Tourniquet effects on muscle oxygen tension in dog limbs. Experiments with cooling and breathing intervals.

The effects of repeated tourniquet applications with breathing periods on muscle pO2 was studied in adult dogs. A tourniquet was applied to one hind limb. The tourniquet was repeatedly inflated for 1 h; four ischemic periods were separated by 20-min recirculation intervals. In other series the limb was cooled prior to tourniquet application, or the animal was treated with the proteinase inhibitor Trasylol. Following tourniquet deflation, the pO2 value in the gastrocnemius muscle initially increased, reaching a peak within 5 min. This initial increase became less apparent with repeated periods of ischemia as well as with prolongation of the ischemic period. The results indicate that cooling prior to tourniquet application represents a better technic than the use of breathing periods or Trasylol.