Table 3 Lung function test results in VLBW infants according to the duration of mechanical ventilation
Not ventilated infants | Intubated and ventilated < 7days | Intubated and ventilated ≥ 7days | p-value | |
|---|---|---|---|---|
N = 84 | N = 47 | N = 45 | ||
Tidal breathing | ||||
VT (mL/kg) | 8.61 | 8.01 | 7.68** | 0.034 |
(7.37 - 9.80) | (6.70 - 9.67) | (6.96 - 8.64) | ||
RR (1/min) | 40.9 | 44.8 | 44.4* | 0.045 |
(36.0 - 47.1) | (35.5 - 56.1) | (38.0 - 55.7) | ||
V’E (mL/min/kg) | 346.2 | 373.0 | 353.0 | 0.452 |
(297.8 - 398.4) | (311.2 - 407.3) | (299.0 - 402.7) | ||
tptef/te (%) | 20.7% | 22.1% | 21.1% | 0.898 |
(17.4% - 26.2%) | (16.3% - 27.0%) | (17.1% - 27.2%) | ||
te (s) | 0.857 | 0.770 | 0.753* | 0.025 |
(0.720 - 0.962) | (0.593 - 0.990) | (0.577 - 0.861) | ||
PTIF (mL/s/kg) | 18.9 | 19.6 | 18.0 | 0.351 |
(15.4 - 21.3) | (16.6 - 22.6) | (16.4 - 20.7) | ||
PTEF (mL/s/kg) | 17.1 | 18.0 | 17.9 | 0.150 |
(14.6 - 19.4) | (15.2 - 22.0) | (14.5 - 20.9) | ||
MTIF (mL/s/kg) | 13.4 | 14.0 | 13.1 | 0.642 |
(11.5 - 15.4) | (12.0 - 16.3) | (11.8 - 15.7) | ||
MTEF (mL/s/kg) | 10.0 | 11.1 | 10.4 | 0.375 |
(8.6 - 12.0) | (9.3 - 12.5) | (8.9 - 13.0) | ||
Respiratory mechanics | ||||
Crs (mL/kPa/kg) | 10.6 | 9.2 | 8.9*** | 0.002 |
(9.0 - 11.0) | (7.6 - 11.6) | (6.7 - 10.5) | ||
Rrs (kPa/L/s) | 5.96 | 6.55 | 6.15 | 0.094 |
(4.61 - 7.30) | (5.07 - 8.62) | (5.17 - 7.86) | ||
Exhalation gas analysis | ||||
eNO (ppb) | 10.0 | 6.6** | 10.4 | 0.005 |
(6.3 - 13.6) | (4.2 - 10.7) | (7.2 - 13.8) | ||
V’NO (nL/s) | 0.50 | 0.39** | 0.54 | 0.005 |
(0.34 - 0.72) | (0.24 - 0.54) | (0.37 - 0.66) | ||
Blood gas analysis | ||||
paO2 (mmHg) | 73.3 | 66.6* | 65.6*** | < 0.001 |
(65.5 - 83.0) | (58.6 - 78.0) | (58.5 - 70.9) | ||
paCO2 (mmHg) | 39.9 | 42.2* | 44.6*** | < 0.001 |
(37.7 - 43.7) | (39.1 - 45.8) | (41.1 - 47.3) |