Regional and temporal variation in oscillatory blood flow in sickle cell disease.

We examined 55 patients with sickle cell anemia (HbSS) and 16 with hemoglobin SC disease (HbSC) to ascertain the presence of periodic microcirculatory flow (PMF) using laser-Doppler velocimetry. Forty-nine percent of patients with HbSS and 12.5% of HbSC patients had PMF on at least one occasion and in at least one site. The presence of PMF could be correlated with an increase in packed cell volume (PCV) and hemoglobin in individuals with HbSS and an increased white blood cell and platelet count in patients with HbSC. PMF may result from complex interactions among perfusion pressure, capillary tone, and the numbers and intrinsic properties of formed blood elements.