title: Hyperventilation-induced changes in periodic oscillations in forehead skin blood flow measured by laser Doppler flowmetry.
abstract: Rhythmic oscillations in forehead skin blood flow were studied with the laser Doppler technique in thirteen healthy subjects. During voluntary hyperventilation, a three-fold increase in relative amplitude of the spontaneous rhythmic oscillations in forehead skin blood flow was observed, whereas mean blood flow decreased by 15%. During hyperventilation, the relative amplitude of the oscillations was on average 36% of the mean blood flow value. The mean incidence of the oscillations increased significantly, from 68% of the measuring time before, to 96% of the measuring time during hyperventilation. The oscillation frequency was not affected by hyperventilation. Before, during and after hyperventilation the average oscillation frequency was 0.140 Hz (8.4 min-1), 0.145 Hz (8.7 min-1) respectively. The application of heat or a local anaesthetic to the skin attenuated the relative amplitude of the oscillations in forehead skin blood flow during hyperventilation as well as before and after.
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity; D001784:Blood Gas Analysis; D005260:Female; D005546:Forehead / Q000098:blood supply*; D006358:Hot Temperature; D006801:Humans; D006985:Hyperventilation / Q000097:blood; D007834:Lasers; D008012:Lidocaine / Q000494:pharmacology; D008297:Male; D012212:Rheology
chemical_list: D008012:Lidocaine