Clinical research study
Clinical Characteristics of Patients with Acute Pulmonary Embolism: Data from PIOPED II

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Abstract

Background

Selection of patients for diagnostic tests for acute pulmonary embolism requires recognition of the possibility of pulmonary embolism on the basis of the clinical characteristics. Patients in the Prospective Investigation of Pulmonary Embolism Diagnosis II had a broad spectrum of severity, which permits an evaluation of the subtle characteristics of mild pulmonary embolism and the characteristics of severe pulmonary embolism.

Methods

Data are from the national collaborative study, Prospective Investigation of Pulmonary Embolism Diagnosis II.

Results

There may be dyspnea only on exertion. The onset of dyspnea is usually, but not always, rapid. Orthopnea may occur. In patients with pulmonary embolism in the main or lobar pulmonary arteries, dyspnea or tachypnea occurred in 92%, but the largest pulmonary embolism was in the segmental pulmonary arteries in only 65%. In general, signs and symptoms were similar in elderly and younger patients, but dyspnea or tachypnea was less frequent in elderly patients with no previous cardiopulmonary disease. Dyspnea may be absent even in patients with circulatory collapse. Patients with a low-probability objective clinical assessment sometimes had pulmonary embolism, even in proximal vessels.

Conclusion

Symptoms may be mild, and generally recognized symptoms may be absent, particularly in patients with pulmonary embolism only in the segmental pulmonary branches, but they may be absent even with severe pulmonary embolism. A high or intermediate-probability objective clinical assessment suggests the need for diagnostic studies, but a low-probability objective clinical assessment does not exclude the diagnosis. Maintenance of a high level of suspicion is critical.

Section snippets

Patients and Methods

PIOPED II was a prospective multicenter investigation of multidetector computed-tomography angiography alone and combined with venous phase imaging of the pelvic and thigh veins for the diagnosis of acute pulmonary embolism.5 A composite reference test was used.5 Patients aged 18 years or more with clinically suspected acute pulmonary embolism were potentially eligible.5 Exclusion criteria included an inability to complete tests within 36 hours, critical illness, ventilatory support, shock,

Results

Acute pulmonary embolism was present in 192 patients, among whom 133 (69%) had no prior cardiopulmonary disease. Pulmonary embolism was excluded in 632 patients, among whom 366 (58%) had no prior cardiopulmonary disease.

Discussion

The data show a broad range of severity of clinical findings in patients with pulmonary embolism. The syndrome of pleuritic pain or hemoptysis, in the absence of circulatory collapse, was the most frequent mode of presentation in PIOPED, occurring in 65% of patients with pulmonary embolism and no prior cardiopulmonary disease.10 The present data from PIOPED II showed somewhat fewer patients with pleuritic pain or hemoptysis, and more had the uncomplicated dyspnea syndrome. Circulatory collapse

Conclusions

Symptoms may be mild and generally recognized symptoms may be absent in patients with the largest pulmonary embolism in the segmental pulmonary branches, but typical symptoms may be absent even in patients with large emboli. A high or intermediate-probability objective clinical assessment may suggest the need for diagnostic studies, but a low-probability objective clinical assessment was sometimes present, even in patients with proximal pulmonary embolism. Maintenance of a high level of

Acknowledgment

Nikunj R. Patel, MD, assisted in analyzing the data.

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This study was supported by Grants HL63899, HL63928, HL63931, HL063932, HL63940, HL63941, HL63981, HL63982, and HL67453 from the U.S. Department of Health and Human Services, Public Health Services, National Heart, Lung, and Blood Institute, Bethesda, Maryland.

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