Hemodynamics & Critical Care Nursing

Flashcards covering key concepts in hemodynamics, invasive and non-invasive monitoring, various types of shock and their management, pharmacologic interventions, and essential nursing considerations in critical care settings. These questions and answers are designed to test understanding of definitions, physiological processes, and nursing interventions related to blood flow, circulation, and perfusion.

What does hemodynamics refer to?

Blood flow, circulation, and perfusion.

What are the key concepts in hemodynamics?

Preload, afterload, contractility, cardiac output, and systemic vascular resistance.

What is preload?

The volume of blood in ventricles at the end of diastole (end diastolic pressure).

What factors can increase preload?

Hypervolemia, regurgitation of cardiac valves, and heart failure.

What is afterload?

The resistance the left ventricle must overcome to circulate blood.

What factors can increase afterload?

Hypertension and vasoconstriction.

What is the effect of increased afterload on the heart?

Increased cardiac workload.

How is Cardiac Output (CO) calculated?

Stroke Volume (SV) x Heart Rate (HR).

What factors affect Stroke Volume (SV)?

Preload, afterload, and contractility.

What is the formula for Mean Arterial Pressure (MAP)?

[(2 x Diastolic) + Systolic] / 3.

What MAP is required for adequate organ perfusion?

At least 65 mmHg.

What does an arterial line provide in hemodynamic monitoring?

Continuous blood pressure monitoring and arterial blood gas sampling.

What do Pulmonary Artery Catheters (Swan-Ganz) measure?

Pulmonary artery pressures, cardiac output, and preload.

What does a Central Venous Catheter (CVC) measure?

Central venous pressure (CVP), assessing fluid volume status and right heart function.

What are key nursing safety and care considerations for an arterial line?

Ensure proper securement, maintain continuous pressure monitoring, use aseptic technique, regularly assess distal circulation/capillary refill, and calibrate/zero the transducer at the phlebostatic axis.

What initial steps are crucial before inserting a pulmonary artery catheter?

Prime the catheter, ensure it is absent of air, and ensure the system has been properly zeroed.

What should be monitored during the placement of a pulmonary artery catheter?

The patient's monitor for dysrhythmias and appropriate waveforms as the catheter passes through cardiac chambers.

What are the normal values for Right Atrial Pressure (RAP)?

0-6 mmHg.

What are the normal values for Pulmonary Artery Pressure (PAP)?

15-25 mmHg systolic, 8-10 mmHg diastolic (mean 10-20 mmHg).

What are the normal values for Pulmonary Capillary Wedge Pressure (PCWP)?

8-12 mmHg.

What might increased pulmonary artery catheter readings indicate?

Heart failure.

What might decreased pulmonary artery catheter readings indicate?

Hypovolemia.

What is Central Venous Pressure (CVP)?

Pressure within the Superior Vena Cava/Right Atrium.

What are the normal CVP values?

3-8 mmHg.

How is the transducer zeroed for CVP monitoring?

At the mid-axillary line, 4th intercostal space (right atrium).

When should CVP readings be documented for a patient on a ventilator?

At end-expiration.

Which non-invasive method evaluates cardiac function, preload, and contractility?

Echocardiography.

Which non-invasive method assesses blood flow velocity and cardiac output?

Doppler ultrasound.

What is shock?

The inability of the circulatory system to deliver adequate oxygen and nutrients to tissues.

What are the hemodynamic characteristics of hypovolemic shock?

Decreased preload, low cardiac output, high systemic vascular resistance.

What are the hemodynamic characteristics of cardiogenic shock?

Low cardiac output, high preload, high systemic vascular resistance.

What are the hemodynamic characteristics of distributive shock?

Low systemic vascular resistance, variable cardiac output.

What are common causes of hypovolemic shock?

Hemorrhage, dehydration, burns, or third-spacing.

What are key clinical signs of hypovolemic shock?

Tachycardia, hypotension, low central venous pressure, and cold, clammy skin.

What is a primary nursing intervention for hypovolemic shock?

Rapid fluid resuscitation with crystalloids and blood products.

What typically causes cardiogenic shock?

Myocardial infarction, heart failure, or severe arrhythmias.

What are key clinical signs of cardiogenic shock?

Hypotension, pulmonary edema, jugular vein distention, and weak peripheral pulses.

What is included in the management of cardiogenic shock?

Inotropic support (e.g., dobutamine), diuretics, vasodilators, and possible mechanical circulatory support.

What causes septic shock?

Systemic infection and inflammation leading to profound vasodilation.

What are the early signs of septic shock?

Warm skin, tachycardia, and low blood pressure.

What are the late signs of septic shock?

Cold extremities and multi-organ dysfunction.

What is the treatment for septic shock?

Aggressive fluid resuscitation, vasopressors, and early antibiotic therapy.

What typically causes neurogenic shock?

Spinal cord injury.

What are the primary signs of neurogenic shock?

Hypotension and bradycardia.

What typically causes anaphylactic shock?

A severe allergic reaction.

What is the general management for neurogenic and anaphylactic shock?

Vasopressors, epinephrine, fluid resuscitation, and airway support.

What is the action of vasopressors (e.g., norepinephrine, dopamine, phenylephrine) in hemodynamic management?

Increase blood pressure by vasoconstriction.

What is the action of inotropes (e.g., dobutamine, milrinone) in hemodynamic management?

Enhance myocardial contractility.

What is the action of vasodilators (e.g., nitroglycerin, nitroprusside) in hemodynamic management?

Reduce preload and afterload.

What are important nursing considerations when administering vasopressors?

Titrate carefully based on blood pressure/perfusion status, administer via central line to prevent extravasation, and monitor for signs of excessive vasoconstriction.

How does heart failure affect hemodynamics?

It leads to elevated central venous pressure and low cardiac output.

How does pulmonary hypertension affect hemodynamics?

It results in high pulmonary artery pressures and right heart strain.

How does sepsis affect hemodynamics?

It causes widespread vasodilation, fluid shifts, and an increased risk of multi-organ failure.

What are key nursing management actions for hemodynamic instability?

Monitor vital signs, perfusion status, and urine output; optimize oxygen delivery; ensure adequate fluid resuscitation; and adjust medication therapy.

How can Positive End-Expiratory Pressure (PEEP) affect cardiac output during mechanical ventilation?

It can reduce cardiac output by increasing intrathoracic pressure.

How can high tidal volumes during mechanical ventilation affect hemodynamics?

They may decrease venous return and cause hypotension.

What are nursing priorities when managing hemodynamics?

Assess for inadequate perfusion, initiate fluid resuscitation early in shock states, titrate vasopressors as needed, and ensure oxygenation/mechanical ventilation support.

What critical finding related to a pulmonary artery catheter requires immediate nursing action?

A sudden flattening of the pulmonary artery waveform, indicating a potential issue like dislodgement or malfunction.

To ensure accurate arterial blood pressure readings, where should the transducer be positioned?

At the level of the phlebostatic axis.

In a patient with cardiogenic shock, low MAP, low CO, and low CVP while on norepinephrine, what intervention might be prioritized to address potential hypovolemia?

Administering a fluid bolus (e.g., 500 mL normal saline).

Why is understanding hemodynamics essential in critical care?

For comprehending circulatory stability and organ perfusion.

What is the impact of early intervention in shock states?

It significantly improves patient outcomes.

What is a crucial role of nurses regarding hemodynamic changes?

To recognize changes and implement timely interventions.