Hemodynamic Monitoring Flashcards
What is the purpose of hemodynamic monitoring in anesthesia? (list 5)
- assess homoestasis, trends
- observe for adverse reactions
- assess therapeutic interventions
- manage anesthetic depth
- evaluate equipment function
Which 2 types of anesthesia providers are considered “qualified” anesthesia providers?
- Anesthesiologists
- CRNAs
The standards for monitoring include monitoring which 4 things?
- oxygenation
- ventilation
- circulation
- temperature
What are some good ways to monitor oxygenation?
- pulse ox
- ABG
- Pt. color
- O2 analyzer on the machine
What are some good ways to asses ventilation?
- end tidal CO2
- chest rise
- breath sounds
- bag moving
What are some good ways to assess circulation?
- color
- BP
- EKG
- pulse
- heart tones
Does temperature need to monitored continuously in surgery?
Yes in the pediatric population. In adults it needs to be readily available
There are 2 populations in which we do not need to adhere to the complete standard of care surrounding monitors in anesthesia, they are?
- laboring OB patients
- Chronic pain modalities
How often do you document the information from your monitors?
Q5min
Monitors to be used to meet the minimal AANA standard are: (list 6)
- EKG (heart rate and rhythm)
- BP
- Precordial stethescope
- Pulse ox
- O2 analyzer
- ETCO2
According to the AANA, which 5 monitors have to be visible on a graphic display?
- EKG
- BP
- HR
- Ventilation status
- O2 sat
Do all alarms need to be audible?
Yes, at all times!
Name 4 basic monitoring techniques that don’t require any fancy equipment.
- Inspection
- Ausculation
- Palpation
- Alert and vigilant providers
What are some considerations you should ponder before applying monitoring modalities to your patient? (list 5)
- Indications/ contraindications
- Risk/ benefit
- Techniques/ alternatives
- Complications
- Cost
What does the esophageal or precordial stethescope give you?
Continual assessment of breath sounds and heart tones
In which patients can you use an esophageal stethescope?
In intubated patients only
How far down do you place an esophageal stethescope?
28-30cm in the esophagus
What is the esophageal stethescope really good at detecting?
Very sensitive monitor for bronchospasm and changes in pediatric patients
What is the added benefit of using an esophageal stethescope?
It has a thermistor port for continous temperature monitoring
How long should the patient have continuous EKG monitoring in relation to a surgery?
It is standard for every patient to have continuous monitoring from the beginning of anesthesia until the patient leaves the anethetizing location
What is the purpose of continous EKG monitoring during anesthesia? (list 5)
- detect arrhythmias
- monitor heart rate
- detect ischemia
- detect electrolyte changes
- monitor pacemaker placement
The 3 lead EKG has how many electrodes?
It has 3, RA, LA, LL
How many views of the heart do you get with a 3 lead EKG?
You get 3 views
With a 3 lead EKG, which view of the heart is missing?
anterior view
Is the 3 lead EKG adequate for measuring ischemia?
No, you need at least a 5 lead to get some anterior view.
With the 5 lead EKG you get the addition of which 2 areas, which gives you a better view of ischemia?
LAD and septum
What are the current recommendations for lead number in EKG monitoring for the perioperative period?
3 lead is recommended. This is good for rhythm detection, and it is though that any chest lead will help detect ischemia, V3, V4, and V5 are better for this.
How many electodes are used in a 5 lead EKG?
There are 5, RA, RL, LA, LL, and a chest lead.
Which leads are viewed in a 5 lead EKG?
I, II, II, aVR, aVF, aVL, and a V lead
How many views of the heart do you get with a 5 lead EKG?
7 views
Each little block on the EKG strip reflects how many mV of voltage going up and down?
0.1 mV of elevation or depression
What is the 1500 method of calcuating HR?
count the little boxes from R to R and divide that number into 1500
If a patient is in a first degree HB, do you care?
They are usually stable but you should check their BP and oxygenation
When a patient is in ST, should you treat it with a beta blocker?
ST is the most overtreated rhythm in the OR, you should look for the underlying cause of the ST and treat that.
Why should you not change the gain on your EKG monitor in the OR?
Changing the gain will alter the ST segment monitoring
When gain is set to standardizaton, how many mm calibration pulse is produced by a 1mV signal?
10mm calibration pulse
So in order for a 1mm ST segment change to be monitored accurately, gain should be set at:
standardization
Filtering capacity on the EKG monitor should be set at:
diagnostic mode
Why should filtering be set at diagnostic mode?
because filtering out the end of the bandwidth can distort the ST segment
What are the 5 principal indicators of ischemia on EKG?
- ST segment elevation >1mm
- T wave inversion
- Development of Q waves
- ST segment depression, flat or downslope of > 1mm
- Peaked T waves
The peak pressure generated by the heart is the:
Systolic BP, generated during systolic ventricular contraction
SBP correlates with the time when there is the most:
O2 demand on the heart
Changes in SBP correlate with?
changes in myocardial O2 requirements
The trough pressure of the heart is the :
diastolic BP. it occurs during diastolic ventricular relaxation
Changes in DBP reflect:
coronary perfusion pressure
How do you calculate pulse pressure?
SBP-DBP
What is MAP
It is a time weighted average of arterial pressure during a pulse cycle
What is the formula for calculating MAP?
SBP + 2(DBP) / 3
As a pulsation moves peripherally, what happens to the waveform?
- Wave reflection distorts the pressure waveform-
- exaggerated SBP and
- wider pulse pressure.
Describe the palpation method for measuring BP?
Palpating the return of arterial pulse while an occlusive cuff is deflated.
Does the palpation method of BP measurement give an accurate measurement of BP?
No. It underestimates systolic pressure and it only mesures SBP, but it is simple and inexpensive
What is the doppler method of measuring BP?
It is based on shift in frequency of sound waves that is reflective of RBCs moving through an artery.
Is the doppler method of measuring BP reliable?
It only reliably measures SBP
Is the auscultation method of measuring BP reliable?
It is unreliable in hypertensive patients, patients are usually lower than the number it projects. This method permits an estimation of SBP and DBP
Describe the oscillometry method of measuring BP?
oscillometry senses oscillations/ fluctuations in cuff pressure produced by arterial pulsations while deflating a BP cuff
The first oscillation, when taking oscillometry BP, reflects what?
It correlates with SBP
When measuring BP by oscillometry, the maximal/ peak oscillations occur at?
MAP
When measuring BP by oscillometry, oscillations cease at:
DBP
How do automated BP cuffs work?
By oscillometry. they measure changes in oscillatory amplitude electronically and derives MAP, SBP and DBP by using algorithms
How big should the bladder width of a BP cuff be?
40% of the circumfrerence of the extremity
How long should the BP cuff bladder be?
It should be sufficient to encircle at least 80% of the extremity
How should the BP cuff be applied?
Snugly, with bladder centered over the artery, and resdual air removed.
Name 4 things that will give you a falsely high BP.
- cuff too small
- cuff too loose
- extremity below the level of the heart
- arterial stiffness, HTN, PVD
Name 4 things that will give you a falsely low BP.
- cuff too large
- extremity above the level of the heart
- poor tissue perfusion
- too quick deflation
Will improper placement of cuff, dysrhythmias, and tremors/shivering affect BP?
It will affect your BP reading and could give you erroneous values.
Name 7 complications that can occur with non invasive BP measurement.
- edema of the extremity
- petechiae/ bruising
- ulnar neuropathy
- interference with IV flow
- altering timing of IV drug adminstration
- pain
- compartment syndrome
How does invasive arterial BP monitoring work?
involves percutaneous insertion of catheter into an artery, which is then transduced to convert the generated pressure into a electrical signal to provide a waveform.
Name 3 benefits to invasive BP monitoring.
- generates real time beat to beat BP
- allows access for arterial blood samples
- measurement of CO/ CI/ and SVR
Name 8 indications for using invasive BP monitoring in the OR.
- elective deliberate hypotension
- wide swings in intra-op BP
- risk of rapid changes in BP
- rapid fluid shifts
- titration of vasoactive drugs
- end organ disease
- repeated blood sampling
- failure of indirect BP measurement
What size catheter should be used in an aline?
small, even a 20ga angiocath would suffice
Name 6 possible sites that you could use for an aline.
- radial
- ulnar
- brachial
- femoral
- dorsalis pedis
- axillary
What is the most common site for aline placement?
radial artery
Before using the radial artery, you must peform what test?
Allen’s test
Describe the transducer system on an aline.
It has a continuous flush device, it gives 1-3mL/hr of NS to prevent thrombus formation, it allows for rapid flushing
How would your improve the system dynamics and accuracy of an aline transducer system?
- minimize tube length
- limit stopcocks
- no air bubbles
- the mass of fluid should be small
- use noncompliant stiff tubing
- calibrate at the level of the heart
Aline accuracy depends on what 2 things?
- correct calibration
- zeroing
Where should the aline transducer be leveled?
- at the midaxillary line in supine patients, level with the right atrium
- Level of the ear (circle of Willis) in sitting patients
Name 2 problems that can happen with aline waveforms.
- dampening
- overshooting
The rate of upstroke on the aline waveform is indicative of?
contractility
The rate of downstroke on the aline waveform is indicative of?
SVR
You will get exaggerated variations in size of aline waveforms with what 2 conditons?
- naturally with respirations
- and in hypovolemia
The area under the aline curve is reflective of?
MAP
The dicrotic notch signals that what has occured?
aortic valve has closed
Describe the 6 phases of the aline waveform.
- Systolic upstroke
- Systolic peak pressure
- Systolic decline
- Dicrotic notch (aortic valve closure)
- diastolic runoff
- end diastolic pressure
What is distal pulse amplification?
it is the changes that occur to arterial BP waveforms as they travel through the arterial tree to the periphery.
What happens to the SBP peak as the waveform moves toward the periphery.
SBP peak increases
What happens to the DBP wave as it moves toward the periphery?
The DBP wave decreases
What happens to the MAP wave as it moves toward the periphery
MAP waves are unchanged
What happens to the dicrotic notch as waves move toward the periphery?
it becomes less and appears later
Where is this waveform likely from?
the aorta
Where is this waveform likely from?
Brachial artery
Where is this waveform likely from?
Radial artery
Where is this waveform likely from?
Femoral artery
Where is this waveform likely from?
Dorsalis Pedis
Name the likely locations where these waveforms occur.
Name 10 complications that can occur with alines.
- nerve damage
- hemmorhage/ hematoma
- infection
- thrombosis
- air embolus
- skin necrosis
- loss of digits
- vasospasm
- arterial aneurysm
- retaines guidewire
What is the typical size of a central venous catheter?
7 french
Name 5 indications for placing central venous catheters.
- measuring right heart filling pressures
- assess fluid status/ blood volume
- rapid adminstration of fluids
- administration of vasoactive drugs
- removal of air emboli
- insertion of transvenous pacing leads
- vascular access
- sample central venous blood
- pulmonary artery catheters/ pressure measurement
Name 5 common insertion sites for cental venous catheters.
- right IJ
- left IJ
- subclavian veins
- EJs
- femoral veins
What french central venous catheter would you use in a child?
4 or 5 french
how long is the typical central venous catheter?
20cm
How do you confirm central line placement in the OR?
No x-ray of lines in OR. Aspirate blood from all ports. Get an x-ray after surgery.
Where would ideally want the tip of the central line to be, as viewed on x-ray?
- withing the SVC
- just above the junction of the venae cava and the RA
- parallel to the vessel walls
- positioned below the inferior border of the clavicle
- above the level of the 3rd rib
- above the T4/T5 interspace
- above the carina
- above the takeoff of the right main bronchus
Name 2 contraindications to placing a cental venous catheter.
- Right atrial tumor
- Infection at the insertion site
Name 9 risks to placing a central line (most are due to poor technique)
- air or thromboembolism
- dysrhythmia
- hematoma
- carotid puncture
- pneumo/hemothorax
- vascular damage
- cardiac tamponade
- infection
- guidewire embolism
What is the most commonly recorded risk that occurs in central line placement?
carotid puncture
What causes the waveforms in central venous monitoring?
The ebbs and flows of blood in the right atrium
What does CVP also show?
CVP is the same as the right atrial pressure (RAP) and RV preload
What is the normal value for a mean CVP in a spontaneously breathing patient?
1-7 mmHg
How does CVP change in a mechanically ventilated patient?
It increases 3-5 mmHg
the peak of the ‘a’ wave coincides with ?
the point of maximal filling of the right ventricle.
So, the ‘a’ wave measurement should be read as?
RVEDP
If you are looking for an accurate RVEDP, why do want to measure it right at the ‘a’ wave.
Because the machine just averages pressures, the actual RVEDP is at the peak of the ‘a’ wave.
When should you measure RVEDP?
at end expiration
How many phasic events occur in the CVP waveform?
5
How many peaks and how many descents?
3 peaks, 2 descents
What is happening that causes the ‘a’ wave?
The a wave occurs due to contraction of the right atrium, which results in increased pressure in the atrium (since there is no pressure difference between the vena cava and the right atrial pressure)
When comparing the ‘a’ wave (atrial contraction) where which part of the EKG would it compare to?
It would occur right after the P wave.
The ‘a’ wave coincides with the end of ventricular diastole and is commonly known as:
the atrial kick, which causes the completed filling of the r. ventricle.
What does the ‘c’ wave on the CVP waveform indicate?
Due to the closure of the tricuspid valve and isovolumetric contraction, this results in the tricuspid valve bulging back into the atrium.
Why is the ‘c’ wave a little smaller than the ‘a’ wave?
There is now some atrial relaxation and a decrease in atrial pressure after it has pumped out its blood into the right ventricle.
Is part of the heart contracting during the ‘c’ wave?
Yes, the right ventricle is contracting and causing the tricuspid valve to bulge back a little bit.
Where does the ‘c’ wave occur when compared to the EKG?
right after the upstroke of the QRS, during early systole.
What is happening during the ‘x’ descent of the cvp waveform?
atrial pressure continues to decline during ventricular contraction due to atrial relaxation.
The ‘x’ wave has also been referred to as:
systolic collapse in atrial pressure. It is lowest at midsystole, it is a midsystolic event.
What does the ‘v’ wave in the CVP waveform show?
It reflects venous return against a closed tricuspid valve (which encompasses a portion of RV systole)
The ‘v’ wave is the last atrial pressure increase and is caused by:
filling of the atrium with blood from the vena cava.
Does the v wave occur after systole?
No, it occurs in late systole while the tricuspid valve is still closed
where does the v wave occur when compared to the EKG?
It occurs just after the T wave
What is happening during the ‘y’ descent of the CVP waveform?
after ventricular relaxation, the tricuspid valve opens due to the venous pressure, and blood flows from the atrium into the ventricle.
What is happening to atrial pressure during the ‘y’ descent?
It is falling, following the opening of the tricuspid valve.
The y descent is also known as:
diastolic collapse in atrial pressure
R. sided heart cath (PA cath) monitoring is used for direct bedside assessment of which 6 things?
- intracardiac pressure (CVP, PAP, PCWP)
- estimate LV filling pressures
- assess LV function
- CO
- Mixed venous O2 saturation
- PVR and SVR
Using a PA catheter, in addition to giving you pressure readings, also gives you the option of:
pacing
What size are the typical PA caths?
7 or 9 french
How long is a PA cath?
110cm, marked off in 10cm increments
How many lumens are there on a PA cath?
4 lumens.
Describe what the 4 lumen are for in the PA cath?
- distal port for PAP
- proximal port for CVP (usually 30cm more proximal than PAP)
- Third lumen for balloon
- Fourth lumen for thermistor
Name 8 indications for which you may want use a PA cath during the procedure?
- LV dysfunction
- Valvular disease
- Pulmonary HTN
- CAD
- ARDS/ Resp. failure
- Shock/ sepsis
- ARF
- Surgical procedures: cardiac, aortic, OB
Name 10 possible complications of PA catheters.
- Arrhythmias (vfib, RBBB, complete HB)
- catheter knotting
- balloon rupture
- thromboembolism/ air embolism
- pneumothorax
- pulmonary infarct
- PA rupture
- Infection (endocarditis)
- damage to cardiac structures (valves)
- relative contraindications (WPW syndrome and complete HB)
Where would you expect to see this waveform in your PA cath waves?
R. atrium. this is a CVP waveform
Where would you expect to see this waveform in your PA cath?
in the RV. you will only see this on insertion.
Where would you expect to see this waveform in your PA cath?
PA
What is this waveform reflective of, in your PA waveforms?
Wedge
What is the typical distance from the RIJ to the Vena cava/ RA junction?
15cm
What is the typical distance from the RIJ to the R. atrium?
15-25 cm
What is the typical distance from the RIJ to the RV?
25-35 cm
What is the distance from the RIJ to the PA?
35-45 cm
What is the typical distance from RIJ to wedge in the PA?
40-50cm
Look at these PA waveforms.
That is all.
What does the ‘a’ wave represent on the PCWP waveform?
It represents contraction of the left atrium.
The ‘a’ wave of the PCWP waveform is normally a small deflection, if it is enlarged, what does that indicate?
There is resistance in moving blood into the left ventricle as in mitral stenosis
What causes the ‘c’ wave in the PWCP waveform?
The c wave is due to a rapid rise in left ventricular pressure in early systole, causing the mitral valve to bulge backwards into the left atrium, so that the atrial pressure increases momentarily.
What causes the ‘v’ wave on the PWCP waveform?
It is produced when blood enters the left atrium during late systole.
What would a prominent ‘v’ wave mean?
mitral insufficiency, causing large amounts of blood to reflux into the left atrium during systole.
Look at the wedge compared to the CVP.
That is all.
Name 5 possible ways to measure cardiac output.
- Thermodilution
- Continuous thermodilution
- Mixed venous oximetry
- Ultrasound
- Pulse contour (flowtrac)
What could cause a loss of the ‘a’ wave in both CVP and PAOP (pulmonary artery occlusive pressure)? (list 2)
- a fib
- v pacing
What could cause giant ‘a’ waves, cannon ‘a’ waves on the CVP, PAOP waveforms? (list 6 )
- junctional rhythms
- complete HB
- Mitral stenosis
- diastolic dysfunction
- myocardial ischemia
- vent. hypertrophy
What would cause large ‘v’ waves on the CVP or PAOP waveforms? (list 2)
- mitral regurg
- acute increase in intravascular volume
The TEE evaluates which 7 cardiac parameters?
- Ventricular wall characteristics and motion
- Valve structure and function
- Estimation of end diastolic and end systolic pressures and volumes (EF)
- CO
- Blood flow characteristics
- Intracardiac air
- Intracardiac masses
Name 6 cases in which you would want to use TEE.
- unusual causes of hypotension
- pericardial tamponade
- pulmonary embolism
- aortic dissection
- myocardial ischemia
- valvular dysfunction
List 4 complications of TEE.
- Esophageal trauma
- Dysrhythmias
- Hoarseness
- Dysphagia
Most of the complications of TEE occur in awake or asleep patients?
awake patients
