Medical Image of the Month: Air Bronchogram Sign

Figure 1. Chest radiograph showing bilateral dense airspace disease with air bronchograms. Veno-venous ECMO catheter is visible tracking from the right internal jugular vein to the inferior vena cava.

Figure 2. Chest radiograph on day 5 of ECMO after 4 days of induction chemotherapy demonstrating marked improvement of his airspace disease.

An 18-year-old man without any known past medical history presented with a one-day history of progressive shortness of breath. He reported a sudden onset of symptoms the morning of presentation, and an accompanying sensation of confusion with difficulty concentrating. Initial laboratory evaluation was significant for leukocytosis over 60 K/mm³. Due to his increased work of breathing and worsening lethargy, the patient was intubated and sedated for airway protection and ventilatory support. The patient was admitted to the ICU, and his initial chest radiograph was concerning for acute respiratory distress syndrome. Subsequent hematologic analyses from his admission CBC were consistent with a new diagnosis of acute myelogenous leukemia.

Despite aggressive alveolar recruitment maneuvers and maximum ventilator support, the patient’s oxygen saturation remained poor and his respiratory reserve continued to decline. The decision was made to place the patient on veno-venous extracorporeal membrane oxygenation (ECMO) prior to initiating therapy with doxorubicin and cytarabine (7+3 induction protocol). A dual-lumen ECMO catheter was placed in the right internal jugular vein. His initial chest radiograph demonstrated complete bilateral air bronchograms (Figure 1). The patient was started on chemotherapy while on ECMO and was successfully decannulated after five days on the circuit. His chest radiograph on day 5 of ECMO was significant for marked improvement in bilateral airspace disease (Figure 2).

In patients with hematologic malignancy, an inflammatory response can be generated by either the malignant cells themselves, or more commonly as a reaction to subsequent infection. This inflammation often results in protein-rich fluid infiltrating the alveoli. When this process becomes severe enough to cause hypoxic respiratory failure, it can progress to acute respiratory distress syndrome (ARDS) (1). The chest radiograph demonstrates dense airspace disease which developed in this patient. The fluid-filled alveoli in this extreme example of ARDS created a volume of uniform opacities throughout his lung parenchyma which make the conducting airways stand out clearly (2). Segmental air bronchograms can be seen in localized airspace disease, such as atelectasis or pneumonia, but a full-pulmonary air bronchogram of this clarity can only be seen on a patient undergoing ECMO as there are effectively no functional alveoli to participate in gas exchange.

Eric Brucks, MD and Richard Young, MD

Department of Internal Medicine

Banner University Medical Center

University of Arizona

Tucson, AZ USA

References

1. Papazian L, Calfee CS, Chiumello D, Luyt CE, Meyer NJ, Sekiguchi H, Matthay MA, Meduri GU. Diagnostic workup for ARDS patients. Intensive Care Med. 2016 May;42(5):674-85. [CrossRef] [PubMed]
2. Natt B, Raz Y. Air Bronchogram. N Engl J Med. 2015 Dec 31;373(27):2663. [CrossRef] [PubMed]

Cite as: Brucks E, Young R. Medical image of the month: air bronchogram sign. Southwest J Pulm Crit Care. 2019;19(4):119-20. doi: https://doi.org/10.13175/swjpcc036-19 PDF 

Medical Image of the Week: Chemotherapy-Induced Diffuse Alveolar Hemorrhage

Figure 1. Panel A: Chest X-ray on admission consistent showing some pulmonary edema and effusions at the bases. Panel B: Chest X-ray after initiation of chemotherapy showing diffuse bilateral infiltrates and consolidation.

Figure 2. CT scan of the chest after initiation of chemotherapy showing patchy ground glass consolidation throughout the lung fields bilaterally. Large bilateral pleural effusions can also be seen.

A 65-year-old man presented with relapse of his acute myeloid leukemia (AML). On admission he was seen to have a reduced ejection fraction at 40-50%. His chest X-ray showing pulmonary edema and bilateral pleural effusions (Figure 1A). He was diuresed to his dry weight to improve his clinical status. The decision was made to re-induce him for his AML with fludarabine and cytarabine without idarubicin (due to his reduced ejection fraction). After 2 doses of each the fludarabine and cytarabine the patient showed worsening respiratory distress, had increasing oxygen requirements and started having hemoptysis. Repeat imaging of his chest showed bilateral infiltrates in his lungs on both chest x-ray (Figure 1B) and chest CT (Figure 2). Infectious causes for the changes were sought and ruled out. He was transferred to the ICU where he was put on high flow oxygen and received methylprednisolone 1000 mg IV daily for 3 days. During this period his blood hemoglobin also dropped from 8.2 g/dl to 6.8 g/dl requiring transfusion of 1 unit of packed red blood cells. After 3 days of supportive care he was transferred back out of the ICU on oxygen by nasal cannula with progressive improvement in his lung function. Pulmonary toxicity is a known side effect resulting from both fludarabine and cytarabine and can present in a variety of forms. Their prompt recognition is important due to the steroid responsive nature of many of these once infectious causes have been ruled out.

Saud Khan, MD and Huzaifa A. Jaliawala, MD

Department of Internal Medicine

University of Oklahoma Health Sciences Center

Oklahoma City, OK USA

References

1. Helman DL Jr, Byrd JC, Ales NC, Shorr AF. Fludarabine-related pulmonary toxicity: a distinct clinical entity in chronic lymphoproliferative syndromes. Chest. 2002 Sep;122(3):785-90. [CrossRef] [PubMed]
2. Rudzianskiene M, Griniute R, Juozaityte E, Inciura A, Rudzianskas V, Emilia Kiavialaitis G. Corticosteroid-responsive pulmonary toxicity associated with fludarabine monophosphate: a case report. Turk J Haematol. 2012 Dec;29(4):392-6. [CrossRef] [PubMed]
3. Forghieri F, Luppi M, Morselli M, Potenza L.Cytarabine-related lung infiltrates on high resolution computerized tomography: a possible complication with benign outcome in leukemic patients. Haematologica. 2007 Sep;92(9):e85-90. [CrossRef] [PubMed]

Cite as: Khan S, Jaliawala HA. Medical image of the week: chemotherapy-induced diffuse alveolar hemorrhage. Southwest J Pulm Crit Care. 2017;15(5):219-20. doi: https://doi.org/10.13175/swjpcc131-17 PDF