- Sickle cell chronic lung disease stages.
| Stages | ABG | CXR | PFT | ECHO | PA pressure |
|---|---|---|---|---|---|
| 1 | NL | Increased interstitial marking | FEV1/FVC ratio <80% | NL | NL |
| 2 | NL | Fine interstitial fibrosis | FEV1/FVC ratio <60% | Balanced ventricular hypertrophy | NL |
| 3 | PaO2 <70 mmHg | Pulmonary fibrosis | FEV1/FVC ratio <40% | RVH, RA enlargement | Borderline |
| 4 | PaO2 <60 mmHg | Severe pulmonary fibrosis | Unable to do the test | Severe RVH, RAH | Elevated |
Data are modified from Powars et al’s study.37 ABG: denotes arterial blood gas, CXR: chest X-ray, PFT: pulmonary function test, ECHO: echocardiogram, PA: pulmonary artery, NL: normal, FEV1: forced expiratory volume for the 1st second, FVC: forced vital capacity, PaO2: partial oxygen pressure, RVH: right ventricular hypertrophy, RA: right atrium, RAH: right atrial hypertrophy