The traps of pulmonary embolism.

The clinical diagnosis of pulmonary embolism (PE), even massive, remains di fficult and perplexing. In our hospital, the percentage of exact clinical d iagnoses has not significantly changed over recent years, with a false-nega tive rate of 78%, and a false-positive rate of 2%. In approximately 20% of cases, autopsy showed several emboli and pulmonary infarctions of various a ges, indicating recurrent embolic episodes. The diseases most frequently as sociated were cardiac diseases (51%) and tumours (24%). Pneumonia considera bly decreases the probability of an exact diagnosis of PE; hospitalisation in the Cardiology department or Intensive Care Unit increased the probabili ty of this diagnosis. While the numerous diagnostic algorithms recently pro posed have a limited value, the process integrating clinical and instrument al data in order to establish a prospective clinical probability, should fa cilitate identification of acute PE in live patients.