I read with interest the article by Sorkin et al1 in the October 1995 issue of the Archives. Given that vascular isolation has been expertly done and the tourniquet has been adequately applied, the authors have correctly observed that decreasing the flow rate to the isolated extremity will decrease the leakage of recumbent tumor necrosis factor α into the general circulation. Our unpublished data suggest that decreasing the flow rate by 20% will decrease the leakage from the extremity to the general circulation by 50%.
Caution should be used in decreasing the flow. Flow rates of less than 30 cm3 per limb volume result in a decrease of flow into the microcirculation and hypoxia. Monitoring flow in the microcirculation using the laser Doppler in the unoperated-on extremity will give a good idea of the minimum level to which the flow rate can be decreased without causing hypoxia. The