Aim Several complications of sickle cell anaemia, including pain, cardiac dysfunction, stroke, silent cerebral infarction (SCI) and cognitive dysfunction appear to be related to low daytime and night-time oxygen saturation (SpO2). SCA complications can be made worse if patients have extra dips in night time oxygen levels when the upper airway closes repeatedly during sleep: this obstructive sleep apnoea (OSA) is common in SCA. Treatments used for low SpO2/OSA in the general population include autoadjusting Continuous Positive Airways Pressure (APAP) but safety remains a concern for haematologists and the feasibility of using this longer term are unknown for this population. A feasibility study was therefore designed to address these issues.

Methods Randomised trial involving 60 patients with HbSS (30 children and 30 adults) randomised to APAP or a control arm (standard treatment with no APAP) for 6 months. Adherence data from a removable card in the machine is available for patients randomised to APAP.

Results 30 children and 27 adults have been randomised. Adherence data are available for 24 patients using the APAP machine over the past 6–186 (median 73) days; they adhered mostly more than 4 hours/night for 12%–98% of nights (median 77%). After two weeks, the mean change in haemoglobin in those on APAP was 0.0 (SD 5.3) g/L compared with 0.75 (SD 5.1) g/l in those on standard care. Mean change in red cell count in those on APAP was 0.0 (SD 0.26) g/L compared with 0.06 (SD 0.24) g/l for standard care. The mean change in reticulocyte count in those on APAP was 41 (SD 76) g/L compared with 18 (SD 74) g/l. There was no significant difference in haemoglobin, red cell count or reticulocytes at 2 weeks or 3 months in patients in either arm. Two patients in the standard care arm were admitted for pain and one was admitted for gastrointestinal problems while one patient on APAP was admitted 4 times for pain.

Conclusions It is feasible to enrol and retain patients with SCA in RCTs of APAP, which does not appear unsafe in terms of causing bone marrow suppression or pain admissions.