Lowering risk of DVT and PE following surgery

Surgery is a well recognised cause of deep vein thrombosis, both during and after operation. The risk is particularly dependent upon:

• type of surgery - incidence (without prophylaxis)
  • knee - 75%
  • hip fracture - 60%
  • elective hip surgery - 50-55%
  • retropubic prostatectomy - 40%
  • general abdominal surgery - 30-35%
  • gynaecological surgery - 25-30%
  • neurosurgery - 20-30%
  • transurethral resection of prostate - 10%
  • inguinal hernia repair - 10%
    
    
• age of patient - DVT is rare post-operatively before the age of 40 years

Following surgery without prophylaxis, DVT developed in 22% of general surgical patients and 47% of orthopaedic patients. Of these, 2% had non-fatal pulmonary embolism and 0.8% had a fatal PE.

NICE state that all patients should be assessed for risk of bleeding before offering pharmacological VTE prophylaxis

• pharmacological VTE prophylaxis should not be offered to patients with any of the risk factors for bleeding shown in box 1, unless the risk of VTE outweighs the risk of bleeding
• patients' risks of bleeding and VTE should be reassessed within 24 hours of admission and whenever the clinical situation changes, to:
  • ensure that the methods of VTE prophylaxis being used are suitable
  • ensure that VTE prophylaxis is being used correctly
  • identify adverse events resulting from VTE prophylaxis
    
    
• Box 1: Risk factors for Major Bleeding (1)

Hospital acquired VTE (2):

• Hospital-acquired venous thromboembolism (VTE), also known as hospital-acquired or hospitalassociated thrombosis (HAT), covers all VTE that occurs in hospital and within 90 days after a hospital admission
  • common and potentially preventable problem.
  • HAT accounts for 50-60% of all VTE seen
  • in 2013-14, there were around 24,700 admissions for pulmonary embolism and 19,400 for DVT in England. In 2013 in England and Wales, there were 2,191 deaths recorded as due to pulmonary embolism and 2,816 due to DVT

Reference:

• 1) NICE (January 2010). Reducing the risk of venous thromboembolism
• 2) NICE (March 2018). Venous thromboembolism in over 16s: reducing the risk of hospital-acquired deep vein thrombosis or pulmonary embolism