Sickle cell disease (SCD) is characterized by abnormal polymerization of deoxygenated hemoglobin S. This polymerization leads to the distinctive sickling of red blood cells (RBC), and resultant painful episodes and progressive multiorgan vasculopathy [1]. At high altitudes, barometric pressure drops, as does the partial pressure of oxygen (PaO2), also known as “hypobaric hypoxia” [2]. Above ≥ 8000 ft (the approximate air pressure of commercial air travel), atmospheric hypoxia can exacerbate or uncover occult hypoxemia in high-risk people, including those with SCD and other cardiopulmonary diseases [3-5]. As a way to assess the risk of hypoxemia (low blood oxygen) prior to travel, the hypoxia altitude simulation test (HAST) simulates high altitude conditions to assess for tolerance and for the need for prophylactic supplemental oxygen [6]. At our institution, following anecdotal reports from people living with SCD of symptom exacerbation with or following air travel, we have routinely offered HAST evaluations as part of pretravel evaluation for our patients. The goal of this cross-sectional study is to assess the prevalence of high-altitude hypoxemia in tested adults with SCD over a 5-year period, and to explore the association between high-altitude hypoxemia and disease characteristics.
