The role of ultrasound in lung recruitment

Dr Chor Yek Kee

Sarawak General Hospital

Outline

•History, principle and practise of lung ultrasound

•Comparing lung ultrasound with CXR, CT scan and MRI

•The role of lung ultrasound in lung recruitment and evidence

“The lung is a major hindrance to the use of ultrasound at the thoracic level” - 1992

Harrison’s Principles of Internal Medicine, 1992: p1043

“Ultrasound imaging is not useful for evaluation of the lung parenchyma” - 2001 Harrison’s Principle of Internal Medicine, 2001; p1454

Removed - 2012 Harrison’s principle Of Internal Medicine. 18th edition New York ; McGraw-Hill: 2012

Prof. Daniel Lichtenstein

Ultrasound vs CXR

Sensitivity Ultrasound CXR

Interstitial syndrome 94% 46%

Consolidation 100% 38%

Pleural effusion 100% 38%

Pneumothorax 88% 52% N. Xirouchaki, E. Magkanas, K. Vaporidi, et al.: Lung ultrasound in critically ill patients: comparison with bedside chest radiography. Intensive Care Med.37:1488-1493 2011 W. Ding, Y. Shen, J. Yang, et al.: Diagnosis of pneumothorax by radiography and ultrasonography: a meta-analysis. Chest. 140:859-866 2011

Ultrasound Vs CT Thorax

• 14 patient elective brain MRI, intubated and perform lung MRI then lung ultrasound to compare

MRI VS LUS

• Taking MRI as reference for the diagnosis of atelectasis

• LUS showed

• 88% of sensitivity (95% CI, 74 to 96%), • 89% of specificity (95% CI, 83 to 94%), • 88% of accuracy (95% CI, 83 to 92%)

Basic Principles Of Lung Ultrasound

1. A simple, 2D apparatus is the most appropriate for lung ultrasound.

2. Signs are aroused from pleural line

3. The thorax is an area where air and water are intimately mingled.

4. Lungs signs are mainly based on analysis of artifacts

5. Most lungs signs are dynamic

6. Nearly all acute disorders of thorax come in contact with surface, deep structure defect might be missed

Other additional benefit of US

1. Assessment can be done at bedside and fast

2. Reduced radiation and cost

3. Pleural fluid can be • Characterized : Hematocrit sign/plankton sign • Quantified • US guided drainage • Post procedure evaluation

4. Differentiating different lung pathology namely pneumonia, pulmonary edema, ARDS and pneumothorax

5. Ventilation recruitment

The Machine

The probe

• Equipment • Microconvex probe 4 – 7 MHz • Curvilinear Probe 4 – 7 MHz • Linear probe 7 – 15 MHZ

• Setting • Convention- marker to left of screen • No harmonic

• Techniques • Probe place perpendicular to the rib

Area of Scanning

Lung Ultrasound

IMAGE OF LUNG ULTRASOUND

LUNG ULTRASOUND IN SMALLER CHILDREN USING CURVILINEAR PROBE

Air filled alveolar Fluid filled alveolar

• This paper is to describe the usefulness of lung sonography (LUS) to conduct and personalize RM in a real-time way at the bedside.

• Deciding opening and closing pressure using ultrasound

N B1 B2 C

Ultrasound Reaeration Score VS Aeration calculation from CT scan

• Intervention : Antibiotic • Single center, • 30 patients • Compare reaeration

measured at day 0 and day 7 of VAP by • CXR • LUS • CT thorax

N B1 B2 C

• Lung US reaeration score > 5 • CT reaeration >400 mL and • Successful antimicrobial therapy.

• LUS reaeration score < –10 • loss of CT aeration >400 mL • Failure of antibiotics.

Ultrasound Reaeration Score

Compare Pressure-volume (PV) curve with lung ultrasound for assessing lung recruitment in patient with ARDS/ALI

• A highly significant correlation was found between PEEP-induced lung recruitment measured by PV curves and ultrasound reaeration score (Rho 50.88;P,0.0001).

• LUS reaeration score > 17 : PEEP lung recruitment greater than 600 ml. • LUS reaeration score < 15 : PEEP lung recruitment between 75 to 450ml • PEEP-induced lung recruitment can be adequately estimated with

bedside LUS.

B line Consolidation

Prof Dr Song’s Lung Scoring system

Ultrasound-guided recruitment manoeuvres with positive end-expiratory pressure proved useful in reducing the incidence of anaesthesia-induced atelectasis in infants

0

1

2

3

0

1

2

3

B line Consolidation

Prof Dr Song’s Lung Scoring system

Ultrasound-guided recruitment manoeuvres with positive end-expiratory pressure proved useful in reducing the incidence of anaesthesia-induced atelectasis in infants

0

1

2

3

0

1

2

3

Consolidation B line Pleural effusion

Prof Dr Song’s Lung scoring version 2

RCT looking at effect of ultrasound guided peri-

operative lung recruitment in term of outcome vs

control

Tidal Recruitment • Histological • Repetitive opening and closing of collapsed

alveoli during the mechanical respiratory cycle • The resultant high tissue stress in these

atelectatic zones, and especially in the boundary areas between collapsed and open lung areas,

• It can trigger a local inflammatory response and injure the alveolar–capillary membrane.

• This is one of the proposed mechanisms of ventilator-induced lung injury (VILI) that impairs the outcome of patients with acute respiratory distress syndrome.

Before Recruitment

After Recruitment

TIDAL RECRUITMENT

68 years old

3 years old

Example

Lung ultrasound of posterior lobe

24 Hours post Prone nursing

Case 2 Pre-recruitment

4 hours post recruitment

Anterior Lung Field

Posterior Lung Field

Summary

1. Lung ultrasound (LUS) assessment can be done at bedside and fast

2. LUS reduced radiation and cost as compare to CXR, CT scan and MRI

3. LUS can be used in ventilation recruitment

THANK YOU

Confluent B line