Table 1.
Study variables during use of an elastomeric air-purifying respirator at 1.7-mph and 2.5-mph work rates over a 1-hour period
| Variables | 1 min | 15 min | 30 min | 45 min | 60 min |
|---|---|---|---|---|---|
| 1.7 mph | |||||
| Respirator dead space O2 [%] | 17.74 (±0.55) | 17.99 (±0.51) | 17.67 (±0.54) | 17.84 (±0.26) | 17.90 (±0.37) |
| Respirator dead space CO2 [%] | 2.47 (±0.50) | 2.47 (±0.42) | 2.65 (±0.52) | 2.49 (±0.33) | 2.49 (±0.35) |
| SaO2 [%] | 98.56 (±0.71) | 98.59 (±0.77) | 98.49 (±0.66) | 98.47 (±0.67) | 98.47 (±0.57) |
| tcPCO2 [mm Hg] | 40.83 (±3.87) | 44.56 (±5.24) | 44.71 (±5.15) | 44.84 (±5.78) | 44.95 (±5.96) |
| fB | 21.71 (±5.36) | 22.83 (±5.09) | 22.33 (±4.43) | 23.61 (±4.12) | 23.42 (±3.13) |
| VT [mL] | 904 (±227) | 927 (±217) | 920 (±275) | 882 (±264) | 901 (±198) |
| VE [L] | 18.75 (±5.34) | 20.67 (±4.70) | 19.95 (±5.34) | 20.32 (±5.32) | 21.08 (±5.52) |
| HR | 92.60 (±6.27) | 95.58 (±8.04) | 96.47 (±8.82) | 95.55 (±9.15) | 96.82 (±8.67) |
| 2.5 mph | |||||
| Respirator dead space O2 [%] | 17.46 (±0.68) | 17.87 (±0.46) | 17.95 (±0.82) | 17.85 (±0.79) | 17.89 (±0.60) |
| Respirator dead space CO2 [%] | 2.47 (±0.45) | 2.47 (±0.44) | 2.47 (±0.34) | 2.49 (±0.40) | 2.43 (±0.36) |
| SaO2 [%] | 98.43 (±0.96) | 98.53 (±0.87) | 98.53 (±0.80) | 98.38 (±0.91) | 98.33 (±0.49) |
| tcPCO2 [mm Hg] | 40.31 (±4.17) | 43.98 (±7.01) | 43.40 (±6.80) | 43.41 (±7.70) | 43.89 (±8.20) |
| fB | 23.35 (±5.48) | 23.46 (±5.88) | 23.84 (±5.26) | 23.14 (±4.68) | 23.90 (±4.14) |
| VT [mL] | 925 (±231) | 988 (±244) | 958 (±244) | 921 (±223) | 941 (±218) |
| VE [L] | 21.08 (±6.16) | 21.09 (±6.88) | 22.72 (±7.54) | 22.69 (±6.21) | 21.10 (±5.21) |
| HR | 96.82 (±8.67) | 95.07 (±10.35) | 100.02 (±8.77) | 101.07 (±9.01) | 101.06 (±9.14) |
NOTE. Values are mean (±standard deviation). 1.7 mph = 2.74 km/h and 2.5 mph = 4.03 km/h.
fb, breathing rate in breaths per minute; HR, heart rate; min, minute; SaO2, percentage oxygen saturation; tcPCO2, transcutaneous partial pressure of carbon dioxide in millimeters of mercury; VE [L], minute ventilation in liters; VT [mL], tidal volume in milliliters.