Critical Care and Hemodynamic Monitoring Study Guide

Critical Care and Hemodynamic Monitoring

Role of the Critical Care Nurse

• Critical care nurses require:

  • Astute assessment skills.

  • Clinical judgment.

  • Ability to provide complex nursing support, including:

    • Vasoactive medications and titrations.

    • Polypharmacy.

    • Mechanical ventilation.

    • Hemodialysis (HD) or Continuous Renal Replacement Therapy (CRRT) → dialysis 24/7.

    • Intracranial pressure (ICP) monitoring.

    • Hemodynamic monitoring (CO, BP, HR and rhythms, RR)

• Critically ill patients are at high risk for serious complications.

ICU Admission Criteria

• Patients sent to the ICU are typically:

  • Physiologically unstable.

  • At risk for serious complications requiring frequent assessments and invasive interventions.

  • Need intensive nursing support related to IV medications and/or advanced technology.

  • Some post-surgical patients

    • Ex. Pt has a lap cholecystectomy that turns into an open cholecystectomy and must leave belly open for a few days.

Critical Care RN Skills

• Critical Care Registered Nurses (RNs) require:

  • Advanced assessment skills with higher frequency, continuous monitoring, and trending patterns.

    • Cranial nerves, etc.

  • In-depth knowledge of pathophysiology and pharmacology.

  • The ability to anticipate, recognize, and act on complications.

    • Ex. Subtle changes in BP, urine output decreasing every few hours, etc.

  • Proficiency in managing advanced biotechnology.

  • Effective communication and collaboration with interdisciplinary team (IDT) members.

    • Ex. Rounds → all team members involved; how patient did overnight and any concerns for today. Family recommended to be around.

Common Patient Problems in Critical Care

• Immobility, which may necessitate restraints or devices.

  • Most patients are sedated, restrained, or intubated.

  • Even if pts are ventilated, they need to be mobilized (ex. Sitting on edge of bed for 10-15 mins).

• Communication difficulties due to nonverbal status or cognitive impairment.

• Nutritional considerations:

  • Enteral vs. parenteral nutrition.

    • Enteral: mesenteric ischemia, traumatic injury in abdomen or face = contraindicated.

    • Enteral preferred. Start early.

• Pain management (observed), which can be challenging in nonverbal patients; unmanaged pain can lead to agitation and anxiety.

  • Pain observation = what does pain seem to be?

• Anxiety stemming from fear of the unknown, loss of control/independence, unfamiliar surroundings, and impaired communication.

• Sleep disturbances caused by environmental noise and frequent interruptions for assessments and medications.

  • Lights on during day, lights low or off during night.

  • Cluster care.

• Sensory issues, including delirium from sensory overload → common.

Agitation and Confusion Assessment Scales

Richmond Agitation-Sedation Scale (RASS)

• A tool to assess the level of consciousness and agitation in patients. Do this with neuro checks (minimum q4h).

• Levels range from:

  • +4 (violent) to -5 (comatose/completely unresponsive).

  • Ideal to be between -1 (drowsy & easily arousable) and +1 (slightly anxious, not aggressive).

• Scores indicate the degree of agitation or sedation, guiding appropriate interventions.

Confusion Assessment Method for the ICU (CAM-ICU)

• Used to assess for delirium in ICU patients.

• Involves assessing for:

  1. Acute change or fluctuating course of mental status? (ex. AOx4 → AOx1 = yes, move down flowsheet).

  2. Inattention (e.g., squeeze hand when 'A' is said in a sequence → spell “CASA BLANCA” → allow up to 2 errors, if 2+ errors move down flowsheet).

  3. Altered level of consciousness (RASS score → score other than 0 means ICU delirium)

  4. Disorganized thinking (answering yes/no questions).

• A patient is considered delirious if they have features 1 and 2, along with either feature 3 or 4.

Pain Assessment: Critical-Care Pain Observation Tool (CPOT)

• A behavioral pain assessment tool for nonverbal patients.

• Evaluates:

  • Facial expressions (0-2) →

    • 0 = Relaxed

    • 1 = Tensed

    • 2 =Grimacing

  • Body movements (0-2).

    • 0 = Absent or normal movements

    • 1 = Protection (against painful stimuli)

    • 2 = Restlessness and agitation

  • Compliance with ventilation or vocalization (0-2) (as applicable).

  • Muscle tension (0-2).

    • 0 = Relaxed

    • 1 = Tense, rigid

    • 2 = Very tense and rigid.

• Total score ranges from 0-8, with higher scores indicating greater pain.

Family-Centered Care

• Involves family participation in patient care to:

  • Connect patients to their previous reality.

  • Offer support and assistance at the bedside.

  • Provide factual information to the healthcare team.

  • Function as healthcare decision-makers.

  • However, be aware that family involvement can sometimes do more harm than good, necessitating patient advocacy.

• Addressing family issues includes:

  • Communicating the plan of care, including medical and nursing goals.

  • Explaining procedures and tests.

  • Providing access to their loved ones.

  • Ensuring cultural sensitivity.

  • Allowing presence during care, procedures, or resuscitation attempts, and IDT rounds (if appropriate).

  • Addressing end-of-life issues.

    • Advocate for pt who has poor prognosis → would an elderly pt want to be full code?

Hemodynamic Monitoring

Basic Terminology**

• Systemic Arterial Pressure: Regular BP

• **Mean Arterial Pressure (MAP): Calculated as MAP = (SBP + 2DBP) / 3

  • 70 is normal (in ICU there will be acceptable parameters like 60-65)

• Pulmonary Arterial Pressure (PAP): Pressure within the arteries of the lungs

  • Viewing CO values for cardiac pts

• **Central Venous Pressure (CVP): Normal range is 2-8 mmHg.

  • Indicator of fluid volume status and if there’s enough fluid to perfuse the organs.

  • If CVP is 1, then we are hypovolemic.

  • If CVP is 12, 13, 15 = hypervolemia, which could lead to fluid overload and potential heart failure if treatment is not initiated.

• Pulmonary Artery Wedge Pressure (PAWP): Normal range is 6-12 mmHg.

  • Pressure we measure when wedging catheter into artery and inflating balloon.

  • Assesses left ventricular function and reflects the left ventricular and diastolic pressure.

• Cardiac Output (CO) / Cardiac Index (CI):

  • Normal CO range is 4-8 L/min.

  • CO=SV\cdot HR

  • CI = CO / BSA

• Stroke Volume (SV) / Stroke Volume Index (SVI)

• **Systemic Vascular Resistance (SVR): Calculated as SVR=(MAP-CVP)\cdot80/CO

• Pulmonary Vascular Resistance (PVR): Resistance in pulmonary vascular bed.

Types of Invasive Pressure Monitoring

• Arterial Blood Pressure (ABP) monitoring

• Arterial Pressure-Based Cardiac Output (APCO)

• Pulmonary Artery Flow-Directed Catheter (Swan-Ganz catheter)

• Central Venous Pressure (CVP) / Right Atrial Pressure Measurement

Purposes of Invasive Hemodynamic Monitoring

• Early detection, identification, and treatment of life-threatening conditions, such as: Want to identify deterioration quickly

  • Cardiogenic pulmonary edema

  • Non-cardiogenic pulmonary edema (ARDS)

  • Cardiac tamponade

  • Shock (all types)

• Evaluate effectiveness of treatment with:

  • Drugs (vasoactive medications)

    • Ex. Norepinephrine → we’ll be titrating up and down based on the patient's blood pressure response

  • Mechanical ventilatory support

Components of Pressure Monitoring Systems

• Bedside monitor: Contains the amplifier to increase signal size.

• Transducer: Converts mechanical pressures of the pulse into electrical energy; must be leveled to the phlebostatic axis for accurate readings (flushing device).

• Recorder: Records the information.

• Zeroing: Calibrates the system to atmospheric pressure.

• **Radial is easiest access point

Arterial Line Monitoring

• Invasive catheter placed in an artery for continuous arterial pressure monitoring.

  • Pressure tracing should show a P wave and correlates with ECG (if clotted off → might see tall spikes which means recalibration needed).

  • Arterial line always red, CVP is blue, pulmonary catheter is yellow.

  • Placement: Loop around patients thumb to prevent it being pulled out.

• Allows visualization of arterial pressure tracing with:

  • QRS complex on ECG with corresponding arterial waveform

  • Dicrotic notch

  • Systolic and end-diastolic pressures

• Ulnar artery occlusion test is performed to assess collateral circulation.

Square Wave Test

• Performed to assess the dynamic response of the arterial line system.

• A fast flush is activated and quickly released, producing a sharp upstroke followed by a rapid downstroke extending below baseline with 1-2 oscillations within 0.12 seconds and a quick return to baseline.

• The pressure waveform should be clearly defined, including the dicrotic notch.

• If that doesn’t work → Is it clotted?

Complications of Arterial Monitoring

• Necrotic tissue

  • Often happens if wrong medication is given through arterial line.

• Hemorrhage

• Thrombus formation

• Neurovascular impairment

• Loss of limb

• Infection

• Waveform abnormalities:

  • Normal waveform

  • Overdamped waveform

  • Underdamped waveform

Arterial Pressure-Based Cardiac Output (APCO)

• A minimally invasive method for continuous CO measurement.

  • Usually used for cardiac patients who’ve gone through cardioversion.

• Attaches to a traditional arterial line.

• Assesses the patient's ability to increase SV in response to fluid administration (preload responsiveness).

• Helps determine if the patient would benefit from additional IV fluids.

• Uses arterial waveform data plus demographic information.

• Often used with central venous oxygen saturation (CVO2) catheter.

  • O2 sat of blood return to the heart after defibrillation

Pulmonary Artery Catheter (Swan-Ganz Catheter)

• Used for hemodynamic monitoring but carries a high risk of complications if used without proper knowledge.

  • Was primarily used to monitor hemodynamic status of patients

Indications for PA Catheter Use

• Assessment of response to therapy in mixed types of shock.

• Cardiogenic shock

• Pulmonary hypertension (PAH)

• Myocardial infarction (MI) with complications such as heart failure.

• Potentially reversible systolic heart failure.

• Severe chronic heart failure requiring vasoactive drug therapy.

• Transplantation workup.

Contraindications for PA Catheter Use

• Coagulopathy (Clotting disorder)

  • Huge risk when inserting a catheter because clots will form around it.

• Endocardial pacemaker

• Endocarditis

• Mechanical tricuspid or pulmonic valve

• Right heart mass (thrombus or tumor)

PA Catheter Components and Insertion

• Components include:

  • Distal lumen hub

  • Proximal infusion lumen hub

  • Balloon inflation valve: measure wedge pressure (only insert air and use catheter it came with)

  • Thermistor connector

  • Thermistor sensor

  • Proximal injectate port

  • Balloon

• Prior to insertion:

  • Check electrolyte levels and coagulation studies.

    • Particularly magnesium and potassium electrolytes

    • INR/PT and PTT

  • Prepare necessary monitoring equipment.

• Insertion sites include the internal jugular (IJ), subclavian, axillary, or femoral vein.

• Observe waveforms as the catheter is advanced.

• Confirm positioning with chest X-ray.

• Secure the catheter and record the measurement at the exit point.

  • Measured every shift

Positional Waveforms During PA Catheter Insertion (in order)

• Right atrium

• Right ventricle

  • If cath dislodged here = increased risk for ventricular dysthymia’s

  • Pull out into right atria (less likely for a dysrhythmia in atria than ventricle → tell provider after)

    • About 5 cm or so to pull into atria

• Pulmonary artery

  • This is here the cath should sit

• Pulmonary artery wedge

  

Central Venous Pressure (CVP) / Right Atrial Pressure

• Reflects fluid volume status.

• Usually measured with a CVP catheter in the IJ or subclavian vein.

• Can also be measured with a PA catheter.

• CVP is the mean pressure at the end of expiration.

• High CVP indicates right ventricular failure or volume overload.

• Low CVP indicates hypovolemia (ex. trauma or liver failure).

Pulmonary Artery Wedge Pressure (PAWP)

• Measured from the distal port of the catheter when the balloon is inflated, "wedging" the catheter in a small PA branch.

• PAWP reflects the preload of the left heart.

• Normal range: 6-12 mmHg.

• Elevated in left-sided heart failure.

• High PAWP indicates volume overload

  • Treatment includes diuretics and inotropes if left ventricular dysfunction is present.

• Low PAWP indicates volume deficit

  • Treatment includes IV fluids.

Systemic Vascular Resistance (SVR) and Pulmonary Vascular Resistance (PVR)

• Calculated on monitor, not directly measured with a PA catheter.

• Both measure afterload: the resistance the ventricle overcomes to pump blood into the systemic circulation.

• SVR: SVR = 800-1200 \frac{dyn \cdot s}{cm^5} : Afterload of the left heart

  • Low SVR: Use vasopressors to increase vascular tone.

  • High SVR: Use vasodilators and positive inotropes.

• PVR: PVR < 250 \frac{dyn \cdot s}{cm^5} : Afterload of the right heart

  • Low PVR: Can be due to overuse of vasodilators.

  • High PVR: Treat the underlying cause (e.g., oxygen, diuretics, bronchodilators).

Nursing Management for Invasive Hemodynamic Monitoring

• Integrate data from multiple sources.

• Collect baseline data.

  • Trending upward? Downward?

• Assess the patient's appearance.

• Perform a full physical assessment.

• Recognize early cues of deterioration.

• Intervene before a decline occurs.

Complications of Invasive Hemodynamic Monitoring

• Infection/sepsis: Prevent with central line bundle, occlusive dressings (change PRN), and Biopatch at the insertion site.

• Dislodgment into the right ventricle (RV): Can cause ventricular dysrhythmias; requires immediate notification of the physician and pulling the catheter back into the right atrium.

• Air embolism: Caused by overinflating the balloon, leading to rupture.

• Thrombus: Clot formation on the end of the catheter can result in pulmonary embolism.

• Pulmonary infarction/PA rupture: Considered an emergency, requires immediate notification of the physician.

  • Can occur when the balloon is left inflated too long or the catheter migrates too far into the pulmonary artery.

  • Never inflate the wedge balloon beyond its capacity (1-1.5 mL) or for longer than 8-15 seconds.

Mechanical Circulatory Support Devices

Intra-Aortic Balloon Pump (IABP)

• Temporary mechanical support device.

• Reduces afterload.

• Improves coronary blood flow.

• IABP therapy = counterpulsation.

Hemodynamics of IABP

• Helium is rapidly shuttled into and out of the balloon (about 40 mL).

  • Helium is less risk for air embolism

• Inflation displaces blood superiorly and inferiorly, perfusing coronary arteries and other organs.

  • Diastole → balloon inflated

  • Systole → deflate (vacuum-like pressure)

• Deflation drops pressure within the aorta, reducing afterload.

• ECG rhythm triggers inflation and deflation.

• Dicrotic notch in arterial pressure tracing refines timing.

• IABP assist ratio is 1:1.

  • Every heart beat, balloon deflates and inflates

Indications

• Acute MI

• Ventricular aneurysm accompanied by ventricular dysrhythmias

• Acute ventricular septal defect

• Acute mitral valve dysfunction

• Cardiogenic shock, pre-shock syndrome

• Refractory chest pain with or without ventricular dysrhythmias

• Short-term bridge to heart transplantation

• Unstable angina unresponsive to drug therapy

• High-risk cardiac procedures

• Cardiac surgery

Contraindications

• Irreversible brain damage

  • Ex. Pt who is brain dead

• Moderate to severe aortic insufficiency

• Abdominal aortic and thoracic aneurysms

  • Could lead to an aortic dissection

  • may become uncoordinated

• Aortic dissection

• Generalized PVD

• Major coagulopathy

• Thrombocytopenias

  • Bleeding risk

• End-stage cardiomyopathies

• Severe atherosclerosis

• Terminal illnesses

Principles of IABC

• Flexible catheter inserted into the femoral artery and passed into the descending aorta.

• Correct positioning is critical to avoid blocking the subclavian, carotid, or renal arteries.

• When inflated, the balloon blocks 85-90% of the aorta.

  • Complete occlusion can damage the walls of the aorta, red blood cells, and platelets.

• When deflated, it creates a vacuum that decreases aortic pressures.

Effects of Inflation

• Increases diastolic pressure, enhancing perfusion to distal organs and tissues.

• Increases systemic perfusion, improving MAP numbers.

• Increases pressure in the aortic root during diastole.

• Increases coronary artery perfusion pressure, improving O2 delivery to the myocardium.

• Reduces angina and ECG evidence of ischemia; reduces ventricular ectopy.

Effects of Deflation

• Decreases afterload due to decreased aortic end-diastolic pressure.

• Decreases peak systolic pressure.

• Decreases O2 demands due to decreased myocardial workload and O2 consumption.

• Increases stroke volume.

• Improves cardiac output and reduces left ventricular preload (PAWP=wedge).

• Result: Increased urinary output and decreased heart rate

Complications of IABC and Nursing Management

• Infection/sepsis

• Balloon leak or rupture

  • Tell physician ASAP

• Effects of immobilization

• Thrombocytopenia (can destroy platelets)

  • Increased bleeding risk

• Thromboembolism

  • Blood pools around balloon and causes a clot

• Hemorrhage from insertion site

• Trauma to the aorta & femoral artery

• Frequent extremity neurovascular checks q2h & hourly urinary outputs are essential for early identification of problems!

Nursing Management (Cont’d)

• Cardiovascular Assessments

• Hemodynamic Monitoring

• Heart/Lung Auscultation

• ECG evaluation

  • Look for any changes

  • Oftentimes get a 12 lead as baseline

• Tissue Perfusion

  • Urinary output a good indicator (especially if it drops below 30/hr)

• Neuro Status q2h

• As patient improves, 1:1 ratio can decrease with Re-evaluation

Ventricular Assist Devices (VAD)

• Support for the failing heart (advanced stages)

• Placed into the path of flowing blood to alter the action of one or both ventricles.

• May be placed internally or externally.

  • External is easier and often temporary

• Blood is shunted from the left atrium to the device and then to the aorta.

• Better mobility than IABP.

Indications

• Failure to wean from cardiopulmonary bypass after surgery.

• Post-surgical cardiogenic shock.

• Recovery after heart transplant.

• HF NY Class IV resistant to drug therapy

Contraindications

• BSA less than manufacturer’s limits

• Irreversible end-stage organ damage

• Co-morbidities that make life expectancy less than 3 years

Nursing Management

• Nursing care is similar to that of the patient with an IABP.

• Observe the patient for bleeding, cardiac tamponade, ventricular failure, infection, dysrhythmias, renal failure, hemolysis, and VTE.

• The patient must be mobile and needs an activity plan.

• Patients may go home with one. Preparation for discharge is complex and needs in-depth teaching about the device and support equipment, such as battery chargers.

  • May have dressing around site and needs to be changed every 24-48 hours

  • Educate when to change battery pack.