Hemodynamics. Hemodynamic Monitoring: An Introduction. What is Hemodynamics? Interrelationship of Blood Flow. The study of BLOOD FLOW

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1 Hemodynamics Hemodynamic Monitoring: An Introduction *Brett Fladager, RN, ADN, is a Senior Staff Nurse in SICU at Hennepin County Medical Center 1. Define Hemodynamics 2. Discuss Normal and Abnormal Hemodynamics 3. Discuss Key Parameters 4. Set-up Lines 5. Discuss trouble shooting of lines What is Hemodynamics ABP CVP PAP PAWP ICP RAP CPP SV SVV CO CI RVFP SVI SVR SVRI THIS IS IT ANY QUESTIONS THANKS FOR COMING PLEASE FILL OUT YOUR EVAL HAVE A NICE DAY We seek knowledge and enjoy learning We love to understand the Why questions Once we understand, we love terminology When we use the terminology, when teaching we can easily confuse people with our use of terminology What is Hemodynamics? The study of BLOOD FLOW Interrelationship of Blood Flow 1. Volume-amount of fluid/blood 2. Pressure-stretch 3. Resistance-ventricles pump against to distribute blood 1

2 Blood Flow What is a Parameter? Pa ram e ter n : Any of a set of physical properties whose values determine the characteristics or behavior of a system. Parameters used in hemodynamic monitoring are values obtained or observed from technologies. It is our job to determine if these obtained parameters are normal or abnormal and intervene when appropriate. Parameters Monitored in ICU MAP-Mean Arterial Pressure CO-Cardiac Output CI-Cardiac Index SV-Stroke Volume SI-Stroke Index SVR-Systemic Vascular Resistance Wedge (PAOP)- Pulmonary Artery Wedge Pressure SVO2-Saturated Venous blood O2 level SCVO2- Saturated central venous 02 level ABG s Arterial Blood Gases CVP-Central venous pressure WHAT IS PAWP Most confusing of our parameters Measures Left side of Heart through Lungs Normal is 4-12 mmhg Mitral valve problems Pulmonary edema Will be explained further What is our main goal for monitoring Hemodynamics? We want to optimize Tissue Perfusion and Oxygen Delivery! Three Key Parameters 1. Measures of Tissue Oxygenation 2. Cardiac Output 3. Stroke Volume 2

3 Key Parameters How do I know someone is adequately oxygenating their tissues? 1. Measures of Tissue Oxygenation Nurse itis A condition by which a Nurse becomes so involved with a monitor that she/he doesn t notice a patient is in the room Symptoms include blurry vision, rapid heart rate and general malaise. CURE: look at the patient at least twice a shift as needed PRN Physical Assessment Skin Color: Pink, cyanotic Skin Warmth: warm, cool, cold Pulse: fast, slow, irregular B/P SB/P >90, MAP>65 LOC Alert and oriented X3 O2 Sats 90% or above Common Forms of Threats to Tissue Perfusion and Oxygen Delivery 1. Hypovolemia Trauma Postoperative blood loss GI bleed 2. Left Ventricular Dysfunction Myocardial Infarction Heart Failure Cardiomyopathy 3. Vasodilation Sepsis / Systemic Inflammatory Syndrome (SIRS) Neurogenic shock Measures of Tissue Oxygenation Tissue Oxygenation Parameters: 1. SVO2 or SCVO2 2. Lactate 3

4 Tissue Oxygenation Parameter: SVO 2 SVO 2 : Mixed Venous Oxyhemoglobin Sats from pulmonary artery From Lab draw, PA catheter Group Question What is a normal SVO2 in a healthy person? What can cause a low SVO2 SCVO 2 : Central venous oxygen saturation Sats from Right Atrium Triple lumen catheter oximetry Slightly higher than SVO 2 Tissue Oxygenation Parameter SVO 2 Normal SVO 2 : 60-80% Low SVO 2 Too little delivered or High demand If tissues are deprived of oxygen, the tissues will extract more from the hemoglobin. Tissue Oxygenation Parameter SVO 2 Normally, 25% of the oxygen in hemoglobin is removed at the capillary level. So, amount of oxygen returning to the lungs should be about 75% Continuous SVO 2 is pulse oxymeter in pulmonary artery Decreased Oxygenation Delivery VS Consumption Causes of Decreased O2 delivery CO hypovolemia, shock, MI. arrhytmias, PEEP O2 saturations pulmonary edema, ARDS, inspired O2 HBG level anemia, blood loss, dysfuncional HBG O2 consumption pain, anxiety, agitation, restless, hyperthermic, burns, tachycardia, shivering 4

5 Tissue Oxygenation Parameter 2. Lactate Level Lactate Washout Effect If Lactate >4 and ph is less than 7.30, consider tissue hypoxia Normal levels are <2 mmol Delay. Follow Trend Make sure with interventions Should decrease by 10% every hour Correlate with SVO2 Epinephrine Washout effect Key Parameters Measures of Tissue Oxygenation SvO2 or ScVO2 Lactate level 2. Cardiac Output Cardiac Output = HR X SV Cardiac Output 3. Stroke Volume Heart Rate (beats/min) Stroke Volume ( ml/beat) Cardiac Output / Index Cardiac Output Normal Cardiac Output 4-8 L/min Amount of blood ejected by the heart each minute Evaluates cardiac function Monitored by Swan Ganz or FloTracVigeleo monitor Normal Cardiac Index L/min/m 2 CO corrected by body size height and weight Levels less than 2.2 indicate a threat to tissue oxygenation consider treatment Look at SVO2 too! Monitor Trends! It is important to understand HR and SV in order to know how to treat an abnormal cardiac output MOST COMMONLY, A DECREASED CARDIAC OUTPUT IS RELATED TO A DECREASED STROKE VOLUME=less blood ejected per beat less blood pumped per minute 5

6 What can change your CO? Decreased myocardial contractility Decreased Left Ventricular filling pressure Increased systemic vascular resistance Key Parameters Measures of Tissue Oxygenation SvO2 or ScVO2 Lactate level Cardiac Output/Index HR x SV 3. Stroke Volume Decreased ventricular flow Stroke Volume Stroke Volume (SV): ml/beat (amount of blood pumped with each heart beat) HR X SV=CO Stroke Volume Index (SVI) is ml/beat Consider intervention if <25 Ejection Fraction >60% Ejection Fraction Amount of blood pumped with each contraction of the heart in relation to the amount available to be pumped normal EF is greater than 60%. Two ways of assess the EF 1. Echocardiogram 2. Cardiac Cath procedure : Inject dye into the left or right ventricles and watch it being pumped out under fleuro. Stroke Volume Stroke Volume is important piece of information regarding cardiac function!!! SV will fall if blood volume becomes low! Hypovolemia SV will fall if left ventricle becomes too weak to eject blood! Left Ventricular dysfunction Stroke Volume question? If your patient has a low stroke volume is fluid the answer???maybe If it is from hypovolemia maybe, but what about left ventricle dysfunction? 6

7 Factors regulating Stroke Volume 1. Preload 2. Afterload 3. Contractility 1. Preload a. Volume Factors regulating Stroke Volume Greater the Stretch, The Greater the force of contraction (Starlings Law) b. Stretch Stroke Volume cont. Stroke Volume Cont. 2. Afterload a. Pressure that the ventricular muscles must overcome to pump the blood out b. The pressure that the heart must eject blood against c. RESISTANCE 3. Contractility a. The force and velocity with which the ventricles contract b. Can be Influenced by Preload and Afterload c. Greater the stretch, greater the force of contraction (Starlings Law) Starling s Law The more the muscle stretches, the more forceful the contraction. Cardiac Output Heart Rate Stroke Volume If the muscle stretches too much, the muscle becomes weaker. Preload Volume Filling Pressure Afterload Resistance Contractility Squeeze Strength 7

8 Left and Right hearts Preload Afterload Contractility (Volume, (Resistance) (Squeeze Strength) Filling Pressure) Effects of Preload and Afterload on the Heart Factor Possible Causes Effects on Heart Increased Preload filling Decreased Preload Increased afterload resistance Increased fluid volume Vasoconstriction Hypovolemia Vasodilatation Hypovolemia Vasoconstriction Increases stroke volume Increases ventricular work Increases myocardial Oxygen requirements Decreases stroke volume Decreases ventricular work Decreases myocardial oxygen requirements Decreases stroke volume Increases Ventricular work Increases myocardial oxygen requirements Decreased afterload Vasodilatation Increases stroke volume Decreases ventricular work Decreases myocardial oxygen requirements Balloon Analogy Preload (filling)=balloon stretching as you blow in the air Stroke Volume and CO by Physical Assessment Contractility (stretch)=more air in the balloon the greater the stretch Afterload (resistance)=the knot at the end of the balloon which the balloon has to work against the get the air out. Volume: Urine Output; JVD; Edema; S3 Resistance: Skin; HTN, Lung ascultation Contractility: Pulse Quality; EF *You can t measure CO directly but a physical assessment can give you an idea. Key Parameters Measures of Tissue Oxygenation SvO2 or ScVO2 Lactate level Cardiac Output/Index HR x SV Stroke Volume/Index Preload, Afterload, Contractility Heart Rate Evaluate HR to detect early changes in hemodynamics CO=HR x SV If Stroke Volume decreases, HR will normally increase. 8

9 Heart Rate An increased HR can compensate for a decrease in SV but there is always a potential for a decrease in SV related to a fast HR. CO=HR x SV A sudden Bradycardia almost always reflects a threat to cardiac output. Heart Rate The faster the HR, the higher the myocardial oxygen demand. Muscle hypoxia causes decreased strength of contraction. Keeping HR as low as possible is one way to protect ventricular function. CVP Central Venous Pressure Central venous pressure (CVP) describes the pressure of blood in the thoracic vena cava, near the right atrium of the heart. CVP reflects the amount of blood returning to the heart and the function of the right side of the heart 10. Fill in the Blank If Stroke Volume decreases, Heart Rate will normally. Monitored by the SWAN or a Central Venous Line Normal 2-6 mmhg 10. Fill in the Blank Why do we give an IV fluid bolus? If Stroke Volume decreases, Heart Rate will normally increase. CO=HR x SV To Increase Stroke Volume and Increase Blood Flow OR Improve hemodynamic parameters 9

10 Starling s Law How do we know if we gave enough fluids? If we haven t given enough volume, stroke volume is low If we give too much volume, stroke volume is low. Monitor Hemodynamic Parameters CVP HR SV Blood Pressure Look at Trends!!!! Example: 70 year old male with hypovolemia secondary to post op fluid loss. He received 2 liters of NS over 1 hour. Has the treatment been successful? Improvement? Before: After: BP- 84/50 BP 86/56 HR- 114 HR SVO SVO Lactate 4.3 Lactate 2.2 SI 19 SI - 29 Before: After: BP- 84/50 BP 86/56 HR- 114 HR SVO SVO Lactate 4.3 Lactate 2.2 SI 19 SI - 29 Parameters look Good Example #2 62 year old female with CHF. She is given 20 mg of Lasix IV. Has the treatment been successful? The parameters show improvement What can go wrong by looking at parameters Remember there s a PT there Before: After: BP- 90/52 BP 98/54 HR- 105 HR SI - 19 SI - 19 SVO SVO U.O. last hour- 25 cc U. O. in last hour-35cc What other parameters would be helpful 10

11 Example #3, 65 year old man POD #2 total colectomy, because of a bowel obstruction that perforated part of colon BP 90/40 map 60 CVP 3 PH 7.25 K 3.5 Mg 3 Lactate 3 HR 125 SVO2 50 O2 Sat 94% 4L NC Whats Wrong What do the numbers tell you What does the pt look like I need more Information Visual Clues Patient s respiratory rate 38 Abdominal breathing using accessory muscles Pt Skin is clammy Pt is able to answer simple questions but appears to have altered LOC, lethargic Requiring higher levels of oxygen to maintain sats now on venturi mask 10L 50% FI02 Further INFO Temp 102 F UOP 10 ml Q2hrs Sats 90% 10L Facemask. Pt receives 2L normal saline bolus, and electively intubated because of oxygenation problems. BP 93/50 map 64 CVP 8 HOLY SWELLING Fluid in the mysterious THIRD SPACE Is the patient volume overloaded? Is it in the right place? +3 pitting edema on all 4 extremities. HR 105 SVO

12 Pt now started on norepinephrine gtt.03mcg/kg/min BP 110/80 map 70 CVP 12 HR 110 SVO2 60 Labs from previous draw show WBC 25 PUT THE PUZZLE TOGETHER No one parameter will tell the story. Put the puzzle pieces together and you will find your answer most of the time Example: UOP decreases with Hypotension KIDNEYS HATE HYPOTENSION acute renal failure will open another can of worms GOTTA LOVE THIS STUFF Pressure Monitoring Learn by Heart Worksheet Arterial Blood Pressure Pulmonary Artery Pressure: PA Central Venous Pressure: CVP Pulmonary Artery Occlusion Pressure: WEDGE Intra-Cranial Pressure: ICP Intra-abdominal Pressure Airway Pressure: Ventilator Hemodynamic Monitoring Technology Arterial Line MAP and SBP & DBP PICC and Triple Lumen Lines CVP SCVO2 Monitoring Vigeleo Monitor Pulmonary Artery Catheter PA catheter, Swan-Ganz, Swan CCO/SVO 2 PA Catheter Arterial Blood Pressure Direct Arterial BP which monitors the Systolic, Diastolic and MAP continuously. More accurate than B/P cuff since it monitors systemic vascular resistance and blood flow. Not an early indicator of trouble Does not reflect early clinical changes in blood flow Look for threats to tissue oxygenation! 12

13 Arterial Blood Pressure: Not an early indicator of trouble Blood pressure is determined by: 1. Cardiac Output (CO) 2. Systemic Vascular Resistance (SVR) Arterial Blood Pressure: Not an early indicator of trouble BP does not reflect early clinical changes in blood flow (hemodynamics)! B/P is controlled by: Autonomic Nervous system Baro-receptors Vasomotor center Capillary fluid shift Hormones Adrenalin, noradrenalin Renin /Angiotensin conversion Compensatory changes keep BP close to adequate initially in shock states Arterial BP Compensation HR goes up: Arterial Blood Pressure same If CO starts to decrease, blood vessels vasoconstrict--bp stays the same. If blood vessels start to vasodilate, the CO will increase--bp stays the same. If Blood Volume decreases the HR goes up to maintain the CO --BP stays the same. Examples: Active bleeding; Heart failure BP is not an early signal of changes! By the time it does, the patient may be in big trouble! Arterial Blood Pressure Hypotension is present if there is evidence of inadequate blood flow Threat to Tissue Oxygenation? SVO2 and Lactate? Hypertension is present when there is a potential for injury to the peripheral circulation (generally SBP>140) Question True or False: Blood pressure reflects early clinical changes in hemodynamics. False! Body usually compensates for a while first! 13

14 RAP/CVP Central Venous Pressure Describes the pressure of blood in the Right Artium or Vena Cava of the heart. Components of Monitoring System CVP reflects the intravascular blood volume, right ventricular end-diastolic pressure and right ventricular function Monitored by the SWAN (RAP)or a Central Venous Line (CVP) Normal 2-6 mmhg Components of a Vascular Pressure Monitoring System Saline and Pressure bag Firm, fluid-filled tubing Flush device Transducer Monitor Cable and Cartridge Pressure Bag with Flush Solution Maintain at 300 mg Hg Delivers 3 ml/hr Prevents back flow of blood in tubing Prevents clot formation NS 500cc, solution is used Assuring Accuracy Leveling the Transducer Leveling Transducer to Phlebostatic Axis: 1. Zeroing the Transducer 2. Leveling (or Referencing) the Transducer 3. Dynamic Response Testing 4. Troubleshooting the line set-up 5. Patient Positioning 14

15 Zeroing the Transducer Like Zeroing a scale! Level patient at the phlebostatic axis with transducer Turning stopcock off to patient and open to air So that the monitor can call atmospheric pressure and circuit pressure "zero. These pressures are eliminated when the stopcock is turned back on to the patient. Tells system atmospheric pressure and line is Zero Zeroing Procedure 1. Turn Transducer stopcock off to the patient. 2. Remove cap to open stopcock to air. 3. Press Zero 4. See 0 on the monitor 5. Replace cap. 6. Turn stopcock to see waveform. Square Wave Test or Dynamic Response Testing Example of Overdamped Causes of a Overdamped Line Underdamping example 1. The pt hand or wrist is flexed or extended 2. The Pressure in your bag has gone out 3. Line has been displaced or a clot is present. 15

16 Causes of Underdampening 1. The line from the transducer to the pt is extremely long 2. The diameter of the line to the pt is small. Basically too much play in the system Intravascular Pressure Monitoring Set Up Gather Supplies: Cartridge and Cable Pressure Tubing Safeset for blood draws Flush Solution Pressure Bag Pole and Holder Or Arm holder band Line Preparation: Remove all Air 1. Tighten connections, close roller clamp, turn stopcock OFF to patient, remove vented stopcock caps. 2. Gather 500ml NS bag, insert a-line tubing into bag remove and squeeze air out of the bag 3. Take pressure bag and inflate to 300mmHg Line Preparation: Remove all Air Cont. 4. Hang the IV bag and activate fast-flush device, advance fluid, priming the tubing. 5. Open stopcocks to air then turn off and flush the rest of the line. 6. Complete flushing the line and all stopcocks. Inspect line for any air bubbles. Line Preparation: 7. Cap stopcocks with solid cap using sterile technique. 8. Place IV bag into pressure bag and inflate to 300 mm Hg New Parameter with Flo trac SVV Or Stroke volume variance Higher the Variance less volume Usually want variance less than around 13 16

17 Vigeleo monitor Vigeleo Monitor SVV only works with a mechanically vented patient Can give you all the same numbers as Swan-Ganz Only as good as your arterial line Guide to the Flo trac CVP etailpage&v=7putxzn7ij4 Measured from a Central line FloTrac Sensor Product Animation and User Guide - YouTube Estimate of fluid status Where we start Vigeleo and SCvO2 Able to get continuous SCvO2 Calibrate like a swan with SVO2 from venous sample Numbers Goal is for SVV to be around 13 SVV not reliable if pt not mechanically ventilated and sedated CO/CI can be consistently measured 17

18 Warning There are limitations to the technology Arterial waveform must be correct for any of the numbers to be correct Mechanics is no substitution for judgement. Normals Parameter Normal value Blood Pressure Systolic (SBP) mmhg Diastolic (DBP) 60-90mmHg Mean Arterial Pressure (MAP) mm Hg Cardiac Index (CI) L/min/m2 Cardiac Output (CO) 4-8 L/min Central Venous Pressure (CVP) (also known as 2-6 mmhg Right Atrial Pressure (RA)) Systolic mmhg (PAS) Pulmonary Artery Pressure (PA) Diastolic 8-12 mmhg (PAD) Mean 25 mmhg (PAM) Pulmonary Capillary Wedge Pressure (PWCP) 4-12 mmhg Pulmonary Vascular Resistance (PVR) dynes/sec/cm5 Right Ventricular Pressure (RV) Stroke Index (SI) Stroke Volume (SV) Systemic Vascular Resistance (SVR) Systolic mmhg Diastolic 0-5 mmhg ml/m ml dynes/sec/cm5 Lets Look Interactive Putting puzzle together Armed with information Lets Dive in I have a hypotensive pt that is mechanically ventilated Trauma to Chest and head from an MVC Where do we start Pt Numbers BP 80/40 MAP 53 HR 110 CVP 4 SVV 30 Hgb 8.2 Troubleshooting the line set up Loose Connections Kink in catheter Stopcocks not closed all the way Presence of Air Bubbles Pressure bag not at 300 mm Hg Empty Flush Bag Be careful! Blood in tubing Presence of Extra tubing or Stopcocks 18

19 Patient Positioning Patient Positioning during Hemodynamic Monitoring: Supine Upper body anywhere from flat to about 40 degrees -Not necessary to be flat -Little evidence about accuracy prone or on side Re Cap: Assuring Accuracy 1. Zeroing the Transducer 2. Leveling (or Referencing) the Transducer 3. Dynamic Response Testing 4. Troubleshooting the line set-up 5. Patient Positioning Arterial Pressure Monitoring Non-Invasive Cuff Pressure (NIBP) Continuous Arterial Pressure Line monitoring a.k.a. Art Line A-line Complications Acute Arterial Insufficiency bad! Check CMS frequently Hemorrhage During insertion Especially femoral Disconnect Keep alarms on Secure connections Air Embolism Clot Never Have an Arterial line in a patient that is unmonitored or capped. Allen s Test Ask patient to clench fist Compress both the radial & ulna arteries together with thumbs Have patient open hand; observe for pallor Patient relaxes hand Release pressure over ulnar artery, observe capillary refill Lets Try The Test I m a visual learner so I ll give an example of how to do the test then each person will get a partner and perform test on each other 19

20 Continuous Arterial Pressure Obtaining Printed Strip 2 channel waveform recording ECG Monitored Vascular Pressure Waveform Look at Scale Printout may be only way to get accurate reading Examples of Artline Tracings Normal vs OverDampened Normal vs Underdamped Underdamped Waveform 20

21 Overdamped waveform Examples of Artline Tracings Examples of Artline Tracings Examples of Artline Tracings Examples of Artline Tracings Examples of Artline Tracings Note the tracing follows ecg 21

22 Pulsus Paradoxus Examples of Artline Tracings Examples of Artline Tracings References Edwards Life Science Lippincott Williams & Wilkins (2007)Hemodyanmic Monitoring Incredibly Visual Lippincott Williams &Wilkins (2005) Critical Care Nursing A Holistic Approach Thank you! 22