Purpose: The purpose of this investigation is to assess
the level of leukocytosis in acute pulmonary embolism (PE).
Background: Limited data exist regarding leukocytosis in
acute PE. One reason that the prevalence of leukocytosis in acute PE is
unknown, despite an extensive number of investigations of PE, may
relate to the fact that acute PE is usually associated with other
conditions that themselves may cause leukocytosis.
Methods: Hospital records of 386 patients with a diagnosis
of acute PE were reviewed retrospectively. Patients with no other
possible or definite cause of leukocytosis were analyzed separately. A
diagnosis of PE was made by a high-probability interpretation of the
ventilation/perfusion lung scan or pulmonary angiogram.
Results: Among patients with PE in whom other possible or
defined causes for leukocytosis were eliminated, 52 of 266 (20%) had a
WBC count > 10,000/mm3. None had a WBC count that was≥
20,000/mm3. Patients with the pulmonary
hemorrhage/infarction syndrome had an increased WBC count in 32 of 183
(17%) vs 20 of 83 (24%) in patients who did not have pulmonary
hemorrhage/infarction syndrome (not significant).
Conclusion: A modest leukocytosis may accompany (and
possibly be caused by) PE. Its presence should not dissuade the
clinician from objectively pursuing the diagnosis of
Abbreviations: CI = confidence interval;
PE = pulmonary embolism