Venous thromboembolism (VTE) comprises both deep vein thrombosis (DVT) and pulmonary embolism (PE). DVT occurs when an abnormal blood clot forms inside a vein deep in the leg. DVT may cause leg pain and/or swelling but is often clinically silent. PE occurs when all or part of a DVT breaks away from its site in a vein and travels through the venous system to lodge in the lungs. PE may cause chest pain, shortness of breath, tachycardia, hemoptysis, or pre-syncope but is often clinically silent.
In pregnancy, due to hormonal influences on vascular tone and compressive effects on veins by the enlarging uterus, DVT in pregnancy generally presents in the lower extremities, with a predisposition for the left leg (70 to 80 per cent). In contrast to their presentation in non-pregnant patients, DVTs are often isolated to the iliac and/or femoral vein during pregnancy (61 per cent) (Chan et al., 2014).The first and second trimesters of pregnancy convey similar risks for DVT, with a higher risk in the third trimester and the first three weeks postpartum. PE occurs more commonly postpartum, decreasing in incidence after the first six weeks (Chan et al., 2014).
VTE is one of the most common and preventable complications of hospitalization. The rate of asymptomatic hospital-acquired DVT, if thromboprophylaxis is not used, is 10 to 40 per cent after general surgery and 40 to 60 per cent after hip surgery. The rate of symptomatic VTE is up to five per cent (or more) of medical and surgical patients if thromboprophylaxis is not used (Geerts et al., 2008).
VTE remains an important cause of maternal morbidity and mortality in Canada with an overall incidence of DVT and PE of 12.1 per 10,000 and 5.4 per 10, 000 pregnancies, respectively (Chan et al., 2014). VTE occurs at a rate of 5.4 per 10,000 antepartum, 7.2 per 10,000 peripartum, and 4.3 per 10,000 pregnancies postpartum. Postpartum PE is a leading cause of maternal mortality in Canada, with up to 17 maternal deaths each year (Chan et al., 2014).
To prevent VTE in hospitalized adult and obstetrical patients by implementing strategies which increase the use of evidence-based thromboprophylaxis.