PP 97 RULING OUT PE: A NOVEL APPROACH USING END-TIDAL CO2 WITH COMPRESSION ULTRASONOGRAPHY AND TRANSTHORACIC ECHOCARDIOGRAPHY IN PULMONARY EMBOLISM DIAGNOSIS (CUEPED)

Abstract

INTRODUCTION

Pulmonary embolism (PE) is a common illness with substantial morbidity and mortality. The aim of this study was to evaluate the diagnostic accuracy of CUEPED, a novel method of ruling out pulmonary embolism using a combination of end-tidal CO2 (ETCO2), Compression Ultrasonography (CUS) and Transthoracic Echocardiography (TTE).

MATERIALS AND METHODS

In this prospective study, patients who presented to Emergency Department at University Malaya Medical Centre with suspected acute pulmonary embolisms from December 2013 to October 2014 were assessed using CUEPED. CUEPED was considered positive if the measured ETCO2 was less than 35 mmHg, or if there was presence of venous incompressibility in lower limb ultrasonography or if tricuspid annular plane systolic excursion (TAPSE) in transthoracic echocardiography was less than 1.6cm. All patients were diagnosed using computed tomography pulmonary angiography (CTPA). Data obtained was analyzed to determine if a negative CUEPED would be able to conclusively rule out a pulmonary embolism. All patients received a CTPA for confirmation of diagnosis.

RESULTS

30 patients (mean age 48 years) were included with an equal distribution between genders. The incidence of PE was 56.7%. CUEPED had a sensitivity of 100% (95% CI 80.3% to 100%) for PE. Negative CUEPED ruled out PE (P=0.001) with a negative predictive value of 100% (95% CI, 58.9% to 100%). Positive CUEPED ruled in PE with a low specificity (53.8%, 95% CI 25.2% to 80.6%) and moderate positive predictive value (73.9%, 95% CI 51.5% to 89.7%).

DISCUSSION

This prospective diagnostic study showed conclusively that a negative CUEPED proved reliable in ruling out pulmonary embolism.