LAUSR

BACKGROUND The heterogeneity of inpatient pulmonary embolism (PE) presentations may lead to Computed Tomography Pulmonary Angiograms (CTPAs) being over requested. Current clinical predictors for PE, including Wells criteria and Pulmonary Embolism Rule-out Criteria (PERC), have predominantly focused on outpatient and Emergency Department populations. AIM To determine the clinical indicators for ordering inpatient CTPAs and the predictors of positive scans for PE. METHODS Consecutive inpatient CTPAs (performed >24hours after admission) from January 2017 to December 2017 were retrospectively reviewed. Variables including baseline characteristics, vital signs and risk factors for PE were extracted. RESULTS 312 CTPAs were reviewed (average patient age 67 years, 46% male) and 36 CTPAs were positive for PE (11.5%). The average time to inpatient CTPA request was 7 days. Clinical indicators associated with positive scans were hypoxia (OR 2.4; CI 1.1 - 5.6), tachypnoea (OR 2.5; CI 1.2 - 6.0), recent surgery or immobilisation (OR 2.7; CI 1.2 - 6.4), S1Q3T3 pattern on ECG (OR 7.2; CI 1.4 - 35.7), and right bundle branch block pattern on ECG (OR 4.7; CI 1.6 - 13.1). Hypotension, fever and malignancy were not significant. Both PERC and Wells criteria had poor positive predictive value (27% and 12% respectively), but the negative predictive value for PERC was 100% and 95.8% for Wells. CONCLUSION Inpatient CTPAs appear to be over-requested and can potentially be rationalised based on a combination of clinical predictors and Wells' criteria and/or PERC rule. Further prospective studies are needed to develop accurate clinical decision tools targeted towards inpatients. This article is protected by copyright. All rights reserved.