This is a retrospective assessment of the clinical appropriateness of D-dimer requests from the A&E department in patients with suspected pulmonary embolism (PE), with the aim to optimise practice and therefore maximise cost-effectiveness.
We audited the first 50 patients for whom D-dimers were requested by the A&E department from January 2009 onwards. D-dimers ordered for suspected Deep Vein Thombosis were excluded. The selection of criteria audited was based on the standards set by the British Thoracic Society (BTS)for A&E middle grade medical staff for testing D-dimers. The following data were collected from the patients’ notes: The actual D-dimer result (D-dimer < 220 is taken to be negative as per haematology laboratory values), and whether the following were done prior to requesting the D-dimer: A PA chest X-ray, senior review, documentation of pre-test clinical probability for PE.
Overall, it was found that 30 out of the 50 patients had raised D-dimers. A chest X-ray was not done at all for 4 patients. 23 chest X-rays were done after blood D-dimer was requested. Most of the X-Rays were AP view. 33 patients for whom D-dimers were requested were not reviewed by a middle grade doctor. Only 4 patients were documented to have major risk factors for PE and 3 out of those 4 had raised D-dimers. Finally, only 4 out of the 30 patients with a raised D-dimer had a CT pulmonary angiogram or V/Q Scan, which revealed that none of them had a PE.
This audit proves that D-dimers are being ordered inappropriately by the A&E staff, leading to false positives and unnecessary further investigations, thus wasting the finite resources of the overburdened National Health Service.
We recommend that junior A&E doctors should receive formal teaching on BTS guidelines in the management of PE. We also recommend that the BTS guidelines are incorporated into the trust guidelines for reference when dealing with suspected PE.
Dodiy Herman, No Financial Disclosure Information; No Product/Research Disclosure Information