Table 2.
Breathing pattern and ventilator functioning in automatic tube compensation and low-pressure support periods during spontaneous breathing trial
| ATC | Low PS | P value | |
|---|---|---|---|
| Tidal volume (l) | 0.35 (0.30; 0.45) | 0.35 (0.32; 0.50) | 0.22 |
| Tidal volume (ml/kg predicted body weight) | 5.3 (4.5; 6.3) | 5.6 (4.7; 7.7) | 0.21 |
| Respiratory rate (breaths/min) | 27 (21; 33) | 25 (21; 28) | 0.007 |
| Minute ventilation (l/min) | 9.5 (7.4; 11.7) | 9.4 (8.3; 10.4) | 0.22 |
| Respiratory rate/tidal volume ratio (breaths/min/l) | 77 (52; 105) | 70 (43; 88) | 0.048 |
| Inspiratory time (s) | 0.95 (0.78; 1.11) | 0.88 (0.80; 1.05) | 0.79 |
| Expiratory time (s) | 1.44 (1.10; 1.78) | 1.72 (1.36; 1.96) | 0.05 |
| Inspiratory/expiratory time ratio (%) | 0.67 (0.54; 0.81) | 0.55 (0.49; 0.71) | 0.04 |
| PEEP (cmH2O) | 5 (4; 5) | 5 (4–5) | 0.60 |
| DPtrig (cmH2O) | − 2 (− 3; − 1) | − 2 (− 3; − 2) | 0.60 |
| DTtrig (s) | 0.19 (0.12; 0.22) | 0.15 (0.13; 0.19) | 0.007 |
| Maximal inspiratory pressure (cmH2O) | 8 (7; 8) | 12 (12–12) | 0.00006 |
| Maximal inspiratory flow (l/s) | 1 (1; 1) | 1 (1; 1) | 0.18 |
ATC automatic tube compensation, PS pressure support, PEEP positive end-expiratory pressure, DPtrig maximal depression in airway pressure from PEEP during activation of inspiratory trigger, DTtrig time delay between onset of inspiratory effort and return to baseline PEEP before inspiratory valve opening
Values are median (1st; 3rd quartiles)