The behavior of the fibrinolytic system during long-term orthopedic immobilization]

Our previous experimental studies on rats motionless for 7 to 60 days in special devices limiting their movements revealed a significantly increased activity of the fibrinolytic system (Groza, Artino) due to the "detention stress" rather then to the immobilization. Starting from these studies we have tried to observe the behaviour of the fibrinolytic system during long-term orthopedic immobilization (7-28 days) on patients having different injuries of the lower limb and submitted to orthopedic therapy (with or without osteosynthesis) to which an anticoagulant preventive treatment was added (heparin or low-molecular-weight substitutes such as Clivarine, Fraxiparine). We studied on 23 patients (11 male and 12 female) motionless for 14, 21, 28 days the plasma fibrinolytic activity (PFA) through euglobulin lysis time (ELT). Clinical investigation revealed that PFA did not change significantly during long-term orthopedic immobilization regardless of the duration of immobilization (14,21,28 days). Rosenfeld et al. (1994) described in healthy volunteers on bedrest for 36 hours an increase of PFA beginning at 24 hours of immobilization, this variation being capable of preventing stasis effects. Our results suggest that preventive anticoagulant therapy properly given during immobilization prevents thromboembolic events.