group developed clinically significant desaturation (SpO₂ <94%) or required supplemental oxygen during the perioperative or postoperative period; therefore, practical challenges related to oxygen delivery beneath an N95 respirator could not be evaluated. Conclusion Perioperative use of either N95 respirators or triple-layer surgical masks does not result in clinically significant oxygen desaturation or increased need for supplemental oxygen in low-risk surgical patients undergoing regional anaesthesia.