Pt Monitoring Unit 2 - Advanced Hemodynamic Monitoring

What is a normal Pulmonary artery pressure (PAP)? when is PAP not considered as accurate? what are the three different classifications of pulmonary hypertension and their values?

15-30/10 mmHg It's not considered as accurate if a patient is truly "sitting" •For the same reason listed previously with CVP Pulmonary hypertension Mild (36-49 mmHg systolic), (moderate (50-59 mmHg), severe (>60 mmHg)

What is a normal central venous pressure (CVP)? CVP is most accurate if measured when? when is it not considered as accurate?

5-12mmHg (mean) CVP is most accurate if measured at the end of expiration It's not considered as accurate if a patient is truly "sitting" "CVP, PAP, and PCWP readings can only be considered reliable if the backrest positions are from 0 to 60 degrees

What is a normal mixed venous oxygen saturation (mvO2) in an awake pt? what is this value roughly equal to?

60-80% in awake patient This value is roughly equal to central venous oxygen saturation (ScvO2)

What is a normal coronary perfusion pressure?

Autoregulated between 50-120mmHg

Stroke Volume Variation Summary

If pt starts to get hypovolemic stroke volume variation starts to increase above 10-15 for example.

How does low Cardiac Output look on a thermodilution curve?

If the cardiac output is low, the temperature at the thermistor will stay cold for a longer period Therefore, the total area under thermodilution curve will be HIGHER than normal

A patient has the following vital signs: Heart Rate = 98(High) MAP = 89mmHg CVP = 9mmHg(Normal) PAP = 25/8mmHg(Normal) Weight = 61kg PCWP = 15mmHg Cardiac Output = 4L/min Hemoglobin = 9.4g/dL What is their SVR?

Quiz question. Know how to do this.

What are the 5 Causes Of High CVP And 2 Causes Of Low CVP?

Side note: Hypervolemia usually only happens because someone either has HF or decreased kidney function. Hypervolemia decreases CO bc the heart is stretched too much and will not be able to contract as effectively. Vasodilation increases SV and CO but decreases BP.

What are the two equations for coronary perfusion pressure (CPP)?

Slow HR = more diastolic filling time = better coronary perfusion Tachycardia and hypotension can decrease CPP.

When Applying This Concept To The Pulmonary System what other two things can voltage also be analogous to?

Voltage can also analogous to the difference in blood pressure at the PULMONARY arterial end of the body (pulmonary artery pressure) and the blood pressure at the PULMONARY venous end of the body (pulmonary capillary wedge pressure)

If a patient has hypotension due to decreased contractility, would the anesthetist expect the following to be increased or decreased? Cardiac index? CVP? SVR?

-Cardiac index? •decreased -CVP? •Increased -SVR? •Increased CVP will increase bc fluid will back up into central veins. This is HF. SVR would increase bc we are hypotensive so our body is going to vasoconstrict to increase the BP.

If a patient has hypotension due to hypovolemia, would the anesthetist expect the following to be increased or decreased? Cardiac index? CVP? SVR?

-Cardiac index? •decreased -CVP? •decrease -SVR? •Increased SVR increased bc of vasoconstriction. There is an increase in resistance. The body is trying to keep the BP normal. SV and BP will decrease. Cause vasoconstriction peripheral to send blood to the vital organs in an effort to increase BP. Peripheral vascular resistance IS SVR.

If a patient has hypotension due to vasodilation, would the anesthetist expect the following to be increased or decreased? SVR? Cardiac index?

-SVR? •decreased -Cardiac index? •Increased Think of liver failure when you vasodilate you are decreasing the resistance of artery. So the heart can inject more blood out. SVR and cardiac index are pretty much inversely related. If one increases the other decreases

What are the 3 main Treatments For Hypotension?

1. Hypovolemia treatments -Treated with fluids and/or blood products 2. Vasodilation treatments -1. Vasopressors -2. Reversing the cause of the vasodilation (i.e., decreasing the level of anesthetic) 3. Heart failure (decreased contractility) treatments 1. Inotropes 2. Diuretics (because fluid overload can cause decreased contractility) - The heart doesn't contract as well when it's overly stretched out

Pulse pressure can be affected by stroke volume because? what does an increase in stroke volume mean? decrease in stroke volume?

1. Pulse pressure is affected by stroke volume, because stroke volume affects (and is proportional to) SYSTOLIC blood pressure -Increased stroke volume = increased systolic pressure -Decreased stroke volume = decreased systolic pressure SV mainly affects systolic pressure If SV increases pulse pressure increases

What are the 3 Factors That Affect Pulse Pressure?

1. stoke volume 2. systemic vascular resistance (SVR) 3. aortic compliance

What is a normal Pulmonary vascular resistance (PVR) value?

100-300 dynes·sec·cm-5

Pulse pressure can also be affected by systemic vascular resistance (SVR) because? What does an increase in SVR mean? decrease?

2. Pulse pressure is also affected by systemic vascular resistance (SVR), because SVR affects (and is proportional to) DIASTOLIC blood pressure -Increased SVR (vasoconstriction) = increased diastolic BP -Decreased SVR (vasodilation) = decreased diastolic BP

What is a normal cardiac index (CI)?

2.2-4.2 L/min/m^2 MEMORIZE ALL OF THESE VALUES

Pulse pressure can also be affected by aortic compliance because? what does it mean if the aorta has good vascular compliance? noncompliant/stiff?

3. Pulse pressure is also affected by aortic compliance -If the aorta has good vascular compliance (like in younger, healthy patients), the systolic pressure will be lower during systole -If the aorta is noncompliant/"stiff" (like in older patients), systolic pressure will be much higher during systole -In other words, systolic pressure (and thus pulse pressure) is inversely proportional to aortic compliance The older you are the stiffer and less compliant the systolic pressure increases. This is why we get hypertensive as we age Aorta gets stiff.

What is Mixed Venous O2 Saturation (mvO2)?

A "mixed" venous sample "is taken at the pulmonary artery (distal tip of pulmonary artery catheter). This allows for adequate mixing of blood from the superior vena cava (SVC), inferior vena cava (IVC), and coronary sinus." Would need a pulmonary artery catheter. Central venous would be higher than mixed. Know why it is lower.

Interpretation Of Thermodilution Waves - what does a small wave indicate? large wave?

A small wave indicates high cardiac output, so any factor that decreases the area under the curve will overestimate cardiac output A large wave indicates low cardiac output, so any factor that increases the area under the curve will underestimate cardiac output In other words, the cardiac output reading is inversely proportional to the area under the thermodilution curve

What is Thermodilution? how it is preformed?

A way to estimate CO 1. 10mL of cold saline is injected into the right atrium (through the CVP port on the Swan). The injection must be fast (<4 seconds) 2. This cold fluid travels to the pulmonary artery, where it encounters the thermistor on the Swan -The cold fluid is warmed to a degree (from normal body heat) before it gets to the thermistor - Getting cooler as the curve goes up 3. The monitor produces a waveform based on how cold the fluid at the thermistor is (see the next few slides) If the pt has a low CO the curve would be larger. It would take longer for the blood to warm up.

How can a Prolonged Injection Time affect the thermodilution curve?

If the anesthetist injected the saline too slowly (>4 seconds), the thermodilution curve would be larger than normal (because the blood at the thermistor would stay cold for a longer period), which means that the cardiac output reading would be underestimated (i.e., give a reading lower than what it really is)

How does High Cardiac Output look on a thermodilution curve?

If the cardiac output is high, the temperature at the thermistor will only be cold for a short few seconds (because the cold fluid will race past the thermistor really quickly) Therefore, because the temperature only stays cold for a short period, the total area under the thermodilution curve will be LOWER than normal

Exaggerated Stroke Volume Variation (Pulsus Paradoxus) - what is Pulsus Paradoxus? when is a pt considered to have it? how can we detect pulsus paradoxus?

If the stroke volume/systolic blood pressure has wider than expected fluctuations during inspiration and expiration, it is referred to as "pulsus paradoxus" -In other words, a patient is considered to have pulsus paradoxus if: •1. Their systolic BP decreases more than 10mmHg during SPONTANEOUS inspiration •2. Their systolic BP increases more than 10-15% during MECHANICAL inspiration Pulsus paradoxus (exaggerated decreases in systolic BP during inspiration) can be detected on SpO2 and arterial line waveforms When stroke volume variation is exaggerate and BP and greatly changing during inspiration and expiration. Most common cause is hypovolemia.

In healthy MECHANICALLY ventilated patients, systolic blood pressure normally (increases or decreases?) during inspiration. What is the percentage of change? what are the 2 reasons this occurs?

In healthy MECHANICALLY ventilated patients, systolic blood pressure normally INCREASES 5-10% during inspiration, because lung inflation: -1. Displaces the left ventricular wall inward during systole, assisting ventricular contraction (increasing ejection fraction) -2. Squeezes blood out of the pulmonary capillaries and into the left atrium, increasing blood volume and stroke volume during inspiration Opposite of spontaneous vent. NEED TO KNOW THIS STUFF. QUIZ/TEST QUESTION. BP increases during inspiration.

In healthy, SPONTANEOUSLY ventilating patients, systolic blood pressure normally (increases or decreases?) during inspiration. What is the pressure change? what are the 4 reasons it increases or decreases?

In healthy, SPONTANEOUSLY ventilating patients, systolic blood pressure normally DECREASES 5-10mmHg during inspiration, because: -1. Pulmonary vessels vasodilate during inspiration -2. The vasodilation causes blood to pool in the lungs -3. When blood pools in the lungs, less blood is available to pump to the body -4. This leads to a slight drop in blood pressure during inspiration

A patient is adequately anesthetized and has a pulmonary artery catheter in place. Monitors show the following values: Heart Rate = 60(Normal) Blood Pressure = 170/105mmHg (High) CVP = 7mmHg(Normal) PAP = 35/10mmHg(Normal) SVR = 1700 dynes·sec·cm-5 (High) PVR = 350 dynes·sec·cm-5 (High) Cardiac Index = 2.8L/min/m2 (Normal) PCWP = 9mmHg Of the following options, which treatment will best normalize the patient's vital signs? A. Fluid bolus B. Vasopressor C. Inotrope D. Vasodilator E. Diuretic F. Beta blocker

Increase BP increase SVR Give vasodilator they are hypertensive

A patient is adequately anesthetized and has a pulmonary artery catheter in place. Monitors show the following values: Heart Rate = 98(High) Blood Pressure = 88/40mmHg (Low) CVP = 8mmHg(Normal) PAP = 25/8mmHg(Normal) SVR = 400 dynes·sec·cm-5 (Low) PVR = 200 dynes·sec·cm-5 (Normal) Cardiac Index = 3.0L/min/m2 (Normal) PCWP = 7mmHg Of the following options, which treatment will best normalize the patient's vital signs? A. Fluid bolus B. Vasopressor C. Inotrope D. Vasodilator E. Diuretic F. Beta blocker

Increased HR, low BP. If pt was hypovolemic then CVP would be low. So we would give a vasopressor they are hypotensive. Pt is hypotensive D would drop BP and SVR even more E would not make since bc pt is not hypervolemic F would fix high HR but not fix BP

Just remember that cardiac output is not the ONLY thing that can affect mvO2/scvO2 values...what are the two things that can cause them to decrease? increase?

Just remember that cardiac output is not the ONLY thing that can affect mvO2/scvO2 values... -Low ScvO2/mvO2 can also be caused by: 1. Hypoxia/hypoventilation -Makes sense right? If you intubate the esophagus, not only will the arterial SpO2 go down, the ScvO2/mvO2 will also go down, even if the cardiac output is normal 2. Increased metabolic rate -High ScvO2/mvO2 can also be caused by: 1. Decreased metabolic rate 2. Mitochondrial dysfunction (as seen in sepsis) -Here, the mitochondria are not able to uptake oxygen as well, leaving a higher concentration of oxygen in the blood

What information do you need to accurately determine a patients Cardiac Output?

Knowing a patient's cardiac output is great, but, it's impossible to determine whether or not that cardiac output is normal without first knowing the patient's weight. For example, a cardiac output of 5L/min is: -Normal for a 70kg patient -Abnormal (abnormally low) for a 200kg patient -Abnormal (abnormally high) for a 30kg patient "Normal cardiac output varies with the size of a patient (you would expect a 200kg patient to have a higher cardiac output than a 50kg patient because of the increased body mass that must be perfused)." 5 is a normal CO. obese pt have a CO that is higher than 5. Neonate is less than 5L/min. CO depends on weight so there really is no normal CO. BUT there is a normal cardiac index bc it takes body surface area out of the mix to normalize the number

What is Stroke Volume? what information do you need to accurately calculate it?

Knowing a patient's stroke volume is great, but, it's impossible to determine whether or not that stroke volume is normal without first knowing the patient's weight. For example, a stroke volume of 70mL/beat is: -Normal for a 70kg patient -Abnormal (low) for a 200kg patient -Abnormal (high) for a 30kg patient Just like cardiac output varies with the size of a patient, stroke volume also varies with the size of a patient. If we want a stroke volume number that is not skewed by weight, we go with the stroke volume index (see next slide...)

Pulse pressure is defined as "narrow" when?

Pulse pressure is defined as "narrow" when the pulse pressure is <25% of the systolic pressure -For example, if a patient has a blood pressure of 100/80... 1. 25% of the patient's systolic pressure (100mmHg) is 25mmHg 2. The patient's pulse pressure is 20mmHg The patient in the above example has a NARROW pulse pressure, because it is less than 25mmHg (less than 25% of their systolic pressure) -In other words, any diastolic blood pressure greater than 75mmHg would constitute narrow pulse pressure in this patient

Pulse pressure is defined as "wide" when?

Pulse pressure is defined as "wide" when the pulse pressure is >50% of the systolic pressure -For example, if a patient has a blood pressure of 170/80... 1. 50% of the patient's systolic pressure (170mmHg) is 85mmHg 2. The patient's pulse pressure is 90mmHg The patient in the above example has a WIDE pulse pressure, because it is greater than 85 (greater than 50% of their systolic pressure) -In other words, any diastolic blood pressure less than 85mmHg would constitute wide pulse pressure in this patient

What are the three main causes of Pulsus Paradoxus?

Pulsus paradoxus is most commonly caused by hypovolemia! -The mechanism isn't well understood, and you don't need to know it, but I included some proposed mechanisms on the next slide just for fun Pulsus paradoxus is also classically seen in cardiac tamponade and tension pneumothorax -These mechanisms are better understood and it is expected that you know them Less commonly, pulsus paradoxus can be caused by vasodilation, CHF, hypervolemia, and PEEP - don't really need to know this part. Know main causes of this. The most common cause is hypovolemia. The other cause is cardiac tamponade and tension pneumothorax. KNOW THESE THREE THINGS. A fluid blouse is how you treat it.

Coronary Perfusion Pressure Clinically

Remember how slow heart rates increase coronary perfusion through increased diastolic filling time? Well, these equations teach us that coronary perfusion isn't only affected by diastolic filling time; it's also affected by BLOOD PRESSURE (specifically diastolic blood pressure). We need to have BOTH adequate diastolic filling time AND adequate blood pressure to have adequate coronary perfusion pressure - And remember from our "Blood Pressure Monitoring" lecture that coronary blood flow is autoregulated between MAPs of 50-120mmHg

ScvO2 and mvO2 are rarely used anymore to estimate cardiac output for what two reasons?

ScvO2 and mvO2 are rarely used anymore to estimate cardiac output, because: -1. It requires drawing blood from a central line and/or Swan -2. Cardiac output can be estimated by other effective methods (CCO Swan, TEE, FloTrac sensor, etc) There are other things that can affect mvO2, but for now (1st semester), we'll just assume that mvO2 in most cases will directly correlate with cardiac output (i.e., if mvO2 is low, cardiac output is low, and vice versa)

What is Central Venous O2 Saturation (ScvO2)?

ScvO2 refers to the oxygen saturation of blood taken from the superior vena cava This blood sample can be drawn from a central venous line port

Difference Between ScvO2 and mvO2

Since the coronary sinus drains into the right atrium, any blood drawn proximal to the right atrium (ScvO2) will not include coronary sinus blood, while any blood drawn distal to the right atrium (mvO2) will include coronary sinus blood -Therefore, ScvO2 does not include venous blood from the heart, but mvO2 does Since the heart burns more oxygen than most other organs, coronary sinus blood is more deoxygenated, which means mvO2 will be slightly lower than ScvO2 Both values are an indication of CO. but we have better ways of obtaining CO so we typically use other methods.

What is stroke volume index? how is it calculated? what is a normal value? how does the stroke volume index differ in an obese pt vs a thin pt?

Stroke volume index (like cardiac index) allows more accurate interpretation of stroke volume because the number is not skewed by weight. In other words, as long as stroke volume is normal, a child and adult will have a similar stroke volume index (even though they will have different stroke volumes. In other words (again), the normal range for cardiac index is the same for all patients, regardless of their size

What is Stroke Volume Variation (SVV)?

Stroke volume variation (SVV) refers to stroke volume and systolic blood pressure fluctuating during inspiration and expiration -Stroke volume variation can also be referred to as "pulse pressure variation" When we inhale our blood vessels dilate which causes blood to pull in the vasculature a little which decrease SV. BP decreases due to dilations as well. When you are spontaneous vent BP decreases during inspiration Just know what happens when you breathe on your own vs mechanically

We can use Ohm's law to create an equation to calculate what two things? what is the equation for solving theses two values?

Summary -V is analogous to MAP minus CVP -I is analogous to cardiac output (CO) -R is analogous to SVR When we put all of these analogies together, we can use Ohm's law to create an equation to calculate SVR and/or cardiac output (see on next slide) So, if we can measure CVP (with a central line) and monitor MAP (with an A-line) and cardiac output (with a Swan), we can CALCULATE SVR V = IR is analogous to (MAP - CVP) = (CO)(SVR) We use the number "80" in the cardiac output equation to convert the units used for blood pressure and SVR into the units for cardiac output. So the equation can be rewritten to solve for cardiac output via: CO = (MAP - CVP/SVR) (80) and can also be rewritten to solve for SVR: SVR = (MAP - CVP/CO ) (80)

What does the Bainbridge Reflex respond to? what does it cause?

The Bainbridge reflex responds to changes in blood volume inside the heart -If right atrial pressure increases (if blood volume in the right atrium increases), the Bainbridge reflex causes: 1. An increased heart rate (in an effort to get the excess blood out) 2. Vasodilation, which causes venous pooling in the legs (and decreased venous return) HR increasing in hypervolemia due to Bainbridge reflex

What does the baroreceptor reflex respond to? what happens when BP is low? high?

The baroreceptor reflex responds to changes in blood pressure (inside the carotid sinus & aortic arch) -When blood pressure is low, the heart rate increases -When blood pressure is high, the heart rate decreases

What is Ohm's law?

The equation for Ohm's law is V = IR -V = Voltage -I = Current -R = Resistance What's interesting is that this equation can be applied to cardiac output and used to describe the factors that affect blood flow through the body

A patient has tricuspid regurgitation. Would thermodilution in this patient lead to an overestimation or underestimation of cardiac output?

Underestimation. Blood is going to be pumped back through the valve into the atrium and making the blood stay colder for a longer period and make the curve larger

Therefore, if we can measure PAP, PCWP, and cardiac output (with a Swan), we can CALCULATE PVR - what are the two equations?

V = IR is analogous to (PAP - PCWP) = (CO)(PVR) can be rewritten to solve for cardiac output: CO = (PAP - PCWP/PVR) (80) and can also be rewritten to solve for PVR: PVR = (PAP - PCWP/CO) (80) Again, we use the number "80" in the equation to convert the units used for blood pressure and SVR into the units for cardiac output

Voltage (the difference in energy between two ends of a circuit) can be analogous to?

Voltage (the difference in energy between two ends of a circuit) can be analogous to the difference in blood pressure at the arterial end of the body (MAP) and the blood pressure at the venous end of the body (CVP)

What is pulse pressure?

difference between systolic and diastolic pressure

A patient has aortic stenosis (narrowing of the aortic valve). Should an anesthetist expect a wide or a narrow pulse pressure?

narrow? due to increased SVR and decreased SV? - ask on this. did not do this one in class.

What do the Bainbridge Reflex and Baroreceptor Reflex have in common?

Both of these reflexes control the heart rate, but differ in how they accomplish it

How does Cardiac Tamponade cause Pulsus Paradoxus? what is the mechanism?

Cardiac Tamponade Mechanism For Pulsus Paradoxus 1. During inspiration, blood volume in the right ventricle increases -Normally, the right ventricular wall would expand and absorb the increase in pressure that resulted from the increase in volume that occurs during inspiration (as seen on the right) 2. However, in cardiac tamponade, the right ventricular wall can't expand (because of the fluid in the pericardial sac) 3. This means that the increase in right ventricular volume/pressure that occurs during inspiration will force the interventricular septum to bulge over to the left 4. This causes a decrease in the volume of the left ventricle, a decrease in stroke volume, and a greater decrease in blood pressure during inspiration NEED TO KNOW HOW CARDIAC TAMPONADE CAUSES IT. IT WILL BE A QUESTION ON THE EXAM.

What is cardiac index? how is it calculated? what is a normal cardiac index for an adult? for a child?

Cardiac index allows a more accurate interpretation of cardiac output because the number is not skewed by weight. In other words, as long as heart function is normal, a child and an adult will have a similar cardiac index (even though they won't have the same cardiac output). In other words (again), the normal range for cardiac index is the same for all patients, regardless of their size If you were to compare two pt with fully functioning hearts they should have a CI between 2.2 and 4.2. If the CI falls below 2.2 it tells us that the pt has a low CO.

A patient has a right to left intracardiac shunt. Would thermodilution in this patient lead to an overestimation or underestimation of cardiac output?

Overestimation. Only half injection fluid will make it to the thermometer that is in the PA. it will appear warmer thermometer

Estimating Left Ventricular End Diastolic Pressure - what is LVEDP? how do we find LVEDP?

LVEDP is essentially blood pressure in the left ventricle at the end of diastole. In the coronary perfusion pressure equation, we need to know LVEDP in order to know what the coronary perfusion pressure is. The problem is that we can't really KNOW LVEDP from our monitors, so we have to ESTIMATE it. Here's how it works: -Blood pressure in the left VENTRICLE at the end of diastole (LVEDP) is roughly equal to the systolic pressure in the left ATRIUM (left atrial pressure). And since left ATRIAL pressure (LAP) is roughly equal to pulmonary capillary wedge pressure (PCWP), PCWP gives us a good estimate of LVEDP 1. LVEDP is roughly equal to left atrial pressure (LAP) -As explained on the previous slide 2. Left atrial pressure (LAP) is roughly equal to pulmonary capillary wedge pressure (PCWP) -As explained in the "pulmonary artery catheter" PPT 3. Pulmonary capillary wedge pressure (PCWP) is roughly equal to PA diastolic pressure -"Diastolic pressure in the pulmonary artery will almost always equal the wedge pressure" •THEREFORE, LVEDP ≈ LAP ≈ PCWP ≈ PA diastolic pressure

What is a normal Pulmonary capillary wedge pressure (PCWP)?

Less than 12mmHg (mean pressure) •1-4mmHg less than pulmonary artery diastolic pressure Not considered as accurate if a patient is truly "sitting" •For the same reason listed previously with CVP

The limitations of monitoring stroke volume variation with the EV1000 are that, in order for stroke volume variation to be accurate 5 things need to occur. What are these 5 things?

Limitations Of The FloTrac Sensor (EV1000) The limitations of monitoring stroke volume variation with the EV1000 are that, in order for stroke volume variation to be accurate: -1. The patient must be 100% mechanically ventilated (stroke volume variation monitoring is not as accurate on spontaneously ventilating patients -2. The respiratory rate needs to be fixed (constant) -3. The tidal volume needs to be >8mL/kg -4. The patient's heart rhythm must be regular (stroke volume variation monitoring is not as accurate with an irregular rhythm/atrial fibrillation) -5. PEEP & vasodilators may alter SVV So it is Not as accurate as an a line.

How mvO2 & ScvO2 Relate to Cardiac Output - Low cardiac output = lower or higher mvO2/ScvO2? what about High cardiac output?

Low cardiac output = lower mvO2/ScvO2 -In low cardiac output states, blood is more deoxygenated by the time it returns to the heart, simply because it traveled more slowly through the body and had more time to unload oxygen to the tissues -"A decrease in cardiac output results in slower flow of blood, and subsequently greater oxygen extraction by the body tissue. This increased oxygen extraction decreases venous oxygen saturation." High cardiac output = higher mvO2/ScvO2 -In high cardiac output states, blood is less deoxygenated by the time it returns to the heart, because it traveled faster through the body and had less time to unload oxygen to the tissues

A patient is hypovolemic. Should an anesthetist expect a wide or a narrow pulse pressure?

Narrow due to lower SV (systolic pressure) and vasoconstriction (higher diastolic pressure)

A patient has congestive heart failure (CHF). Should an anesthetist expect a wide or a narrow pulse pressure?

Narrow. SV (systolic pressure) and vasoconstriction (higher diastolic pressure). CHF means lower EF and SV with leads to lower CO

A patient has cardiac tamponade (blood in the pericardial sac). Should an anesthetist expect a wide or a narrow pulse pressure?

Narrow. due to lower SV (systolic pressure) and vasoconstriction (higher diastolic pressure)

Currently, what is the 3 most common methods to assess volume status? How can we use The EV1000 For Fluid Management?

Options For Assessing And Managing Volume Status Currently, the most common methods to assess volume status are: -1. Monitoring urine output -2. Looking for hypotension and tachycardia -3. Monitoring CVP (requires a central line) Most of the time, anesthetists decide how much fluids to give by: -1. Calculating ("guessing") fluid replacement •(using maintenance, deficit, insensible, and blood loss) -2. Monitoring blood pressure, heart rate, urine output, and CVP With a FloTrac sensor, fluid management is simplified, because all you have to do is monitor stroke volume variation on the monitor -If the stroke volume increases more than expected (>10-15%) during mechanical inspiration, hypovolemia is suspected, and the anesthetist simply gives fluid until the stroke volume variation gets down towards 10% So with this monitor, we just titrate fluids until the stroke volume variation gets to a normal range

A patient has a left to right intracardiac shunt. Would thermodilution in this patient lead to an overestimation or underestimation of cardiac output?

Overestimation. Blood from the LV is going to warm up the cold fluid from the RV faster bc it is diluted by the warm blood from the LV. Resulting in the blood in the PA being warmer and the curve being smaller

What are the two main Disadvantages To The EV1000 (FloTrac Sensor)?

The main disadvantages to the EV1000 compared to arterial lines are that: -1. Arterial lines give access to drawing blood for labs (while the EV1000 does not) -2. The blood pressure readings on the EV1000 aren't always as accurate as an A-lines

Tension Pneumo Mechanism For Pulsus Paradoxus

The mechanism for pulsus paradoxus in tension pneumothorax is roughly the same as it is for cardiac tamponade -1. Blood volume in the right ventricle increases with inspiration -2. The right ventricular wall can't expand because of external compression on the heart from the increased intrathoracic pressure -3. Therefore, the increase in right ventricular volume/pressure that occurs during inspiration will force the interventricular septum to bulge over to the left -4. This causes a decrease in the volume of the left ventricle, a decrease in stroke volume, and a greater decrease in blood pressure during inspiration

Baroreceptor & Bainbridge Reflex Summary

Therefore, BOTH a low CVP (through the baroreceptor reflex) and a high CVP (through the Bainbridge reflex) will cause an increase in heart rate

What are the two ways to estimate cardiac output?

Thermodilution and mvO2

Thermodilution is rarely used anymore to approximate cardiac output. It has been replaced with what two thing?

Thermodilution is rarely used anymore to approximate cardiac output. It has been replaced with: 1. Continuous cardiac output (CCO) pulmonary artery catheters •These pulmonary artery catheters can estimate cardiac output without the anesthetist injecting saline -Video (https://www.youtube.com/watch?v=3mmfsYVMMAM ) (0.10-0.47) 2. Transesophageal echocardiography (TEE) CCO has a thermal filament which is a brown area on the swan Ganz catheter - Know that not all pulmonary artery catheters are capable of CCO. Only the ones with the brown thermal filament. QUIZ QUESTION.

LVEDP & Coronary Perfusion Pressure (CPP) Estimation - Thus, coronary perfusion pressure can be estimated by either one of the following three equations:

Thus, coronary perfusion pressure can be estimated by either one of the following three equations:

How do we monitor Stroke Volume Variation?

We have a monitor (the EV1000, or FloTrac Sensor) that can tell us the exact stroke volume variation (SVV), and whether or not SVV is normal or exaggerated 1. The first cool thing about the EV1000 is that it's a noninvasive monitor. It's just like a pulse oximeter in the sense that you just place it on the finger, and it can give you the stroke volume variation (and all of this other great hemodynamic information) by just sensing the pulse through the probe (we don't have to cannulate a blood vessel) 2. The second cool thing about the EV1000 is that it gives you a real time blood pressure. Just like an arterial line, but without having to cannulate an artery! Measures pulse and blood pressure. Pulse ox does not do this. We can the benefits of a line without having to do an a line. A lines will still be useful in the future though for lab samples 3. And last but not least, in addition to giving the stroke volume variation and a real time blood pressure reading, the EV100 can also tell us the following values that previously required us to start a central line and float a Swan Ganz catheter into the pulmonary artery: -1. SVR (from waveform downstroke) -2. Cardiac output/index (by using the SVR equation...see next slide...) -3. Stroke volume/stroke volume index (from calculated cardiac output & HR) •Stroke volume = cardiac output/heart rate Gives SVR without pulmonary catheter SVV Stoke volume variation so we can tell if a pt is hypovolemic. Fluid -If pt has a folly -100 kg 1 hour surgery - 50 mL fluid output per hour If they do not have folly you limit it to 1500mL so they do not pee all over themselves. 100 kg at 7 am and surgery is going to 10 am. 140 ml/hr which is fluid deff x by NPO with is 10hr = 1400 The EV1000 uses CO = (MAP-CVP)/SVR to CALCULATE cardiac output. It knows the MAP (from the blood pressure waveform) and it knows the SVR (from waveform downstroke). All it needs to know is CVP and then it could calculate cardiac output. -Since it doesn't know the CVP, it plugs in a normal CVP value (7mmHg) so that it can complete the equation and calculate cardiac output and cardiac index value for us •So even though the CVP may not be exactly 7mmHg, the estimation of cardiac output is still fairly accurate, because CVP has minimal effect on the cardiac output equation So to recap, the EV1000 will tell us the blood pressure in real time, stroke volume variation (SVV), stroke volume and stroke volume index, SVR, and cardiac output, all without having to place an invasive line!

A patient is adequately anesthetized and has a pulmonary artery catheter in place. Monitors show the following values: Heart Rate = 65(Normal) Blood Pressure = 85/40mmHg (Low) CVP = 7mmHg(Normal) PAP = 25/8mmHg(Normal) SVR = 1100 dynes·sec·cm-5 (Normal) PVR = 250 dynes·sec·cm-5 (Normal) Cardiac Index = 1.8L/min/m2 (Low) PCWP = 8mmHg Of the following options, which treatment will best normalize the patient's vital signs? A. Fluid bolus B. Vasopressor C. Inotrope D. Vasodilator E. Diuretic F. Beta blocker

What is the CPP? 40-LV end diastolic pressure Low BP and CI. A no bc normal CVP SVP is normal. So B would increase BP but would give us an abnormally high SVR. We would give C inotrope. It would increase contractility to increase SV which would increase CO and blood pressure. Prob epi

You just got done running 3 miles on a treadmill. Would you be expected to have a wide or a narrow pulse pressure?

Wide Bc increase SV and vasodilation

A patient has aortic regurge. Should an anesthetist expect a wide or a narrow pulse pressure?

Wide Due to lower diastolic pressure bc a lot of the blood that should have contributed to BP went back into left ventricle

A patient is on a Milrinone drip, which causes an increase in cardiac contractility and a decrease in SVR. Should an anesthetist expect a wide or a narrow pulse pressure?

Wide SV increase SVR decrease

A patient is adequately anesthetized and has a pulmonary artery catheter in place. Monitors show the following values: Heart Rate = 100(High) Blood Pressure = 84/55mmHg (Low) CVP = 2mmHg(Low) PAP = 20/5mmHg(Low) SVR = 1500 dynes·sec·cm-5 (High) PVR = 100 dynes·sec·cm-5 (Low) Cardiac Index = 2.0L/min/m2 (Low) PCWP = 4mmHg Of the following options, which treatment will best normalize the patient's vital signs? A. Fluid bolus B. Vasopressor C. Inotrope D. Vasodilator E. Diuretic F. Beta blocker

Would give fluid. Low CVP, vasoconstricted, low CO, high HR, low BP.