TABLE 2.
DEVICE CHARACTERISTICS
| Device | Performance Category | Actuation Style | Trigger ΔP (cm H2O) | O2 Bolus Delivered (ml) Setting 2 | Setting 5 | Continuous* |
|---|---|---|---|---|---|---|
| D1 | Pulse | Pneumatic | 0.3 | 23.4 ± 1 | 43.4 ± 2.0 | 136 |
| D2 | Pulse | Pneumatic | 0.4 | 3.2 ± 0.2 | 7.1 ± 0.5 | 146 |
| D3 | Pulse | Pneumatic | 0.3 | 22.8 ± 0.7 | 35.4 ± 1.6 | 132 |
| D4 | Demand | Electronic | 0.3 | 33.2 ± 1.1 | 83.4 ± 1.6 | 136 |
Definition of abbreviations: D = device; ΔP = change in pressure.
The performance category indicates whether O2 is delivered only early in inspiration (pulse) or throughout (demand). The activation style describes the mechanism by which the flow from the conserver is initiated. Trigger pressure refers to the magnitude of the pressure drop necessary to start flow. The O2 bolus is the volume of gas delivered during activation. These data are means ± 1 SEM.
In the continuous setting, O2 boluses were not generated. Here, O2 was provided at a constant flow varying from 1.60 to 2.40 L/min. The data in this column represent the volume of O2 in ml that would be contained in a 500-ml tidal breath. (See text for details of calculation).