Periodic microcirculatory flow in patients with sickle-cell disease.
We have applied the technique of laser-Doppler velocimetry to compare patterns of cutaneous blood flow in the forearms of patients with stable sickle-cell disease, with the patterns in normal subjects matched for age, race, and sex, and in patients with anemia due to beta+-thalassemia. The mean resting blood flow in the patients with sickle-cell disease was comparable to that of the control groups but was associated with large, local oscillations in flow with periods of 7 to 10 seconds and peak-to-trough magnitudes about half the mean flow. Oscillations occurred simultaneously at sites separated by 1 cm but were independent in phase and frequency. Since these laser-Doppler measurements represent the average flow pattern in about 1 mm3 of skin (i.e., in approximately 50 to 70 capillary loops), these results suggest that microcirculatory flow in patients with sickle-cell disease proceeds by synchronization of rhythmic flow in large domains of microvessels. These findings indicate that periodic flow may be a compensatory mechanism to offset the deleterious altered rheology of erythrocytes containing polymerized hemoglobin S, and suggest that laser-Doppler velocimetry may be a useful method to investigate microvascular physiology in patients with sickle-cell disease.
D000328:Adult; D000755:Anemia, Sickle Cell / Q000503:physiopathology*; D001783:Blood Flow Velocity; D002196:Capillaries / Q000503:physiopathology; D004301:Doppler Effect; D005260:Female; D006801:Humans; D007834:Lasers; D008297:Male; D008833:Microcirculation / Q000503:physiopathology*; D008875:Middle Aged; D010507:Periodicity; D012867:Skin / Q000098:blood supply