Audit evaluating the factors contributing to the incidence of pulmonary embolism in patients at a specialist orthopaedic centre

1AP4-7

Background and Goal of Study: An estimated 25,000 people die in the UK from venous thromboembolism (VTE) in hospital every year [1]. The incidence of a fatal pulmonary embolism (PE) following a joint replacement is 0.19% to 3.4%. In 2010 NICE issued new recommendations on assessing and reducing the risk of VTE in hospital in-patients. The aim of this audit was to evaluate the factors contributing to the occurance of pulmonary embolism in the orthopaedic patient population between 1/06/2007 to 9/07/2009.

Materials and Methods: All patients at our institution who had a positive CT pulmonary angiogram (CTPA) within the above time frame were evaluated. We assessed information regarding age, type of surgery, risk factors, the type of anticoagulation commenced. We assessed any peri-operative VTE prophylaxis taken.

Results and Discussion: There were 32 positive CTPA from 1/06/07 to 9/07/ 09, 3 cases were excluded as case notes were missing. Overall 29 cases were evaluated. 41% (12/29) of the PE occured in patients undergoing spinal surgery and 41% (12/29) in those undergoing lower limb surgery. Post operative days one to three had the highest incidence of PE. Pre-operative low molecular weight heparin (LMWH) was instituited in only one case. Presence of intraoperative thromobo-embolism deterent stockings (TEDS) was documented in 45% (13/29) of cases and calf compression devices present in 14% of cases (4/29). Post operative TEDS was documented in 75% (22/29) cases and calf compression device in 59% (17/29) cases.

Table: [Percentage of patients with risk factors]

Conclusion(s): In our institution patients undergoing spinal and lower limb surgery were at highest risk of developing a post operative PE. In spinal surgery the risk of post operative bleeding needs to be balanced with the risk of post operative VTE. However simple mechanical prophylaxis should be instituted pre-operatively and continued post operatively in all cases. Following the NICE recommendations a risk assessment form has been implemented for VTE including guidance on prescribing thromboprophylaxis. A re-audit can be undertaken to look at compliance with guidelines and success in preventing episodes of VTE.