Risk Assessment and Prophylaxis of Venous Thromboembolism in Acutely and/or Critically Ill Patients

Abstract

Both undetected and clinically evident venous thrombosis and venous thromboembolism (VTE) can seriously impact the prognosis of acutely and/or critically ill patients. Pulmonary embolism (PE) is harder to diagnose in the acutely and/or critically ill, many of whom also have developed respiratory failure for other reasons. Deep vein thrombosis (DVT) of the upper and lower extremities can subsequently complicate insertion of central venous catheters, leading to PE, sepsis and septic shock. Recovery from the original critical illness (e.g. weaning from mechanical ventilation) can be adversely affected by these complications. There are recent data suggesting that, for prophylaxis, low-molecular-weight heparin (LMWH) is more effective than unfractionated heparin (UFH) in critically ill trauma patients, and that high-dose LMWH is more effective than placebo or low-dose LMWH in seriously ill medical 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 thrombi after acute myocardial infarction, but there was a significant safety cost. Current questions surrounding prophylaxis of VTE and the use of LMWH in acutely and/or critically ill patients include whether monitoring levels and dosage adjustment in some of these patients would improve outcome, and whether the diagnosis of VTE can be improved so that treatment can be instituted when prophylaxis has failed.

Systemic hemodynamic effects of sequential pneumatic compression of the lower limbs: a prospective study in healthy volunteers

“…Thromboembolic complications represent a prominent cause of morbidity and mortality worldwide, and fatal pulmonary embolism remains a significant risk in patients undergoing major surgical procedures [1][2][3]. Low-molecularweight heparin represents the most effective antithrombotic prophylaxis, but it is associated with a remarkable risk of bleeding complications [3,5,11].…”

“…Low-molecularweight heparin represents the most effective antithrombotic prophylaxis, but it is associated with a remarkable risk of bleeding complications [3,5,11]. Sequential pneumatic compression of the lower limbs is an efficient alternative for thromboprophylaxis, especially in those patients at high risk of bleeding complications [4][5][6][7][8]; however, sequential pneumatic compression may influence systemic hemodynamics by affecting venous flow to the heart and arterial flow in the lower limbs.…”

“…Risk factors, diagnostic criteria, and treatment of this condition have been extensively studied, and many efforts have been made to prevent this disorder and its potentially life-threatening complications [1][2][3].…”

Prophylactic anticoagulation with enoxaparin: Is the subcutaneous route appropriate in the critically ill?*

“…Critically ill patients are believed to carry a higher risk of venous thromboembolism due to venous stasis as a result of immobility, sedation and relaxation, hypercoagulability resulting from acute phase responses, and vessel injury caused by catheterization or other invasive interventions (15)(16)(17). Prevalence of deep vein thrombosis in medical and surgical critically ill patients receiving no prophylaxis was reported in the range of 14% to 32% (18 -20).…”

Desafios na profilaxia do tromboembolismo venoso: abordagem do paciente crítico

“…A TVP e o TEP contribuem significativamente para aumentar a morbimortalidade de pacientes críticos 10,11 . Em pacientes internados em UTI a ocorrência de TVP é alta 12 .…”