Table 1.
Effect of nCPAP and HFNC on the efficiency, safety, and rhythmic stability of feeding in full-term lambs.
| Control, n = 8 | nCPAP 6 cmH2O, n = 8 | HFNC 7 L/min, n = 8 | |
|---|---|---|---|
| End-expiratory tracheal pressure (cmH2O) | 0.2 (0.1, 0.4) | 5 (5, 6)*,‡ | 2 (1, 2)* |
| Efficiency | |||
| Feeding duration (s) | 31 (28, 40) | 25 (16, 34)*,‡ | 57 (31, 68) |
| Rate of milk transfer (mL/sec) | 1.9 (1.5, 2.2) | 2.4 (1.9, 3.8)*,‡ | 1.1 (0.9, 2.0) |
| Expression amplitude (mmHg) | +32 (26, 45) | +34 (30, 41) | +24 (20, 38) |
| Total number of SU | 68 (58, 90) | 52 (46, 67) | 69 (66, 83) |
| Total number of SW | 81 (69, 103) | 67 (51, 83) | 88 (82, 98) |
| Safety | |||
| Number of coughs | 0 (0, 0) | 0 (0, 0) | 0 (0, 0) |
| Number of cardiac decelerations | 5 (0, 10) | 0 (0, 4) | 1 (0, 3) |
| Minimal HR | 85 (71, 121) | 138 (79, 186) | 109 (93, 147) |
| % decrease in HR | 53 (42, 61) | 26 (23, 55) | 33 (31, 59) |
| Duration of cardiac inhibition (s) | 5 (0, 11) | 0 (0, 3) | 0 (0, 3) |
| Minimal SpO2 (%) | 85 (78, 92) | 92 (89, 95) | 91 (84, 93) |
| % decrease in SpO2 | 5 (4, 14) | 1 (1, 4) | 4 (2, 8) |
| SU–SW–BR coordination | |||
| % feeding time spent in apnea | 18 (16, 42) | 38 (24, 70) | 19 (13, 37) |
| % SW occurring during apnea | 22 (19, 57) | 53 (28, 72) | 30 (22, 60) |
| SU–SU covariance | 0.8 (0.4, 1) | 0.1 (0.1, 0.8) | 1.2 (0.4, 2) |
| SU–SU interval (s) | 0.4 (0.4, 0.4) | 0.3 (0.3, 0.5) | 0.6 (0.3, 0.9) |
| SU–SW covariance | 0.2 (0.2, 0.3) | 0.2 (0.09, 0.2) | 0.3 (0.2, 0.4) |
| SU–SW interval (s) | 0.2 (0.2, 0.3) | 0.2 (0.1, 0.2) | 0.3 (0.1, 0.4) |
| SW–SW covariance | 0.4 (0.3, 0.6) | 0.3 (0.2, 0.5) | 0.7 (0.4, 1) |
| SW–SW interval (s) | 0.4 (0.4, 0.4) | 0.3 (0.3, 0.4) | 0.5 (0.3, 0.7) |
| SW–BR covariance | 0.8 (0.7, 0.9) | 0.8 (0.7, 0.9) | 0.9 (0.7, 1) |
| SW–BR interval (s) | 1.6 (1.3, 2.7) | 2.4 (1.4, 4) | 2.4 (1.4, 4.5) |
Results are presented as median (Q1, Q3).
Cardiac deceleration was defined by a % decrease in HR ≥ 33%, regardless of the duration.
No deceleration longer than 5 s was noted.
*p < 0.05 vs. control.
‡p < 0.05 vs. HFNC.
nCPAP, nasal continuous positive airway pressure 6 cmH2O; HFNC, high-flow nasal cannula 7 L/min; SU, sucking; SW, swallowing; HR, heart rate; SpO2, arterial hemoglobin saturation in oxygen; BR, breathing; covariance, coefficient of variation of the time interval between SU, SW, and BR.