Comparison of clinical course according to pulmonary artery ratio (PAR)
| PAR ≥0.762 (n=41) | PAR <0.762 (n=13) | P value | |
| NO requirement* | 24/41 (58.5%) | 12/13 (92.3%) | 0.0244 |
| HFOV requirement* | 31/41 (75.6%) | 13/13 (100%) | 0.0485 |
*For more than 24 hours.
HFOV, high-frequency oscillatory ventilation; NO, nitric oxide.