The Effect of Surgery, Injury, and Prolonged Bed Rest on Calf Blood Flow

Using strain gauge plethysmography, the resting calf blood flow, mainly a measure of muscle blood flow, has been estimated in control subjects, in patients during and after surgical procedures, and in patients during prolonged bed rest following surgery or operation. During general surgical procedures, the calf blood flow was reduced by 38% of the preoperative values. After operation, there was a progressive fall in calf blood flow, the lowest values showing a reduction averaging 58% of the preoperative flow. The reductions in blood flow were associated with an increase in peripheral resistance, indicating that local vasoconstriction was the cause of the reduced flow. Low calf blood flow was also shown to occur in patients who were confined to bed for long periods after injury or operation. It is suggested that by reducing venous return, the decreased calf blood flow during and after surgery, and during prolonged bed rest, may be a factor in the development of deep vein thrombosis in. surgical patients.