Risk assessment and prophylaxis of venous thromboembolism in acutely and/or critically ill patients

Both undetected and clinically evident venous thrombosis and venous thrombo embolism (VTE) can seriously impact the prognosis of acutely and/or critica lly ill patients. Pulmonary embolism (PE) is harder to diagnose in the acut ely and/or critically ill, many of whom also have developed respiratory fai lure for other reasons. Deep vein thrombosis (DVT) of the upper and lower e xtremities can subsequently complicate insertion of central venous catheter s, leading to PE, sepsis and septic shock. Recovery from the original criti cal illness (e.g weaning from mechanical ventilation) can be adversely affe cted by these complications. There are recent data suggesting that, for pro phylaxis, low-molecular-weight heparin (LMWH) is more effective than unfrac tionated heparin (UFH) in critically ill trauma patients, and that high-dos e LMWH is more effective than placebo or low-dose LMWH in seriously ill med ical patients. In both populations, LMWH appeared safe. While LMWH appears superior to UFH in acute stroke patients to prevent venographically-proven lower-extremity DVT, whether it provides a superior long-term outcome after acute stroke is uncertain. One study found that a high dosage of the LMWH dalteparin was more effective than placebo in preventing left ventricular t hrombi after acute myocardial infarction, but there was a significant safet y cost. Current questions surrounding prophylaxis of VTE and the use of LMW H in acutely and/or critically ill patients include whether monitoring leve ls and dosage adjustment in some of these patients would improve outcome, a nd whether the diagnosis of VTE can be improved so that treatment can be in stituted when prophylaxis has failed. Copyright (C) 2001 S. Karger AG, Base l.