Table 3.
Ventilation variables at the three different levels of assist.
| Variable | PAV + Assist Level |
||
|---|---|---|---|
| 20 % | 50 % | 80 % | |
| VT (ml/kg) | 7 ± 2 | 7 ± 2 | 8 ± 2## |
| RR br/min | 28 ± 6** | 27 ± 6^ | 26 ± 6### |
| PmusPVI (cmH2O) | 17 ± 8*** | 15 ± 10^^ | 14 ± 10### |
| dP/dt (cmH2O/sec) | 20 ± 13*** | 18 ± 15^^ | 16 ± 9### |
| ElastancePVI (cmH2O/L) | 22 ± 11* | 23 ± 12^^ | 26 ± 16### |
| ResistancePVI (cm2O/L/sec) | 10 ± 7 | 10 ± 7 | 11 ± 8## |
| PEEPi (cmH2O) | 2 ± 2 | 2 ± 2 | 2 ± 2 |
Values represent means ± SD and differences were calculated using repeated-measures analysis of variance with Tukey post test. P-values: *<0.05, **<0.01, ***<0.001 for PAV20 % vs. PAV50 %; ^<0.05, ^^<0.01, ^^^<0.001 for PAV50 % vs. PAV80 %; ##<0.01, ###<0.001 for PAV20 % vs. PAV80 %. PAV: Proportional assist ventilation, VT: Tidal volume, RR: Respiratory rate, PmusPVI Inspiratory muscle effort calculated by PVI, dP/dt Respiratory drive estimated using the PmusPVI to neural inspiratory time ratio.