Diagnostic Management Of Pulmonary Embolism (PE)

The diagnostic management of PE should be based on the hazards of a suprious diagnosis versus the hazards of a missed diagnosis. Clinical diagnosis of PE is notoriously unreliable. Ancillary tests such as routine chest x-ray, blood gases, and EKG are non-sensitive and non-specific. Perfusion lung scanning has high sensitivity but low specificity. Thus a negative perfusion scan tends to rule out PE, but a positive scan does not mean PE. Ventilation scans are worthless when the perfusion scan is negative and lead to unacceptable errors when positive. Angiography is the gold standard of diagnosis. When negative, PE is operationally ruled out. When positive, PE is an overwhelming indication for treatment. Approximately 60% of patients who are suspects require angiography for optimal decision making.