Lung POCUS (PEM Summary of Evidence)

Question 1

What are the main questions lung POCUS can help you answer?

Answer 1

1. In a patient presenting with respiratory distress, do they have pneumothorax, hemothorax or pleural effusion?
2. Can differentiate between pneumonia and bronchiolitis/viral pneumonia
3. Can differentiate between parapneumonic pleural effusion vs. empyema

Question 2

What is the sensitivity and specificity of POCUS for identifying pleural effusions in adults?

Answer 2

Sensitivity 92%

Specificity 93-97%

Question 3

What is the sensitivity and specificity of POCUS for identifying pneumonia in adults?

Answer 3

Sensitivity 88-90% and specificity of 95-98.5% using CT as reference standard
-CXR has sensitivity of only 75% for diagnosing pneumonia using CT as reference standard

Question 4

What is the sensitivity and specificity of POCUS for identifying pneumonia in children?

Answer 4

Meta analysis showing that there is high sensitivity and specificity

• pooled sensitivity 96%, pooled specificity 93%, PLR 15.3, NLR 0.06.
• one study though found that ultrasound detected pneumonia more so an CXR when using CT as reference standard

Question 5

What is the utility of lung POCUS in acute chest syndrome in children with sickle cell?

Answer 5

Sensitivity 87% and specificity 94%

Question 6

In children with bronchiolitis or viral pneumonia, what lung ultrasound findings might you see?

Answer 6

Small subpleural consolidations (0.25 cm in depth) with associated pleural line abnormalities, single or confluent B lines

Question 7

What areas are still in need of further research in lung POCUS?

Answer 7

1. To date, no studies have evaluated if POCUS can be used to improve antibiotic stewardship when evaluating for pneumonia
2. Serial lung POCUS evaluation may have a role in the management of ventilator supported critically ill children and neonates
3. Additional studies are needed to evaluate the differences between lower respiratory tract infections as well as causes of wheezing in infants and children

Question 8

Describe the indications for lung POCUS. (3)

Answer 8

1. Pediatric trauma patients to assess for presence of pneumothorax and hemothorax
2. Patients presenting with respiratory symptoms to evaluate for pneumonia vs. bronchiolitis/viral pneumonia and presence of pleural effusion versus empyema
3. Premature or full term infants presenting with RDS and/or TTN

Question 9

Describe the limitations of lung POCUS.

Answer 9

Lung ultrasound may not recognize centrally located pneumonias that do not abut the chest wall (1.5% of cases)

Question 10

Describe relevant anatomy to be identified with lung POCUS.

Answer 10

1. For a complete lung exam, each lung should be scanned in the longitudinal and transverse orientation in the mid clavicular line anteriorly and posteriorly and the mid axillary line for a total of 6 scanning zones. Scan superiorly and inferiourly from apices/clavicles to the diaphragm with liver on the right and the diaphragm and stomach or spleen on the left vialized
2. Different relevant lung ultrasound characteristics should be identified such as A lines, B lines, confluent B lines, lung sliding and lung consolidations with air bronchograms and small subpleural consolidations (0.25 cm with no air bronchograms)
3. M mode can be used to confirm presence or absence of lung sliding and a diagnosis of pneumothorax

Question 11

What are the specific pitfalls in lung POCUS?

Answer 11

1. Need to identify the left diaphragm since the combo of spleen and air in stomach can be mistaken for pneumonia (lung consolidation with air bronchograms)
2. Mistaking pneumonia for thymus - thymus may appear as a lung consolidation on ultrasound but the absence of air bronchograms should differentiate tissue from pneumonia