Reusable elastomeric air-purifying respirators: Physiologic impact on health care workers

BACKGROUND: Elastomeric air-purifying respirators offer the benefit of reusability, but their physiological impact on health care workers is unknown. METHODS: Ten health care workers exercised at 2 health care-associated work rates wearing an elastomeric air-purifying respirator. Mixed inhalation/exhalation respirator dead space gases (oxygen, carbon dioxide) were sampled, and physiological parameters were monitored (heart rate, breathing rate, tidal volume, minute volume, oxygen saturation, transcutaneous carbon dioxide). Numerical rating scales were used to evaluate comfort and exertion. RESULTS: Compared with controls (no respirator), significant decreases in the breathing rate at both work rates (P < .05) and increases in tidal volume at the lower work rate (P < .01) were noted with respirator use. Approximately half the subjects had transcutaneous carbon dioxide levels above the upper limit of normal after 1 hour of use. Although well tolerated, comfort was negatively impacted by elastomeric air-purifying respirators wear. CONCLUSION: Reusable elastomeric air-purifying respirators impose little additional physiological burden over the course of 1 hour at usual health care work rates. However, the potential for carbon dioxide retention in a significant proportion of users exists and requires further investigation.