N95 Respirator Masks- Impact on Pulmonary and Heart Rate Responses

For some, wearing a PFR N95 (respirator) mask, used for the care of patients on airborne precautions (TB, Pandemic Influenza), is uncomfortable. What impact does a PFR N95 mask have on physiology? Here is a publication that attempts to specifically answer this question.

Twenty young, healthy subjects exercised on a treadmill at a low-moderate (5.6 km/h) work rate while wearing 4 different models of N95 filtering facepiece respirators for 1 hour each, 2 models of which were equipped with exhalation valves, while being monitored for physiologic variables.

Compared with controls, respirator use was associated with mean 1 hour increases in heart rate (range, 5.7-10.6 beats per minute, P < .001), respiratory rate (range, 1.4-2.4 breaths per minute, P < .05), and transcutaneous carbon dioxide (range, 1.7-3.0 mm Hg, P < .001). No significant differences in oxygen saturation between controls and respirators were noted (P > .05).

These physiologic changes are statistically significant yet relatively small. As such, they may not be concerning from a clinical perspective. In other words, the use of a N95 mask should not have any deleterious health impact on a HCWs without cardiopulmonary disease who wear them for periods of less than an hour. 

Fortunately, the majority of HCWs are in the clear on the above criteria.