155 The PIC Protocol: A Novel Emergency Department Ultrasound Protocol for Patients Presenting With Dyspnea

Lung ultrasound in heart failure: Lessons from re-analysis of Lung Ultrasound 2011 database

Introduction: In the setting of patients presenting with shortness of breath to an Emergency Department a simple lung ultrasound protocol aimed at detecting pulmonary oedema has been shown to have diagnostic accuracy of 85%. This article reviews data from the original study, in an attempt to determine whether adjusting the protocol and/or interpretive criteria would improve results. Method: A large lung ultrasound project provided the dataset. Inter-rater and intertest discrepancies were reviewed. Then original stored images and comments were retrospectively analysed using alternate interpretive criteria. Specific variations included changing the number of B-lines required to define 'wet lung' and assessing other pleural line abnormalities. Where they had been acquired cardiac loops were reviewed in addition to the lung images. Results: The 204 original studies available were reviewed. Some disagreement could be attributed to inexperience and unclear definitions. Adjusting the number of B-lines did not improve diagnostic accuracy. All positive scans, with numerous B-lines were reviewed using more advanced diagnostic criteria (pleural line abnormalities) and the number of false positives was decreased. In cases where cardiac views were available, their inclusion was beneficial. Conclusion: A simple lung ultrasound protocol to assess for 'wet lung' in patients presenting to Emergency Departments provides diagnostic accuracy of around 85% in the hands of relative novices. More advanced interpretation of the same_ultrasound images, and the addition of cardiac views, is likely to further improve diagnostic accuracy.

Comparison of a basic lung scanning protocol against formally reported chest x-ray in the diagnosis of pulmonary oedema

Introduction: Brief lung scan protocols have been recommended as a useful adjunct to identify pulmonary oedema in the breathless elderly patient. Some papers quote diagnostic accuracies above that of chest x-ray. Method: We recruited a prospective convenience sample of patients over sixty years of age reporting any breathlessness on presentation to the emergency department. Those who received both bedside lung scan and chest x-ray later had their case notes audited by an expert cardiologist for the cause of their breathlessness at presentation. Admission diagnosis was also extracted. Results: 204 comparative data sets were collected. Compared with cardiologist chart review, delayed expert radiology report had a diagnostic accuracy of 92.2% (95%CI 87.6 to 95.1). Bedside interpretation of lung scan protocol had a diagnostic accuracy of 85.3% (95%CI 79.8 to 89.5). The difference of 6.9% between the two accuracy measures was significant (95%CI 0.69 to 13.1). Admission diagnosis accuracy, which encompasses inexpert x-ray interpretation was 70.2%(95%CI 62.9 to 76.6), significantly less than either lung scan or expert chest x-ray report. Conclusion: For identifying heart failure in breathless patients, urgent chest x-ray with delayed formal report has not been shown to be redundant. Basic lung scan protocols should not yet replace chest x-ray, but may be more reliable in the interim than inexpert clinician interpretation of chest x-rays.