Hemodynamics Fundamentals for Paramedics

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Questions and Answers

Which factor is NOT directly affected by drugs in relation to hemodynamics?

Blood Pressure Regulation (correct)

Skin Signs

Respiratory Rate

Heart Rate

What is the relationship between Cardiac Output and Heart Rate?

Heart Rate has no effect on Cardiac Output

Cardiac Output is inversely proportional to Heart Rate

Cardiac Output equals Heart Rate multiplied by Stroke Volume (correct)

Cardiac Output is dependent only on Stroke Volume

What term best describes the resistance the heart must overcome to eject blood?

Contractility

Preload

Stroke Volume

Afterload (correct)

Which statement about the Electrical System of the Heart is correct?

It is essential for coordinating heartbeats. Signup and view all the answers

Which of the following is a typical value range for Central Venous Pressure (CVP)?

0-8 mmHg Signup and view all the answers

Which treatment is indicated for elevated Afterload?

NTG (Nitroglycerin) Signup and view all the answers

What does the Mean Arterial Pressure (MAP) represent in hemodynamics?

The average blood pressure in a person's arteries during one cardiac cycle Signup and view all the answers

Which factor is NOT associated with decreased preload?

Fluid administration Signup and view all the answers

What is the normal range for Mean Arterial Pressure (MAP)?

70-110 mmHg Signup and view all the answers

What is the minimum MAP required to perfuse the kidneys?

55-65 mmHg Signup and view all the answers

Which factors significantly influence Mean Arterial Pressure (MAP)?

Cardiac output and stroke volume Signup and view all the answers

Which formula correctly calculates Mean Arterial Pressure (MAP)?

(Systolic + 2*Diastolic)/3 Signup and view all the answers

How long do the ventricles typically spend in diastole relative to systole?

One-third in systole and two-thirds in diastole Signup and view all the answers

What other pressure is MAP part of the calculation for?

Cerebral perfusion pressure Signup and view all the answers

Which condition could potentially indicate a problem with arterial wall compliance?

High Mean Arterial Pressure (MAP) Signup and view all the answers

In the context of MAP, which of the following medications would be used for low afterload?

Nitroglycerin Signup and view all the answers

What is the equivalent mmHg measurement for an inspiratory pressure of 15 cmH20?

11 mmHg Signup and view all the answers

Which medication class works primarily at the presynaptic receptors to inhibit catecholamine release?

Alpha-2 Receptors Signup and view all the answers

What effect do a1-receptors have on the kidneys?

Enhance sodium absorption Signup and view all the answers

Which hemodynamic function does the Renin-Angiotensin System (RAS) influence?

Regulates preload, afterload, and cardiac output Signup and view all the answers

What is the primary effect of Beta-1 receptors in the body?

Increase renin secretion Signup and view all the answers

Which type of medication is Digoxin classified as?

Digitalis Signup and view all the answers

What role do carotid bodies play in hemodynamic compensation?

Respond to changes in PaCO2 Signup and view all the answers

What is a common result of the activation of adrenergic receptors in the body?

Enhanced stress responses Signup and view all the answers

What is the primary goal of treatment aimed at increasing preload?

To improve cardiac output Signup and view all the answers

Which of the following treatments is recommended for low diastolic pressures?

Fluid boluses Signup and view all the answers

What is indicated if the systolic blood pressure does not change after a fluid challenge?

Consider more fluids Signup and view all the answers

Which diuretic is commonly used to treat high diastolic pressures?

Lasix Signup and view all the answers

What does the term 'contractility' refer to in cardiac physiology?

The ability of the myocardium to contract Signup and view all the answers

What role do chronotropic drugs play in cardiac function?

Affect heart rate and rhythm Signup and view all the answers

What is the significance of central venous pressure (CVP) in cardiac assessment?

Assessment of preload Signup and view all the answers

Which of the following is a potential treatment for rate control in dysrhythmias?

Pacemaker Signup and view all the answers

What is a primary function of β2-receptors in the lungs?

Relax smooth muscle in bronchi Signup and view all the answers

In which tissue are β3-receptors primarily located?

Adipose tissue Signup and view all the answers

Which treatment utilizes β2 receptor effects for asthma management?

Albuterol Signup and view all the answers

Which of the following interventions would decrease preload according to the hemodynamic overview?

Diuretics Signup and view all the answers

In terms of contractility, which substance is indicated for increasing cardiac contractility?

Dopamine Signup and view all the answers

Which of the following statements about hemodynamic profiles is accurate?

Increasing afterload decreases cardiac output. Signup and view all the answers

Which physiological role does renin play in the body?

Increase blood pressure Signup and view all the answers

Regarding cardiac electrical activity, which term best signifies the active phase of depolarization?

SAC Signup and view all the answers

What condition is indicated by a Central Venous Pressure (CVP) greater than 12 mmHg?

Fluid volume overload Signup and view all the answers

How does systemic vascular resistance (SVR) primarily affect blood pressure?

Through changes in vessel diameter Signup and view all the answers

What effect does a positive pressure ventilation over 15 cmH20 have on CVP?

It begins to impede venous return Signup and view all the answers

In what scenario would you typically observe a low SVR, specifically below 800 mmHg?

Hypotension Signup and view all the answers

Which of the following factors does NOT directly affect hemodynamics?

Patient age Signup and view all the answers

Which term is defined as the amount of blood the heart pumps per minute, taking body size into account?

Cardiac Index Signup and view all the answers

What role does afterload primarily play in the cardiovascular system?

It represents the pressure the heart must overcome to eject blood. Signup and view all the answers

Which of the following values represents normal Central Venous Pressure (CVP)?

0-8 mmHg Signup and view all the answers

Which factor is crucial for calculating Mean Arterial Pressure (MAP)?

Cardiac Output Signup and view all the answers

Which class of medication would be used to decrease elevated preload?

Diuretics Signup and view all the answers

What does the term 'contractility' primarily refer to in relation to cardiac physiology?

The heart’s ability to contract and generate force. Signup and view all the answers

What parameter does Stroke Volume represent?

Blood volume ejected by the heart with each beat Signup and view all the answers

Which factor could potentially decrease the heart rate during a hemodynamic assessment?

Vagal stimulation Signup and view all the answers

What physiological significance does the Mean Arterial Pressure (MAP) have in evaluating blood pressure?

It indicates the rate at which blood flows from major arteries into arterioles. Signup and view all the answers

Which of the following correctly describes the calculation for Mean Arterial Pressure?

(Diastolic x 2) + Systolic Signup and view all the answers

Which value range represents the normal Mean Arterial Pressure (MAP)?

70-110 mmHg Signup and view all the answers

How does the Mean Arterial Pressure (MAP) relate to cerebral perfusion pressure?

CPP is derived from MAP minus ICP. Signup and view all the answers

Which statement accurately describes arterial wall compliance in the context of Mean Arterial Pressure?

Ventricular systole and diastole significantly impact arterial compliance. Signup and view all the answers

What is the minimum Mean Arterial Pressure (MAP) required to ensure adequate kidney perfusion?

55-65 mmHg Signup and view all the answers

Which factors are considered when determining the clinical significance of MAP?

The average time spent by ventricles in systole versus diastole. Signup and view all the answers

Which medications are commonly used to manage high afterload in the context of MAP?

NTG and Nitroprusside Signup and view all the answers

What is the primary effect of diuretics in the treatment of high diastolic pressures?

Reduce pulmonary pressures Signup and view all the answers

How does a fluid challenge help in assessing a patient's hemodynamic status?

It assesses changes in systolic blood pressure in response to fluid administration. Signup and view all the answers

Which term best characterizes the electrical conduction response in the AV node?

Dromotropic Signup and view all the answers

What is the impact of chronotropic drugs on cardiac function?

Change the heart rate and rhythm Signup and view all the answers

In a scenario where a patient's systolic blood pressure does not rise after a fluid challenge, which steps should be considered next?

Reassess and find the source Signup and view all the answers

Which factor primarily affects the heart's contractility?

Inotropic effects Signup and view all the answers

Which of the following interventions would most effectively decrease preload?

Diuretics Signup and view all the answers

What is the main purpose of using a pacemaker in patients with dysrhythmias?

Control heart rhythm Signup and view all the answers

What primarily determines the contractility of the heart muscle?

Preload Signup and view all the answers

Which treatment is most appropriate for low systolic afterload?

Dopamine Signup and view all the answers

What physiological phenomenon affects preload the most?

Venous return Signup and view all the answers

Which of the following is an indicator of organ perfusion in paramedic assessments?

Urine Output Signup and view all the answers

What is the primary function of the Renin-Angiotensin Aldosterone System (RAAS) in the cardiovascular system?

Increase blood volume Signup and view all the answers

Which drug is primarily a vasodilator used for high systolic pressure?

Nipride Signup and view all the answers

What happens to cardiac output if the heart rate decreases significantly?

It decreases, unless stroke volume increases Signup and view all the answers

In the context of myocardial perfusion, what is the effect of afterload?

It increases systemic vascular resistance Signup and view all the answers

What measurement is affected by the resistance that the left ventricle must overcome during contraction?

Afterload Signup and view all the answers

What is the typical normal range for cardiac output in liters per minute?

5-6 Liters/min Signup and view all the answers

Study Notes

Hemodynamics Fundamentals

Essential for Paramedics; all medications impact hemodynamics.
Key parameters affected include heart rate (HR), respiratory rate (RR), skin signs, EKG, SpO2, and EtCO2.

Key Terms

Cardiac Output (CO): Volume of blood the heart pumps per minute.
Cardiac Index (CI): CO adjusted for body surface area.
Heart Rate (HR): Number of heartbeats per minute.
Preload: Pressure in the ventricles at the end of diastole.
Afterload: Resistance the heart must overcome to eject blood.
Contractility: Strength of heart muscle contractions.
Electrical System: Controls heart rhythm and contractions (ECG).

Mean Arterial Pressure (MAP)

Normal MAP range: 70-110 mmHg; minimum for kidney perfusion: 55-65 mmHg.
Key for assessing end-organ perfusion and arterial wall pressure.
MAP is calculated using the formula: (Diastolic x 2 + Systolic) / 3.

Clinical Significance of MAP

Reflects heart pumping efficiency into larger arteries.
Indicates blood flow to smaller arteries and arterioles.
Serves as a clinical evaluation tool for blood pressure and vascular compliance.

Factors Affecting Preload and Afterload

Elevated Afterload Treatment: NTG, Nitroprusside, Nicardipine, Hydralazine.
Decreased Afterload Treatment: Dopamine, Dobutamine, Epinephrine, Levophed.
Elevated Preload Treatment: NTG, Diuretics, medication to manage blood pressure.
Decreased Preload Treatment: Fluids, blood products in hemorrhagic shock.

Fluid Challenges

Administer isotonic fluid boluses (250ml, 500ml) to assess responsiveness.
Responders categorized as Rapid (SBP increase > 20 mmHg) or Transient (SBP increase within 2-5 minutes).

Contractility

Influenced by inotropic effects and the electrical system of the heart.
Contractility refers to the heart muscle's ability to contract effectively.

Drug Classifications

Chronotropic: Affects heart rate (e.g., Atropine, Epinephrine).
Dromotropic: Influences conduction speed (e.g., beta-blockers).
Inotropic: Modifies strength of muscle contractions (e.g., Dopamine).

Central Venous Pressure (CVP)

Measures preload; compared to pressures during BVM ventilation.
Range: 0-8 mmHg.

Hemodynamic Compensation Mechanisms

Kidneys: Regulate preload via urine output, initiate Renin-Angiotensin System (RAS).
Carotid Bodies: Detect changes in blood gas levels impacting cardiac output.
Baroreceptors: Respond to blood pressure changes.

Adrenergic Receptors' Role

Alpha (α) and Beta (β) receptors in stress response and hemodynamics.
α1-Receptors: Cause vasoconstriction and influence sodium absorption in kidneys (e.g., Phenylephrine).
β1-Receptors: Found in the heart and kidneys; increase renin secretion and affect cardiac output.
β2-Receptors: Present in lungs, relax smooth muscles, and influence insulin secretion.

Ejection Fraction

Normal ejection fraction: 60-70%, indicative of the heart's pumping efficiency.

Summary of Drug Effects on Hemodynamics

Utilization of medications like diuretics and vasodilators is critical for managing blood pressure and fluid balance.
Understanding the interconnection between heart function and vascular health is essential for effective patient management.

Hemodynamics Overview

Critical to understand hemodynamics as a Paramedic; influences from drugs on heart rate (HR), respiratory rate (RR), skin signs, EKG readings, SpO2, and EtCO2.
Key components: Pumps (heart), Pipes (vessels), Fluids (blood), and the Electrical System (ECG).

Important Terms

Cardiac Output (CO): Product of Heart Rate and Stroke Volume; normal range is 5-6 L/min.
Cardiac Index (CI): Cardiac output adjusted for body surface area.
Preload: Left ventricle diastolic pressures; influences filling time.
Afterload: Left ventricle systolic pressure against resistance; measured by systemic vascular resistance (SVR).
Contractility: Power of the cardiac muscle to contract; requires a functioning electrical system.

Mean Arterial Pressure (MAP)

Normal MAP: 70-110 mmHg; critical for organ perfusion.
Minimal MAP for kidneys: 55-65 mmHg to ensure perfusion.
MAP is a crucial indicator for evaluating blood pressure in relation to arterial wall health.

Blood Pressure and Resistance

MAP correlates with cardiac output and stroke volume.
High SVR indicates increased resistance; seen in hypertension.
Low SVR suggests low resistance; associated with hypotension.

Factors Impacting Heart Function

Stroke Volume: Determined by preload, afterload, and contractility; represents blood volume ejected from the left ventricle.
Afterload: Affected by vascular resistance and vessel diameter; controlled by the sympathetic nervous system and RAAS (Renin-Angiotensin-Aldosterone System).
Preload management: Treat low blood pressure with preload replacement before addressing afterload.

Treatment Strategies

Low Afterload: Utilize agents like Dopamine, Epinephrine, and Levophed to increase contractility and vascular tone.
High Afterload: Treat with Vasodilators (e.g., Nitroglycerin, Nipride) to reduce vascular resistance.
Low Preload: Administer fluids, blood, and medications to manage volume deficits.

CVP and SVR Measurements

Central Venous Pressure (CVP): Reflects preload and is influenced by thoracic/abdominal pressures and blood volume; high CVP indicates fluid overload.
Systemic Vascular Resistance (SVR): Measures afterload; higher values indicate increased vascular resistance.

Electrical System of the Heart

Elements influencing cardiac impulse: Chronotropic (rate), Dromotropic (conduction speed), and Inotropic (contractility) effects.
The functioning electrical system is essential for optimal muscle contraction and heart rhythm.

Patient Assessment Techniques

Monitor GCS, skin signs, blood pressure, and urine output to assess cardiac output and perfusion status.
Fluid challenges: Administer isotonic fluids and monitor for blood pressure response to gauge volume responsiveness.

Additional Influences on Hemodynamics

Factors like ventilation pressures, medications, hormones, electrolytes, kidney function, heart and peripheral vascular diseases impact hemodynamic stability.

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Description

This quiz covers essential hemodynamic concepts crucial for paramedics, including key terms and parameters that impact patient care. Topics include cardiac output, mean arterial pressure, and the overall significance of these measurements in assessing patient stability. Test your understanding of how medications and patient data affect hemodynamics.