Pitfalls of Echocardiography as a

Haemodynamic Monitoring Tool

A/Prof Ian Seppelt FANZCA FCICM

Dept of Intensive Care Medicine, Nepean Hospital,

University of Sydney

George Institute for Global Health, University of NSW

Faculty of Medicine and Heath Sciences, Macquarie University

Haemodynamic Monitoring by Echo– Presenter

Disclosure

• No conflicts to disclose

• Thanks to Drs Sam Orde, Marek Nalos and Martin Stefan

Prehistoric

Intensive Care

The value of bedside ultrasound

• Echocardiography

• Thoracic ultrasound

• Vascular access

• Neural blockade

• Hepatic and renal

ultrasound

• FAST in trauma

• Pretracheal ultrasound

Characteristics of „Point of Care

Ultrasound‟

• Exam is for a well-defined purpose

linked to improving patient outcomes

• Exam is focused and goal-directed

• Exam findings are easily recognizable

• The exam is easily learned

• Exam is quickly performed

• Exam is performed at the patient‟s

bedside

From 2014 all trainees must demonstrate

competency in basic echocardiography.

In order for the Trainee to fulfil this requirement,

satisfactory completion of the following is required:

(a) Attend an accredited course in basic echocardiography

(b) Perform, document and appropriately interpret 30 basic

studies.

(c) Perform at a satisfactory level in a „hot-case‟ (live) exam

(d) Complete a short on-line MCQ exam (CICM website)

… the indications seem pretty clear

Indications For Transthoracic Echocardiography in the

Critically Ill Patient

1. Haemodynamically unstable patient:

- Assessment of ventricular contractility

- Identification of major valvular abnormalities

- Assessment of preload

- Assessment of left ventricular diastolic function

- Initial assessment for large intracardiac shunts

2. Unexplained respiratory failure

3. Left ventricular failure

Committee on

Echocardiography in Intensive

Care, ANZICS 2007

… the indications seem pretty clear

Indications For Transthoracic Echocardiography in the

Critically Ill Patient

4. Right heart failure/pulmonary hypertension

5. Suspected valvular disease

6. Sepsis of unknown origin - initial assessment for features of

endocarditis

7. Clinical features suggesting the presence of pericardial effusion

and tamponade

8. Suspected thoracic aortic pathology

9. Onset of new heart murmur.

Committee on

Echocardiography in Intensive

Care, ANZICS 2007

… the indications seem pretty clear

Indications For Trans-oesophageal Echocardiography

in the Critically Ill Patient

1. Inadequate TTE

2. Required detailed assessment of cardiac valves, interatrial and interventricular septum and great thoracic vessels (i.e. suspected aortic dissection).

3. Suspected endocarditis

4. Suspected cardioembolic events or screening for intracardiac thrombi prior to cardioversion.

5. Suspected dysfunction of the prosthetic valve

6. Assistance in interventional techniques and assessment of intracardiac devices.

7. Resuscitation

Committee on

Echocardiography in Intensive

Care, ANZICS 2007

Benefits of TTE

• Immediately available, non invasive

• Best modality for:

– LV function

– Right heart evaluation

– Effusions and tamponade

– Evaluation of aortic stenosis

Benefits of TOE

• Modality of choice for

– Endocarditis

– Evaluation of septal defects and shunts

– Ascending and descending aorta

– Intracardiac masses and thrombi esp LAA

• Also indicated if poor TTE windows due to

surgery, dressings, body habitus etc.

How ICU studies differ from the

cardiology outpatient lab … • Often supine, ventilated, unconscious patients • Other equipment can affect examination • Dynamic situation with concurrent resuscitation

underway • Often a specific question “Is there a cardiac

component to this patient‟s instability” • Repeated studies for monitoring • 24 hours a day requirement

How ICU studies differ from the

cardiology outpatient lab … • Often supine, ventilated, unconscious patients • Other equipment can affect examination • Dynamic situation with concurrent resuscitation

underway • Often a specific question “Is there a cardiac

component to this patient‟s instability” • Repeated studies for monitoring • 24 hours a day requirement

How ICU studies differ from the

cardiology outpatient lab … • Often supine, ventilated, unconscious patients • Other equipment can affect examination • Dynamic situation with concurrent resuscitation

underway • Often a specific question “Is there a cardiac

component to this patient‟s instability” • Repeated studies for monitoring • 24 hours a day requirement

All intensivists should be able to….

do a basic echo to answer the following

questions:

1. Is the heart working?

2. Is it really full or really empty?

3. Is there an acute severe valve lesion?

4. Is there a tamponade?

These are

not subtle

findings!!

„Level two‟ examination

• Let the experts worry about:

– Degrees of diastolic dysfunction

– Tissue doppler imaging

– Quantifying subtler valve lesions and

pressure gradients

– Little ASDs and PFOs and other shunts

– Congenital abnormalities

Focussed Assessment

• Level 1 training for all intensivists

• A FOCUSSED examination to answer

specific questions

– Not a comprehensive examination, and should

not be thought of as such

– Analagous to FAST in trauma

2nd Singapore-ANZICS Intensive Care Forum 2013

12 – 14 July 2013 Max Atria, Singapore Expo

The RACE examination

• Focussed 2D examination

– Cardiac windows

– Basic lung ultrasound

– Vena cava assessment

• Doppler examination de-emphasized

• Course 1 – 2 days with extensive hands

on experience

All registrars do RACE

• Focussed RACE course during orientation

period

• All RACE studies must be documented

– Standard pro-forma

• Consultant review of images off-line

1. Conservatism

• “You can‟t teach an old dog new tricks”

• “What I do now works for me”

• Practicalities – teaching a whole department

2. Turf wars with cardiology or radiology

3. Where do we get training?

4. Maintenance of skills

5. Amateurs „dabbling‟ - making mistakes

So why won‟t we all embrace

ultrasound?

Pitfalls of Level 1 Exams

• Over-interpreting findings

– Statements about preload and filling based

just on IVC collapse in ventilated (or non-

ventilated) patients

– RV function / ventricular interrelationships

• Missing important things

– Dyamic LVOT obstruction

• Not understanding one‟s limitations

A focused examination

Veillard-Baron et al, Bedside echocardiographic evaluation of hemodynamics in sepsis, Am J Resp Crit Care Med 2003 and Intensive Care Med 2006

Echocardiography as a haemodynamic monitor?

Easy

Often visual assessment of cardiac function

sufficient to guide therapy

Difficult

“It is better to be roughly right than precisely wrong.”

Mervyn King, the former governor of Bank of England

Does the patient have adequate cardiac output?

Outcome is improved with source control,

prompt and adequate fluid resuscitation

while striving to achieve early negative

fluid balance

CO monitors - PA catheter, PiCCO, LiDCO, Flowtrac,

oesophageal Doppler, etc…

if trend of haemodynamics and fluid

balance not according to expectation..

perform clinical examination, review the

chart and repeat echo

Does my patient need more fluid?

Static indices do not work

R: Responders

NR: Non-

responders

IVC collapsibility in mechanically ventilated patients

Collapsibility of 12%

in ventilated septic

shock patients,

positive and negative

predictive value 93

and 92%, respectively

for an increase in

cardiac output > 15%

Feissel et al. ICM 2004, Charron et al. COCC 2006

CI (%) = Exp Dmax – Insp Dmin

Exp Dmax

Dynamic parameters - inflow side

IVC diameter

Distensibility Index >

18% in mechanically

ventilated patients,

sensitivity and

specificity of 90 each

for an increase in

cardiac index > 15%

DI (%) = Exp Dmax – Insp Dmin

Exp Dmin

SVC Collapsibility Index

CI (%) = Exp Dmax – Insp Dmin

Exp Dmax

TOE

CI >36% fluid responsive

CI < 30 % NOT responsive

(DmaxSVC-DminSVC) / DmaxSVC

collapsibility index

(DmaxIVC-DminIVC) / DminIVC

distensibility index

Mitral E/E‟ ratio

PW Mitral Inflow TDI Lateral Mitral Annulus

Early mitral flow to mitral annular tissue Doppler velocity

Pulse pressure variation

Inspiration Expiration

Dynamic parameters - outflow side

SVV by Echo - LVOT/Aortic VTI

cut off -

12% for peak

LVOT/aortic

flow

cut off -

20% for

aortic VTi

PLR Volume

CI

SVC

collaps.

Passive leg raising and SVV variation

Positive response

Negative response

Crit Care Med 2006;34:1402

PLR induced changes in Ao VTI

Lamia et at Intens Care Med 2007

PLR induced increase in aortic VTI of 12.5% or more

predicted an increase in SV of 15% or more after volume

expansion with a sensitivity of 77% and a specificity of 100%

Pitfalls of haemodynamic

monitoring with echocardiography

1. Over-interpreting difficult imaging

– Atrial fibrillation

– Poor view of LVOT for CO determination

– IVC collapsibility

2. Intermittent views in a dynamic, rapidly

changing situation

– So keep the machine at the bedside, have

another look

3. Fluid responsiveness does not (necessarily)

mean give more fluid

ian.seppelt@sydney.edu.au

Questions?