PREVALENCE OF CYCLIC CHANGES IN LIMB VOLUME (VOLUMOTION) OF MALE-PATIENTS WITH KNEE INJURY AND THE EFFECTS OF ISCHEMIA/REPERFUSION DUE TO TOURNIQUET

During surgery of limbs tourniquet up to a maximum of 2 h is frequently applied which may cause ischemia/reperfusion injury (IRI). During this condition the presence of vasomotion may have consequences for the perfusion and nutritive state of the tissues. We used a noninvasive plethysmographic method to investigate periodic changes in limb circumference (volumotion) in healthy male patients (n = 24) undergoing surgery for knee injury. To facilitate surgery a tourniquet was applied to the thigh, which caused an IRI of the leg. Results are given as mean of all values +/- SEM. Immediately after tourniquet release (duration 57.75 +/- 5.19 min) blood lactate levels in the femoral vein increased significantly from 1.40 +/- 0.08 to 2.59 +/- 0.20 mmol/l (p < 0.001) and pH fell from 7.39 +/- 0.01 to 7.32 +/- 0.01 (p < 0.00 1). Preoperatively 10 out of 24 patients (42%) showed signs of volumotion on the injured leg with a periodicity ranging from 0.8 to 6.9 cycles/min, whereas none showed volumotion in the control leg (p < 0.001). In the second measurement, taken after surgery and reperfusion while peripheral sympathetic nerves were blocked, 7 out of 18 patients (39%) showed volumotion on the injured leg and O on the control leg (p < 0.004). 6 h after IRI, volumotion was observed in 11 out of 17 patients (65%) on the injured leg and in 1 patient (6%) on the control leg (p < 0.001). The mean volume change in the patients with volumotion on the injured leg was 0.057 +/- 0.007 ml/100 ml tissues. Raising venous pressure to 55 mm Hg did neither significantly change the amplitude of volumotion (0.055 +/- 0.008 ml/100 ml tissue, p = 0.80), nor the incidence of volumotion. There was no significant difference in the incidence of volumotion in the injured leg during the three measurements. We observed periodic changes in limb circumference mainly in the injured leg; it therefore seems unlikely that these events are directly related to central hemodynamic changes. We suggest that volumotion reflects slow wave vasomotion possibly resulting from a change in sympathetic or parasympathetic activity in response to both the knee injury and the ischemia reperfusion injury. These events may originate either from arterioles or arteries in the leg or from cyclic coordinated vascular smooth muscle events, which may be either venous or arterial in origin.