Emergency Ultrasound (EUS)教學(6)

重點式急診心臟超音波之應用

新光醫院急診醫學科

陳國智醫師

中華民國醫用超音波學會指導醫師

臨床情境

• 64歲女性，呼吸窘迫• BP 161/101; HR 136

SpO2 94% (NRM)

• PE:– Diffuse exp. Wheezing

– JVD (-)

– LE edema (-)

• 請問你該怎麼辦 ?

• 急診超音波在此能提供什麼幫忙?

Cardiac Anatomy

Heart Anatomy

Thoracic Cavity

Cardiac Axes

心臟超音波影像認識

Transducer consideration

Classic routes of heart

Subxiphoid Four-Chamber View

Subxiphoid Short-Axis View

Subxiphoid Long-Axis View

(IVC view)

Central Venous Pressure

IVC size for volume assessment

IVC size (cm) Resp. change RA pressure

(cm)

<1.5 Total collapse 0-5

1.5-2.5 >50% collapse 5-10

1.5-2.5 <50% collapse 11-15 (>10)

>2.5 <50% collapse 16-20

>2.5 No change >20

IVC size assessment

Parasternal Long-Axis View

Parasternal Short-Axis View

Parasternal Short-Axis View

papillary muscle level

Parasternal Short-Axis View

mitral valve level

Parasternal Short-Axis View

aortic valve level

Mercedes Benz sign

Apical Four-Chamber View

Apical Two-Chamber View

Suprasternal View

Two-Dimensional Measurement

Two-Dimensional Measurement

M-Mode Left Ventricle

LV systolic function

• LV systolic funciton– Ejection fraction – FS=(LVDd-LVSd)/LVDd– EF=FS * 2

• EF– >50%

• normal

– 30-50%• moderate depressed

– <30%• severely depressed

• Poor LV is often coupled with a dilated IVC

Color Doppler Flow

重點式急診心臟超音波

適應症和限制

Primary Indications

• Detection of pericardial effusion and/or

tamponade

• Evaluation of gross cardiac activity during

CPR

• Evaluation of global LV systolic function

Secondary Indications

• Gross evaluation of intravascular volume

status and cardiac preload

• Indentify acute RV dysfunction and/or

acute pul. HTN for chest pain / dyspnea/or

hemodynamic instability

• Pericardiocentesis guidance

Limitations for EUS

• Focal wall motion abnormality

• Diastolic dysfunction

• Valvular abnormalities and function

• Intracardiac mass or thrombus, ventricular

aneurysm, septal defect, AD, myocarditis,

HCM, and vegetation

Technical limitations

• Thorax abnormalities

• Pulmonary hyperinflation

• Obesity

• Patient can’t cooperate

• Subcutaneous emphysema

Key component

• Evaluation of pericardial effusion– Anechoic or hypoechoic fluid

– Complex echogenicity: inflammation, infection, malignancy, hemorrhage

• Classification– None

– Small, <10 mm in width in dastole, non-circumferential

– Moderate, circumferential, not greater than 10 mm

– Large, 10-20mm in width

– Very large, > 20 mm and/or evidence of tamponade

Pericardial Effusion

Pericardial Effusion

Key component

• Echocardiographic evidence of tamponade

– Diastolic collapse of any chamber in the

presence of moderate or large effusion

– Hemodynamic instability with a moderate or

large pericardial effuion

Cardiac Tamponade

US Guided- Pericardiocentesis

• Subcostal approach

– Traditional approach

– Blind

– Increased risk of injury to liver, heart

• Echo-guided

– Left parasternal preferred for needle entry or…

– Largest area of fluid collection adjacent to the chest wall

Technique

Pericardial Effusion / Tamponade

• Tamponade

– Clinical diagnosis

– Circulatory collapse due to pericardial effusion

• Subxiphoid approach is the best window

– Effusion location – inferior & posterior

• Echo evidence of tamponade

– Diastolic collapse of the right side of the heart

– Plethoric IVC without inspiratory collapse

Key component

• Evaluation of gross cardiac motion (CPR)– Terminal cardiac dysfunction

• Global ventricular hypokinesis

• Incomplete systolic valve closure

• Absence of valve motion

• Absence of ventricular motion

• Intracardiac gel-like densities

– Lack of mechanical cardiac activity• Gravest of prognosis

Chest pain then code

• 55 y/o male suffered witnessed V-fib arrest

in the ED

• ALS protocol - restoration of perfusing

rhythm

• Persistent hypotension

• ED ECHO was performed

Direct Visualization

• Is there effective myocardial contractility?

– Asystole

– Myocardial “twitch”

– Hypokinesis

– Normal

• Is there a pericardial effusion?

ECHO in PEA

• Perform ECHO during “quick look” and in pulse checks

• Change management based on “positive” findings

• Pericardial tamponade– Pericardiocentesis

• Hyperdynamic cardiac wall motion– Volume resuscitate

ECHO in PEA

• RV dilatation– Hypoxic?? – Likely PE

– ECG – IMI with RV infarct?

• Profound hypokinesis– Inotropic support

• Asystole– Follow ACLS protocols (for now)

– Early data suggesting poor prognosis

47

Heart evaluation

Resuscitation (2008) 76, 198—206

Key component

• Evaluation of global cardiac function

– Normal LV systolic funciton (EF > 50%)

– Moderately depressed (EF 30-50%)

– Severely depressed (EF < 30%)

Myocardial Ischemia

LV wall segments

Chronic LV infarction

Dilated left ventricle

RV strain

• Normal RV: LV ratio = 0.6 : 1

• RV strain– RV hypokinesis

– Paradoxical septal motion

• Cause– Pulmonary embolism

– Chronic lung disease

– Pulmonary hypertension

– Pulmonary stenosis

• RV free wall > 5 mm chronic condition

Massive Pulmonary Embolism

Proximal Aortic Dissection

Type A aortic dissection

Aortic dissection (TEE)

Ascending Aortic Aneurysm

LV Thrombus

Vegetations

Ventricular Hypertrophy

Myxoma

Focus Assessed Transthoracic Echo (FATE)

FATE protocol

• Exclude obvious pathology

• Assess wall thickness and dimension of

chambers

• Assess contractility

• Visualize pleural on both sides

• Relate the information to the clinical

context

Pitfalls

1. Contraindications

2. Inability to obtain adequate views

3. Reversed orientation

4. Fluid versus blood clot or fat

5. Gain issues

6. Depth

7. Dynamic range

Orientation Review

Summary

• Bedside ECHO can help assess:

– Overall cardiac wall motion

– Assess preload status

– Identify clinically significant pericardial effusions

• Useful in the assessment of the patient with:

– Unexplained hypotension

– Dyspnea

– Thoracic trauma