Hemodynamic Monitoring

What is Intermittent Thermodilution

A cold or room temperature solution is injected into the RA port of the PAC. A thermistor continuously measures the temperature of blood flowing past it. The change in temperature creates a dilution curve and the CO is calculated by the computer General steps include: •Ensuring the accurate amount of injectate volume in the syringe •Injecting the volume in a smooth and rapid manner, < 4 seconds •Waiting 1 minute between injections to allow the catheter thermistor to return to baseline.

What is Venous Oxygen Saturation?

Analysis of venous blood provides information to evaluate oxygen supply and demand •SvO2 shows mixed venous saturation, venous blood drawn from a pulmonary artery catheter (PAC) also known as a schwann ganz catheter - usually inserted after large heart surgeries to make sure the coronary arteries are actually perfusing -Level of blood saturation in the pulmonary artery -Normal ranges from 60% to 80%. (providers and nurses who are not comfortable with these mointoring devises should not use them)

Color Coding of monitors

Arterial- RED PA (pulmonary artery measurement)- YELLOW CVP (Central Venous Pressure)- BLUE

What is Cardiac Output

CARDIAC OUTPUT = Heart Rate x Stroke Volume = 4 - 8 L/min Volume of blood ejected from the heart per minute

Which hemodynamic parameters cannot be measured by a PA Catheter?

Cardiac Contractility

CARDIAC INDEX =

Cardiac Output ÷ BSA = 2.5 - 4 L/min/m2 The larger body service area usually means a higher cardiac output. The rock will have a harder cardiac output. it's very patient specific.

•Right ventricle preload (RVEDV as estimated by RVEDP)

Central venous pressure (CVP) = right arterial pressure (RAP)

What is Fick's meathod?

Determines cardiac output, by assessing the relationship of arterial blood and mixed venous blood samples to tissue oxygenation

How do you know when a patient has an imbalance of oxygen supply and demand?

Look at their vital signs and EKG -ST can be elevated or inverted based on changes of supply

Square Wave Test: overdamped system

Low bag pressure -Air bubbles, clots, or kinks in the system -Waveform becomes damped, or flattened, and is reflected in square waveform result Problem: Overdamped waveforms Cause •Air bubbles in tubing and near transducer •Blood clot partially occluding catheter tip •Forward migration of catheter •Catheter tip occluded by balloon or vessel wall •Leak in pressure system •Pressure bag not inflated at 300 mm Hg Prevention •Flush system by gravity •Remove any air bubbles •Maintain continuous flush •Tighten all connections and stopcock up on setup Intervention •Flush air from system •On initial setup, expel all air from flush soln. bag •Aspirate clots with syringe •Reposition patient

90/70 MAP ? , pulse pressure ? 150/40 MAP_? , pulse pressure ?

MAP =76.3 PP=20 MAP= 76.7 PP=110

What value is most often used to assess perfusion?

MEAN ARTERIAL PRESSURE

Arterial Pressure and Waveform Based Cardiac Output Determinations

Methods to obtain SV using arterial pulse wave. •Pulse contour: Identification of dicrotic notch required. Pulse power: Mean determined, systolic and diastolic extrapolated •Pulse pressure/flow: Full wave measured for pressure and waveform shape assessed.

Arterial Line Insertion (What do you test first?)

Modified Allen's Test used to determine collateral circulation. •Normally, the palm is pink. •A fist is made and the radial and ulnar arteries are compressed. •The hand is opened and blanches after compression of both ulnar and radial artery. •The palm is pink after release of ulnar artery with radial artery.

What is normal Central Venous Pressure?

Normal CVP is approximately 2 - 8 mm Hg •Measures pressures in the right atrium •Reflects intravascular blood volume, RVEDP, and right ventricular function (Inderectly) -wont be in ventricle, because the tip moving could cause irritation •Causes of low CVP: hypovolemia, diuretic therapy, sepsis, vasodilating drugs •Causes of increased CVP: right ventricular dysfunction and mechanical ventilation

Impact of ventilation on PA pressure Spontaneous ventilation

PULLS down wave form

Impact of ventilation on PA pressure Positive Pressure Ventilation

PUSHES UP WAVE FORM

Interpreting Hemodynamic Monitoring Pressures Pulmonary Artery Occlusion Pressure (PAOP) or Left Atrial Pressure

Pressure and Description PAOP indirectly reflects LA and LVEDPs, unless the patient has obstructions from the tip of the PA catheter to the left ventricle. Changes in PAOP reflect changes in left ventricular filling pressure Normal Values Mean pressure: 8-12 mm Hg Causes of Increased Pressure •Left-sided heart failure •Mitral stenosis or insufficiency •Pericardial tamponade Causes of Decreased Pressure •Reduced circulating blood volume

Interpreting Hemodynamic Monitoring Pressures Pulse Pressure

Pressure and Description PP is the difference between systolic and diastolic arterial pressure. PP can be used to assess the patient's SV (Stroke Volume). Normal Values Normal range: 40-60 mm Hg with a wider range of 30-100 mm Hg Causes of Increased Pressure •Increased SV •Decreased vascular resistance •Peripheral vascular disease •Aortic insufficiency Causes of Decreased Pressure •Decreased SV •Severe vasodilation in conditions such as late sepsis, various shock states

Interpreting Hemodynamic Monitoring Pressures Pulmonary Artery Diastolic Pressure

Pressure and Description Pulmonary artery diastolic pressure is an indirect reflection of LVEDP in a patient without significant PA disease. Normal Values Diastolic pressure: 8-12 mm Hg Causes of Increased Pressure •Any condition causing increased pulmonary arteriolar resistance (such as pulmonary hypertension, volume overload, mitral stenosis, or hypoxia) Causes of Decreased Pressure NONE

Interpreting Hemodynamic Monitoring Pressures Pulmonary Artery Systolic Pressure

Pressure and Description Pulmonary artery systolic pressure results from right ventricular systolic pressure and reflects right ventricular function. Normal Values Systolic pressure: 20-30 mm Hg Mean pressure: 8-15 mm Hg Causes of Increased Pressure •Left-sided heart failure •Increased pulmonary blood flow (left or right shunting, as in atrial or ventricular septal defects) •Any condition causing increased pulmonary arteriolar resistance (such as pulmonary hypertension, volume overload, mitral stenosis, or hypoxia) Causes of Decreased Pressure •Reduced circulating blood volume

Interpreting Hemodynamic Monitoring Pressures Right Ventricular Pressure

Pressure and Description Typically, right ventricular pressure monitored only on initial PA catheter insertion. Right ventricular systolic pressure normally equals PA systolic pressure; RAP reflects RVEDP Normal Values Systolic pressure: 20-30 mm Hg Diastolic pressure: 0-8 mm Hg Causes of Increased Pressure •Mitral stenosis or insufficiency •Pulmonary disease •Hypoxemia •Constrictive pericarditis •Chronic heart failure •Atrial and ventricular septal defects •Patent ductus arteriosus Causes of Decreased Pressure •Reduced circulating blood volume

Troubleshooting Pressure Monitoring Systems and Measurements

Problem: No waveform Cause •Transducer not open to catheter •Settings on bedside monitor incorrect or off •Catheter clotted •Faulty cable •Faulty transducer Prevention •Check stopcocks for proper position •Use correct setting on bedside monitor •Maintain continuous flush •Use functioning cables Intervention •Check and correct stopcock position •Check scale setting and monitor setup •Aspirate blood clot •Do not fast flush or irrigate with syringe •Check function of transducer •Change transducer if necessary

Heart rate has an inverse relationship with...?

SV (Stroke Volume) As the heart volume increases, stroke volume decreases

Arterial Line Insertion: Seldinger Technique

Step 1: Align the bevel of the needle with the numbers on the syringe so that you know the location of the bevel once inside the tissue Enter the skin at approximately a 45 degree angle Once the needle has been introduced through the skin, begin applying suction or negative pressure by pulling back on the plunger of the syringe Once blood starts to enter into the syringe, stop advancing the needle Hold or stabilize the needle in place with your non-dominant hand and then remove the syringe. If you are doing venous line placement, the blood coming out of the hub of the needle should not be pulsating or bright red as that would be concerning for placement into an artery. Using the same hand that is stabilizing the needle in place, place the thumb over the hub to prevent both blood loss as well as prevent air from entering into the needle and creating an air embolism if negative pressure is created. Note: Step 1 assumes that the skin was properly cleaned based on protocols approved by the institution. Step 2: While stabilizing the needle in place, insert the guide wire into the hub of the needle and advance the guide wire. The length of advancement of the guide wire is based on the anatomical location and type of IV line being placed. You should not feel resistance while trying to advance the guide wire. Reasons for resistance can include no longer being inside the lumen of the blood vessel, dissection of the blood vessel wall by the guide wire, the presence of a thrombus. If resistance occurs stop the procedure and pull both needle and guide wire out at the same time. Pulling the guide wire back through the needle's bevel could result in the guide wire being cut by the bevel of the needle. This is most likely to occur when the guide wire is curved at the tip or when the guide wire is already bent from trying to advance the guide wire. Step 3: Once the guide wire has been advanced to an appropriate length, continue to hold onto the guide wire and retract the needle from the puncture site. Without loosing hold of the guide wire, remove the needle from the guide wire and place the needle in a secure location to prevent a needle stick. Important: Never let go of the guide wire as there have been cases of the wire advancing completely into the vessel and requiring surgical removal. Step 4: If placing a larger catheter or Cordis, enlargement of the insertion site is needed using a #11 blade scalpel It is recommended that the back of the blade slide down and along the guide wire enough to create a larger track but without hitting the blood vessel. Note: Some clinicians avoid this because of a theoretical concern that the blade could cut the guide wire. To our knowledge there are no case reports or studies published to prove that this risk actually occurs. If done properly this should not happen. Step 5: While still holding onto the guide wire, place the distal aspect of the IV catheter over the tip of the guide wire and advance the catheter until the guide wire comes out of the IV catheter and then advance the catheter into the vessel while still holding onto the guide wire. Step 6: Once the catheter is in the vessel, gently pull the guide wire out. Check placement of the IV catheter by placing a syringe to the end of the catheter and pulling back on the plunger to verify blood return and then flush all ports with normal saline. Secure the IV catheter in place. Apply occulsive dressing and bio path (if required). When appropriate, obtain radiographic imaging to verify placement of the catheter. (You will be introducing the already primed catheter)

Interpreting Hemodynamic Monitoring Pressures: CVP or RAP

The CVP or RAP reflects right ventricular function and end-diastolic pressure. Normal Values Mean pressure: 2-8 mm Hg Causes of increased preasure •Right-sided heart failure •Volume overload •Tricuspid valve stenosis or insufficiency •Constrictive pericarditis •Cardiac tamponade •Pulmonary hypertension •Right ventricular infarction The CVP or RAP reflects right ventricular function and end-diastolic pressure. Causes of Decreased Pressure •Reduced circulating blood volume

ECG and Arterial Pressure Waveform Relationship

The Normal arterial waveform should have a rapid upstroke, a clear dicrotic notch, and a definite end diastole. The mechanical activity of systole and diastole follows the electrical activity of depolarization and repolarization. (Mechanical follows electrical movement)

What is myocardial contractility?

The degree to which cardiac muscle fibers can shorten when activated by a stimulus. Inotropy is the force of ventricular contraction. •No single hemodynamic number reflects contractility -Changes in PAOP, CO, Ejection Fraction and Left Ventricle Stroke Work Index (LVSWI) provide an idea

What is the goal of hemodynamic monitoring?

The primary goal of management of a critically ill patient is to ensure adequate oxygenation of tissues and organs, indications for hemodynamic monitoring include conditions in which cardiac output is insufficient to deliver oxygen to the cells due to alterations in intravascular volume (preload), alterations in vascular resistance (afterload), or alterations in myocardial contractility. Organs do not work by themselves, so if one organ is injured it will effect other organs.

The nurse will tell the doctor what during PA catheter insertion?

They are going to tell them where the catheter has gone based on the wave reading, the balloon will slowly be inflated during insertion.

The higher the afterload (SVR), the harder the heart has to work to open the valves and eject the blood. Is this a good or bad thing?

This is a bad thing, the heart does not need to get a workout like that.

How is oxygen consumption (VO2) measured at the tissue level??

Venous oxygen content SVO2 and ScVO2 The amount of oxygen remaining in the bloodstream after blood passes through the tissues you need invasive catheters to get these values ( but still not an art stick)

According to franks starlings la, what is the force of ventricular ejection directly related to?

Ventricular stretch

For cells in the body to survive, the amount of oxygen delivered to the tissues must be...

able to meet their metabolic demands. if they do not have enough oxygen they will build up oxygen debt or (lactic acid)

Pulmonary Artery Catheter Uses:

assessment of volume status, fluid management, monitoring cardiac output, titration of vasoactive and inotropic medications •Most frequently used in patients undergoing major cardiac or vascular surgery and refractory shock states (Doing everything for a shock, but its not getting better) Balloon is injected with no more than 1.5ml air, the balloon will only be inflated for testing or when initially inserted (Only by doctor)

What effect does ventricular tachycardia have on cardiac output?

decreased cardiac output from decreased stroke volume

What effect does ventricular tachycardia have on cardiac output?

decreases cardiac output from decreased stroke volume

Intermittent Thermodilution is the gold standard

for Cardiac Output Determination

Your patient's A-line waveform appears to be over damped and shows a BP of 75/45, you should?

get a cuff pressure to verify its accuracy or inaccuracy, and then verify placement is correct, you can then call the provider for further assistance

Spontaneous breaths effects the CVP by?

inspiration creates negative pressure and then decreases pressure and pulls the CVP down read at end of expiration (exhale)

Closed blood sampling

is very helpful in preventing critical care anemia

What is afterload?

resistance left ventricle must overcome to circulate blood •The pressure the ventricle generates to overcome the resistance to ejection created by the arteries and arterioles. -Measurement is obtained from the PA catheter •Left ventricle afterload -Systemic vascular resistance (SVR) 800 - 1200 dynes •Right ventricle afterload -Pulmonary vascular resistance (PVR) 100 - 250 dynes -The pulmonary system is a low pressure system so thus lower resistance) When the heart has to work harder, it requires more oxygen which means it needs more ATP. (We don't want this)

How is the body's oxygen consumption measured?

venous blood saturation (SVo2)

Ventilator breaths effects the CVP by?

ventilator delivers positive pressure breaths and thus moves the wave upward read at end of expiration (exhale)

What is preload?

volume of blood in ventricles at end of diastole •Known as filling pressures ("The Tank") -Volume in the ventricle at end- diastole •The right and left ventricle have their own preload measurements -LVEDP = PAOP = 8 -12 mmHg (Do not see in practice most of the time) -RVEDP = CVP = 2 - 8 mmHg

When working with a patient that has Abnormal SvO2/ScvO2 Saturation what are your nursing considerations?

•Assess patient •Assess cause -O2 -CO (HR, preload, afterload, contractility) -Hgb -Recent nursing action •Postpone additional actions until SvO2 at or above baseline -Clustering care might make it worse

Invasive vs. Non-invasive BP

•Blood pressures obtained by an intra-arterial catheter and with an optimal pressure monitoring system are most accurate. •In normotensive patients, intra-arterial pressures are typically higher by about 5 to 10 mmHg than the pressures obtained using a cuff. (Which is why its the gold standard) •So which is more reliable? - Intra-arterial pressures remain the gold standard.

Normal Hemodynamic Values

•CO (HR X SV) = 4 - 8 L/min •CI (CO / BSA) = 2.5 - 4.5 L/min/m^2 •SV (CO X 1000) = 60 - 100 mL /LV beat •CVP (RAP) = 2 - 8 mmHg •PAOP (PAWP) = 8 - 12 mmHg •PAP -PAS = 20 - 30 mmHg - PAD = 8 - 15 mmHg (avg. 25/10) -PAP map = < 20 •SVR [(MAP-CVP) / CO) X 80 = 800 - 1200 dyne/sec/cm^3 •PVR {(PAM - PCWP) / CO} X 80 = 100 - 250 dynes/sec/cm^3 •SvO2 = 60 - 80% •ScvO2 = 65 - 85%

To incorporate hemodynamic data into the care of the critically ill, the nurse must understand the following:

•Cardiorespiratory anatomy and physiology •Monitoring system components to measure intracardiac and vascular pressures and cardiac output (CO) •Rationales for interventions directed toward enhancing CO, oxygen delivery, and oxygen utilization potential complications •Differences between physiologic changes and mechanical or monitoring system problems.

Why do we continuously monitor SvO2 & ScvO2

•Continuous monitoring of venous oxygen saturation is indicated for: - Critical care pts with potential to develop an imbalance between oxygen supply and metabolic tissue demand you need to solve the problem of what causing the supply and demand problem

What is Pulsus Paradoxus?

•Definition: >10mmHg drop in SBP during inspiration (spontaneous breathing) •It is caused by a fall in CO as a result of increased intrathoracic pressure during inhalation. •May be caused by volume depletion or cardiac tamponade Pulse Pressure Variation (PPV): variation in arterial pressure between inspiration and expiration and is calculated as a percentage. •PPV >13% is likely to respond to a fluid challenge •PPV <13%, less likely to respond to a fluid challenge

What is Stroke volume?

•Definition: The amount of blood (mL) that is ejected from the ventricle with each contraction. •SV is calculated as the difference between end diastolic volume (preload) and end-systolic volume - CO/HR X 1000 = 60 - 100mL/beat/m2

Pulmonary Artery Catheter are measures of what?

•Direct measurement: -CVP (RAP), PAOP (LAP) -SVR/PVR -PAP (PAS/PAD) -CO/CI -SvO2 -RVEDP •Indirect Measurement: -SV -CI -PVR/SVR -LVEDP Four lumens: Proximal, Distal, Balloon inflation, and Thermistor

Pulmonary Artery Catheter Insertion: Nursing Implications

•Ensuring use of sterile technique: everything in sterile garb to include nurse monitoring •Monitoring the changes in hemodynamic waveform •Recording the pressures in each chamber of the heart as the catheter is passed through. •Monitoring the patient for complications - Ventricular dysrhythmias are the most common complications during PA catheter insertion (Black lines occur ever 10cm with heavier black lines every 50cm) •PAOP balloon inflation -Watch waveform -Inflate slowly -Stop when PA wave changes to wedge wave -Never inject > 1.5 mL air -Stop if resistance is met -Leave balloon "up" no longer than 15 sec -Don't use fluid in balloon -Use PAD to estimate PAOP (diastolic pressure use to estimate pulmonary artery occlusion pressure, because the measurement is a diastolic pressure) •When you inflate the balloon, the PAP turns into your wedge -It's the exact same line •Measurements are different whether the patient is on ventilator or spontaneously breathing -Take measurements at end-expiration •Spontaneous breathing pts: negative intrathoracic pressure produced by inhalation pulls the waveform down à artificially low reading •Mechanical ventilated pts: positive pressure inhalation increases the intrathoracic pressures à artificially high reading

TIPS for nursing

•If PAOP and CO are low, suspect hypovolemia •If PAOP is high and CO is low, suspect LV dysfunction •If SVR is low and CO is high, suspect septic shock •If PAOP is normal BUT PAD is elevated, suspect pulmonary HTN, mitral regurgitation, or mitral stenosis

LOW SVO2 or SCVO2 (Things to think about)

•If sustained below 60% assume supply is not meeting demand •Cause must be determined to correct imbalance •What three components make up supply? •CO , Hbg, and SaO2 / PaO2 (CaO2) -SvO2 can be decreased with any action or disease that reduces oxygen supply •Including nursing care like - Endotracheal suctioning and turning can drastically decrease SvO2

Pulmonary Artery Catheter Monitoring and clinical implications

•In most clinical situations, the PAOP accurately reflects the LVEDP •When the balloon is inflated and the catheter is in the wedge position, there is an unrestricted channel between the tip of the catheter and the left ventricle in diastole. (Makes it so it does not get it inserted to far, and the balloon also helps float the catheter into a more upward position) •PAOP thus reflects LVEDP, an important indicator of left ventricular function.

Metabolic Indicators of Oxygen Supply and Demand Imbalance

•Inadequate oxygen consumption causes an anaerobic state and cellular hypoxia •Lactate levels, serum pH, and base deficit/excess •↑ lactate levels ( >2.2 mm/L) or metabolic acidosis (pH less than 7.35 with normal PaCO2) correlate with low oxygen supply You have to Trend Values!

Complications of Central Venous Pressure (CVP) Monitoring

•Infection •Air Embolism •Causes an obstruction to right ventricular outflow •100% oxygen; place patient on left side in the Trendelenburg position •Thrombosis •Usually fibrin sleeve around catheter •Catheter will flush but can't draw. (Always get an X-ray after these have been inserted to make sure that they are placed correctly)

Locations for Central Venous Pressure (CVP) Monitoring

•Internal jugular vein •Most frequently used •Second highest rate of infection •Subclavian vein •Lowest infection rate, least patient discomfort •More difficult to access, higher risk of iatrogenic pneumothorax •The end/ tip of the catheter should be in superior vena cava before R atria •Femoral vein •Easiest to access, highest rate of infection

Arterial Blood Pressure Monitoring

•Intra-arterial pressure monitoring is indicated for any major medical or surgical condition that compromises cardiac output (CO), tissue perfusion, or fluid volume status. •The size of the catheter used is proportionate to the diameter of the cannulated artery. •Most common site: •Radial •Brachial •Femoral

Obtaining Arterial Pressures (MAP)

•Mean Arterial Pressure: 70 - 100mmHg -Most often used to assess perfusion -MAP = [(2 x diastolic) + systolic)] / 3 -HR dependent - Monitor uses proprietary algorithms (more accurate) •Trends are more valuable than isolated values. -(i.e., trending up or down over past x amount of time?)

What is a Square Wave Test?

•Method to check dynamic response of the system. •Steps to perform a square wave test: 1.Activate the snap or pull tab of the flush device. 2.Observe the square wave generated on the bedside monitor. 3.Count the oscillations after the square wave. 4.Observe the distance between the oscillations.

How do you maintain Pressure Monitoring Accuracy?

•Monitor for air, blood, additional stopcocks in the system. •Ensure pressure bag has fluid and is at 300mmHg •Zero system every shift (at a minimum) - Patient returning from O.R. or other road trips, changing positions, line changes (Turning your stop cock off to the patient, you open the transistor to air and then you zero on the monitor) •Square wave (aka "fast flush") (Done after zeroing) o Optimal damping 1 - 2 oscillations •HOB: 0 - 60 degrees •Level at phlebostatic axis (4th ICS/midpoint of anterior-posterior chest diameter) -Aligns transducer with level of the atria -Requires re-leveling whenever patient moves

Pulmonary Artery Occlusion Pressure

•Normal 8 - 12 mm Hg •When the PA catheter is properly positioned, the PAOP (also called pulmonary artery wedge pressure) is obtained by inflating the balloon at the catheter tip. If the balloon is deflated, and the monitor shows a wedge waveform, the catheter has probably permanently wedged and the MD should be notified

Interpretation of Cardiac Output Curves

•Normal CO curves have a smooth upstroke from the rapid injection followed by a gradual decline

Pulmonary Artery Pressure

•Normal PA systolic pressure is 20 to 30 mmHg. •Normal diastolic PA pressure is 8 to 15 mmHg, with a mean of 10 to 20 mmHg •25/10 mmHg •Quarter over dime

Obtaining Arterial Pressures (Looking at the wave form)

•Normal art waveform -Sharp upstroke •Highest point recorded -Systolic peak -Systolic pressure measured •Dicrotic Notch -Closure of aortic valve -End of ventricular systole and the beginning of diastole •Lowest Point recorded -Diastolic pressure is measured If your reading does not look like this,your monitor or catheter may not be in the right location (make sure to check)

Oxygen Consumption

•Oxygen Consumption = VO2 •Oxygen demand •Met through adequate delivery of oxygen and cellular extraction of oxygen •Not directly measurable •Stress increases demand •Reduced oxygen demand is associated with conditions with lower metabolic rates (COMA, paralytic, hypothermia with post cardiac arrest, anesthesia) •Oxygen delivery •Delivery increases > consumption increases > oxygen demand is met. •Oxygen extraction •Amount of oxygen removed from blood for use by cells •CaO2 - CvO2 (a=arterial, v=venous)

Oxygen Delivery

•Oxygen Delivery = DO2 •Oxygen supply comes from: CO, Hgb, and SaO2 / PaO2 (Oxygen dissolved in plasma) •Arterial Oxygen Content = CaO2 •Hemoglobin and oxygen saturation •Arterial Oxygen Delivery = DaO2 •CO and arterial oxygen content. •Delivers oxygen to the cells •Normal is 1,000 mL O2/minute. •Increase in demand results in compensatory increase in CO about 90% Sao2 (oxygen saturation of arterial blood) and 5% in plasma

What are the complications of Pulmonary Artery Catheter

•Pneumothorax - Complication from vessel access through the subclavian vein. •Infection - Systemic infection and sepsis are caused by contamination of the PA catheter, insertion site, or pressure monitoring system. •Ventricular Dysrhythmias - Catheter irritates the irritate the endocardium causing premature ventricular complexes and occasionally ventricular tachycardia as it passes through the right ventricle. •Pulmonary Artery Rupture or Perforation - Perforation of the PA may occur during insertion, manipulation, or upon subsequent rewedging of the PA catheter.

Factors that impact contractility

•Preload -As volume in ventricle increases, contractility increases -If ventricle is over-distended, contractility falls •SVR -If SVR is high, contractility is decreased -If SVR is low, contractility is increased •Myocardial oxygenation •Electrolyte balance •Amount of functional myocardium available

Factors that impact contractility are?

•Preload -As volume in ventricle increases, contractility increases -If ventricle is over-distended, contractility falls •SVR -If SVR is high, contractility is decreased -If SVR is low, contractility is increased •Myocardial oxygenation •Electrolyte balance •Amount of functional myocardium available •Hypoxemia acts as a negative inotrope •Myocardium must have oxygen available to contract efficiently •Positive inotropic medications •Dopamine, dobutamine, and milrinone increase contractility •Left and right ventricle stroke work index (LVSWI and RVSWI) estimate force of cardiac contraction

What is the gold standard for venous oxygen saturation monitoring?

•ScvO2 which is checked by venous blood drawn from a central venous catheter in the superior vena cava - Normal ranges from 65% - 85% SCV02 is a better indicator than Sv02 due to it being the fartest point that deoxygenated blood flows

Square Wave Test: Optimally damped system

•Sharp vertical upstroke, horizontal line, and straight vertical down stroke •1.5 to 2 oscillations close together before returning to baseline. (LESS THAN 2)

Interpretation looking at correlations

•Specific problems with heart rhythm can translate into poor arterial perfusion if CO decreases. •Decreased arterial perfusion -A single, nonperfused beat after a premature ventricular contraction (PVC) -Multiple, nonperfused beats You can correlate echtopic (non-normal beats) with your monitor)

Complications of Arterial Pressure Monitoring

•Steps to ensure accurate pressures from invasive lines include assessing the patient first, checking the pressure monitoring system, and inspecting the monitor itself. Infection •Proper attention to sterile technique during catheter insertion; care of the insertion site; blood sampling; and maintenance of a sterile, closed monitoring system reduce the risk of infection. Accidental Blood Loss •All connections in the system should use a Luer-Lok type connector. (Helps prevent blood loss) Impaired Circulation to Extremity •Circulation to the extremity in which the arterial line is placed must be monitored frequently. •Initial assessment of color, sensation, temperature, and movement of the extremity.

HIGH SvO2 or ScvO2 (Things to think about)

•SvO2 or ScvO2 may increase to an above-normal level (> 80%). •Can occur during times of low oxygen demand (decreased VO2) during anesthesia, hypothermia or some cases of septic shock.

Right Ventricular Pressure

•The RV is a low-pressure chamber. •RVEDP is usually 2 to 8 mmHg. •When the tricuspid valve is open, the RAP and the RVEDP are similar. •Right ventricular systolic pressure is normally 20 to 30 mmHg

What is ejection fraction?

•The percentage of preload volume ejected from the left ventricle per beat. •Measurement is obtained during cardiac catheterization or echocardiogram. •A normal EF is 70% in a healthy heart, but many cardiologists accept an EF > 50% as normal

Right Atrial Pressure

•The right atrium is a low- pressure chamber. •Normal pressure is 2 to 8 mm Hg.

Central Venous Pressure (CVP) Monitoring is indicated

•Whenever a patient has significant alteration in fluid volume •Guide volume replacement in hypovolemia •Assess impact of diuresis •Large amount of volume needed for resuscitations (e.g., burns) •Vaso-caustic medication response (Vasopressors, etc.)

Pulse Pressure?

•reflects the SV from the ventricle -Pulse Pressure = Systolic Pressure - Diastolic Pressure -Normal is approx. 40mmHg - 120/80 and thus 120 - 80 = 40 mmHg

Square Wave Test: underdamped system

->2 oscillations -Caused by a dynamic response within system -Check against cuff (More than 2) Problem: Underdamped waveforms; whip or ringing Cause •Excessive movement of catheter •Air bubbles in tubing Prevention •Correct catheter placement •Use appropriate catheter size for vessel •Eliminate excessive length of pressure tubing •Check for very rigid pressure tubing Intervention •Try different catheter tip position •Eliminate excessive tubing •Change tubing •Eliminate excessive stopcocks

Nursing care of the patient undergoing PA pressure monitoring is complex.

-Critical care nurses must be able to interpret waveforms and pressure data as well as be alert to potential complications. -Small variations in the zero reference point elicit large and erroneous changes in the pressures observed. -Hemodynamic pressures are most accurate when obtained at end expiration, when the intrathoracic pressure is about equal to atmospheric pressure

how do you go about Obtaining cardiac output values

-Fick's method for cardiac output determination -Indicator-dilution methods for cardiac output determination (thermodilution method) -Arterial Pressure and Waveform Based Cardiac Output Determinations

What is Frank-Starling Law of the Heart?

-Force of ventricular ejection is directly related to two elements: •Volume and ventricle(s) at end-diastole (preload) •Amount of myocardial stretch placed on ventricle(s) as a result

•Factors that determine cardiac output

-Heart rate and stroke volume -Alterations are caused by changes in heart rate, preload, afterload, and contractility.

Pulmonary artery diastolic (PAD) can estimate the PAOP

-Must be no more than 1 to 3 mmHg above wedge pressure

Left ventricle preload (LVEDV as estimated by LVEDP)

-Pulmonary artery occlusive pressure (PAOP) = pulmonary artery wedge pressure (PAWP) or "wedge"

What is a Passive Leg Raise

-Raise patient's legs •Essentially a quick bolus of blood -If increase in CVP by at least 2 mm Hg •Suggests patient will have good response to fluid bolus (If not, patient is having a contractility problem instead of a load problem) -Ask yourself, "Tank or Squeeze" problem? (Tank problem= fill problem) (Squeeze problem= Contractility)

Factors that affect HR?

-Sympathetic stimulation -Exercise -Decreased blood volume -Increased afterload -Hypermetabolic states -Medications/stimulants (Important to get PT's history)

CVP Waveform Interpretation

-level and zero -measure at end of expiration -measure the mean of the a wave - compare the a wave to the PR interval •Abnormalities of RA waveform include elevated "a" or "v" waves. •Increased resistance to RV filling and impaired atrial emptying cause an elevated a wave. •Pathologic causes of elevated "a" wave are tricuspid stenosis and RV failure •Pathologic causes of elevated "v" waves are tricuspid insufficiency and RV failure related to the regurgitant flow from the ventricle back into the atrium during ventricular contraction

Decreased oxygen extraction ↑ SvO2/ScvO2

1. Decreased oxygen demand Causes: Sedation, pain relief, hypothermia - We might be doing this for a reason 2. Increased oxygen delivery Causes: Increased CO, Hgb, SaO2 - What is the patients vent settings 3. Impaired cellular oxygen extraction Causes: cytotoxicity, sepsis, cell death -the cells are not exatracting the oxygen (Why is the patient not using their oxygen?)

Increased oxygen extraction ↓SvO2/ScvO2

1. Increased oxygen demand Causes: Stress, pain, anxiety, fever (Trigger limbic system) 2. Oxygen delivery insufficient to meet oxygen demand Causes: Decreased CO, Hgb, SaO2 (Why is the patient using so much oxygen)

the phleobostatic axis is located at the...?

4th intercostal space at midpoint of the anterior-posterior chest diameter

What equipment will you need for Invasive Pressure Monitoring

500ml bas of NS, all of your supplies, pressure bag, ect.

Adult normal values for heart rate are?

60-100 beats/min