hemodynamics monitoring brainstorm

  • these are invasive ways to check a patient’s circulatory status or heart function in critically ill patients.

    • hemodynamic procedure and tools:

      • central venous pressure (CVP)

      • pulmonary artery pressure (PAP)

      • intra-arterial blood pressure (A-line)

      • components: invasive catheter, tubing, transducer, amplifier/recorder

  • Normal hemodynamics values:

    CVP: 2-6 mmhg (5-12 cmH2o)

    —reflects right atrial pressure and right ventricular preload

    —elevated CVP (>6 mmHg or >12 cmH2O) IMPLICATION:

    • Fluid Overload: too much fluid in the circulatory system

    • Heart Failure: inability of the heart to effectively pump blood forward

    • Pulmonary Hypertension: increased resistance in the pulmonary circulation

    • Tricuspid Valve stenosis/regurgitation: impaired blood flow through the tricuspid valve

    • Constrictive Pericarditis/Cardiac Tamponade: conditions that restrict the heart’s ability to fill

    —decreased CVP (<2 mmHg or <5 cmH2O) IMPLICATIONS:

    • hypovolemia: insufficient circulating blood volume due to dehydration, hemorrhage, or third spacing of fluids

    • vasodilation: reduced vascular tone leading to dec venous return

    Pulmonary Artery Pressure (PAP)

  • NV: systolic: 20-30 mmHg, diastolic: 5-10 mmHg, Mean PAP: 10-20 mmHg, reflects pressure in the pulmonary artery

  • ELEVATED PAP IMPLICATIONS

    • Pulmonary Hypertension: high blood pressure in the pulmonary arteries

    • Left Heart Failure: back pressure from the left side of the heart

    • Pulmonary Embolism: blockage in the pulmonary arteries

    • COPD: chronic lung disease causing incr pulmonary vascular resistance

  • DECREASE PAP IMPLICATIONS

    • Hypovolemia

    • Pulmonary Vasodilation: decreased resistance in the pulmonary circulation

    Pulmonary Capillary Wedge Pressurre (PCWP)

  • NORMAL: 5-12 mmHg, indicates left atrial pressure and left ventricular preload

  • ELEVATED PCWP (>12mmHg) IMPLICATIONS

    • left heart failure: inability of the left ventricle to effectively pump blood forward

    • mitral valve stenosis/regurgitation: impaired blood flow thru the mitral valve

    • fluid overload: excessive fluid in the circulatory system

  • DECREASED PCWP (<5mmHg):

    • Hypovolemia: insufficient circulating blood flow

    • Excessive Diuresis: over-removal of fluid from the body

    Cardiac Output (CO): 4-6 L/min

    —amount of blood ejected by the ventricle per minute, normal CO signifies effective cardiac pumping and tissue perfusion

  • ELEVATED CO (>8 L/min) IMPLICATIONS

    • Early Sepsis: inc metabolic demand and compensatory mechanisms

    • Hyperthyroidism: inc metabolic rate

    • Anemia: compensatory inc in CO to deliver adequate oxygen

  • DECREASED CO (<4 L/min) IMPLICATIONS

    • Heart Failure: reduced pumping ability of the heart

    • Hypovolemia: insufficient blood volume

    • Cardiogenic shock: severe reduction in cardiac output due to heart dysfunction

    Cardiac Index (CI): NV 2.2-4.0 L/min/m2

    —cardiac ourput normalized for body surface area, normal CI reflects adequate cardiac function relative to body size, low CI indicates inadequate cardiac performance

  • ELEVATED CI (>4.0 L/…) IMPLICATIONS

    • Early Sepsis: inc metabolic demand

    • Hyperthyroidism: inc metabolic rate

  • DECREASED CI (<2.2) IMPLICATIONS

    • Heart Failure: reduced cardiac function

    • Cardiogenic Shock: Severe heart dysfunction

    • Hypovolemic Shock: insufficient blood volume

    Mixed Venous Oxygen Saturation (SvO2): NV 60-80%

    —reflects balance between oxygen delivery and consumption

  • ELEVATED SvO2(>80%) COMPLICATIONS

    • Sepsis: inability of tissue to extract oxygen

    • Cyanide Poisoning: impaired oxygen utilisation at the cellular level

    • Hypothermia: reduced metabolic demand

  • DECREASED SvO2(>60%) COMPLICATIONS

    • Low Cardiac Output: reduced oxygen delivery

    • Anemia: insufficient oxygen-carrying capacity

    • Hypoxemia: inadequate oxygenation of blood

    • Increased Oxygen Consumption: inc metabolic demand (fever, shivering)

Hemodynamic Monitoring Overview

  • Purpose: assess cardiac function and circulatory status in critically ill patients

  • Key tools: CVP, PAP, arterial line

  • Components include invasive catheters, tubing, transducers, amplifiers, recorders

CVP

  • measures right atrial pressure; reflecs right ventricular preload

  • normal range: 2-6 mmHg, water manometer 5-12 cmH2O

  • inc CVP: RV failure, volume overload, tricuspid valve issues, pumonary hypertension

  • dec CVP: hypovol

  • uses: fluid status, pressure assessment, long term IV access

  • insertion: requires aseptic technique, patient positioning (flat/trendelenburg), monitoring for dysrhythmias

  • complications: pneumothorax, hemorrhage, infection, dysrhythmias, air embolism

  • troubleshooting: kinks, clot, improper position and leaks

Pulmonary Artery Catheter (Swan-Ganz Catheter)

  • measures PAP, PCWP, CO, SvO2

  • indications: diagnosis, therapy evaluation in heart disease, hemodynamic monitoring

  • lumen types: proximal (IV, CVP), distal (PA pressure), balloon inflation, thermistor (CO measurements)

  • insertion sites: subclavian, jugular, brachial femoral veins

  • nsg care: ECG monitoring during insertion, vigilance for pneumothorax, infection and arrhythmias

  • common issues: waveform damping, balloon rupture, catheter migration

  • complications: pulmonary artery perforation, infarction, embolism, infection, arrhythmias, knotting

  • removal: requires careful sreos including balloon deflation, vital signs, pressure application

Cardiac Output Measurements

  • Cardiac output = Stroke Volume x heart rate

  • methods:

    • fick method (gold standard)

    • dye dilution

    • thermodilution (most common)

  • thermodilution: rapid injection of cold saline, measuring temperature changes; three measurements averaged

  • cardiac index = cardiac output/body surface area (normal 2.2-4.0 L/min/m2)

  • body surface area: determined by height and weight nomogram

Mixed Venous Oxygen Saturation (SVO2)

  • indicates balance between oxygen supply and demand

  • normal 60-80%

  • low SVO2: low Hb, hypoxemia, low CO, increased O2 consumption

  • high SVO2: increased supply or decreased demand

Arterial Line (Intra-arterial BP monitoring)

  • continuous BP monitoring and blood sampling

  • indications: complicated surgery, vascular disease, mechanical ventilation, vasoactive drugs, burns, trauma, obesity

  • insertion sites: radial, femoral, brachial, dorsalis pedis

  • nsg care: aseptic technique, monitoring, troubleshooting

  • problems: damped waveform (under or overdamping), hemorrhage, clots, air embolism, infection

  • prevention: use heparinized solutions, secure connections, change solutioons regularly, sterile dressing changes

Nursing Role & Responsibilities

  • prepare equipment, explain procedures, obtain consent, maintain asepsis

  • monitor pts vital signs and ECG during procedures

  • recognize complications early and troubleshoot technical problems

  • ensure accurate readings by proper positioning and equipment care

  • manage catheters, tubing dressings; prevent infection and thrombosis

Prevent Complications!

Central Venous Pressure (CVP) Monitoring

  • Use strict aseptic technique during catheter insertion to prevent infection.

  • Ensure proper patient positioning (flat or slight Trendelenburg) for accurate readings.

  • Monitor carefully for signs of pneumothorax or hemothorax during and after insertion.

  • Secure all catheters and tubing to prevent disconnections and air embolism.

  • Regularly change intravenous fluids (IVF) every 24 hours, tubing every 72 hours, and dressings aseptically daily or as needed.

  • Observe for dysrhythmias caused by catheter irritation.

  • Relieve kinks and check stopcocks to maintain line patency.

  • Avoid pushing against clots; withdraw clots carefully if line occlusion occurs.

Pulmonary Artery Catheterization (Swan-Ganz)

  • Ensure proper balloon inflation and never overinflate beyond recommended limits to avoid pulmonary artery perforation.

  • Monitor ECG throughout catheter insertion to detect dysrhythmias early.

  • Maintain strict sterile technique to reduce infection risk.

  • Watch for pulmonary embolism by avoiding frequent or prolonged balloon wedging.

  • Document all pressure readings, patient position, and signs of impaired circulation.

  • Handle the catheter carefully to prevent knotting or catheter migration.

  • Administer oxygen therapy and medications as prescribed.

  • Prepare emergency equipment such as lidocaine bolus and defibrillator during catheter removal.

  • Apply firm pressure with sterile dressing after removal to prevent bleeding.

Arterial Line Monitoring

  • Use luer-lock connectors and secure catheter with sutures or adhesive to prevent hemorrhage.

  • Flush continuously with heparinized solution to prevent clot formation.

  • Purge air bubbles from catheter, IV bags, and drip chamber to prevent air embolism.

  • Change IV solution every 4 hours and disposable transducer sets every 72 hours to prevent infection.

  • Perform daily dressing changes and site inspection using strict infection control protocols.

  • Regularly monitor arterial blood pressure and waveform quality; troubleshoot damped waveforms by flushing tubing and checking for kinks or air bubbles.

General Measures Across Procedures

  • Explain the procedure to the patient and obtain informed consent.

  • Monitor vital signs and ECG continuously during insertion and maintenance.

  • Keep equipment ready for emergency response.

  • Proper documentation of procedures, readings, and interventions.

  • Education and training of healthcare providers on proper techniques and troubleshooting.

ABGs

pH: 7.35-7.45

PaCO2: 35-45 mmHg

HCO3: 22-26 mmHg

SaO2: 95-100%

PaO2: 80-100 mmHg

PURPOSE

  • Aids in establishing diagnosis.

  • Guides treatment plan.

  • Aids in ventilator management.

  • Improvement in acid/base management; allows for optimal function of medications.

  • Acid/base status may alter electrolyte levels critical to a patient’s status.

PROCEDURE of extracting blood specimen for ABG Test

1. Gather needed equipment

Gloves; Skin disinfectant; Gauze; Local anesthetic agent;

Pre-heparinized syringe; Needle G26

2. Palpate the radial artery using 2-3 fingers

Note: Perform Modified Allen’s Test

3. Extend the wrist slightly

4. Clean the site with alcohol swab or disinfectant

5. Infiltrate local anesthesia (not used in hospital settings)

6. Introduce pre-heparinized syringe (45degrees), extract the arterial blood

  • SaO2 - percentage of hemoglobin saturated with oxygen in arterial blood (O2Sat)

  • PaO2 - partial pressure of oxygen dissolved in arterial blood

  • pH - arterial blood acidity or alkalinity

  • PaCO2 - partial pressure of carbon dioxide dissolved in arterial blood

  • HCO3 - concentration of bicarbonate ions in arterial blood

POTENTIAL PREANALYTICAL ERRORS

  • During preparation prior to sampling

    • Missing or wrong patient/sample identification;

    • Use of the incorrect type or amount of anticoagulant

>dilution due to use of liquid heparin;

> insufficient amount of heparin;

> binding of electrolytes to heparin;

  • Inadequate stabilization of the respiratory condition of the patient; and

  • Inadequate removal of flush solution in arterial lines prior to blood collection.

  • During sampling/handling

    • Mixture of venous and arterial blood during puncturing

    • Air bubbles in the sample.

    • Insufficient mixing with heparin.

  • General Storage Recommendation

    • Do not cool the sample

    • Analyze within 30 min

  • During preparation prior to sample transfer

    • Visually inspect the sample for clots.

    • Inadequate mixing of sample before analysis