basic transesophageal echocardiography Flashcards
what does air look like in a TEE?
light/white
what does blood/fluid look like in a TEE?
dark
what is color flow good to determine?
regurgitation
blue away, red toward
how does the Echo work?
piezoelectric crystals (quartz)
- reflect sound waves
- generate dynamic images of the heart
- high frequency sound (ultrasound) 2-10 Mhz
- sound wave velocity based on tissue type, speed of sound through tissue is constant
what is B-mode for image display?
brightness mode
- amplitude of the returning echo gives 2 dimensional view
- 2D mode: send ultrasound pulses across a sector of cardiac anatomy displaying a tomograph
- displays shape and lateral motion
- normal mode
what is M-mode for image display?
motion mode
- one dimensional view
- pulsations at very high rates yielding real-time dynamic images
- best mode for timing cardiac events
describe category I indications for TEE
- supported by strong evidence or expert opinion
- TEE improves clinical outcomes
describe category II indications for TEE
- supported by weaker evidence or expert consensus
- TEE MAY improve outcomes
describe category III indications for TEE
- little current scientific evidence or expert support
- TEE infrequently improves clinical outcomes and may even be harmful
what are some category I indications for TEE?
- acute, persistent life threatening disturbances
- RV & LV global and regional function & contractility
- myocardial ischemia: assessing wall motion
- valve repair (primarily mitral valve)
- obstructive cardiomyopathy
- infective endocarditis and valve vegetation
- aortic valve dissection or aneurysm
- congenital heart surgery
- detection of intracardiac shunting
- thoracic aortic aneurysm
- pericardial window
- detect residual intracardiac air & embolic matter
- atrial thrombus (stroke etiology)
what is the best use of TEE?
looking at contractility and volume
what are some category II indications for TEE?
- valve replacement
- myocardial aneurysm repair
- cardiac assist devices
- pulmonary endarterectomy
- suspected cardiac trauma
- myocardial/intracardiac mass resection
- foreign body detection and/or removal
- pericardial surgery
- cardiac or pulmonary transplantation
what is an absolute contraindication for TEE?
esophageal surgery
what are relative contraindications for TEE?
- inexperienced anesthetist
- hx of sysphagia
- esophageal varices or strictures
- hiatal hernia
- coagulopathy
- cervical spine instability
- mediastinal radiation
- upper airway pathology
what are the advantages of TEE as a cardiac monitor?
- doesn’t interfere with surgical field
- probe is stabilized, no loss of image
- regional wall abnormalities; ischemia can be detected before appearing on EKG
- sound waves pass only through esophagus not chest wall or boney structures, so image distortion d/t interference is very unlikely
when may basic TEE intraop exams be utilized?
- unexplained hemodynamic instability
- pulmonary embolism
- hypovolemia
- depressed myocardial function (abnormal wall motion indicative of acute ischemia
- pneumothorax
- pericardial effusions
- cause of PEA
describe an advanced comprehensive perioperative TEE exam
- 20 multiplane views
- assessing volumes and chamber size
- assessing cardiac output
- assess stroke volume, ejection fraction
describe non-comprehensive basic perioperative TEE exam
- 11 most relevant views
- hx of significant comorbidities
- hemodynamic instability expected during surgery
- known or suspected CV compromise
- unexplained persistent hypotension, hypoxemia, or major thoracic or abdominal trauma
how does TEE knobs work?
- bottom knob: clockwise anteflex, counterclockwise retroflex
- top knob: right and left flex
- side button: rotates beam from 0-180 degrees
describe TEE insertion and technique
-insert through mouth down esophagus
-keep probe in “unlocked” neutral position
three levels:
-upper esophageal 20-30 cm
-mid esophageal 30-40 cm
-transgastric 40-45 cm
what are the most common views?
- Mid esophageal (ME) 4 chamber: looks at a 0 degree plane
- mid esophageal 2 chamber: turns 90 degrees to isolate the LV
what view is good to assess ischemia?
transgastric mid short axis view (TG mid SAX)
what does the ME 4 chamber view show?
- Left atrium
- left ventricle
- right atrium
- right ventricle
- mitral valve
- tricuspid valve
- 0 degree plane, 30-35 cm
what can the ME 4 chamber view be used to assess?
- valve disease
- ventricular function
- atrial septal defect (ASD)
- effusions
what does the ME 2 chamber view show?
- left atrium
- left ventricle
- mitral valve
- left atrial appendage (LAA)
- coronary sinus
- 90 degree plane, 30-35 cm
what can be assessed with the ME 2 chamber view?
- mitral valve disease
- LV size and function
- LAA thrombus
what does the ME LAX view look at?
- mitral valve
- aortic valve
- left ventricular outflow tract (LVOT)
- septal
- 120-130 degree plane, 30-35 cm
what can be assessed with the ME LAX view?
- LVOT
- Aortic valve disease
- anterior mitral valve leaflet (AMVL)
- posterior mitral valve leaflet (PMVL)
what does the transgastric mid SAX look at?
views 6 LV segments
*0 degree plane, down about 40 cm
what can be assessed with the TG mid SAX view?
- LV size
- LV function (contractility)
- ejection fraction
- effusions
- volume status
what does the ME AV SAX look at?
- aortic valve
- LA size
- atrial septum
- left atrial appenadage (LAA)
what can be assessed with the ME AV SAX view?
- atrial septal defect
- aortic valve disease
- thrombus in LAA
describe TEE use during resuscitation
- identify reversible causes of PEA
- can identify images during chest compressions
- pulse detection inaccurate
- allows full resuscitation efforts (esophageal damage during chest compressions rare; able to deliver shock)
what is the one view to monitor effective chest compressions?
-ME 4 chamber
