COVID & The Lung (Ultrasound)

Image 3. Lung ultrasound at the posterolateral alveolar/pleural syndrome  (PLAPS) point. The “Tissue-like” sign can be appreciated. A tissue-like sign is a representation of complete loss of aeration to the point that the sonographic appearance of the lung matches that of other tissues such as the liver.  Air bronchograms and a lung pulse can help differentiate viral pneumonia vs. atelectasis. Based on this lung ultrasound finding, APRV was initiated leading to gradual improvement in lung recruitment and oxygenation.   https://youtu.be/Y9qKpAShdto

So are there different lung ultrasound findings for the different phenotypes of COVID patients? 

• Confluent B lines with adjacent areas of the spared lung with an A-line pattern. These findings correlate with ground glass opacities on the CT chest. These are seen in both “L” and “H” phenotypes.

• Subpleural consolidations and irregular pleural lines are commonly seen in both phenotypes of COVID-19 ARDS patients. 

• Dense consolidation with tissue-like sign and PLAPS can be seen in COVID 19 patients. Some of these patients who have atelectasis may benefit from a ventilator strategy with higher mean airway pressures.  This is seen more in the “H-type” COVID phenotype.
• Large pleural effusions are atypical for COVID-19 patients. 

So for which patient should I perform a lung ultrasound? Is there a situation in which I should not perform a lung ultrasound? 

•  Lung ultrasound ideally should be performed if it would change your clinical management or to answer a clinical question. 

•  In the ED, if you have decided to admit a patient to the medicine floor or the ICU based on your clinical assessment, then a thoracic ultrasound should not change that decision. A patient with typical lung ultrasound findings may be at a higher risk for worsening disease so it may help with risk stratification. 

•  In the ED if you have decided to discharge a patient home, then a lung ultrasound should not change that decision.  https://pubmed.ncbi.nlm.nih.gov/32976318/ 

• On the medicine floor, patients with typical lung ultrasound signs may be at a higher risk for worsening disease.
• In the ICU, lung ultrasound can help guide ventilator management. A patient with typical loss of aeration of the lower lobes (i.e. atelectasis ) may benefit from a ventilator strategy with higher mean airway pressures ( image 3 ).  

Glossary of Terms

• ARDS- Acute Respiratory Distress Syndrome 
• PLAPS- Postero Lateral Alveolar Pleural syndrome 
• APRV- Airway Pressure Release Ventilation