The patterns of ordering Computed Tomography Pulmonary Angiogram (CTPA) for diagnosis of pulmonary embolism (PE) in a rural health setting

Abstract

Background: Pulmonary embolism (PE) is a life-threatening condition with overall mortality of up to 20 % when left untreated. CTPA is the preferred investigation for diagnosis of PE for patients with normal kidney function. Several studies showed this test is being over employed without using available predictive tools i.e. Wells score, Modified Geneva score & D-Dimer Methodology: A retrospective review of patients' records who had CTPA for suspected pulmonary embolism from the period of 1st March 2015 to 28th Feb 2016. Patient's demographics and components of different scoring system were obtained by manual review of patient's electronic records.Result: A total of 249 CTPAs were done during this study period. In term of patient demographics, median age was 63 years and 48.6 % of patients were females. PE was diagnosed in 34 (13.7%) patients. Only 196 (76.6%) patients had a CXR as an initial investigation. Acute kidney injury was noted in 23 (14.0%) patients post CTPA.Revised Geneva score was calculated for all patients who had CTP for PE, only 10 (4 %) patients had a high probability on Revised Geneva score (score >11). Wells score could not be accurately calculated due to the retrospective nature of the study. Conclusion:The diagnostic yield of CTPA with a positive result for pulmonary embolism was 13.7%, which is below the recommended standards by the Royal College of Radiology (UK) (15.4% to 37.4%). Also, these findings were noted to be inferior compared with a similar study done in an Australian hospital. These findings may be attributed to the poor utilization of risk assessment tools (Geneva, Wells and D-Dimer) and not performing simple chest X-ray prior to CTPA. A protocol to request CTPAs is needed which is suited to the regional settings to avoid unnecessary CTPAs and its complications.