Table 3.
Modifications in PaCO2 values during follow-up period in study population stratified by intervention (high flow nasal therapy and noninvasive ventilation)
| HFNT group | NIV group | p value | |
|---|---|---|---|
| Per-protocol 2 h | |||
| PaCO2 (mmHg) on patients who completed the treatment originally allocated at 2 h, mean ± SD | |||
| Subjects, n | 34 | 37 | – |
| At baseline ( T0) | 74.0 ± 13.5 | 72.2 ± 13.3 | 0.5845 |
| After 2 h ( T2h ) | 67.2 ± 16.4 | 62.7 ± 13.5 | 0.1933 |
| After 6 h ( T6h ) | 64.5 ± 15.8 | 57.9 ± 12.2 | 0.0630 |
| ΔT2h − T0 | − 6.8 ± 8.7 | − 9.5 ± 8.5 | 0.4040 |
| ΔT6h − T0 | − 9.5 ± 13.0 | − 14.3 ± 11.1 | 0.0962 |
| ΔT6h − T2h | − 2.7 ± 9.7 | − 4.8 ± 7.1 | 0.1637 |
| Per-protocol 6 h | |||
| PaCO2 (mmHg) on patients who completed the treatment originally allocated at 6 h, mean ± SD | |||
| Subjects, n | 24 | 29 | − |
| At baseline ( T0) | 72.7 ± 10.3 | 74.0 ± 13.7 | 0.7955 |
| After 2 h ( T2h ) | 64.7 ± 8.7 | 63.7 ± 14.5 | 0.7493 |
| After 6 h ( T6h ) | 61.4 ± 7.7 | 59.8 ± 12.6 | 0.5632 |
| ΔT2h − T0 | − 8.0 ± 6.5 | − 10.3 ± 8.9 | 0.5200 |
| ΔT6h − T0 | − 11.3 ± 7.3 | − 14.2 ± 12.0 | 0.4475 |
| ΔT6h − T2h | − 3.3 ± 6.9 | − 3.9 ± 7.6 | 0.8163 |
| Intention-to-treat analysis | |||
| PaCO2 (mmHg) of enrolled patients, mean ± SD | |||
| Subjects, n | 40 | 39 | |
| At baseline ( T0) | 73.7 ± 12.8 | 72.0 ± 13.0 | 0.5270 |
| After 2 h ( T2h ) | 68.2 ± 15.6 | 63.4 ± 13.6 | 0.1387 |
| After 6 h ( T6h ) | 64.0 ± 14.9 | 58.1 ± 12.4 | 0.0610 |
| ΔT2h − T0 | − 5.5 ± 9.3 | − 8.6 ± 9.3 | 0.2940 |
| ΔT6h − T0 | − 9.7 ± 13.2 | − 13.9 ± 11.3 | 0.1329 |
| ΔT6h − T2h | − 4.2 ± 11.1 | − 5.3 ± 7.5 | 0.3670 |
HFNT high flow nasal therapy, NIV noninvasive ventilation, PaCO2 partial pressure of carbon dioxide, SD standard deviation, Δ difference in PaCO2 values between timepoints