Patients with suspected pulmonary embolism should be stratified according to an objective clinical assessment before other diagnostic tests are performed. NEW YORK (Reuters Health) - Patients with suspected pulmonary embolism should be stratified according to an objective clinical assessment before other diagnostic tests are performed, according to new guidelines issued by members of the PIOPED II (Prospective Investigation of Pulmonary Embolism Diagnosis II) research team.

The new guidelines are being jointly published in the December issues of Radiology and the American Journal of Medicine.

"The choice of diagnostic tests depends on the clinical probability of pulmonary embolism, condition of the patient, availability of diagnostic tests, risks of iodinated contrast material, radiation exposure, and cost," Dr. Paul D. Stein, from Wayne State University in Detroit, and his associates write.

In any case, they note that "a venous ultrasound or magnetic resonance venography is optional."

For patients with low to moderate probability, the investigators advise a rapid ELISA test for D-dimer. If the ELISA is negative, further testing is probably not required.

If the D-dimer test is positive, most PIOPED II investigators recommend CT angiography and CT venography.

If CT results are delayed, or if they indicate the presence of a pulmonary embolism, starting treatment with anticoagulants may be appropriate.

In contrast, physicians should skip the D-dimer test for patients with a high probability clinical assessment, and should instead initiate anticoagulant treatment immediately, before sending them for CT imaging.

Dr. Stein and his associates follow these recommendations with guidance for exceptional patients, including those allergic to iodinated contrast material, those with impaired renal function, women of reproductive age, pregnant women, and for patients in extremis.

Discordant findings will require clinical judgment as to further evaluation.

Ultimately, they add, "the sequence for diagnostic testing in patients with suspected pulmonary embolism depends on the clinical circumstances."

Am J Med 2006;119:1048-1055.