Lung Ultrasound in Diagnosis of Respiratory Distress

Muzafar Gani Abdul WahabAssociate Professor, Pediatrics

Chair, TnECHO & POCUSNEO Program

McMaster University, Hamilton Canada

Objectives

• Basics and key principles of Lung Ultrasound

• What is Normal and Abnormal

• How to differentiate in different lung pathologies by US

What we can do with it?

• Diagnostic;

– RDS, TTN, pneumonia, Atelectasis, CLD, pleural effusion, PTX, and CCAM/CPAM.

• Early Prediction of complications;

– LUS can early predict BPD in infants < 29 weeks GA

– Predict the need for surfactant therapy in preterm infants with RDS.

– LUS can predict non-invasive ventilation failure.

– LUS can predict clearance of lung fluids in TTN infants

• Reduce radiation exposure; decrease # CXR requests in NICU

Sensitivity and specificity of LUS

Understand Key principles of LUS

• Simple

• Air & Fluid mix

• All signs arise from pleural line

• Artifacts fundamental

• Dynamic movement

• Acute pathology around pleura

Selection of probe

Attenuation

• Penetration is primarily determined by the center frequency of the transducer,

• The higher the frequency, the shallower the penetration because the absorption of the ultrasound wave traveling through tissue increases with frequency

Likes or dislikes of USG:

https://pubs.rsna.org/doi/full/10.1148/rg.294085199

Penetration of US waves in different tissues

Anatomical Landmarks of LUS

Lung US zones

Bat sign

Pleural Line

Upper rib Lower rib

A line – Normal Lung

• Indicate Air - physiological ”Normal Lung”

• Reverberation artifact, Horizontal repetitive lines parallel to the pleural line

• Equidistant; The distance between two A-lines is equal to the skin-pleural

line distance.

B Line (Compact)

• ( B=Bad)Fluid in the interstitial space or in the alveoli

• Originates from Pleural line

• Reaches to the base of the screen.

• Move with Lung sliding

• Erase A lines

• More then 2 is Abnormal

B line – Coalescent

Means increase severity e.g. RDS, Significant PDA, interstitial lung disease,…etc

C - Consolidation

Pleural line, Lung Sliding

Pleural LineAppear as a shimmering echogenic linear structure

Respiratory cycle: Sliding Sign

Absence of lung sliding: pneumothorax, apnea

Lung pulse / sliding

1. RDS

What is What??:

Double Lung Point - TTN

RDS Vs TTN

RDS Vs TTN

3. Surfactant need

LUS Score

0 1 2 3

Lung US scores

0-30-3

0-3 0-3

0-30-3

Total score: 0 - 18

LUS Score

Sandy Beach / Sea Shore or Stratosphere sign• The sea-shore sign• Normal pleural line

• M-mode (image), a sandy pattern, arising from the pleural line.

• Above the pleural line is a regular pattern, completely distinct from the sandy pattern seen below.

Lung Point - Pneumothorax

M - Mode

Pleural Effusion

Pericardial Effusion

Atelectasis / Pneumonia

RDS

BPD

Normal

Diagnosing Vocal cord Palsy

Right side paralysis

Diagnostic Algorithm