Prophylaxis

Prophylaxis

Prophylactic methods can be divided into mechanical and pharmacological. A variety of mechanical methods have been tried, but only the use of graduated elastic compression stockings and external pneumatic compression have been William Morrant Baker , 1839–1896, surgeon, St Bartholomew’s Hospital, London, UK, described these cysts in 1877. - - - - - shown to be worthwhile by reducing the incidence of throm - bosis. Newer devices, such as electronic nerve stimulators, lack evidence of e ffi cacy to date. More recent emerging evidence is - casting some doubt on the benefit of mechanical prophylaxis in surgical patients and ther e are further studies underway . Compression-based prophylactic measures should be avoided in patients with peripheral vascular disease. Pharmacological methods are more e ff ective than mechanical methods at risk reduction, although they carry an increased risk of bleeding. In the past, low-dose unfractionated heparin was used both intravenously and subcutaneously . In the absence of renal impairment, most centres currently use low-molecular-weight heparin (LMWH) given subcutaneously . This is given once daily , does not require monitoring and has a lower risk of bleeding complications. Patients who are being admitted for surgery may be graded as low , moderate or high risk for pulmonary embolism and VTE ( Tables 62.5 and 62.6 ). Patients in the medium- or high-risk groups should be considered for pharmacological

Figure 62.34 An ascending venogram of a deep vein thrombosis seen as /f_i lling defects (arrows) with contrast passing around the thrombus. Figure 62.35 A computed tomography pulmonary angiogram show

ing pulmonary emboli as /f_i lling defects (arrow) in the pulmonary artery. TABLE 62.5 Modi /f_i ed Wells criteria for predicting pulmonary embolism (PE). Variable Score Clinical signs and symptoms of DVT (minimum of leg 3 swelling and pain on palpation of deep veins) Alternative diagnosis less likely than PE 3 Heart rate >100 /uni00A0 bpm 1.5 Immobilisation >3 days or surgery within past 4 weeks 1.5 Previous DVT or PE 1.5 Haemoptysis 1 Malignancy (treatment or palliation within past 6 1 months) A score of <4 means PE is unlikely (12.4%); >4 is suggestive of PE (37.1%). bpm, beats per minute; DVT, deep vein thrombosis.

/uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF prophylaxis with an anticoagulant medication. Recent level 1 evidence suggests that the addition of mechanical prophylaxis in such patients a ff ords no additional benefit.

for venous thromboembolism. Low Minor surgery <30 minutes; any age; no risk factors Major surgery >30 minutes; age <40; no other risk factors Minor trauma or medical illness Medium Major surgery; age 40+ or other risk factors Major medical illness: heart/lung disease, cancer, in /f_l ammatory bowel disease Major trauma/burns Minor surgery, trauma, medical illness in patient with previous DVT, PE or thrombophilia High Major orthopaedic surgery or fracture of pelvis, hip, lower limb. Major abdominal/pelvic surgery for cancer Major surgery, trauma, medical illness in patient with DVT, PE or thrombophilia Lower limb paralysis (e.g. stroke, paraplegia) Major lower limb amputation DVT, deep vein thrombosis; PE, pulmonary embolus.