Table 3.
The effect of HFNC and NC intervention on respiratory impedance evaluated by PFT.
| HFNC (n = 19) | Mean difference | NC (n = 19) | Mean difference | p value | |
|---|---|---|---|---|---|
| FEV1/FVC (%) | |||||
| Before | 45.68 ± 12.16 | −0.05 | 46.32 ± 11.72 | + 0.26 | 0.72 |
| After | 45.63 ± 11.44 | 46.58 ± 12.31 | |||
| FEV1 (L) | |||||
| Before | 1.01 ± 0.33 | + 0.02 | 1.01 ± 0.38 | + 0.04 | 0.31 |
| After | 1.03 ± 0.32 | 1.05 ± 0.36 | |||
| FEV1 (% predicted) | |||||
| Before | 47.53 ± 16.68 | + 0.63 | 47.42 ± 18.71 | + 1.79 | 0.24 |
| After | 48.16 ± 16.22 | 49.21 ± 18.58 | |||
| FVC (L) | |||||
| Before | 2.27 ± 0.61 | + 0.03 | 2.21 ± 0.61 | + 0.08 | 0.32 |
| After | 2.30 ± 0.60 | 2.29 ± 0.61 | |||
| FVC (% predicted) | |||||
| Before | 74.58 ± 14.70 | + 1.05 | 72.79 ± 16.76 | + 2.47 | 0.37 |
| After | 75.63 ± 14.42 | 75.26 ± 15.44 | |||
| FEV3 (L) | |||||
| Before | 1.60 ± 0.45 | + 0.02 | 1.59 ± 0.51 | + 0.05 | 0.36 |
| After | 1.62 ± 0.44 | 1.64 ± 0.45 | |||
| FEV3 (% predicted) | |||||
| Before | 55.05 ± 14.53 | + 0.48 | 54.68 ± 16.72 | + 1.43 | 0.36 |
| After | 55.53 ± 14.27 | 56.11 ± 15.20 | |||
| FEF 25–75% (L/s) | |||||
| Before | 0.42 ± 0.23 | −0.01 | 0.42 ± 0.26 | + 0.02 | 0.27 |
| After | 0.41 ± 0.22 | 0.44 ± 0.26 | |||
| FEF 25–75% (% predicted) | |||||
| Before | 28.05 ± 18.68 | −0.37 | 27.89 ± 18.76 | + 1.74 | 0.17 |
| After | 27.68 ± 18.32 | 29.63 ± 22.06 | |||
| PEF (L/s) | |||||
| Before | 2.32 ± 0.73 | + 0.05 | 2.46 ± 0.86 | -0.02 | 0.66 |
| After | 2.37 ± 0.80 | 2.44 ± 0.82 | |||
| PEF (% predicted) | |||||
| Before | 38.37 ± 11.67 | + 1.00 | 40.95 ± 15.33 | 0 | 0.67 |
| After | 39.37 ± 13.07 | 40.95 ± 15.84 | |||
| RV (L) | |||||
| Before | 3.42 ± 0.82 | + 0.25 | 3.42 ± 0.77 | + 0.12 | 0.73 |
| After | 3.67 ± 1.31 | 3.54 ± 0.96 | |||
| RV (% predicted) | |||||
| Before | 160.3 ± 44.2 | + 12.5 | 160.0 ± 40.8 | + 6.10 | 0.71 |
| After | 172.8 ± 69.3 | 166.1 ± 49.8 | |||
| TLC (L) | |||||
| Before | 5.80 ± 1.02 | + 0.26 | 5.79 ± 0.88 | + 0.18 | 0.79 |
| After | 6.06 ± 1.17 | 5.97 ± 1.03 | |||
| TLC (% predicted) | |||||
| Before | 119.9 ± 26.6 | + 8.50 | 118.1 ± 17.8 | + 3.10 | 0.55 |
| After | 128.4 ± 47.8 | 121.2 ± 16.7 | |||
| RV/TLC (%) | |||||
| Before | 58.9 ± 8.90 | + 0.80 | 58.7 ± 8.4 | + 0.40 | 0.87 |
| After | 59.7 ± 11.2 | 59.1 ± 10.2 | |||
| FRC (L) | |||||
| Before | 4.45 ± 0.89 | + 0.26 | 4.44 ± 0.88 | + 0.09 | 0.56 |
| After | 4.71 ± 1.18 | 4.53 ± 0.93 | |||
| FRC (% predicted) | |||||
| Before | 147.4 ± 29.8 | + 12.1 | 147.5 ± 33.7 | + 3.10 | 0.48 |
| After | 159.5 ± 57.9 | 150.6 ± 32.8 | |||
| IC (L) | |||||
| Before | 1.34 ± 0.40 | 0 | 1.36 ± 0.34 | + 0.08 | 0.37 |
| After | 1.34 ± 0.50 | 1.44 ± 0.38 | |||
| IC (% predicted) | |||||
| Before | 75.4 ± 23.9 | −0.10 | 77.3 ± 28.7 | + 5.10 | 0.38 |
| After | 75.3 ± 29.7 | 82.4 ± 33.7 | |||
Analysis of Covariance (ANCOVA) test, p < 0.05.
HFNC high flow nasal cannula, NC nasal cannula, FEV1 forced expiratory volume that has been exhaled at the end of the first second of forced expiration, FVC forced vital capacity, FEV3 forced expiratory volume that has been exhaled at the end of the third second of forced expiration, FEF 25–75% forced expiratory flow at 25–75% of the pulmonary volume, PEF peak expiratory flow, RV residual volume, TLC total lung capacity, FRC functional residual capacity, IC inspiratory capacity.
*Significance between high-flow nasal cannula and nasal cannula.