Patients with low pretest probability and a negative d -dimer result had no further tests and were considered to have a diagnosis of pulmonary embolism excluded. order viagra All other patients underwent ventilation-perfusion lung scanning. If the scan was nondiagnostic, bilateral deep venous ultrasonography was done. Whether further testing (by serial ultrasonography or angiography) was done depended on the patients' pretest probability and the lung scanning results. viagra effects babies Measurements: patients received a diagnosis of pulmonary embolism if they had a high-probability ventilation-perfusion scan, an abnormal result on ultrasonography or pulmonary angiography, or a venous thromboembolic event during follow-up. Patients for whom the diagnosis was considered excluded were followed up for 3 months for the development of thromboembolic events. viagra viagra or viagra side effects Results: the pretest probability of pulmonary embolism was low, moderate, and high in 527, 339, and 64 patients (1. 3%, 16. 2%, and 37. viagra overnight 5% had pulmonary embolism), respectively. Of 849 patients in whom a diagnosis of pulmonary-embolism had initially been excluded, 5 (0. prix de viagra 10 mg 6% [95% ci, 0. 2% to 1. 4%]) developed pulmonary embolism or deep venous thrombosis during follow-up. viagra patienteninformation However, 4 of these patients had not undergone the proper diagnostic testing protocol. In 7 of the patients who received a diagnosis of pulmonary embolism, the physician had performed more diagnostic tests than were called for by the algorithm. discount viagra online In 759 of the 849 patients in whom pulmonary embolism was not found on initial evaluation, the diagnostic protocol was followed correctly. Only 1 (0. 1% [ci, 0. 0% to 0. safe generic viagra india 7%]) of these 759 patients developed thromboembolic events during follow-up. Of the 437 patients with a negative d -dimer result and low clinical probability, only 1 developed pulmonary embolism during follow-up; thus, the negative predictive value for the combined strategy of using the clinical model with d -dimer testing in these patients was 99. generic viagra usa 5% (ci, 99. viagra effects babies 1% to 100%). Conclusion: managing patients for suspected pulmonary embolism on the basis of pretest probability and d -dimer result is safe and decreases the need for diagnostic imaging. cheap viagra