Table 1.

Etiology of hypoxia in patients with SCD

Mechanism of hypoxiaCauses in SCD
HypoventilationSDB (OSA, upper airway obstruction)
Thoracic splinting due to chronic pain
Restrictive pulmonary disease
Reduced chest excursion due to hepatomegaly
Central hypoventilation (eg, due to excessive use of narcotics)
Diffusion impairmentSCD-associated interstitial lung fibrosis
Pulmonary vascular disease
ShuntIntracardiac shunt (eg, ventriculoseptal defect)
Extracardiac shunt
Arterial-venous malformations
Intrapulmonary shunt (eg, due to consolidation or atelectasis resulting in decreased perfusion to affected area)
Ventilation-perfusion inequalityChronic VTE
Plastic bronchitis
Obstructive lung disease without asthma
Chronic airway inflammation due to asthma
  • OSA, obstructive sleep apnea; SDB, sleep-disordered breathing.