electrical impedance tomography ; new marker for lung...

Electrical Impedance Tomography

; New Marker for Lung Protective Strategy in ARDS?

Department of Intensive Care Medicine

Department of Pulmonology

Dong Hyun, LEE

Conflict of Interest

• Drager Korea

• Pulmovista 500: Free demonstration (2 months)

• EIT analysis software (EIT analysis tool 6.3)

• Savina 300 Ventilator: Free demonstration (2 months)

• Planned to equip additional mechanical ventilator (4)

Electrical Impedance Tomography전기 임피던스? 단층촬영

Electrical Impedance Tomography전기 임피던스? 단층촬영

임피던스 (Impedance)- 저항 (비슷한 것)- 교류의 저항


Phys. Physiol. Meas. 1985;6:109

EIT at Present

How to Measure EIT?

Electric Impedance Tomography


Visualize!!



Impedance의 차이 (변화)를수치로 제공할 수 있다.

Tidal Variation

Tidal Variationof

Impedance

Tidal Variation



부분 별 impedance의 값을 알 수 있다.

Tidal Variation

Tidal Variation & Tidal Volume

Equine Veterinary Journal51(2019) 222–226

Tidal Variation & Tidal Volume

Electrical Impedance Tomography, Dräger Medical

① Tidal Volume② Tidal Variation

TV

EIT for Pulmonary Monitoring

Non-Invasive & Radiation Free

TV (Tidal Variation) (of Impedance)

Global & Regional TV (360 segments)

Real Time (50 /sec)

Tidal Volume during HFNC

J Appl Physiol. 2013;114(8):1058-1065 / Respir Care. 2013;58(4):589-596

HFNC만 달아도 폐 환기가 좋아진다!!

폐의 모든 부위에서 일관되게 증가할까?

• > 20 years

• Subjective dyspnea

• SaO2 < 90% in room air

• Unstable vital sign

– SBP < 90 mmHg

– DBP < 60 mmHg

– HR > 120 bpm

– RR > 30 bpm

– Persistent dyspnea with NP

• PaO2/FiO2 < 200 mmHg

• Unable to cooperate

• Symptomatic IHD

• Labored breathing

• Impossibility of HFNC or NP application (facial deformity)

Acute Crit Care. 2018;33(1):7-15

Regional Ventilation Assessment with EIT

Quadrants

Q1 Q2

Q4Q3

Layers

L1

L2

L4

L3

Quadrangular Plane Dorso-ventral Plane


Global Ventilation with EIT

Higher tidal variation

with HFNC

≒

Higher tidal volume

with HFNC 22412543

500

1000

1500

2000

2500

3000

3500

4000

Nasal Cannula HFNC

p < 0.001TidalVariation


Quadrangular Distribution of Ventilation

436.2413.2

796.3

527.4513.4488.5

885.8

576.3

200

400

600

800

Q1 Q2 Q3 Q4

NC HFNC

TidalVariation

p = 0.014p = 0.042

p = 0.050

p = 0.027


Regional Ventilation Distribution of Lung

Minimal & Maximum Ventilated Quadrant

121.7

167.5

100

200

NC HFNC

1101.7

1188.3

800

1000

1200

NC HFNC

p = 0.056

p = 0.035

37.6% 7.9%

TidalVariation

TidalVariation


HFNC Favors Hypo-Ventilated Lung


EIT during Endotracheal Intubation

British Journal of Anaesthesia 101 (3): 411–18 (2008)

EIT for Pneumothorax Detection

Crit Care Med 2008; 36:1230–1238

EIT of Healthy Lung

EIT of OOOOOOO???

Drager, Pulmovista 500 Manual

• Unilateral left dorsal pleural effusion

?

EIT of OOOOOOO???


• Patient after right pneumectomy

?

EIT of OOOOOOO???


?

EIT of OOOOOOO???


• ARDS patient

?

EIT는 Regional Ventilation Defect를 잘 찾아낼까?


Regional Ventilation; EIT vs CT

Am J Resp Cric Care Med; 2004:169:7

Regional Ventilation; EIT vs Electron beam CT

Chest. 2003;124:314–22

Lung with ARDS

Br J Anaesth 2004; 92: 261±70

Ventilator Induced Lung Injury, VILI

VILI in ARDS

Br J Anaesth 2004; 92: 261±70

BarotraumaVolutrauma

Atelectrauma

Stretch Injury (Overdistension)

Lung Protective Ventilation

Lung Protective Ventilation

Low Tidal Volume Ventilation

Limit Plateau Airway Pressure

Proper PEEP Titration

Prone Positioning

Recruit Maneuver

Overdistension

Overdistension

Atelectrauma

Atelectrauma

Atelectrauma

OverdistensionECMO

VILI in ARDS

Br J Anaesth 2004; 92: 261±70

EIT를 이용하면Overdistension 되었거나,

collapse 된 alveoli를 확인할 수 있다?

EIT for Overdistended Alveoli Detection

Intensive Care Med (2009) 35:1132–1137

Finding Overdistended Alveolous

PEEP: 8 / TV: 150

PEEP: 2 / TV: 100

PEEP: 14 / TV: 100

PEEP: 20 / TV: 50

PEEP & Tidal Variation in a Single Alveolous

0

30

60

90

120

150

180

24 20 16 12 8 4

PEEP

TidalVariation

PEEP & Tidal Variation in a Single Alveolous

0

30

60

90

120

150

180

24 20 16 12 8 4

TidalVariation

PEEP

Intensive Care Med (2009) 35:1132–1137

Finding Best PEEP Level!!

Segments of EIT

• 340 element

• 50 EITs / sec

Decremental PEEP Trial

PEEP Trial Analysis

Clinical Application of EIT for ARDS

• Lung collapse & overdistension

• Recruitable alveoli prediction

• Detecting airway closure

• Pneumothorax detection

• Ventilator dyssynchrony

• Regional ventilation delay

Regional Ventilation Delay

Filtering Raw EIT Data

Thorax 2017;72:83–93

Anesth Analg. 2018 Jan;126(1):102-110

Respiration. 2009;77:282–91.


• Non-Invasive

• Radiation free

• Real time

• Promising (development → clinical application)

Electrical Impedance Tomography in ARDS

• Brand new Information

• Efficacy in MV / ARDS / …

• Further studies…

electrical impedance tomography ; new marker for lung...

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