ABSTRACT
OBJECTIVE: The objective of the current study was to determine gas exchange abnormalities and physiological changes among healthcare workers during a 4-hour emergency department (ED) shift while wearing the N95 respirator. METHODS: Single-center prospective observational study. Comparisons of paired measurements were performed using a non-parametric Wilcoxon matched-pairs signed-rank test. Results: Forty-one subjects were included. Prolonged N95 respirator use was associated with a significant decline in plasma pH (7.35 mmHg vs 7.34 mmHg, P = 0.02), PvO 2 (23.2 mmHg vs 18.6 mmHg, P < 0.001) and a concurrent increase in EtCO 2 (32.5 mmHg vs 38.5 mmHg, P < 0.0001). PvCO 2 and bicarbonate levels did not differ. No significant change was observed for heart rate or oxygen saturation. CONCLUSION: Using an N95 respirator for prolonged periods by healthcare professionals may provoke changes in gas exchange. The clinical significance of these changes remains to be determined.