Hemodynamic Monitoring By Nancy Jenkins RN,MSN

What is Hemodynamic Monitoring? It is measuring the pressures in the heart

Hemodynamic Monitoring  Baseline data obtained – General appearance – Level of consciousness – Skin color/temperature – Vital signs – Peripheral pulses – Urine output

Hemodynamic Monitoring  Baseline data correlated with data obtained from technology (e.g., ECG; arterial, CVP, PA, and PAWP pressures **Single hemodynamic values are rarely significant. Look at trends!!

Purpose of Hemodynamic Monitoring Evaluate cardiovascular system Pressure, flow, resistance Establish baseline values and evaluate trends Determine presence and degree of dysfunction Implement and guide interventions early to prevent problems

Hemodynamic Monitoring Components Heart Rate Blood Pressure and MAP CVP Pulmonary Artery Pressures Systemic Vascular Pressure (SVR) Pulmonary Vascular Pressure (PVR) Cardiac Output/ Cardiac Index Stroke Volume

IVI fluid=preload IV I

Comparing Hemodynamics to IV pump  Fluid =preload  Pump= CO or contractility (needs electricity)  Tubing =afterload

Types of Invasive Pressure Monitoring  Continuous arterial pressure monitoring – Acute hypertension/hypotension – Respiratory failure – Shock – Neurologic shock

Types of Invasive Pressure Monitoring  Continuous arterial pressure monitoring (cont’d) – Coronary interventional procedures – Continuous infusion of vasoactive drugs – Frequent ABG sampling

Components of an Arterial Pressure Monitoring System Fig. 66-3

Arterial Line

Arterial Pressure Monitoring  High- and low-pressure alarms based on patient’s status  Risks – Hemorrhage, infection, thrombus formation, neurovascular impairment, loss of limb

Arterial Pressure Tracing Fig. 66-6

Arterial Pressure Monitoring  Continuous flush irrigation system – Delivers 3 to 6 ml of heparinized saline per hour Maintains line patency Limits thrombus formation – Assess neurovascular status distal to arterial insertion site hourly

Dicrotic notch signifies the closure of the aortic valve.

Pulmonary Artery Pressure Monitoring  Guides management of patients with complicated cardiac, pulmonary, and intravascular volume problems – PA diastolic (PAD) pressure and PAWP: Indicators of cardiac function and fluid volume status – Monitoring PA pressures allows for therapeutic manipulation of preload

Manipulating the PA pressures affects the preload 1.True 2.False

Pulmonary Artery Pressure Monitoring  PA flow-directed catheter – Distal lumen port in PA Samples mixed venous blood  Thermistor lumen port near distal tip – Monitors core temperature – Thermodilution method measuring CO

Pulmonary Artery Pressure Monitoring  Right atrium port Measurement of CVP Injection of fluid for CO measurement Blood sampling Administer medications

The proximal port or right atrial port is used to: 1.Measure the CVP 2.Administer meds 3.Measure the wedge pressure 4.Draw blood

Pulmonary Artery Catheter Fig. 66-7

PA Waveforms during Insertion Fig. 66-9

Hemodynamics: Normal value Mean Arterial Pressure (MAP)Mean Arterial Pressure (MAP) mm Hg mm Hg Cardiac Index (CI)Cardiac Index (CI) L/min/m L/min/m2 Cardiac Output (CO)Cardiac Output (CO)- 4-8 L/min Central Venous Pressure (CVP)Central Venous Pressure (CVP) (also known as Right Atrial Pressure (RA)) 2-8 mmHg Pulmonary Artery Pressure (PA) Systolic mmHg (PAS) Diastolic 4-12 mmHg (PAD) Mean mmHg Pulmonary Capillary Wedge Pressure (PWCP) 6-12 mmHg Systemic Vascular Resistance(SVR)

Cardiac Output

Central Venous Pressure Monitoring  Measurement of right ventricular preload – Obtained from PA catheter using one of the proximal lumens Central venous catheter placed in internal jugular or subclavian vein

Central Venous Pressure Waveforms Fig

Measuring Cardiac Output  Intermittent bolus thermodilution method  Continuous cardiac output method

Measuring Cardiac Output Fig

Measuring Cardiac Output  SVR, SVRI, SV, and SVI can calculated when CO is measured – ↑ SVR Vasoconstriction from shock Hypertension ↑ Release or administration of epinephrine or other vasoactive inotropes Left ventricular failure

Best indicator of tissue perfusion. Needs to be at least 60 to perfuse organs

If a patient’s B/P is 140/80 the MAP would be:

Complications with PA Catheters  Infection and sepsis – Asepsis for insertion and maintenance of catheter and tubing mandatory – Change flush bag, pressure tubing, transducer, and stopcock every 96 hours  Air embolus (e.g., disconnection)

Complications with PA Catheters  Ventricular dysrhythmias – During PA catheter insertion or removal – If tip migrates back from PA to right ventricle  PA catheter cannot be wedged – May need repositioning

Which would be complications in a patient with a PA catheter? 1.Arrhythmias 2.Infection 3.Air embolism 4.Bleeding

Complications with PA Catheters  Pulmonary infarction or PA rupture – Balloon rupture (e.g., overinflation) – Prolonged inflation – Spontaneous wedging – Thrombus/embolus formation

Noninvasive Hemodynamic Monitoring  Impedance cardiography (ICG) – Continuous or intermittent, noninvasive method of obtaining CO and assessing thoracic fluid status Impedance-based hemodynamic parameters (e.g., CO, SV, SVR) are calculated from Zo, dZ/dt, MAP, CVP, and ECG

Noninvasive Hemodynamic Monitoring  Major indications – Early signs and symptoms of pulmonary or cardiac dysfunction – Differentiation of cardiac or pulmonary cause of shortness of breath – Evaluation of etiology and management of hypotension

Noninvasive Hemodynamic Monitoring  Major indications (cont’d) – Monitoring after discontinuing a PA catheter or justification for insertion of a PA catheter – Evaluation of pharmacotherapy – Diagnosis of rejection following cardiac transplantation

hemodynamic caseshemodynamic cases (1 and 4)

Three main types of hypotension (“shock states”) that you’re going to see in the ICU  1. “Pump”- Cardiogenic shock  2. “Volume”- Hypovolemia  3. Squeeze” - Sepsis

- Pump” problems? “Cardiogenic” shock? The cardiac output will be low, because the pump isn’t pumping. Blood pressure drops. The body says to itself: “What to do? Got to keep the blood pressure up somehow!”, and starts to tighten up the arterial bed. What number tells how tight the arterial system is? – SVR. So – in cardiogenic shock, the cardiac output goes down, the SVR goes up – the pattern is usually plain as day. “Ooh, look! The output is only 2.2, and the SVR is 2400!” What does the wedge pressure do? (Remember, the LV is pumping poorly, and can’t empty itself…)

- “ Volume” problems? “Hypovolemic” shock? Lost a lot of blood? Running too many marathons? Cardiac output will probably be low, since there isn’t enough volume to pump with. CVP and wedge pressures? Low, right? – again, not enough volume. SVR? Same as cardiogenic: the arteries clamp down, trying to maintain pressure. Hypovolemic shock: cardiac output low, central pressures low, SVR high.

- “ Squeeze” problem? Any idea what makes this happen? Anybody say, “sepsis”? All that bacteremic endotoxin makes the arteries dilate – blood pressure drops. What to do? Now the body uses the mirror reflex of what it did in the cardiogenic setting: instead of clamping down the arteries, which it can’t do, because that’s where the problem is – now the heart picks up the slack, pumping both faster and harder: heart rate goes up, and cardiac output does too. Septic shock: cardiac output high, central pressures low, SVR low.