Early biochemical and hemodynamic changes after operation in a bloodless field.

Biochemical and hemodynamic changes during and after operation in a bloodless field have been investigated in 13 patients. The patients were athletes between the age of 21 and 38 years who were healthy except for an inveterate ligament injury of the knee joint. Capillary blood flow in the tibialis anterior muscle was measured by the radioactive-Xenon-clearance technique. Fine plastic catheters for blood sampling were inserted into both femoral veins and into one radial artery. A significant increase in blood flow occurred immediately after release of the occlusion. After release of the tourniquet, there was a marked decrease in pH both in the venous blood draining the operated leg and in the arterial blood. 40 min after release of the tourniquet, there was still a significant decrease in base excess. An increase of venous pO2 in the blood draining the operated leg was observed after re-establishment of blood flow. The estimated oxygen consumption was increased in the operated leg the first 10 min after tourniquet release.