Blood Oxygen Saturation and Prolong Face Mask Use in Healthcare Workers in Port Harcourt Nigeria, in the COVID 19 Pandemic Era

Introduction: The World Health Organization (WHO) declared the Corona Virus disease 2019 (COVID 19) caused by Severe Acute Respiratory Syndrome Corona Virus 2(SARS-Cov-2) a pandemic in March 2020. Aerosolized infected droplets and airborne transmission have been proffered as means of transmission, and as such, the use of face masks has been advocated as a key strategy in the disease control - more so in health care workers who are at the fore-front of the pandemic. However, the use of face masks for prolonged periods has raised concerns on possible adverse effect on blood oxygenation, potentially affecting compliance.

Aim: To monitor the blood oxygen saturation (SPO2) of healthcare workers wearing facemasks for 8-hours in the course of their duties, in a tertiary institution in Port Harcourt, Nigeria.

Methods: A cross-sectional study of healthcare workers wearing face masks while working. Baseline pre-face mask use SPO2 was done at Zero hour. Subsequently, serial hourly SPO2 were recorded until completion at the eight-hour. The respiratory and pulse rates were recorded at zero and eight hours. The results were analysed and presented as Means, Medians, Graphs and Tables.

Results: There were 220 participants with more females 147(66.8%). Doctors constituted 133(60.5%). The baseline pre-facemask Mean SPO2 was 97.9% ±0.75. The Median SPO2 was 98%. The overall SPO2 trend across 8 hours was maintained above 97.7% for all participants. Age was significantly associated with differences in SPO2 trend (P=0.032) (P=006); while Type of Facemask use had no significant effect on mean SPO2 trend (p=1.00). There was no significant difference in respiratory and pulse rates pre and post 8-hours face mask use.

Conclusion: Healthcare workers using facemasks continuously over eight hours maintained normal SPO2 level, with physiologic adaptation of respiratory and pulse rates.