CO-Hb levels with time (DOL) and severity of BPD
| CO-Hb at DOL 1–5 | CO-Hb at DOL 6–10 | CO-Hb at DOL 11–14 | P value | |
| Overall population | 2.58± (0.45)* | 2.37± (0.45) | 2.22± (0.49)* | <0.01 |
| No to mild BPD (n=34) | 2.65± (0.44)** | 2.41± (0.42) | 2.32± (0.51)** | 0.01 |
| Moderate to severe BPD (n=24) | 2.49± (0.45)*** | 2.31±(0.51) | 2.07± (0.42)*** | 0.01 |
Numbers are expressed as mean± (SD).
*P< 0.01, **P<0.01, ***P<0.01.
BPD, bronchopulmonary dysplasia; CO-Hb, carboxyhemoglobin; DOL, day of life.