Wearing a surgical mask during chemotherapy session is safe.

Surgical masks(SM) have become essential to our daily lives with the COVID-19 pandemic. It is recommended as the cheapest, most effective preventive method. The effects of SM on patients receiving chemotherapy are unknown. Our study aimed to investigate the effects of SM on oxygenation and CO2 retention in cancer patients receiving chemotherapy and to examine its possible clinical consequences. Patients diagnosed with cancer and receiving chemotherapy were included in the study. Venous blood gas, SO2 by pulse oximeter, and vital signs were recorded before and after treatment. Acute toxicities encountered during treatment were recorded. One hundred twenty-six patients with a median age of 60 (33-85) were evaluated in the study. The comparison of pre-post treatment parameters showed statistically significant changes in Ph (7.37 vs. 7.35, p < 0.01), pCO2 (44.2 vs. 45.8, p = 0.049), HCO3 (25.7 vs. 25.3, p = 0.003), SpO2 (97.0 vs. 96.0, p = 0.08), fever (36.4 vs. 36.3, p = 0.023). All the changes were clinically insignificant and in normal ranges. Chemotherapy-related acute toxicity was noted in 4 (3.2%) of the patients. Lung morbidity, cancer type, lung metastasis status, treatment applied, duration of therapy, and acute toxicity do not affect the current parameters. In our study, it was shown that constantly wearing a SM in patients receiving chemotherapy caused CO2 retention and a tendency to hypoxemia. However, the current changes were clinically insignificant and within the normal range. Surgical masks can be used safely in cancer patients receiving systemic treatment.