Medical Image of the Week: Septic Emboli

Figure 1. Panels A-F: Selected static images from the thoracic CT showing numerous septic pulmonary emboli with cavitation. Lower panel: movie of selected images from thoracic CT scan.

A 46-year-old man was admitted with altered mental status. His past medical history included HIV/AIDS on HAART therapy, hepatitis B and C, non-Hodgkin's lymphoma (NHL), deep venous thrombosis with insertion of an inferior vena caval filter, and poly-substance abuse. Vitals revealed fever and tachycardia. On exam, he was lethargic and confused, and had bilateral crackles on lung auscultation. Computerized axial tomography (CT) of the head was unremarkable and chest X-ray revealed patchy nodular infiltrates in the right upper lobe and bilateral lower lobes. Work up for an infectious cause was initiated including opportunistic infections and he was started on empiric antibiotics for pneumonia. On Day 2, his roommate who came to visit him, revealed that he was recently admitted in another hospital for headache and flu-like symptoms, and discharged with a peripherally inserted central catheter (PICC) in place as he was scheduled for a positron emission tomography (PET) the next morning for evaluation of recurrence of NHL. However, he presented for the PET scan 10 days after discharge, during which period he was abusing heroin through the PICC line. A thoracic CT was also obtained which showed innumerable scattered cavitary pulmonary opacities with peripheral ground glass opacities consistent with septic pulmonary emboli in the right and left upper lobe and right middle lobe (Figure 1). Blood and urine cultures grew methicillin-resistant Staphylococcus aureus, CD4 count was 180, cryptococcus and histoplasma antigens were negative, as were urine antigens for pneumococcus and legionella. He was also found to have deep venous thrombosis of the right upper extremity. Trans-esophageal echocardiogram was negative for valvular vegetations. He was successfully treated with vancomycin and rifampin and discharged home.

Septic pulmonary emboli are embolization of infectious particles into the lungs via the pulmonary arterial system. Septic pulmonary emboli can occur from varying sources. Patients may be asymptomatic or present with sepsis. CXR shows multiple nodules in the periphery of the lower lobes. CT chest may show feeding vessel sign (a vessel coursing directly to a nodule or mass) in 50% of patients. Early diagnosis and prompt treatment can lead to a successful outcome.

Nanditha Malakkla MD and Chandramohan Meenakshisundaram MD

St. Francis Hospital

Evanston, IL

References

1. Fidan F, Acar M, Unlu M, Cetinkaya Z, Haktanir A, Sezer M. Septic pulmonary emboli following infection of peripheral intravenous cannula. Eur J Gen Med. 2006;3:132–5.
2. Kuhlman JE, Fishman EK, Teigen C. Pulmonary septic emboli: Diagnosis with CT. Radiology. 1990;174:211–3. [CrossRef] [PubMed]
3. Hind CR. Pulmonary complications of intravenous drug misuse. 1. Epidemiology and non-infective complications. Thorax 1990; 45:891-8. [CrossRef] [PubMed]

Reference as: Malakkla N, Meenakshisundaram C. Medical image of the week: septic emboli. Southwest J Pulm Crit Care. 2014;9(3):183-4. doi: http://dx.doi.org/10.13175/swjpcc120-14 PDF 

Medical Image Of The Week: Secondary Pneumonia Presenting as Hemoptysis

Figure 1. A-C: Axial images of the chest demonstrating bilateral consolidation of the lung with air bronchograms. D: Chest radiograph on presentation. E: BAL findings. F: Bronchoscopic images of diffuse airway sloughing; this is the main carina.

A 44 year-old man with a history of asthma presented to the hospital with encephalopathy, severe hypoxia and what was reported to be hematemesis. The patient was intubated in the Emergency Department and mechanical ventilation was instituted. Upper endoscopy was performed but source of bleeding could not be identified. Imaging of the chest showed pulmonary consolidation on both plain radiograph (D) and computed tomography (A-C). Bronchoscopy revealed a very friable mucosa with sloughing of the respiratory epithelium from the main carina (F) to at least the subsegmental level. Bronchoalveolar lavage (BAL) returned bloody fluid (E) but without any increase in blood with subsequent aliquots of fluid. The patient had progressively worsening hypoxia consistent with the acute respiratory distress syndrome (ARDS) requiring rescue maneuvers including paralysis, airway pressure release ventilation, and inhaled nitric oxide but we were unable to implement proning or transfer for extracorporeal life support due to profound cardiovascular collapse refractory to treatment. Ultimately, he succumbed from multiorgan failure. On laboratory evaluation of the BAL both Staphylococcus aureus and Influenza B virus were detected.

Bacterial pneumonia is a common complication of influenza infection. Historically, patients at the extremes of age have been most susceptible to secondary pneumonia. However, during the recent 2009 influenza pandemic an unusually high rate of secondary pneumonia among young adults was observed (1). The most common bacterial pathogens isolated following influenza infection include Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus mitis, Streptococcus pyogenes and Haemophilus influenzae (2). A number of pathogenic mechanisms for synergies between influenza and bacteria have been proposed including disruption of the respiratory epithelium leading to enhanced bacterial adhesion (3).

Cameron Hypes MD MPH^1,2, Christian Bime MD MSc¹, Kevin Sun MD³, and Elizabeth Ulliman MD³

¹ Department of Medicine, Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, University of Arizona Medical Center; Tucson, AZ

² Department of Emergency Medicine, University of Arizona Medical Center; Tucson, AZ

³ Department of Medicine, University of Arizona Medical Center; Tucson, AZ

References

1. Chowell G, Bertozzi SM, Colchero MA, Lopez-Gatell H, Alpuche-Aranda C, Hernandez M, et al. Severe respiratory disease concurrent with the circulation of H1N1 influenza. New Engl J Med. 2009;361(7):674-9. [CrossRef] [PubMed]
2. Centers for Disease Control and Prevention (CDC). Bacterial coinfections in lung tissue specimens from fatal cases of 2009 pandemic influenza A (H1N1) - United States, May-August 2009. MMWR Morb Mortal Wkly Rep. 2009;58(38):1071-4. [PubMed]
3. Metersky ML, Masterton RG, Lode H, File Jr TM, Babinchak T. Epidemiology, microbiology, and treatment considerations for bacterial pneumonia complicating influenza. Int J Infect Dis. 2012;16(5):e321-e31. [CrossRef] [PubMed]

Reference as: Hypes C, Bime C, Sun K, Ulliman E. Medical image of the week: secondary pneumonia presenting as hemoptysis. Southwest J Pulm Crit Care. 2014;9(3):177-8. doi: http://dx.doi.org/10.13175/swjpcc116-14 PDF