Respiratory consequences of N95-type Mask usage in pregnant healthcare workers—a controlled clinical study

Tong, Pearl Shuang Ye; Kale, Anita Sugam; Ng, Kailyn; Loke, Amelia Peiwen; Choolani, Mahesh Arjandas; Lim, Chin Leong; Chan, Yiong Huak; Chong, Yap Seng; Tambyah, Paul Anantharajah; Yong, Eu-Leong

The fine adjustments were made to the treadmill speed every 3 min to maintain energy expenditure at 3 MET. Similar treadmill speed profile was repeated in the second exercise cycle for each subject. For both Control and N95 cycles, respiratory parameters were measured during an initial 10-minute rest period, followed by a 15-minute exercise period, and subsequently a 25-minute rest period. There was a 30-minute break between control and N95 cycles. Prior to the N95 cycle, an additional 15-minute conditioning period was allowed to enable patient to adapt Fig. 1 Determination of average work intensity of Health care workers: In phase I pregnant subjects performed simulated patient care activities while breathing through a tight fitting mask with a pneumotachometer. Oxygen content was sampled at every breath and measured with a portable telemetric metabolic cart to N95-respirator conditions. The subjects breathed through the N95 mask materials continuously throughout the N95 cycles (Fig. 3) .