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Ultrasound in the ICU

Kristine E. W. Breyer, MD

Assistant Professor

Anesthesia & Critical Care Medicine UCSF

DISCLOSURES: NONE

Objectives

• Definition

• The Ultrasound

• Exam Types & Uses

• Training

• Clinical Examples

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DEFINITIONCRITICAL CARE ULTRASOUND

Critical Care Ultrasound

• Intensivist performs & interprets exam at bedside 

• Immediately integrates results into assessment and plan

• Repeated as needed, as often as needed

• Performed within a few minutes

• Non‐invasive

Schmidt GA; Chest 2012

Clinician Performed

≠

Not a study by trained sonographer interpreted by radiologist

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≠

Focused & Limited

Bedside cardiac ultrasound ≠ Echocardiogram

Cardiac Ultrasound for ICU

J Am Soc Echo 2002; 15: 369

Know Your Limits!! 

• Do not comment on findings that are not within your expertise

• If you see something you do not understand or that concerns you, obtain appropriate imaging performed by a specialist PROMPTLY

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EXAM TYPES & USES

Scope of Critical Care Ultrasound

DIAGNOSTIC INTERVENTIONAL

INTERVENTIONAL

VASCULARVASCULAR

• PERIPHERAL VENOUS

• CENTRAL VENOUS

• ARTERIAL

THORACICTHORACIC

• THORACENTESIS

• CHEST TUBE PLACEMENT

ABDOMINALABDOMINAL

• PARACENTESIS

Adapted from: Curr Op Anesth 2014; 27: 123

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DIAGNOSITC

CARDIAC

• CONTRACTILITY & GROSS FUNCTION

• EFFUSION

THORACIC

• PNEUMOTHORAX

• EFUSSION

• PULMONARY EDEMA

VASCULAR

• THROMBOSIS

ABDOMEN

• FLUID

• GALL BLADDER

Adapted from: Curr Op Anesth 2014; 27: 123

Cardiac Ultrasound

Perera; Emerg Med Clin N  Am 2010

IVC Dispensability

Barbier, Intensive Car Med 2004

MAX – MIN

MIN

Sens 90%Spec 90%

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Charron; Cardiopulm Monit 2006

• ∆DIVC predicts volume responsiveness

– r=0.82,  p<0.001

• 12% ∆DIVC

– PPV 93%

– NPV 92%

Fiessel; Intensive Care Med 2004

IVC Dispensability

Barbier, Intensive Car Med 2004

MAX – MIN

MIN

Sens 90%Spec 90%

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Charron; Cardiopulm Monit 2006

Evidence

• Data Supports Use Of Cardiac US • By Intensivists• • 10 hour training allowed successful cardiac US • by intensivists with 84% correct interpretation• • Emergency physicians learn cardiac US during 6 • hour program• • ICU trainees can learn cardiac ultrasound in a • short course and use it to answer relevant • clinical questions• • Intensivists can accurately assess LV function

Manasia. J of CT and CV Anesthesia, 2005; Jones. Academic EM, 2003; Vignon. Intensive Care Med, 2007; Vignon. Crit Care Med, 2011; Melamed. Chest, 2009.

Vascular Ultrasound

• Structures: IJ, carotid, subclavian, axillary, aorta, vena cava, femoral

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• Physics not fully understood –resonance phenomenon

• Sonographic artifacts • Normal lung has ≤ 3 comets

per rib space

• Reach lower edge of screenwithout fading

• Move with pleural sliding

• Erase A lines

Thoracic Ultrasound

Normal Lung Findings: B-lines/Comet Tails

• Physics not fully understood –resonance phenomenon

• Sonographic artifacts • Normal lung has ≤ 3 comets

per rib space

• Reach lower edge of screenwithout fading

• Move with pleural sliding

• Erase A lines

US vs Chest X-ray

• US can detect as little as 5-50 ml fluid

• AP film can detect >100 ml of fluid

• In the ICU finding pleural fluid by chest xray is even more difficult due to positioning and parenchymal lung disease (ARDS, PNA etc)

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CT + CT ‐ Sens (%) Spec (%) DA (%)

L US + 63 0 100 100 100

L US ‐ 0 21

CXR + 41 4 65 81 69

CXR ‐ 22 17

Pleural Effusion Evaluation

* Comparison of CXR and LUS with CT as gold standard in 42 Patients

Monitoring sequeleof fluid administration

• A lines in anterior lung predicts PAOP <18mmHg

• Extensive anterior B lines (in combo with smooth pleural line) sensitive and specific for hydrostatic pulmonary edema

Copetti R et al US in Med and Bio 2012 

Abdominal

– (FAST exam)

• Structures: kidneys, Morrison’s pouch, liver, gallbladder, diaphragm, spleen, bladder, pouch of Douglas

• Abnormal findings: free fluid

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EVIDENCE

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TRAINING

Why train in CCUS ?

• Mounting evidence that CCUS is helpful in the diagnosis and treatment of critically ill patients. 

“The use of cardiothoracic ultrasound…seems able to contribute to an early therapeutic decision based on reproducible physiopathological data.”

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Why train in CCUS ?

• Anesthesiology October 2012: 

Implementation of CCUS “led to findings that prompted further testing in 18.4%, led to changes in medical therapy in 17.6%, and to invasive procedures in 21.6%”. 

THANK YOUbreyerk@anesthesia.ucsf.edu