Hemoptysis associated with Klebsiella pneumoniae respiratory infection and severe thoracic aortic aneurysm

Abstract

Hemoptysis has a broad differential diagnosis, including infectious, neoplastic, chronic bronchopulmonary, and vascular causes. In smokers with probable chronic obstructive pulmonary disease, blood-streaked sputum may initially suggest a respiratory infection; however, concomitant thoracic vascular disease requires a comprehensive diagnostic approach. Case presentation a 64-year-old male smoker was admitted with dyspnea and hemoptysis. Symptoms began one month before admission with paroxysmal nocturnal dyspnea, exertional dyspnea, and lower limb edema, followed by approximately 5 kg weight loss, productive yellowish cough with blood-streaked sputum, and progression of dyspnea to minimal exertion. On admission, he was alert, afebrile, hemodynamically stable, and required supplemental oxygen. Laboratory tests showed leukocytosis with neutrophilia, and empirical antimicrobial therapy was started. Sputum culture isolated Klebsiella pneumoniae, susceptible to levofloxacin, amikacin, meropenem, and trimethoprim/sulfamethoxazole; GeneXpert was negative. Contrast-enhanced computed tomography revealed severe thoracic aortic aneurysmal dilatation measuring 62 mm, immediately distal to the origin of the left subclavian artery, without signs of acute aortic syndrome. The patient received targeted antimicrobial therapy, bronchodilators, oxygen therapy, and cardiovascular management. This case emphasizes that hemoptysis should not be attributed solely to infection after the first positive finding. Contrast-enhanced computed tomography identified a high-risk vascular condition that changed follow-up and therapeutic planning.