Immobility and DVT Prophylaxis

Venous thromboembolism (VTE) includes deep-vein thrombosis (DVT) and pulmonary embolism (PE). Immobility removes the calf-muscle pump that normally propels venous blood back toward the heart. Blood flow slows in the deep veins, particularly during prolonged bed rest, while acute illness may add inflammation, endothelial activation, and a hypercoagulable state. For an acutely ill hospitalised medical patient, immobility lasting at least 3 days is a major independent VTE risk factor. The risk is not cancelled by the absence of leg pain; DVT may be clinically subtle or silent. Prevention therefore requires two simultaneous judgements: - Is the patient likely to develop VTE? - Is anticoagulant-related bleeding more likely than the benefit of prevention? That balance can change quickly. A new gastrointestinal bleed, falling platelet count, renal deterioration, or preparation for surgery may require a different prophylaxis plan even if the patient remains immobile.