Blood Flow Studies in Man in Shock.
Abstract
In the severely ill surgical patient, there may be a deficit in the transport capacity of the skeletal muscle vascular bed out of proportion to the changes in blood flow. Normally a reduction in skeletal muscle blood flow gives a normal or increased transport function of the capillary bed. The double-isotope technique shows an increase in the extraction of the water-soluble isotope (Iodide-131 or Cr-51-EDTA) in relation to the isotope used to measure blood flow (Xenon-133). Small doses of thrombin intraarterially (dog) increase transiently both flow and transport but this response disappears with repeated thrombin injections, the transport response disappearing before the flow response. Normovolemic hemodilution (dog) with dextran-60 down to a hematocrit of 20% is associated with compensations of both the central and the peripheral circulatory systems. Below this level there is metabolite accumulation in the tissues. With normovolemic hemoconcentration there is marked metabolite accumulation with hematocrit above 55%. Trauma to skeletal muscle (dog) increases regional venous pO2, pCO2, lactate, K+ and osmotic pressure and decreases pH. Release of vascoactive kinins may be a factor in the disturbance in local circulatory regulation after trauma since a proteinase inhibitor given prior to trauma alters the flow response. The lung has a selective affinity for trapping of platelets. The hemodynamic changes seen with platelet trapping in the lung are not due to a mechanical blocking of the vascular bed. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1971
- Accession Number
- AD0721751
Entities
People
- David H. Lewis
Organizations
- University of Gothenburg