Usefulness of Clinical Pre-test Scores for a Correct Diagnostic Pathway in Patients with Suspected Pulmonary Embolism in Emergency Room

ABSTRACT

Background:

Pulmonary Embolism (PE) is a disease characterized by not specific signs and symptoms. In Italy, there are about 65,000 cases per year; mortality is about 30% if PE is not identified and decreases to 2-8% if PE is recognized and treated. International guidelines include several strategies for diagnosing the disease with confidence. The diagnostic pathway includes a clinical approach with the Wells and Revised Geneva scores, the use of D-dimer and, eventually, a Computed Tomography (CT). The CT seems to be the ideal investigation to confirm or exclude PE but it is not free from complications. Sometimes in medical practice clinicians tend to order CT more frequently than necessary, reflecting a defensive behavior instead of an evidence based behavior. This practice exposes patients to some risks, especially for kidney.

Objective:

To identify the efficiency of the use of clinical scores and diagnostic algorithms following the latest guidelines in patients with suspicion of PE. To analyze how many CTs could be avoided using the right approach and to evaluate the importance of any clinical variable. Eventually, to apply the two scores together (Wells score and Revised Geneva score).

Methods and Materials:

A retrospective, single centre, cohort study was performed from January 2011 to April 2012. All patients who made a CT in the Emergency Room for suspicion of PE were collected and classified in two groups: PE - and PE +. In all patients Wells Score and Revised Geneva Score were calculated.

Results:

111 patients (64% female; mean age 72±16 years) were studied. There were no differences in anamnestic, clinical and laboratory variables between the two groups. With the classic pathway 6 patients could have been safely ruled out without performing a CT. With the Wells score one PE+ patient had a low pre-test probability; with the Revised Geneva score actually 7 PE+ patients had a low pre-test probability. These results were source of doubt about the reliability of the scores. So we tried to use the two scores together, and we achieved these results: in 7 patients PE could have been safely excluded without even using CT scan.

Conclusions:

The study focuses on the clinical approach to PE. The clinical scores proposed by guidelines (Wells score and Revised Geneva score) are unreliable if used alone, out of a pathway. We propose to the application of the two score together to exclude PE safely without performing CT when not necessary.

Keywords:

Pulmonary Embolism, Wells score, Revised Geneva score, CIN (contrast-medium-induced nephropaty), clinical diagnosis, Guidelines.