Scintigraphic lung scans and clinical assessment in critically ill patients with suspected acute pulmonary embolism.

Abstract

PURPOSE: The purpose of this investigation was to evaluate the diagnostic accuracy of radionuclide scintigraphic lung scans and clinical assessment in critically ill patients with suspected acute pulmonary embolism. MATERIALS AND METHODS: Critically ill patients were defined as follows: (1) patients who were hypoxemic on room air, and not given ventilatory support (n = 89); (2) patients given ventilatory support (n = 46); and (3) patients in ICUs, but not given ventilatory support (n = 85), and hypotensive patients who were not hypoxemic or given ventilatory support (n = 3). Comparisons were made with patients who had none of these characteristics of critically ill patients (n = 627). Data are from the Prospective Investigation of Pulmonary Embolism Diagnosis. RESULTS: The sensitivities, specificities, and positive predictive values of high probability lungs scans among each of the four categories of critically ill patients were not statistically significantly lower than values in noncritically ill patients. The positive predictive values of the clinical assessments did not differ to a statistically significant extent from noncritically ill patients. Clinical assessment, when concordant with the lung scan interpretation, usually increased the positive predictive value for pulmonary embolism. CONCLUSION: Scintigraphic lung scans and clinical assessment retain their diagnostic value even in critically ill patients.