1. Probability Assessment Method for Pulmonary Embolism
Wells et al * have developedthe followingclinicalpredictionrules to determine the probabilityof PE, assigning
a score to each finding:
a. Clinical signs/symptoms ofDVT (minimumof legswelling andpainwith palpation ofthe deep veins of
the legs (score = 3.0)
b. No alternate diagnosis likelyor more likelythanPE (score = 3.0)
c. Heart rate >100/min(score = 1.5)
d. Immobilizationor surgeryinlast 4 wk (score = 1.5)
e. Previous historyof DVT or PE (score = 1.5)
f. Hemoptysis(score = 1.0)
g. Cancer activelytreated withinlast 6 mo (score = 1.0)
Probabilityof PE is highiftotal score is >6;moderate if 2-6;andlowif<2.
DVT, Deepvein thrombosis; PE, pulmonaryembolism.
* Wells PS et al:Use of a clinicalmodel for safe management of patients withsuspectedPE, Ann Intern Med
129:997, 1998.
CT-based diagnostic strategy used in patients with
suspected pulmonary embolism.
Determine if PE
Unlikely or PE likely
PE
unlikely
PE likely
D – dimer assay
Negative Positive
PE excluded
CT pulmonary
angiogram CT-PA
Negative Positive
PE
Excluded
PE
confirmed