Table 2 Effects of positive pressure (NRB vs Helmet-CPAP)
Group | COVID-19 patients (N = 28) | Healthy controls (N = 7) | ||||
|---|---|---|---|---|---|---|
Respiratory support | NRB | Helmet-CPAP | p | NRB | Helmet-CPAP | p |
Respiratory effort, cmH2O | 5.0 ± 3.7 | 8.3 ± 3.9 |  < 0.01 | 2.7 ± 0.8 | 6.7 ± 0.9 | 0.02 |
Helmet’s pressure drop, cmH2O | 0 ± 0 | −3.1 ± 1.0 |  < 0.01 | 0 ± 0 | -2.5 ± 0.6 |  < 0.01 |
Dynamic stress, cmH2O | 5.0 ± 3.8 | 4.9 ± 3.8 | 0.97 | 2.7 ± 0.8 | 4.2 ± 0.5 | 0.03 |
Static stress, cmH2O | 0 ± 0 | 0.9 ± 2.4 | 0.07 | 0 ± 0 | 1.5 ± 2.0 | 0.08 |
Total stress, cmH2O | 5.0 ± 3.8 | 5.7 ± 5.0 | 0.09 | 2.7 ± 0.8 | 5.7 ± 2.0 | 0.02 |
Respiratory Rate, bpm | 25 ± 5 | 25 ± 5 | 0.33 | 14 ± 2 | 14 ± 5 | 0.93 |
Work of breathing Scale (WOB) | 2 ± 1 | 3 ± 1 | 0.37 | 1 ± 0 | 2 ± 0 |  < 0.01 |
Borg dyspnea scale | 0 ± 0 | 0 ± 0 | 0.16 | 0 ± 0 | 0 ± 0 |  > 0.99 |
PaO2, mmHg | 107 ± 55 | 156 ± 57a |  < 0.01 | / | / | / |
SaO2, % | 95 ± 6 | 96 ± 4 |  < 0.01 | / | / | / |
PaCO2, mmHg | 36 ± 4 | 36 ± 3 | 0.23 | / | / | / |
pH | 7.46 ± 0.02 | 7.46 ± 0.03 | 0.19 | / | / | / |
Systolic blood pressure, mmHg | 136 ± 22 | 134 ± 19 | 0.54 | 116 ± 15 | 129 ± 11 | 0.06 |
Diastolic blood pressure, mmHg | 77 ± 15 | 79 ± 12 | 0.50 | 70 ± 8 | 87 ± 10 | 0.02 |
Heart Rate, bpm | 75 ± 14 | 74 ± 12 | 0.85 | 73 ± 9 | 75 ± 14 | 0.83 |
Cardiac index, L/min/m2 | 3.2 ± 0.7 | 2.9 ± 0.5 | 0.02 | 3.4 ± 0.6 | 3.2 ± 0.5 | 0.09 |
Oxygen delivery, ml/min/m2a | 577 ± 125 | 555 ± 115 | 0.18 | / | / | / |