Table 1.
Peak inspiratory airway pressure, applied positive end-expiratory airway pressure, breathing pattern and timing on various modes of mechanical ventilation a
| Control | CPAP | CPAP-8 | AMV | AMV-8 | CMV | CMV-8 |
|---|---|---|---|---|---|---|
| Peak inspiratory airway pressure (cmH2O) above PEEP | ||||||
| −0.8 ± 0.2 | 3.2 ± 0.3 | 3.7 ± 0.6 | 8.2 ± 0.3b | 7.7 ± 0.3b | 8.1 ± 0.2b | 7.4 ± 0.3b |
| Applied positive end-expiratory airway pressure (cmH2O) | ||||||
| N/A | N/A | 8.3 ± 0.2 | N/A | 8.1 ± 0.1 | N/A | 8.4 ± 0.3 |
| Tidal volume (ml/kg) | ||||||
| 3.6 ± 0.1b | 5.8 ± 0.6 | 6.4 ± 0.6 | 7.5 ± 0.3 | 7.4 ± 0.5 | 7.5 ± 0.4 | 5.1 ± 0.2c |
| Respiratory frequency (breaths/min) | ||||||
| 51.6 ± 4.8b | 36.6 ± 2.2 | 29.8 2.8 | 30.4 ± 2.9 | 28.7 ± 2.9 | 40.1 ± 0.1 | 40.0 ± 0.1 |
| Minute ventilation (L/min) | ||||||
| 0.6 ± 0.1 | 0.8 ± 0.1 | 0.7 ± 0.1 | 0.8 ± 0.1 | 0.7 ± 0.1 | 1.2 ± 0.1c | 0.7 ± 0.0 |
| Inspiratory time (seconds) | ||||||
| 0.40 ± 0.04 | 0.58 ± 0.02c | 0.51 ± 0.03 | 0.47 ± 0.01 | 0.48 ± 0.01 | 0.48 ± 0.01 | 0.47 ± 0.01 |
| Duty cycle | ||||||
| 0.35 ± 0.07 | 0.35 ± 0.02 | 0.25 ± 0.03 | 0.24 ± 0.02 | 0.23 ± 0.03 | 0.32 ± 0.01 | 0.32 ± 0.01 |
aValues are mean ± SE average of those after 1 and 2 days of various modes of mechanical ventilation (n = 6 animals in each group). AMV, Assist-control mechanical ventilation; CMV, Controlled mechanical ventilation (numerical value of 8 next to the ventilatory mode denotes the set CPAP or PEEP of 8 cmH2O); CPAP, Continuous positive airway pressure; N/A, Not applicable; PEEP, Positive end-expiratory airway pressure; VT, Tidal volume. Peak inspiratory airway pressure: b P < 0.01 compared with CPAP and CPAP-8; VT: b P < 0.01 compared with CPAP, CPAP-8, AMV, AMV-8 and CMV. c P < 0.05 compared with CMV, AMV-8 and AMV. Respiratory frequency: b P < 0.01 compared with CPAP, CPAP-8, AMV and AMV-8. Total minute ventilation: c P < 0.05 compared with control, CPAP-8, AMV-8 and CMV-8. Ti: c P < 0.05 compared with control, AMV, AMV-8, CMV and CMV-8.