Table 1.
Mean inspiratory airway pressure (Paw mean), expiratory pressure time product (PTPexp), and maximum CO2 concentration (CO2 max) within the helmet at a respiratory rate of 15 and 30 breaths per minute
| Normal lung condition | |||||||||
| Respiratory rate | 15 breaths/minute | 30 breaths/minute | |||||||
| Δ pressure | 5 cmH20 | 15 cmH20 | 5 cmH20 | 15 cmH20 | |||||
| Effort | low | high | low | high | low | high | low | high | |
| Paw mean (cmH2O) | HF-BiPAP | 10.2 ± 0.3 | 10.4 ± 0.4 | 15.2 ± 0.4 | 14.7 ± 0.3 | 10.7 ± 0.2 | 11.1 ± 0.5 | 15.1 ± 0.5 | 15.0 ± 0.2 |
| BiVent | 10.1 ± 0.1 | 9.8 ± 0.1 | 14.8 ± 0.3 | 14.5 ± 0.1 | 10.6 ± 0.2 | 9.8 ± 0.2 | 15.0 ± 0.3 | 15.2 ± 0.3 | |
| PSV | 8.7 ± 0.2 | 8.4 ± 0.2 | 11.9 ± 0.6 | 11.6 ± 0.7 | 9.6 ± 0.4 | 8.7 ± 0.2 | 12 ± 0.4 | 13.2 ± 0.9 | |
| PTPexp. (cmH20/sec) | HF-BiPAP | 4.3 ± 1.1 | 10.6 ± 3.2 | 13.9 ± 1.1 | 21.4 ± 1.7 | 3.1 ± 0.4 | 7.4 ± 1.4 | 2.7 ± 0.7 | 9.2 ± 1.2 |
| BiVent | 4.6 ± 0.5 | 5.7 ± 0.3 | 18.7 ± 0.7 | 21.7 ± 0.8 | 2.8 ± 0.2 | 2.9 ± 0.8 | 9.8 ± 0.6 | 9.4 ± 0.8 | |
| PSV | 1.9 ± 0.5 | 3.2 ± 0.7 | 6.7 ± 0.4 | 7 ± 0.6 | 1.9 ± 0.9 | 2.5 ± 0.3 | 4.4 ± 4.9 | 2.2 ± 0.7 | |
| CO2 max (%) | HF-BiPAP | 0.1 ± 0 | 0.1 ± 0 | 0.1 ± 0 | 0.1 ± 0 | 0.1 ± 0 | 0.1 ± 0 | 0.2 ± 0 | 0.2 ± 0 |
| BiVent | 4.2 ± 0 | 4.0 ± 0.1 | 2.1 ± 0 | 3.2 ± 0 | 3.9 ± 0.1 | 2.6 ± 0 | 1.9 ± 0 | 1.4 ± 0.2 | |
| PSV | 0.2 ± 0 | 1.2 ± 0 | 1 ± 0 | 0.8 ± 0 | 0.9 ± 0 | 0.7 ± 0 | 1 ± 0.2 | 0.5 ± 0 | |
| Obstructive lung condition | |||||||||
| Respiratory rate | 15 breaths/minute | 30 breaths/minute | |||||||
| Δ pressure | 5 cmH20 | 15 cmH20 | 5 cmH20 | 15 cmH20 | |||||
| Effort | low | high | low | high | low | high | low | high | |
| Paw mean (cmH2O) | HF-BiPAP | 10.4 ± 0.1 | 9.9 ± 0.1 | 14.1 ± 0.1 | 14 ± 0.1 | 10.2 ± 0.1 | 10.7 ± 0 | 14.6 ± 0.1 | 15.6 ± 0.2 |
| BiVent | 9.9 ± 0.2 | 10.1 ± 0.1 | 15.5 ± 0.1 | 14.9 ± 0 | 9.9 ± 0.1 | 10.3 ± 0 | 15.3 ± 0.2 | 15.8 ± 0.2 | |
| PSV | 9.3 ± 0.1 | 9.1 ± 0 | 11.6 ± 0.1 | 10.6 ± 0.1 | 9.1 ± 0.1 | 9.3 ± 0.1 | 11.2 ± 0.5 | 12.3 ± 0.1 | |
| PTPexp. (cmH20/sec) | HF-BiPAP | 9 ± 0.5 | 3.4 ± 0.6 | 15.9 ± 1.1 | 19.4 ± 0.9 | 7.7 ± 0.9 | 5.7 ± 0.8 | 11.1 ± 2.3 | 16.9 ± 3.5 |
| BiVent | 6 ± 0.5 | 7.4 ± 0.6 | 18.5 ± 0.7 | 19.5 ± 0.3 | 5.9 ± 0.4 | 6.1 ± 0.1 | 9.4 ± 0.3 | 8 ± 0.4 | |
| PSV | 3.7 ± 0.7 | 2.4 ± 0.3 | 3.2 ± 0.9 | 2.2 ± 0.3 | 3.8 ± 0.4 | 5.5 ± 0.3 | 2.5 ± 2 | 4 ± 0.3 | |
| CO2 max (%) | HF-BiPAP | 0.1 ± 0 | 0.1 ± 0 | 0.2 ± 0 | 0.2 ± 0 | 0.1 ± 0 | 0.1 ± 0 | 0.2 ± 0 | 0.2 ± 0 |
| BiVent | 2.5 ± 0 | 3 ± 0.1 | 2.8 ± 0 | 3.2 ± 0 | 4.8 ± 0 | 4.8 ± 0 | 2.3 ± 0 | 2.2 ± 0 | |
| PSV | 0.2 ± 0 | 0.9 ± 0 | 0.1 ± 0 | 0.6 ± 0 | 0.4 ± 0 | 0.4 ± 0 | 0.1 ± 0 | 0.2 ± 0 | |
| Restrictive lung condition | |||||||||
| Respiratory rate | 15 breaths/minute | 30 breaths/minute | |||||||
| Δ pressure | 5 cmH20 | 15 cmH20 | 5 cmH20 | 15 cmH20 | |||||
| Effort | low | high | low | high | Low | high | low | high | |
| Paw mean (cmH2O) | HF-BiPAP | 9.9 ± 0.3 | 10.7 ± 0.3 | 14.6 ± 0.2 | 14.3 ± 0.3 | 10.1 ± 0.2 | 11.5 ± 0.3 | 14.4 ± 0.1 | 14.9 ± 0.1 |
| BiVent | 9.9 ± 0.2 | 9.9 ± 0.1 | 14.9 ± 0.1 | 14.9 ± 0.2 | 10.0 ± 0.3 | 9.8 ± 0.1 | 16.3 ± 0.2 | 16.3 ± 0.2 | |
| PSV | 11.6 ± 0.6 | 9.3 ± 0.1 | 10.1 ± 0.1 | 9.8 ± 0.1 | 10.2 ± 0.3 | 9.1 ± 0 | 15.9 ± 0.4 | 11.3 ± 0.1 | |
| PTP exp. (cmH20/sec) | HF-BiPAP | 6.4 ± 2.9 | 10.1 ± 3 | 13.8 ± 1.5 | 15.0 ± 9.6 | 3.3 ± 1 | 4.8 ± 1.1 | 9.5 ± 2.4 | 11.7 ± 1.3 |
| BiVent | 5.4 ± 1.7 | 6.6 ± 1 | 9.0 ± 0.6 | 12.1 ± 0.6 | 3.0 ± 0.3 | 2.5 ± 0.3 | 6.6 ± 0.5 | 8.9 ± 0.7 | |
| PSV | 5.2 ± 0.5 | 4.5 ± 0.7 | 3.1 ± 0.4 | 3.3 ± 0.4 | 3.0 ± 0.8 | 2.5 ± 0.3 | 5.6 ± 0.8 | 4.9 ± 0.6 | |
| CO2 max (%) | HF-BiPAP | 0.1 ± 0 | 0.1 ± 0 | 0.2 ± 0 | 0.2 ± 0 | 0.1 ± 0 | 0.1 ± 0 | 0.1 ± 0 | 0.3 ± 0 |
| BiVent | 4.7 ± 0 | 4.7 ± 0.1 | 4.2 ± 0 | 4.4 ± 0.1 | 4.1 ± 0 | 3.0 ± 0.1 | 3.8 ± 0 | 2.9 ± 0 | |
| PSV | 0.4 ± 0 | 0.8 ± 0 | 0.3 ± 0 | 0.4 ± 0 | 0.4 ± 0 | 0.7 ± 0 | 1.0 ± 0.1 | 0.6 ± 0 | |
Measurements were made in normal (compliance 90 ml/cmH2O, resistance 3 cmH2O/l/s), restrictive (compliance 30 ml/cmH2O, resistance 3 cmH2O/l/s) and obstructive (compliance 90 ml/cmH2O, resistance 15 cmH2O/l/s) lung conditions, during varying delta pressure (5 and 15 cmH2O) and inspiratory efforts (low: 2.5 cmH2O, high: 10 cmH2O) at a set positive end-expiratory pressure of 8 cmH2O.
HF-BiPAP = high flow biphasic positive airway pressure ventilation; BiVent = biphasic positive airway pressure delivered by a ventilator; PSV = pressure support ventilation delivered by a ventilator.