Improving the diagnosis of pulmonary embolism in the emergency department

The diagnosis of pulmonary embolism (PE) in the emergency department is challenging due to the wide range of non-specific symptoms, lack of clinical diagnostic criteria, and imperfect investigations. Various scoring systems exist in an attempt to limit unnecessary investigations in those with low risk of PE. Following a baseline audit and subsequent PDSA cycles we implemented a flowchart for use in patients suspected of pulmonary embolism encouraging the correct use of the Wells Score and Pulmonary Embolism Rule out Criteria (PERC). The standard used for comparison was based on the NICE guidelines for diagnosis of PE with the addition that PERC could also be used if appropriate. Data was collected over four week periods before and after the introduction of our flowchart in two emergency departments in Melbourne. We aimed to increase documentation of pre-test probability, reduce inappropriate investigations, and increase the use of interim parenteral anticoagulation where there was a delay to imaging. Results showed an increase in the documentation of pre-test probability and the proportion of investigations requested that were inappropriate was reduced. The percentage of inappropriate d-dimers was reduced from 36% to 24%; the percentage of inappropriate CTPAs was reduced from 34% to 10%; and the percentage of inappropriate V/Q scans was reduced from 42% to 14%. Implementation of a simple diagnostic algorithm led to an increase in documentation of pre-test probability and a reduction in inappropriate and unnecessary investigations. This intervention may be applicable to other emergency departments where similar issues in diagnosing pulmonary embolism exist.