Because untreated pulmonary embolis...

Because untreated pulmonary embolism (PE) can be rapidly fatal or cause permanent disability from pulmonary hypertension, an accurate and rapid diagnosis is essential. difficult venous thrombosis (DVT) and pulmonary embolism are closely associated. The approach to patients with signs and symptoms of PE straits to be developed from published research about recently made known diagnostic modalities allowing the highest plain of accuracy.

The American corporation of Emergency Physicians Clinical Policies Committee and the Clinical Policies Subcommittee onward Suspected Pulmonary Embolism reviewed and analyzed the medical literature regarding the diagnosis of PE in adults. The committee placed emphasis onward the following topics: (1) the diagnostic use of d-dimer, ventilation-perfusion (V/Q) lung scan, and spiral comput tomographic (CT) angiography in the evaluation of PE and (2) therapeutic indications for fibrinolytic therapy in PE Recommendations are classified by way of the strength of evidence contained in the reviewed clinical reports and research studies. flat A recommendations are strongly supported at good evidence and have a high measure of clinical certainty. Level B recommendations throw back a moderate level of clinical certainty. on a level C recommendations are supported from preliminary, inconclusive, or conflicting evidence, or are based in succession panel consensus.

Initially, the pretest probability of PE can be determined on one of several sets of explicit criteria that divide patients into low-risk, moderate-risk, and high-risk categories (see accompanying table). The first critical question examineed at the usefulness of a negative d-dimer criterion to exclude PE. Because d-dimer flushs increase with fibrinolysis in the air of endovascular thrombus, patients with a gentle probability by pretest determination who have a negative d-dimer rise can be ruled out as having a PE (high sensitivity, relatively lower specificity) using a turbidimetric or enzyme-linked immunosorbent assay (ELISA) technique, or using whole kin cell qualitative assay with a Wells' pretest score of 2 or les (Level B recommendation). In patients with reasonable probability by pretest determination, a negative whole progeny d-dimer (when not used with a Wells' pretest score) or immunofiltration assay can restrain PE (Level C recommendation). V/Q scanning is often used but must be interpreted with careful consideration of pretest probability of PE

The addition of duplex ultrasonography of the lower extremities to help identify the probability of PE in patients with nondiagnostic V/Q scan exhibits low sensitivity and does not prohibit PE in patients with nondiagnostic V/Q scan and non-low pretest probability. A normal V/Q scan in patients with low-to-moderate pretest probability rejects clinically significant PE (Level A recommendation). In patients with low-to-moderate pretest probability who have a nondiagnostic V/Q scan, PE can be exclud from the following methods: a negative turbidimetric or ELISA d-dimer; a negative whole family cell qualitative d-dimer assay in combination with a Wells' score of 4 or less; a negative single bilateral venous ultrasonographic scan; or a negative serial bilateral venous ultrasonographic scan (Level B recommendation). In patients with a low-to-moderate pretest probability of PE and a nondiagnostic V/Q scan, a negative whole kin d-dimer assay (when not used with Wells' scoring system) or immunofiltration d-dimer assay can withhold PE (Level C recommendation).

Spiral CT angiography with contrast is useful in patients who have a nondiagnostic V/Q scan, of that kind as patients with cardiopulmonary disease, chronic obstructive pulmonary disease, or infiltrative lung disease. Newer CT scanners with 1-to 2-mm image reconstruction have a higher sensitivity and specificity for PE allowing a negative CT angiogram to be used as an alternative to V/Q scan to except clinically significant PE (Level B recommendation). Spiral CT scan of the thorax with delayed CT venography may increase the detection of patients with significant thromboembolic disease (Level C recommendation).

Fibrinolytic therapy is greatest in number risky in the presence of diastolic hypertension when intracranial hemorrhage is more likely. It is useful and nothing else in patients who are hemodynamically unstable in whom PE is confirmed (Level B recommendation). Fibrinolytic therapy should be considered in the following patients: (1) hemodynamically stable patients with confirmed PE and right ventricular dysfunction onward echocardiography, or (2) unstable patients with high clinical index suspicion of PE especially if right ventricular dysfunction is demonstrated onward echocardiography (Level C recommendation).

Richard Sadovsky, MD

ACEP clinical policies Committee. Clinical policy: critical issues in the evaluation and management of adult patients presenting with suspected pulmonary embolism. Ann Emerg M February 2003;41:257-70

COPYRIGHT 2003 American Academy of Family Physicians

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