Quality of Ultrasound Requests for Suspected Lower Limb Deep Vein Thrombosis: A Clinical Audit
By Gemma Campbell, Gary Scott, Dumfries and Galloway NHS Board
Introduction:
National Institute for Health and Care Excellence (NICE) guidelines recommend ultrasound (US) for patients with suspected lower limb Deep Vein Thrombosis (DVT) based on a high WELLS score ≥2 or WELLS score ≤1 + elevated D-dimer. The British Medical Ultrasound Society (BMUS) states requests should include a specific clinical question and an accurate clinical history to support the suspected diagnosis. This audit aimed to determine whether adequate clinical history is provided on DVT US requests.
Methods:
Retrospective audit of DVT lower limb US scans performed at an NHS health board between 1st March 2023 – 31st May 2023, including a sample of 241 scans. Data collected from US requests, reports and clinical portal were evaluated, and clinical history was correlated with WELLS score
criteria to determine whether adequate information +/- d-dimer was provided to justify requests.
Results:
Of 241 US scans, 36 (15%) were positive and 205 (85%) were negative for DVT. The majority of requests included a clinical question (89%); however, only 46% of requests included a WELLS score. D-dimer was performed in 153 (63%) cases; however, only 124 (81%) stated the value on the request. In total, 347 clinical history insufficiencies/ errors were identified, including vague descriptions of swelling and tenderness, failure to deduct points for alternative diagnoses, i.e. infection, and errors regarding immobility and cancer history. Overall, 61% of requests were justified, and 39% provided inadequate clinical history (22% equivocal and 17% unjustified). Unjustified requests (17%) accounted for a loss of 13 hours and 40 minutes of scanning time over three months.
Conclusion:
Over a third (39%) of DVT US requests failed to provide adequate clinical history in accordance with NICE and BMUS guidelines. Improving US request quality would enhance patient care and service efficiency. To achieve this, a standardised DVT request format will be proposed, alongside re-education for referrers and sonographers.