Venous blood gas analysis for evaluation of blood circulation of the hand during continuous axillary block.

Computer analysis of blood gas measurements was used to evaluate the effect of a continuous axillary block on the circulation of the hand of a patient suffering from regional circulatory insufficiency due to ligation of the brachial artery. Venous blood samples drawn from the cephalic vein were analysed at 0, 1, 2.5 and 18 hours after the blockade. Improved circulation of the hand was indicated by decreased arterio-venous oxygen difference and increased venous oxygen partial pressure following the blockade. The advantage in using the extended blood gas analysis is the possibility of estimating the main factors influencing tissue oxygenation: oxygen capacity, oxygen partial pressure and the haemoglobin oxygen affinity.