Blood flow rate measurements with indicator techniques revisited.

In view of the emerging role, disturbances in regional blood flow rate seem to play in the pathogenesis of the metabolic syndrome; we review the concepts of the classical indicator dilution and washout techniques used for determinations of regional blood flow rate. Prerequisites, assumptions, necessary precautions for the application of these experimental techniques are emphasized. Special attention has been carried out to elucidate the consequence of a choice of indicators having a large distribution volume in the tissues.

Supraorbital cutaneous blood flow rate during carotid endarterectomy.

Background: The supraorbital skin region is supplied by the supraorbital artery, which is a branch of the internal carotid artery. The supraorbital cutaneous blood flow rate may therefore be influenced by changes in the internal carotid artery flow during carotid endarterectomy.

Methods: The supraorbital cutaneous blood flow rate was measured by the application of heat to the skin and following the subsequent dissipation of the heat in seven patients undergoing carotid endarterectomy.

Smokers have severely disturbed peripheral micro-circulation.

Aim: The aim of this study was to determine the effect of smoking a single cigarette on the blood flow rates in capillaries and arteriovenous anastomoses (AVAs) in light and heavy smokers in: a) the skin fold between the first and second fingers, and b) the pulp of the thumb.

Methods: Five light (10-12 cigarettes/day) and 5 heavy (>20 cigarettes/day) chronic smokers participated (4 men and 6 women, median age 40.5 years).

Thoracic sympatholysis with epidural blockade assessed by quantitative measurement of cutaneous blood flow.

Background: Quantifying sympathetic activity is difficult. Direct measurement is possible and superior to indirect techniques, but nerves to internal organs are not accessible in humans. Recently, we validated a quantitative technique for measurement of cutaneous blood flow using heat as an indicator.

Is non-specific aneurysmal disease of the infrarenal aorta also a peripheral microvascular disease?

Objectives: to examine whether aneurysmal disease of the aorta has a functional component in the peripheral microIvasculature.

Materials: ten normal persons; and 15 patients who had been operated on for ruptured non-specific infrarenal aortic aneurysm months to years previously were studied.

Methods: blood flow rates were measured: (a) in the subcutaneous adipose tissue of the forefoot by the(133)xenon local washout method (perfusion through nutritive capillaries supplied by arterioles with elastin in the tunica media); and (b) in the arteriovenous anastomoses of the pulp of the first toe as measured by the heat washout method (perfusion predominantly through thick-walled tubes without elastin).