Unit 5C: Advanced Cardiac Assessment & Hemodynamic Monitoring

Flashcards covering key concepts, definitions, and facts from the Advanced Cardiac Assessment and Hemodynamic Monitoring lecture notes for exam preparation.

Advanced Cardiac Assessment

Includes components related to a patient with invasive hemodynamic monitoring.

Hemodynamic Monitoring System

A system composed of an invasive catheter, noncompliant pressure tubing, a transducer and stopcocks, a flush system, and a bedside monitor.

Accurate Hemodynamic Pressure System Data

Ensured by proper leveling, zero referencing, and dynamic response testing (square wave test).

Altered Hemodynamic Values

Values that deviate from normal ranges, indicating clinical relevance for patient assessment and management.

Effects of Aging on Arterial Pressure

Increases, leading to systemic hypertension (HTN).

Effects of Aging on LV Hypertrophy

Increases with age.

Effects of Aging on Heart Rate (HR)

Decreases with age.

Right Atrium (RA) Pressure Normal Range

2-6 mm Hg.

Aorta Systolic Pressure Normal Range

100-130 mm Hg systolic.

Aorta Diastolic Pressure Normal Range

60-90 mm Hg diastolic.

Pulmonary Artery Systolic Pressure Normal Range

15-25 mm Hg systolic.

Pulmonary Artery Diastolic Pressure Normal Range

8-15 mm Hg diastolic.

Left Atrium Pressure Normal Range

8-12 mm Hg.

Left Ventricle Systolic Pressure Normal Range

110-130 mm Hg systolic.

Left Ventricle Diastolic Pressure Normal Range

8-12 mm Hg diastolic.

Right Ventricle Systolic Pressure Normal Range

15-25 mm Hg systolic.

Right Ventricle Diastolic Pressure Normal Range

0-8 mm Hg diastolic.

Pressure (Cardiovascular)

Force exerted on the liquid, measured in mm Hg.

Flow (Cardiovascular)

Amount of fluid moved over time, measured in L/min or mL/min.

Resistance (Cardiovascular)

Opposition to flow within the cardiovascular system.

Pressure-Flow-Resistance Relationship

Pressure = flow × resistance.

Cardiac Output (CO)

Volume of blood ejected from the heart per minute.

Cardiac Output Formula

CO = HR × Stroke volume.

Normal Cardiac Output Range

4 to 8 L/min.

Cardiac Index (CI)

Cardiac output adjusted for body surface area; normal range 2.5-4.2 L/min/m2.

Stroke Volume (SV)

Volume of blood ejected with each heartbeat; affected by preload, afterload, and contractility.

Ejection Fraction (EF)

Fraction of blood ejected with each beat; normal is 55% to 70%.

Preload

Volume coming into the ventricles (end-diastolic pressure), which stretches the muscle fibers before systole.

Afterload

Resistance the left ventricle must overcome to circulate blood.

Factors Increasing Preload

Hypervolemia, regurgitation of cardiac valves.

Factors Increasing Afterload

Hypertension, vasoconstriction (which increases cardiac workload).

Frank-Starling Law

Describes that increased volume leads to increased stretch, which in turn increases contractility, within physiological limits.

Central Venous Pressure (CVP) / Right Atrial Pressure (RAP) Normal Value

2-6 mm Hg (measures right heart preload).

Systemic Vascular Resistance (SVR) or Index (SVRI)

Force overcome by the left ventricle upon contraction.

Pulmonary Vascular Resistance (PVR)

Force overcome by the right ventricle upon contraction.

Contractility

Force of ventricular contraction, indicating how well the heart is pumping.

Noninvasive Hemodynamic Monitoring Methods

Noninvasive blood pressure (NIBP), assessment of jugular venous pressure, assessment of serum lactate levels.

Invasive Hemodynamic Monitoring Methods

Arterial pressure monitoring (A-line), Right atrial/central venous pressure monitoring (RAP/CVP), Pulmonary artery pressure monitoring (PAP).

Phlebostatic Axis

Fourth intercostal space, midaxillary line, approximating the level of the right atrium; used for leveling the transducer to ensure accuracy.

Zero Reference

Process of negating atmospheric pressure, achieved by leveling the zeroing stopcock at the phlebostatic axis and 'zeroing' the system.

Dynamic Response Testing (Square Wave Test)

Method used to assess the accuracy and responsiveness of the hemodynamic monitoring system.

Arterial Line (A-line)

An invasive technique to monitor arterial blood pressure.

Allen's Test

Performed prior to radial artery A-line insertion to verify collateral circulation.

Indications for Arterial Line

Hemodynamic instability, assessment of vasoactive medication efficacy, frequent BP monitoring, frequent ABG analysis.

Arterial Line Nursing Responsibilities

Level, zero, waveform test; neurovascular checks every 2 hours; neutral position of extremity; assess waveform/cuff correlation; hold pressure for 5 minutes when discontinuing; NO medications via A-line; alarms on at all times; check connections.

Common Arterial Line Complications

Thrombosis, embolism, blood loss, infection.

Pressure Bag Requirement for A-line

Maintained at 300 mm Hg to overcome arterial pressure and provide continuous flush.

Arterial Pressure Tracing Dicrotic Notch

Represents aortic valve closure on the arterial pressure waveform.

Right Atrial Pressure (RAP)

Pressure measured with a catheter in the right atrium (e.g., proximal port of a PA catheter).

Central Venous Pressure (CVP)

Pressure measured with a catheter in the superior or inferior vena cava (e.g., triple lumen catheter).

Right Ventricular (RV) Preload / Right Ventricular End Diastolic Pressure (RVEDP)

Directly measured by RAP/CVP, reflecting the volume in the right ventricle prior to contraction.

Indications for CVP Monitoring

Measure right heart filling pressure, estimate fluid status, guide volume resuscitation, assess ScvO2, administer large volume fluid resuscitation or irritant medications, access for transvenous pacemaker.

Pulmonary Artery Catheter (PAC)

An invasive catheter (also known as a Swan-Ganz catheter) that reflects left ventricular function.

PAC Features

Balloon-tipped, multiple lumens, flow-directed, can have SvO2 monitoring and continuous cardiac output (CCO) capabilities.

Indications for PAC Monitoring

Identify and treat cause of hemodynamic instability, assess PAPs, assess SvO2, directly measure CO.

Thermodilution Cardiac Output (TdCO)

A method of cardiac output measurement using injectate volume and temperature changes.

Continuous Cardiac Output (CCO)

A method of continuous cardiac output monitoring using a specialized PAC with a copper filament, accurate with HOB up to 45 degrees.

Cardiac Index (CI) Calculation

Calculated value (CO ÷ body surface area) which provides a better assessment of cardiac function adjusted for body size.

SvO2 (Mixed Venous Oxygen Saturation)

Calculated value obtained via specialized PAC, reflecting the balance between oxygen supply and demand at the tissue level.

ScvO2 (Central Venous Oxygen Saturation)

Calculated value obtained via specialized central line, reflecting oxygen saturation in the central venous blood.

Normal SvO2 Range

60%-75%, indicating adequate balance between oxygen supply and demand.

Normal ScvO2 Range

65%-85%, indicating adequate balance between oxygen supply and demand.

High SvO2/ScvO2 Values

Indicate that tissues are unable to use oxygen effectively (demand is less than supply or impaired utilization).

Low SvO2/ScvO2 Values

Indicate that oxygen demand exceeds delivery (tissues are extracting more oxygen due to insufficient supply).

Causes of Decreased SvO2 (Decreased Delivery)

Hypoxia, hemorrhage, anemia, cardiogenic shock, dysrhythmias, heart failure, tamponade, transfusions of stored blood, VQ abnormalities.

Causes of Decreased SvO2 (Increased Consumption)

Strenuous activity, fever, pain, anxiety or stress, hormonal imbalances, increased work of breathing, septic shock, shivering, seizures.

Causes of Increased SvO2 (Increased Delivery)

Increased FiO2, hyperoxygenation, shunt.

Causes of Increased SvO2 (Decreased Consumption)

Hypothermia, anesthesia, hypothyroidism, neuromuscular blockers (NMB), early sepsis.

Afterload Reducers

Medications that decrease the resistance the left ventricle must overcome to circulate blood (e.g., Nitrates, ACE-Inhibitors, Vasodilators, Beta Blockers).

Nitrates (e.g., Nitroglycerine, Sodium Nitroprusside)

A class of afterload reducers.

ACE-Inhibitors (e.g., Enalapril)

A class of afterload reducers.

Vasodilators (e.g., Hydralazine)

A class of afterload reducers.

Beta Blockers (e.g., Labetalol, Esmolol)

A class of afterload reducers.

Vasopressors/Vasoconstrictors

Medications that increase systemic vascular resistance and blood pressure (e.g., Vasopressin, Epinephrine, Phenylephrine, Norepinephrine, Dopamine).

Positive Inotropes

Medications that increase the force of myocardial contraction (e.g., Dobutamine, Digoxin).