Pulmonary embolism (PE) is a leading cause of morbidity and mortality.
Clinical features are nonspecific and a certain diagnosis is often
difficult to make. Attempts to simplify and improve the diagnostic
process in evaluating patients for possible PE have been made by
the introduction of two components: determination of pretest probability
and d-dimer testing. Pretest probability
is determined by developing explicit criteria for determining the
clinical probability of PE. d-dimer
assays measure the formation of d-dimer
when cross-linked fibrin in thrombi is broken down by plasmin.Elevated levels of d-dimer
can be used to detect deep venous thrombosis (DVT) and PE. Some d-dimer tests are very sensitive for
DVT and a normal result can be used to exclude venous thromboembolism.
Kline and colleagues (2002) wished to develop a set of clinical
criteria that would define a subgroup of patients with a pretest
probability of PE of greater than 40% (high-risk group).
These patients would be at too great a risk of experiencing a PE
to have the diagnosis excluded on the basis of d...