Dimensions of nasal continuous positive airway pressure devices and pressure drop with various flows
| Pressure drop (cm H2O) at various flows | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Device | Size | Prong length† (mm) | Internal diameter‡ (mm) | Outer diameter‡ (mm) | 4 l/min | 5 l/min | 6 l/min | 7 l/min | 8 l/min |
| *Refers to Mallinckrodt endotracheal tube cut down to 5 cm length attached to standard endotracheal tube adapter with pressure side port. †Does not include the length proximal to the bridge between the prongs. ‡Internal and outer diameters were measured at the prong tip. | |||||||||
| Duotube | 2.5 | 40 | 1.4 | 2.5 | 9.7 | 15 | 21 | 29 | 38 |
| 3.0 | 40 | 1.8 | 3.0 | 3.0 | 4.5 | 6.2 | 8.3 | 10.5 | |
| 3.5 | 40 | 2.5 | 3.5 | 1.1 | 1.7 | 2.3 | 3.1 | 3.9 | |
| Single prong* | 2.5 | 50 | 2.5 | 3.8 | 2.2 | 3.3 | 4.4 | 5.9 | 7.3 |
| 3.0 | 50 | 3.0 | 4.3 | 1.1 | 1.5 | 2.1 | 2.7 | 3.3 | |
| 3.5 | 50 | 3.5 | 4.9 | 0.6 | 0.9 | 1.2 | 1.6 | 1.9 | |
| Argyle prong | Extra small | 6 | 1.8 | 3.1 | 1.7 | 2.6 | 3.6 | 4.8 | 6.2 |
| Small | 8 | 2.3 | 4.0 | 0.9 | 1.4 | 1.9 | 2.5 | 3.2 | |
| Large | 10 | 2.3 | 4.8 | 0.7 | 1.1 | 1.5 | 2.1 | 2.6 | |
| Hudson prong | 0 | 11 | 2.3 | 3.7 | 1.4 | 2.2 | 3.1 | 4.2 | 5.4 |
| 1 | 11 | 2.6 | 3.9 | 0.8 | 1.3 | 1.8 | 2.5 | 3.3 | |
| 2 | 11 | 3.0 | 4.6 | 0.3 | 0.5 | 0.6 | 0.9 | 1.1 | |
| 3 | 12 | 3.5 | 4.9 | 0.2 | 0.3 | 0.4 | 0.5 | 0.6 | |
| 4 | 15 | 4.0 | 5.4 | 0.1 | 0.2 | 0.3 | 0.5 | 0.6 | |
| Infant Flow Driver | Small | 6 | 3.0 | 3.9 | 0.2 | 0.2 | 0.3 | 0.4 | 0.5 |
| Medium | 7 | 3.5 | 4.3 | −0.1 | −0.2 | −0.3 | −0.4 | −0.5 | |
| Large | 7 | 4.0 | 4.6 | −0.2 | −0.3 | −0.5 | −0.7 | −0.9 | |