Table 1.
Results obtained during three periods of 1 hour of controlled mechanical ventilation in 13 COPD patients during the first 24 after intubation
| First period air-oxygen |
Second period helium-oxygen |
Third period air-oxygen |
|
|---|---|---|---|
| Pmax, cmH2O | 35.4 ± 6.7 | 31.6 ± 7.6* | 34.9 ± 6.9 |
| Ppl, cmH2O | 22.3 ± 4.9 | 20.9 ± 5.5* | 21.7 ± 4.7 |
| P1 - Ppl, cmH2O | 4.5 ± 2.2 | 4.7 ± 1.7 | 4.6 ± 2.3 |
| statPEEPi, cmH2O | 11.7 ± 4.0 | 10.3 ± 4.3* | 10.9 ± 3.8 |
| dynPEEPi, cmH2O | 3.1 ± 1.0 | 2.7 ± 0.7* | 3.0 ± 0.8 |
| PaO2, mmHg | 77 ± 12 | 79 ± 15 | 80 ± 12 |
| PaCO2, mmHg | 59 ± 12 | 62 ± 14 | 61 ± 14 |
| VD/VT, % | 71 ± 6 | 69 ± 5 | 69 ± 7 |
Ppl = plateau pressure measured after an endinspiratory pause of 5 sec; P1 - Ppl = difference between the pressure (P1) measured after the rapid initial fall in pressure during an inspiratory pause, at the first point of zero flow, and Ppl; statPEEPi = static intrinsic PEEP; dynPEEPi = dynamic intrinsic PEEP; VD/VT = physiological dead-space
Results are expressed as mean ± SD
*Indicates a significant difference at the 0.05 level.