Effect of thermal stimuli on peripheral blood flow in homozygous sickle cell disease: a preliminary study

ABSTRACT

Forearm blood flow (FBF) was measured in 23 patients with homozygous sickle cell (SS) disease and 20 controls with normal hemoglobin genotype (AA) using venous occlusion air plethysmography to examine the pattern of peripheral blood flow in both groups at rest, and in response to thermal stimuli. The mean resting in FBF in SSS patients was more than twice that in AA controls (P < 0.05) in FBF in the opposite arm in both SS patients and AA controls, with the response being greater in the controls. Indirect heating for 2 mimutes evoked a similar decrease in FBF of a similar magnitude in both groups. The increased FBF in response to cooling in SSS patients may be a part of an important reflex mechanism which would support the concept of the 'steal' syndrome, as recently postulated, as a possible explanation of the cold-related initiation of the painful crisis of SS disease.(AU)