12 Hospital Physician Board Review Manual www.turner-white.com
placebo-controlled clinical trials are needed to provide evidence to guide the use of drugs such as
bosentan and prostacyclin in clinical practice.
Chronic interstitial lung disease and abnormal
results on pulmonary function testing occur frequently in patients with SCD. Up to 90% of adults
with SCD have abnormal results on pulmonary
function testing. Common abnormalities include
decreased diffusing capacity of the lung for carbon monoxide and a restrictive pattern,101 although
patients can also have features of hypoxemia and
obstructive disease.102,103 Episodes of ACS may
be a risk factor for the development of fibrosis
and restrictive lung disease. The incidence of
obstructive sleep apnea syndrome (OSA) may
be the same among patients with SCD and those
without SCD, but the severity of OSA in terms of
desaturation and hypercapnia is higher among
the former.104 Moreover, up to 40% of children
screened have nocturnal desaturations, which are
associated with a higher rate of vaso-occlusive
SCD is a genetic disease of the hematopoietic
system with diverse pulmonary manifestations and
complications. The treatment of ACS is based
upon recognition of common etiologies; after initial
supportive measures, therapy includes antibiotics
covering atypical and routine pathogens, hydration, transfusion as indicated, and mechanical
ventilation, if required. For spontaneously breathing patients, incentive spirometry can both prevent
ACS as well as prevent worsening of an episode
already in progress. Despite recent advances in
our understanding of this syndrome, treatment
remains challenging and mortality is substantial.
Successful management does not preclude future
events or the development of pulmonary hypertension. Further investigation into the pulmonary manifestations, which have a major impact on quality
of life, is needed. As we know, ACS or acute sickle
cell crisis are the cause of death in 78% of patients
with SCD.12 Future research in this field should
help us to better understand and manage this
1. Ashley-Koch A, Yang Q, Olney RS. Sickle hemoglobin
(HbS) allele and sickle cell disease: A HuGE review. Am J
2. Paixão MC, Cunha Ferraz MH, Januário JN, et al. Reliability
of isoelectrofocusing for the detection of Hb S, Hb C, and
HB D in a pioneering population-based program of newborn
screening in Brazil. Hemoglobin 2001;25:297–303.
3. Loureiro MM, Rozenfeld S. [Epidemiology of sickle cell disease hospital admissions in Brazil]. [Article in Portuguese].
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Figure. Doppler echocardiography showing elevated pulmonary
artery pressure (high tricuspid regurgitation jet velocity). A value
of 348 cm/s of jet correlates with right ventricular systolic pressure of 53.6 mm Hg.