Limb exsanguination. II. The leg: effect of angle of elevation.

Although limb exsanguination prior to tourniquet inflation is usually accomplished using mechanical devices, elevation alone may still be employed under circumstances where mechanical means are contraindicated. The rather confusing advice within the literature as to duration of elevation, stimulated a study in the arm which revealed the optimal duration of elevation to be 5 min, a period somewhat longer than generally advised. Because the pattern of venous drainage within the leg is slightly different to that of the arm, we undertook a similar study to ascertain if our findings for the arm also held true for the leg. Volume changes in the calves of seven male volunteers during elevation at 45 degrees and 90 degrees were assessed using strain gauge plethysmography. To achieve maximal exsanguination it is recommended that the leg should be elevated at an angle of 45 degrees for 5 min. Higher angles of elevation produce slower and less complete exsanguination.