PURPOSE: In sickle cell disease (SCD), sleep-related hypoxemia is associated with frequent pain crises, CNS events, and impaired intellectual function, and may contribute to pulmonary hypertension and priapism. We evaluated sleep-associated hypoxemia in adult SCD patients with and without pain crisis.
METHODS: In 36 hospitalized SCD patients and 11 controls, we monitored oxygen saturation (SpO2) for one or two nights, using a wrist-worn recording pulse oximeter (Nonin 3100). When possible, we monitored the same subjects at home on a subsequent night, without pain crisis. For each period identified as sleep, the times spent with SpO2 less than 80, 85 and 90% were calculated. We characterized the SpO2 pattern as “normal”, “cyclical” (when there were regular cycles of desaturation and resaturation, lasting seconds to a minute), “noncyclical” (when there were abrupt desaturations, lasting 15 minutes or more), and “mixed”, when both abnormal patterns were present.
RESULTS: We collected atleast four hours of data in 31/36 SCD subjects and 10/11 controls. Controls had 0–1.3% and SCD patients had 0–83% sleep time below 85% SpO2. No controls and 11 SCD patients had atleast 10% sleep time below 85% SpO2 (p<.05 by Fisher's exact). Two controls had mildly cyclical SpO2 patterns. 21/31 (68%) SCD patients had abnormal SpO2 patterns (p<.02 vs control subjects): 11 cyclical, 2 noncyclical, and 8 mixed patterns of desaturation. Of the 10 subjects who had repeat studies in hospital, two changed from normal to abnormal, and eight (three normal and five abnormal on the first night) did not change. 5/9 (56%) subjects studied at home had abnormal patterns: two of three who had normal data on the first hospital night demonstrated mixed desaturation patterns at home; three of six who had shown abnormal patterns in the hospital showed normal patterns at home.
CONCLUSION: Sleep-associated hypoxemia is very common in sickle cell patients with pain crisis, and is reproducible in many or most of them, even when they are not in pain crisis.
CLINICAL IMPLICATIONS: Sleep-associated hypoxemia is very common in SCD.
DISCLOSURE: Jaswinderpal Sandhu, No Financial Disclosure Information; No Product/Research Disclosure Information