N401 - Hemodynamic Monitoring
Phlebostatic Angle/Axis
***Level of Right atrium - where the heart is*** - Lies at 4th intercostal at mid-axillary line - Patient is supine but accuracy has been determined to be 0 to 60 degrees **TEST QUESTION**
Common Indications for Hemodynamic Monitoring
**CARDIAC mostly -MI** - Heart failure - Shock (all types) - Fluid therapy - Evaluate pharmacologic medications & treatments - i.e. diuretics, pressors (epi, norepinephrine) - Lopressors- will have continual bleedout so need arterial line
Arterial Pressure Measurement
**Systolic** **Diastolic** **Mean Arterial Pressure (MAP)** - Important to get these 3 --> a lot of drips require MAP
Mixed Venous Oxygen Saturation (SVO2)
- % of O2 bound to hemoglobin in blood returning to the R side of the heart. - This reflects the amount of oxygen "left over" after the tissues remove what they need - Used to help us to recognize when a patient's body is extracting more oxygen than normally **Normal 60 - 80% at rest** - Some PA catheters have a sensor to measure oxygen saturation of the hemoglobin of PSA blood (mixed venous blood) - Mixed venous oxygen saturation (SvO2) can help to determine whether the cardiac output and oxygen delivery is high enough to meet a patient's needs
Remember...Adequate Blood Flow Depends On....
- Adequate amount of blood in the heart to pump *(preload)* - Effective pumping of the heart *(contractility)* - Constriction and dilation of blood vessels to maintain normal blood pressure *(after load)* **Preload = volume** **Afterload = resistance** - Preload- stretch and volume: measure looking at CVP/pulm arterial wedge pressure
Causes for Dampened Waveform (Low Press. Reading)
- Air bubbles - Overly compliant, distensible tubing - Catheter kinks or tubing - Clots in tubing - Low pressure flush bag or syringe pressure - No fluid in pressure bag or syringe - Vessel spasm **This will UNDERESTIMATE blood pressure** - Anytime catheter touches anything- can irritate wall= clamp on catheter and won't get good reading
Radial Arterial Line
- Assess distal perfusion - fingers going white or blue, cap refill is delayed = problem w/catheter and needs to be removed - Must ALWAYS assess for distal circulation or collateral circulation in peripheral sites before catheter placement **art. lines are normally marked in red**
PAP Monitoring Indications
- Assesses left ventricular function (CO) - how well they respond to fluid and dx & etiology of shock - Evaluates the patient's response to fluid administration and vasoactive medications - Other uses: Pacing, Oximetry, CO measurement
Mean Arterial Pressure (MAP)
- Average pressure in the arterial circulation - Reflects the perfusion pressure **70 - 100 mmHg is desirable** **MAP of 60mm Hg to perfuse vital organs** - MAP Calculation = SBP + (DBP x 2) - Would give epi, norepi, dopamine to raise pressure so organs can be perfused
Arterial Blood Pressure Monitoring
- Catheter inserted in radial or femoral artery - Gives constant arterial blood pressure reading - ***CONSTANT BP*** - Can obtain samples blood for ABG's or blood studies ***CAN NEVER EVER INFUSE ANYTHING INTO ARTERIAL LINE B/C COULD INFUSE AIR & IT GOES DIRECTLY TO THE HEART (ARTERIAL SYSTEM)*** - nothing goes in only take things out
What Can We Measure?
- Central Venous Pressure (CVP) - tip of cath in subclavian or right atria - Pulmonary Artery Pressures (PAP) - cath sits in pulm. artery - Pulmonary Artery Occlusive Pressure (PAOP) aka "Wedge pressure" --> blowing up a balloon - Cardiac Output (CO) --> SWAN measures this directly - Cardiac Index (CI) - Stroke Volume - Systemic Vascular Resistance (SVR) - Pulmonary Vascular Resistance (PVR) - Mixed Venous Oxygen Saturation (SV02)
Increased SVO2
- Clinical improvement - Sepsis: O2 is not used by tissues - Ventricular septal defect
Decreased SVO2
- Decreased arterial oxygenation - Low cardiac output - Low hemoglobin - Increased oxygen consumption: fever, movement, pain, increased metabolic rate
CVP Nursing Interventions
- Dry sterile occlusive dressing in place - Confirm catheter placement with CXR before using it - Monitor pressure trends - Change dressing - Frequency of measurements is according to the patient's condition
PAP - Nursing Responsibilities
- Ensure the system is set up and maintained - free of air bubbles - Check that the transducer is positioned at the level of the atrium (phlebostatic axis) prior to obtaining measurements - Establish the zero reference point in order to ensure the system is functioning properly at atmospheric pressure
Nursing Responsibilities
- Ensure the system is set up and maintained - q8 hrs - Establish the **zero** reference point in order to ensure the system is functioning properly at atmospheric pressure - get adequate readings **free of air bubbles --> avoid air emboli** - Check that the transducer is positioned at the level of the atrium (phlebostatic axis) prior to obtaining measurements
AP Nursing Management
- Evaluate the circulation distal to the catheter for compromised arterial flow --> best thing to do is put pulse ox on the finger below the art. line (can tell decreased flow early) **Never have arterial line under blanket- always want it visable b/c tubing could disconnect (high pressure to low pressure and PT WILL BLEEDOUT UNDER BED)** - Maintain continuous flush irrigation system and immobilize it (most time sutured in)
Insertion of a PA Catheter
- Explain procedure to Pt & similar to CVC placement - Inserted using fluoroscopy or watching wave forms on monitor - Catheter sheath used to cannulate the vein (cordis, introducer, side port), introducer sheath remains in place - Threaded into superior vena cava & into the R side of the heart - internal jugular or subclavian vein - inflate balloon when it reaches right atria to float the cath through the RV to the pulmonary artery --> deflated cath stays here ***Keep cath deflated unless doing a reading - if inflated (wedged) it can cause pulmonary infarction --> die immediately***
Maintaining an Arterial Line
- Gentle flushing - Have all stopcocks visible & art. line visible at **all times** - Keep alarms set and turned **ON always** - Minimize blood loss - Use papaverine (antispasmodic - in the arm that vessel keeps spasming)/heparin/saline in lines as ordered - If flattens- need to intervene
Hemodynamic Monitoring
- Hemodynamic monitoring is used to assess cardiac function and determine effectiveness of therapies - Can be **noninvasive (BP cuffs)** or **invasive (swan and central lines)** - Gives more detailed physiological information - Guides treatment of the critically injured patient
AP Complications
- Hemorrhage - when dislodges or disconnected - use luerlock connections - Infection - local or system, EBP guidelines to reduce risk, and cath should be removed under sepsis protocol - Hematoma **Air Embolism --> Death**
CVP Complications
- Infection - Pneumothorax (could potentially pop the lungs after insertion) - Air Embolism - Do NOT use the line until confirmed with Chest X-ray & OK from doctor - Document which doctor said it was OK to use....
Nursing Management of the Pulmonary Artery Catheter
- Informed consent - Proper positioning - Sterile technique - Obtain CXR after insertion - Maintain line placement and integrity - Monitor pressure trends - Obtaining accurate hemodynamic readings by establishing the zero reference point - Equipment must be zero balanced (zero the transducer) - Continually monitor respiratory and cardiac status
System Vascular Resistance (SVR)
- Left ventricular afterload - Calculated as (MAP - CVP) X 80/CO - Pulmonary Vascular Resistance (PVR) - resistance in the pulmonary vasculature and right heart afterload
Causes for Resonant Waveform (High Press. Reading)
- Long tubing - Overly stiff, non-compliant tubing - Increased vascular resistance - Issue in the tubing that cause disharmony that distort the trace (**high systolic or low diastolic pressure**) - Not fully opened stop-cock ***This tracing OVERESTIMATES blood pressure
Contractility
- Measurement of heart "pump" ability - In maintaining CO, first try to adjust HR, Preload, Afterload - If no improvement in CO, then can use positive ionotropic support or intraaortic balloon pumping (IABP) discuss later...
Cardiac Output/Cardiac Index
- Monitored in patients with hemodynamic instability **Amount of blood ejected by the heart in one minute** **CO normal range 4 -8 L/min** **CI 2.5-4.0 L/min/m2** (CI takes BSA into effect - more accurate) - Measured by Swan Ganz catheter (both CO and CI)
Other Catheters...
- Pacemaker wire lumen provides a port for pacemaker electrodes - Can be AV paced - Can pass into R ventricle and ventricle pace if needed - A R volumetric PA catheter is available to measure stroke volume in the R ventricle
Insertion
- Percutaneous or cut down or Ultrasound Guided image - Do NOT use without confirmation from the doctor - Do not need x-ray verification particularly if it is placed using ultrasound - Also document which Physician told you to go ahead and use the line. - You can tell by the color of the blood (very red) and the pulsatile flow of blood as well as the wave form tracing on the monitor if it is in an artery - The venous blood will be darker in color and non-pulsatile of course.
Allen Test
- Performed to confirm that the ulnar artery circulation is sufficient to sustain the hand perfusion - Apply pressure to the radial and ulnar artery simultaneously, open & close hand until it blanches, release the ulnar artery only - If the hand does not turn pink in 6 seconds, circulation to the ulnar artery is insufficient and ischemia may occur -- done before putting in a line
Complications
- Pneumothorax - Infection and sepsis - aseptic technique for insertion, set-up and dressing change (w/occlusive dressing) - monitor for S/S of infection (local or systemic) - remove if infection is suspected - don't leave in place longer than necessary - Thrombus/embolus formation - continuously flushed w/slow infusion of heparinized saline - Bleeding/Hematoma - Pulmonary Infarction & Pulmonary rupture - never inflate more than 1.5mL of air for more than 4 breathing cycles - Pressure tracing will appear wedged if the PA catheter remains or advances into the wedged position - Air embolus - caused by air in tubing, balloon rupture - Pulmonary thromboembolism - Ventricular dysrhythmias - During insertion or removal and from migration of the tip to RV
Swan Ganz #2
- Proximal lumen is where injectate goes - measures how quickly temp. gradient changes (direct CO measurement)
Pressure Measurements
- Pulmonary artery systolic pressure (peak pressure) **Normal 15 - 25 mmHg** - Pulmonary artery diastolic pressure - left end diastolic pressure (LV filling pressure - preload) **Normal 8-15 mmHg** - indicator of fluid volume status & cardiac fx (increased w/fluid overload in HF) - CVP - measures pressure in right atria or vena cava (proximal port) and reflects venous blood return to the right side of the heart, fluid volume status, right ventricular fx and left sided HF (late sign) **Normal 2-6 mmgHg**
Arterial Line Sites
- Radial **Most common site** - Femoral - Brachial - Dorsalis Pedis (less common but more in Peds)
CO = HR x SV
- SV=volume of blood ejected by the heart during each beat (mm's) **Normal adult SV= 60-70ml** - Preload, Afterload, & Contractility affect SV
Preload
- The pressure *(stretch)* in the ventricle at end diastole - Determined by the *volume* left in the ventricles Has measurements for right and left ventricles: -central venous pressure -pulmonary wedge pressure
Afterload
- The pressure against which the ventricle must pump to *eject* blood Measurements for right and left ventricles: - PVR - pulmonary vascular *resistance* - SVR - systemic vascular *resistance*
Transducer
- To convert the pressure coming from the artery or heart chamber into an electrical signal --> transduces the pressures in the body & gives a waveform on the monitor - To zero out - turn stop cock upward and remove cap to atmospheric air - so you can get good accurate readings - set at level of the heart - if pt sits up or down move the transducer
Non-Invasive Hemodynamic Monitoring
- Vital Signs (*BLOOD PRESSURE* cuff) - Pulse Ox - Peripheral Pulses, capillary refill, skin color - 12 lead EKG - CXR - Comprehensive Physical Exam
Swan Ganz Catheter (PAP Catheter)
- balloon tipped port - flow directed caths that have distal & proximal lumens (4 or 5) - measures CVP, PAP, PAOP/PAWP and Cardiac Output - insert peripherally --> comes into RA through tricuspid through pulmonic and migrate to and sits in pulmonary artery (potential for arrhythmias) **blow up the balloon and cause a wedge pressure (PAOP) which tells you more about left sided function than right** - high wedge reading there will be lung congestion (crackles)
Pulmonary Artery Lumen (distal)
- can withdraw blood samples (mixed venous blood samples SVO2) - distal PA lumen located at tip of PA catheter - situated in the pulmonary artery and records PA pressures
Balloon Lumen
- inflate w/0.8mL (7.5 fr) to 1.5 mLs (7.5 fr) of air - too much air will pop the balloon - this is inflated to get a wedge reading (PAOP) if cath tip is place in the pulmonary artery - inflated to ease catheter insertion
Hemodynamic Calibration
- make sure transducer is at phlebostatic axis - Zeroed minimum of every 8 hours, position change, or when entering your line for a blood draw - Or if get a wacky reading --> flush and rezero
Right Atrial Lumen (proximal)
- tells info about the fight atria and gives CVP measurements -Used for IV infusion, venous blood samples and injection of fluids for CO determinations - AKA right atrial port or CVP port
Flush System (Pump or Pressure Bag)
- when putting cath into arterial system (high pressure) anything will move from high pressure to less pressure and if you have no pressure system to flush through the blood will back up into the tubing **don't want air --> use blunt tip needle to push out air** - Composed of *heparinized* saline (institution specific) - Pressure bag placed around the flush solution (usually NSS) --> so blood doesn't flow backwards and keeps system patent - pressure bag is maintained at 300 mmHg, at 3-5 mL/ hour (5 is typical and 3 is for fluid restrictions/child) - make sure air is out of the system (prime w/saline or heparinized saline) - think about pt when using heparinized saline - as long as it's a continuous system flushing you may not need to use heparin
High Cardiac Output
1. Early Sepsis 2. Hyperthyroidism 3. Fever 4. Exercise
Causes for Increased Wedge Pressure
1. Hypervolemia 2. Mitral valve stenosis or regurgitation 3. Left ventricular failure 4. High PEEP
High CVP
1. Hypervolemia (you may want this for some reason) 2. Vasoconstriction 3. Heart Failure (more volume in heart b/c not working well) 4. Pulmonary HTN (fluid backing up) 5. Cardiac Tamponade (fluid inside heart and compressing it) **Gas tank full --> well hydrated (fluid overload)**
Low CVP
1. Hypovolemia 2. Vasodilation (relative hypovolemia) **Gas tank empty --> dehydrated**
Low Cardiac Output
1. MI 2. Heart Failure 3. Hypovolemia 4. Cardiogenic Shock 5. Cardiac Tamponade 6. Late Sepsis
Causes for Decreased Wedge Pressure
1. hypovolemia
Bedside monitor
A monitor which displays the electrical signal into a waveform - need pressure tubing w/system so you get a good BP reading
Indications for Arterial Blood Pressure Monitoring
Critically ill patients with: 1. Hypertension/Hypotension 2. Administration of ***vasoactive medications*** - Sodium Nitroprusside (Nipride) - Dopamine/Dobutamine - Epinephrine, Norepinephrine, Phenylephrine (Neo) and Vassopresson etc.
Arterial Waveform
Dicrotic notch tells you if you are in artery or vein - if notch isn't there then you aren't in the artery - DN will vary depending on where you are
Pulmonary Artery Pressure (PAP) Indications
Indicated for patients who are: - Hemodynamically unstable (BP wise) - Need fluid management - Continuous cardiopulmonary assessment - Receiving multiple/frequently given cardioactive drugs - Shock, trauma, cardiac disease, multi organ system failure
4 Components of Pressure Monitoring
Invasive Catheter, Transducer, Flush System, Bedside Monitor - Anything moved from greater pressure to less pressure
When in doubt.....
Non-invasive blood pressure (blood pressure with a standard BP cuff of correct size of course) ***Correlate it with a cuff pressure*** - beginning of shift always get baseline peripheral BP
CVP Waveform
Normal is 2-6 mmgHg
Dampened Wave Form
Normal, Over, Under - tells us something is going on w/arterial line
PAP Monitoring - Venous Insertion
Performed at the bedside, cardiac cath lab, or in the OR Can be inserted using fluoroscopy Large Vein External jugular Subclavian Femoral
Flow Directed Catheter
Right ventricle - more pressure so higher wave Pulm. Artery - dicrotic notch PAOP - blown up balloon
Low SVR
Shock - septic, neurogenic and anaphylactic
PCWP or PAOP....Why Measure....
To determine the severity: - of left sided heart failure - see how serious aortic stenosis, mitral valve regurgitation or mitral valve stenosis - these all elevate LAP & PAOP
Catheters
Triple Lumen Catheter - can obtain CVP and sits in the distal subclavian above the right atria **brown is always distal and always transduce (CVP reading)** - white is proximal - blue is medial - lines used for meds (vasopressors)
High SVR
Vasoconstriction - Increase catecholamine
Invasive catheter
attached to high-pressure tubing which connects to the transducer - could be a central venous catheter or a swan that is inserted through the groin and fed up into the heart
Central Venous Pressure Monitoring (CVP)
central line in Subclavian or RA (can cause arrhythmia) - CVP line (single, double or triple lumen) - Measures the filling pressure **(preload)** of the vena cava or right atrium ***Normal is 2 to 6 mmHg*** - Most valuable when monitored over time --> looking to see how hydrated patient is - monitor fluid resuscitation is adequate if CVP goes up - Can also administer fluid, blood, meds and draw blood
Central Venous Catheter
measures CVP
Pulmonary Capillary Wedge Pressure (PCWP) (PAOP)
measures left ventricular end diastolic pressure (LV filling pressure/preload) - indicator of fluid volume status & cardiac fx **Measured by inflating balloon w/0.8 to 1.5 mL of air** **Inflate the balloon for < 4 respiratory cycles & observer pressure at the end of expiration** (can cause too much pressure and rupture pulmonary artery) **Normal 6-12 mmHg (mean pressure)** - elevated means left side isn't great or has too much fluid 18 - 20 mmHg onset of pulmonary vascular congestion >30 mmHg pulmonary edema
Waveform with "Fling", "Kick" or Resonance
spike at top
Thermistor Lumen
this is like a thermometer - this tells us cardiac output (via temperature change) - hook up to computer - measures temp change from RA until it gets to the other side