Microvascular blood flow during vascular occlusion tests assessed by diffuse correlation spectroscopy. Issue 1 (20th December 2019)

• Record Type: Journal Article
• Authors: Didier, Kaylin D.; Hammer, Shane M.; Alexander, Andrew M.; Caldwell, Jacob T.; Sutterfield, Shelbi L.; Smith, Joshua R.; Ade, Carl J.; Barstow, Thomas J.
• Is Part Of: Experimental physiology. Volume 105:Issue 1(2020:Jan.)
• Page Start: 201
• Page End: 210
• Publication Date: 2019-12-20
• Subjects: diffuse correlation spectroscopy -- microvascular blood flow -- vascular occlusion test; Physiology, Experimental -- Periodicals; 571.0724
• DOI: 10.1113/EP087866
• Languages: English
• ISSNs: 0958-0670

Abstract

Abstract : New Findings: What is the central question of this study? What are the characteristics of the time courses of blood flow in the brachial artery and microvascular beds of the skin and skeletal muscle following transient ischaemia? What is the main finding and its importance? Skeletal muscle blood flow was significantly slower than the transient increase in the cutaneous tissue, suggesting mechanistic differences between cutaneous and muscular blood flow distribution after transient ischaemia. These results challenge the use of the cutaneous circulation as globally representative of vascular function. Abstract: Vascular function can be assessed by measuring post‐occlusion hyperaemic responses along the arterial tree (vascular occlusion test; VOT). It is currently unclear if responses are similar across vascular beds following cuff release, given potential differences in compliance. To examine this, we compared laser Doppler‐derived blood flux in the cutaneous circulation (LDFcut ) and skeletal muscle microvascular blood flux (BFI) using diffuse correlation spectroscopy (DCS), to brachial artery blood flow (BABF) during VOT. We hypothesized that during a VOT following cuff release, (1) BFI response would be delayed compared to the brachial artery response, and (2) time to peak blood flux in the cutaneous vasculature would be slower than both brachial artery and skeletal muscle responses. Seven healthy men (26 ± 4 years) performed three trials of a brachial artery VOT protocol with 10 min of rest between trials. A combined DCS and near‐infrared spectroscopy probe provided BFI and oxygenation characteristics (total‐[haem]), respectively, of skeletal muscle. BABF was determined via Doppler ultrasound and microvascular cutaneous blood flux was determined via LDFcut . Following cuff release, time to peak of BFI (32.3 ± 6.0 s) was significantly longer than BABF (7.3 ± 2.5 s), LDFcut (10.0 ± 6.4 s) and total‐[haem] (14.2 ± 8.3 s) (all P < 0.001). However, time to peak of BABF, LDFcut and total‐[haem] were not significantly different ( P > 0.05). These results suggest mechanistic differences in control of cutaneous and muscular blood flow distribution after transient ischaemia. Abstract :