The Cardiopulmonary Complications of Sickle Cell Disease

Abstract

Sickle cell disease (SCD) is a genetic hemoglobinopathy associated with extensive morbidity and early mortality. While there have been recent improvements in available disease-modifying therapies for SCD, cardiopulmonary complications remain a major risk factor for death in this population. We provide an overview of current knowledge regarding several of the major acute and chronic cardiopulmonary complications in SCD, including: acute chest syndrome, airway disease, lung function abnormalities, nocturnal hypoxemia and sleep disordered breathing, pulmonary vascular disease, and sickle cell cardiomyopathy.

Keywords: Acute chest syndrome; Lung function; Pulmonary hypertension; Sickle cell cardiomyopathy; Sickle cell disease; Sleep-disordered breathing.

Fig. 1.

Oxyhemoglobin dissociation curve. The rightward shift, as seen in SCD, indicates that oxyhemoglobin saturation at a given arterial oxygen pressure is lower in patients with SCD because of decreased oxygen affinity of HbS, increased 2,3 diphosphoglycerate (2,3 DPG) in sickled erythrocytes, hypoventilation due to pain or opioid use, and as an adaptation to severe anemia to prevent tissue hypoxia. (From Caboot JB, Allen JL. Hypoxemia in sickle cell disease: significance and management. Paediatr Respir Rev. 2014 Mar;15(1):17–23. https://doi.org/10.1016/j.prrv.2013.12.004. Epub 2013 Dec 21. PMID: 24461342.)

Fig. 2.

Overview of causes of PH in SCD. PH in SCD patients may be due to multiple different etiologies and often with multiple underlying causes. An overview of the different etiologies, their hemodynamics, and therapeutic options are listed. BPA, balloon pulmonary angioplasty; CTEPH, chronic thromboembolic PH; mPAP, mean pulmonary artery pressure; OSA, obstructive sleep apnea; PAOP, pulmonary artery occlusion pressure; PVR, pulmonary vascular resistance. (From Prohaska CC, Machado RF. The different facets of sickle cell disease-related pulmonary hypertension. Curr Opin Pulm Med. Sep 1 2021;27(5):319–328.)