Mod1: Monitoring for Cardiac Surgery - TEE

Question 1

_{THE BASICS OF TRANSESOPHAGEAL ECHOCARDIOGRAPHY}

When was TEE first used and what were its limitations?

Answer 1

The first use of TEE was in 1975

Had a very limited range and very little ability to change the angle of the view

Question 2

_{THE BASICS OF TRANSESOPHAGEAL ECHOCARDIOGRAPH}

Which factors have contributed to the improvement of the quality and utility of today’s TEE’s and have expanded its use 100 fold?

Answer 2

Provision of multiple planes of view

Multiple frequency of probes

Color flow mapping

Pulse and continuous wave Doppler

Digital image processing

Question 3

THE BASICS OF TRANSESOPHAGEAL ECHOCARDIOGRAPH

In 2010, the ASA approved updates to guidelines which states that “the TEE should be used in which surgical procedures?

Answer 3

all open heart and thoracic or aortic surgical procedures and should be considered in CABG surgeries

Question 4

_{THE BASICS OF TRANSESOPHAGEAL ECHOCARDIOGRAPH}

In 2010, the ASA approved updates to guidelines which states that “the TEE should be used in all open heart and thoracic or aortic surgical procedures and should be considered in CABG surgeries for what purpose?

Answer 4

To confirm and refine the preop diagnosis

To detect new and unsuspected pathologies

To adjust the anesthetic and surgical plan accordingly

To assess the results of surgical intervention

Question 5

_{TEE COMMON INDICATIONS}

According to ASA TEE Guidelines, the TEE can be used by providers in which two ways?

Answer 5

Basic Perioperative TEE

Advanced Perioperative TEE

Question 6

_{TEE COMMON INDICATIONS}

What’s an advantage of the Basic Perioperative TEE over the PA catheter as a periop measure the determine a pt’s instability?

Answer 6

Previously, the PA catheter was used to determine why pt a may be hempdynamically unstable

Now the provider is able to used the TEE to determine the primary source of the pt’s instability

Question 7

_{TEE COMMON INDICATIONS}

What’s the major added benefit of the Advanced Perioperative TEE over the Basic Perioperative TEE?

Answer 7

The anesthesiologist performing the TEE can make therapeutic and surgical recommendations based upon their TEE interpretation

Question 8

_{TEE COMMON INDICATIONS}

What’s required from the provider to used the Advanced Perioperative TEE?

Answer 8

Requires Training and certification at all levels of perioperative echocardiography reading

It also may require additional credentialing at the practicing institution

Question 9

_{TEE COMMON INDICATIONS}

The TEE can guide the evaluation and treatment of which heart valve abnormalities?

Answer 9

Assessment of valvular function both intra and postop

Evaluation of valvular repairs and prosthetic valve surgery

Assessment of the aorta for arteriosclerosis, calcification and dissections

Question 10

_{TEE COMMON INDICATIONS}

When is it important to Assessment of the aorta for arteriosclerosis, calcification and dissections via TEE?

Answer 10

Before the aorta is clamped, and

Prior to coming off bypass

Question 11

_{TEE COMMON INDICATIONS}

What are other common indications for TEE?

Answer 11

Assessment of Global LVF and regional wall motion abnormalities (RWMA)

Detection of cardiac defects, masses, and vegetation

To see optimal de-airing after open heart surgery

For quick evaluation of severe hypotension intra and postop by ruling out conditions like cardiac tamponade, poor LV volume status, RWMA, malfunction of prosthetic valves, or aortic dissection

Inadequate or impossible transthoracic echocardiography

Question 12

_{TEE IN NON-CARDIAC SURGERY}

T/F: Although TEE is a fast and relatively non-invasive technique, its routine use for NON-cardiac surgery is yet to be established

Answer 12

True

Studies showing the routine use, though, of TEE in non-cardiac surgeries as a benefit are limited in number and equivocal in outcome

Question 13

_{TEE IN NON-CARDIAC SURGERY}

T/F: Many studies have revealed that TEE is more sensitive than EKG for EARLY detection of ischemia

Answer 13

True

Question 14

_{TEE IN NON-CARDIAC SURGERY}

When is TEE indicated in non cardiac surgery?

Answer 14

In situations where it is used to explain life threatening circulatory instability that persist despite corrective therapy

Question 15

_{PROPERTIES OF ULTRASOUND}

How does the TEE ultrsound probe work?

Answer 15

Ultrasound machines generate vibrations that vibrate surrounding tissue (muscle, blood, fat, or bone)

During the vibration, particles within the tissue compress, then spread apart, also known as compression and rarefaction

This sequence of compression and rarefaction is described using sine waves and characterized by:

Wavelength - Frequency - Amplitude - Propagation velocity

Question 16

_{PROPERTIES OF ULTRASOUND}

It is the distance b/t two peaks of the sine wave

It’s measured in millimeters

Answer 16

What is Wavelength?

Question 17

_{PROPERTIES OF ULTRASOUND}

Is the number of cycles that occur in one second

1 cycle/second = 1 hertz (Hz)

Answer 17

What is Frequency?

Question 18

_{PROPERTIES OF ULTRASOUND}

Ultrasound frenquency travel much higher than what is audible with the human ear. Which frequency can the human ear typically hear?

Answer 18

Between 2000 to 5000 Hz

Some experience show that we can hear up to 20,000Hz

Question 19

_{PROPERTIES OF ULTRASOUND}

Which US frequency do TEE uses?

Answer 19

Frequencies above 20,000Hz

TEE uses frequencies of 2.5-7.5 million cycles per seconds (MHz)

Question 20

PROPERTIES OF ULTRASOUND

What does amplitude measure?

Answer 20

Amplitude measures of tissue compression or “loudness” of tissue

Question 21

PROPERTIES OF ULTRASOUND

What is Propagation velocity?

Answer 21

The speed of an ultrasound wave traveling through tissue

Depends on the tissue

Question 22

PROPERTIES OF ULTRASOUND

What’s the ultrasound Propagation velocity in blood?

Answer 22

1540 meters per second (m/s)

Question 23

_{BASICS OF TEE}

How does the TEE probe generate US waves?

Answer 23

Echo probe has piezoelectrode in it that can convert electrical activity delivered to it into ultrasound wave

A piezoelectrode in the probe converts electrical energy delivered to the probe into ultrasound waves

Question 24

_{BASICS OF TEE}

Echocardiography uses ultrasound waves with frequencies of:

Answer 24

2.5 to 7.5 million cycles per seconds (MHz)

Question 25

_{BASICS OF TEE}

What’s the relationship between US frequency, depth of penetration, and resolution?

Answer 25

The slower the frequency, the greater the depth of penetration but produces poor resolution

The faster the frequency, the greater the resolution, but penetration becomes poor

Question 26

_{BASICS OF TEE}

Why are frequencies greater than 7.5 MHz are not used?

Answer 26

d/t poor penetration

Question 27

_{BASICS OF TEE}

Why are frequencies less than 2.5 produce wavelengths not used?

Answer 27

too long for resolution of small objects

Question 28

_{BASICS OF TEE}

With TEE and cardiac procedures, which TEE technique do providers use to examine the function of the heart?

Answer 28

Doppler Technique

Assesses blood flow through heart chambers and valves

Assess LV function, chamber size, wall size and motion

Valve patency

Abnormal flow, structures, plaque, air, or vegetation

Question 29

_{BASICS OF TEE}

What equation does the Doppler effect used the determine pressure gradient between areas of different velocity?

Answer 29

Bernoulli equation

Except for in the fetal heart, the volume of blood flowing through the heart must always be the same as the volume of blood that passes through the aortic valve

When the pathway through which blood flows becomes too narrow, the blood velocity must increase to pass the volume

Providers can read this velocity as it moves pass the ech probe using the Bernoulli equation

The doppler principle creates a visual picture of the heart blood flow by assessing the color codes of the velocities in the heart

Question 30

_{BASICS OF TEE}

Based on the doppler effect, what’s the color difference between blood flow directed towards the probe and blood flow going away from the probe? What is turbulent flow?

Answer 30

Blood flow that is directed towards the probe is red

Blood flow going away from the probe is blue

The higher the velocity of the flow, the lighter the color hues, and this is called turbulent flow

Question 31

_{BASICS OF TEE}

What’s the first mode that echocardiograms were able to reproduce?

Answer 31

M-Mode

Still used today

One dimensional, or Ice pick view

Single, narrow line of sight

Question 32

_{BASICS OF TEE}

What are applications of the M-mode?

Answer 32

Used today to view rapidly moving structures, such as valve leaflets

Used to measure heart chambers, size of heart, and thickness of heart walls

Question 33

_{BASICS OF TEE}

What’s a major drawback of the M-mode?

Answer 33

Only reveals a small portion of the heart at one time, which makes orientation and interpretation of special relationships difficult

Question 34

_{BASICS OF TEE}

Which mode was created to redirect the ultrasound beam over areas of interest, with the advantage that it could recognize anatomical and pathological landmarks

Answer 34

2-D Echo

Sweeps US beam across a plane

Provides views of structures and motion

Question 35

_{BASICS OF TEE}

T/F: Images from 2-D Echo are displayed in real time and can be recorded

Answer 35

True

This allows the provider to view the structures at work, while also being able to record and view them later

Question 36

_{BASICS OF TEE}

What are the 3 types of 2-D Echo?

Answer 36

Pulsed Wave doppler

Continuous Wave

Color Doppler

Question 37

_{BASICS OF TEE}

Which type of 2-D Echo measures velocity and direction of blood flow using single transducer

Answer 37

Pulsed Wave doppler

The operator can define a small area anywhere in the 2-D area which will display in real time blood flow velocity

(left image)

The beam must hit the target and travel back to the probe for interpretation

Question 38

_{BASICS OF TEE}

Which type of 2-D Echo uses two transducers?

Answer 38

Continuous Wave Doppler

One transducer emits the ultrasound wave continuosly

The other transducer receives the ultrasound wave continuously

_{(Right image)}

The ultrasound wave continiously move back and forth

Question 39

_{BASICS OF TEE}

Why is it that the provider cannot precisely define the location of the moving target using the Continuous Wave Doppler 2-D Echo?

Answer 39

Since the Continuous Wave Doppler 2-D Echo has two transducers (One that emits the ultrasound wave continuosly, while the other receives the ultrasound wave continuously) high veolcity can be read, but unfortunately depth from the transducer cannot be read

Question 40

BASICS OF TEE

Which type of 2-D Echo is an enhanced form of continuous wave Doppler that displays real time blood flow in the heart over the 2-D image

Answer 40

Color Doppler 2-D Echo

Displays real time blood flow in the heart over the 2-D image, and this is how direction of flow is determined

Question 41

_{BASICS OF TEE}

What’s the newest TEE technology?

What are its advantages over the older technology?

Answer 41

3-D Echo is the newest technology

An array of transducers are used to reconstruct the heart in 3-D image

Allows for better visualization of heat structures (valves, regurgitant valvular lesions, cardiac chamber volumes, 3-D stress imaging)

Question 42

_{BASICS OF TEE}

According to the Transesophageal Echocardiography Practice Guidelines, what are the two levels of TEE practice?

Answer 42

Basic and advanced

Question 43

_{BASICS OF TEE}

According to the Transesophageal Echocardiography Practice Guidelines which level of training are providers required to acheive?

What minimum number of superivised TEE are they required to perform and interpret?

Answer 43

Providers are required to attain at least an intermediate level of training in echocardiography and to perform and interpret at least 50 supervised TEE examinations

Question 44

_{BASICS OF TEE}

On which prior recommendations are Transesophageal Echocardiography Practice Guidelines based?

Answer 44

On the prior recommendations for TransThoracic Echocardiography and are directed at training for TEE in both operative and non-operative application

Question 45

_{BASICS OF TEE}

How many cross sections constitute a comprehensive TEE examination?

Answer 45

There are 20 cross sections in a comprehensive TEE examination.

Question 46

_{BASICS OF TEE}

In the OR, why are providers not expected to perform a comprehensive TEE exam for each case?

Answer 46

Time contraint

Question 47

_{BASICS OF TEE}

In the OR, how many cross-sections are providers required to produce at a minimum from a TEE exam?

Answer 47

A minimum of 8 different cross sections of the total 20 cross sections;

4 of which should both be in 2-D and color doppler to assess valvular funtcion

Question 48

_{COMPREHENSIVE EXAMINATION}

Describe a comprehensive TEE examination

Answer 48

_{THIS IS A DEPICTION OF THE COMPREHENSIVE EXAMINATION.}

_{FOR A FULL BREAKDOWN OF EACH INDIVIDUAL VIEW, PLEASE VISIT THE WEBSITE TO BE REDIRECTED TO THE GUIDELINES FOR PERFORMING A COMPREHENSIVE TEE EXAMINATION}

http://www.asecho.org/wordpress/wp-content/uploads/2014/05/2013_Performing-Comprehensive-TEE.pdf​

Question 49

_{BASICS OF TEE}

When used in open heart surgery, when is TEE usually placed

Answer 49

Once General Anesthesia is induced

OGT placed to facilitate emptying of stomach

Question 50

_{BASICS OF TEE}

Why is a bite block placed in patient’s mouth prior to insertion of TEE probe?

Answer 50

To prevent damage to the piezoelectrodes in the probe

Question 51

_{BASICS OF TEE}

How is the tip of the TEE probe inserted into the esophagus?

Answer 51

Tip of the TEE probe is covered with surgical lubricant and passed “blindly” into the esophagus

Jaw lift or laryngoscope blade if unable to pass probe “blindly”

Elevate head of resistance

Question 52

_{BASICS OF TEE}

When the TEE probe is inserted, how is it manipulated so the aortic valve can be visualized?

Answer 52

Inserted to TEE probe to 30 cm at the upper incisors

Rotate the transducer until the three cups of the valve are visualized

Question 53

_{BASICS OF TEE}

In what percentage of cases is the provider unable to insert TEE probe?

Answer 53

2%

Question 54

_{COMPLICATIONS OF THE TEE}

T/F: TEE is traumatic and unsafe

Answer 54

False

TEE is very safe and atraumatic if placed correctly

Question 55

_{COMPLICATIONS OF THE TEE}

How can complications such as Esophageal tears or perforations and burns associated with TEE insertion be avoided?

Answer 55

The probe should be introduced with gentleness and care and if ANY resistance is encountered, the probe should be withdrawn and re-lubed and then another attempt can be made to place it

Question 56

_{COMPLICATIONS OF THE TEE}

Why should the TEE machine always be placed on stanby mode when not in use? How is this done?

Answer 56

To avoid burn in the esophagus

This is done by pressing “freeze” on the monitor

Question 57

_{CONTRAINDICATIONS FOR TEE}

Absolute contraindications to TEE placement are:

Answer 57

Presence of an esophageal obstruction

Esophageal perforation

Prior esophagectomy

Esophageal tumor

Recent suture lines as in gastric bypass

Question 58

_{CONTRAINDICATIONS FOR TEE}

Relative contraindications for TEE include:

Answer 58

Hiatal Hernia

Esophageal varices

Esophagitis

Unexplained swallowing difficulties

Mediastinal radiation

Esophageal diverticulum

Unexplained swallowing difficulties