A 78 year old female presents to the ED from a cardiac rehabilitation facility with increasing shortness of breath and a productive cough. She was discharged from the hospital two weeks ago after having a coronary stent placed which was complicated by pneumonia and developing heart failure. She was discharged on PO amoxicillin-clavulanate. Vitals are notable for a heart rate of 101 and are otherwise within normal limits.
Labs are remarkable for an elevated WBC of 18.55 and elevated NT-ProBNP of 2155. Point-of-care cardiac ultrasound shows a normal ejection fraction. Right sided point-of-care lung ultrasound findings are shown below. What’s the most likely diagnosis, and what pathognomonic ultrasound “sign” is seen?
Answer: Pneumonia; Hepatization of the lung
- Normally, lung is not well visualized on ultrasound because the alveoli are filled with air which does not transmit ultrasound beams well to produce an image.
- Aerated lung will produce horizontal “A lines”, a reverberation artifact from the result of sound waves bouncing between the skin and pleural line.
- With consolidation of the lung or pneumonia, ultrasound beams are able to travel through the purulent or fluid filled alveoli.
- The lung will appear hypoechoic and heterogeneous, resembling the liver, hence the term “hepatization of the lung.”
Dawson M, Mallin M. Introduction to Bedside Ultrasound: Volume 1. Emergency Ultrasound Solutions; 2013.
Durant A, Nagdev A. Ultrasound detection of lung hepatization. West J Emerg Med. 2010;11(4):322-323