[Validation of a diagnostic algorithm in non severe pulmonary embolism at the Annecy general hospital. D-dimers, venous lower limb ultra-sound and spiral CT scan].

OBJECTIVE AND METHOD

We have evaluated the sensitivity of a diagnostic algorithm for all patients suspected of pulmonary embolism using: D-Dimer, lower limb venous ultrasonography and helical computed tomography. To validate this approach, a lung scan is systematically carried out if the pulmonary embolism diagnosis is not withheld as a result of the algorithm. Clinical tests are organised between the 3rd and 6th month.

RESULTS

Two hundred patients were involved between January 1998 and October 1999. One hundred and six pulmonary embolisms were diagnosed. Out of the 200 ultrasonography tests carried out we found: 71 proximal deep-vein thrombosis (popliteal or supra-popliteal), 33 distal thrombosis (infra-popliteal). Ninety-two cases were negative (4 tests non conclusive). We have deduced that a deep-vein thrombosis permits the diagnosis of thrombo-embolic illness without any further diagnostic approach (no computed tomography). Out of the 129 computed tomographies carried out we found: 35 pulmonary embolisms and 23 other diagnoses. Seventy-one lung scans were therefore carried out. We recorded 7 discordances (scans showed high and very high probability for pulmonary embolism whilst computed tomographies did not): pulmonary angiography was negative 4 times and diagnosed pulmonary embolism once and two patients refused to take the test (Table 2). There are two recurrences in the follow-up: proximal thrombosis and a pulmonary embolism. This involved two patients who had refused to undergo pulmonary angiography.

CONCLUSION

This diagnostic approach therefore seems satisfactory but would require further investigation on a wider scale.