Chapter 5

(1)

Emergency Medical Responder

First on Scene

CHAPTER

TENTH EDITION

Introduction to

Pathophysiology

(2)

Objectives

1. Define the following terms

a.

Aerobic metabolism

b.

Anaerobic metabolism

c.

Cardiac output

d.

Cell membrane

e.

Cell nucleus

f.

Dead air space

g.

Dehydration

h.

DNA

(3)

Objectives

1. Define the following terms

i.

Edema

j.

Electrolytes

k.

Metabolism

l.

Patent

m.

Pathophysiology

n.

Perfusion

o.

Stroke volume

p.

Tidal volume

(4)

Objectives

2. Explain the importance of

understanding basic pathophysiology.

3. Differentiate between the processes of

aerobic and anaerobic cellular

metabolism.

4. Explain the concept of perfusion,

including the components necessary to

maintain perfusion.

(5)

Objectives

5. Describe the composition of ambient

air.

6. Explain how changes in respiratory

system function can affect ventilation.

7. Describe the transport of oxygen and

carbon dioxide in the blood.

8. Discuss factors that affect cardiac

output.

(6)

Objectives

9. Describe the two ways the heart can

fail resulting in decreased cardiac

output.

10. Model a desire for Continuous Quality

Improvement (CQI) both personally

and professionally.

11. Value the importance of quality

(7)

Topics

Pathophysiology

(8)

(9)

Pathophysiology

• Pathophysiology



The study of how disease processes

affect the body



Allows for better identification of certain

(10)

Pathophysiology

• The Cell



Basic unit of the human body

• All organs and systems



Cell membrane

• Outer protective layer of cell

• Controls movement in and out of cell

• Disease processes can alter

effectiveness.

(11)

Pathophysiology

• The Cell



Nucleus

• DNA



Glucose is a basic nutrient for cell.

• Converts to energy through metabolism

(12)

Pathophysiology

• The Cell



Water

• Membrane regulates movement in and

out.

• Cells dry and die without enough water.

• Cellular function is interrupted with too

much water.

• Influences the concentrations of

electrolytes

(13)

Pathophysiology

• The Cell



Oxygen

• Fuels metabolism

• _{Aerobic metabolism}

-

Normal glucose metabolism using oxygen

-

Carbon dioxide is a byproduct.

(14)

Pathophysiology

• The Cell



Oxygen

• Fuels metabolism

• _{Anaerobic metabolism}

-

Abnormal glucose metabolism without

oxygen

-

Creates increased byproducts of carbon

dioxide and lactic acid

(15)

Figure 5.1a

Aerobic metabolism requires an adequate supply of glucose and oxygen.

(16)

(17)

Pathophysiology

• Fluid Balance



The body is 60% water.



Balance is necessary for proper cellular

function.

(18)

Pathophysiology

• Fluid Balance



Body adjusts fluid levels through intake

and elimination of fluids.

• Drinking fluids

• Sweating

• Breathing

• Urination

(19)

Pathophysiology

• Disruption of Fluid Balance



Dehydration

• Not enough fluid intake

• Excessive fluid elimination

• Vomiting and diarrhea

(20)

Pathophysiology

• Disruption of Fluid Balance



Edema or swelling

• Fluid trapped in the body's tissues from

illness

• Hands, legs and feet

• Injury

(21)

Think About It

• A patient's fluid balance can easily be

assessed externally.



_{Dry mucous membranes, sunken eyes,}

tachycardia, and low blood pressure can

indicate dehydration.



Edema in the ankles and feet can give

(22)

(23)

The Cardiopulmonary System

• Cardiopulmonary System



Cardiovascular and respiratory systems

work together.

• Respiratory system

• _{Transfers oxygen to the bloodstream}

• Cardiovascular system

• _{Transports oxygen to the body's cells}

• _{Brings carbon dioxide back to the lungs for}

(24)

The Cardiopulmonary System

• Respiratory System



Structures

• Airway

• Lungs

• Muscles of respiration

(25)

The Cardiopulmonary System

• Respiratory System



Airway

• Movement of air in and out of the chest

requires a patent airway.

• Upper airway obstructions

• Obstructions above the trachea prevent air

from reaching the lower airway.

-

Altered mental status

-

Foreign bodies

-

Trauma

(26)

The Cardiopulmonary System

• Respiratory System



Airway

• Lower airway complications

• _{Bronchoconstriction increases airway}

resistance and decreases amounts of air

that reaches the alveoli.

(27)

(28)

The Cardiopulmonary System

• Respiratory System



Lungs

• Diaphragm and chest wall responsible for

pressure changes that stimulate

breathing

• Tidal volume

• _{Air moved in and out in one breath}

(29)

The Cardiopulmonary System

• Respiratory System



Lungs

• Dead air space

• _{Air remaining in the space between the}

mouth and alveoli

-

About 150mL

(30)

The Cardiopulmonary System

• Respiratory System Dysfunction



Disruption of respiratory control

• Damage to the medulla oblongata

• _Stroke

• _{Brain tumors}

• _Infection

• Toxins and drugs

• Spinal cord injuries and diseases

(31)

The Cardiopulmonary System

• Respiratory System Dysfunction



Disruption of pressure

• Chest cavity is a closed container.

• Diaphragm, ribs and intercostal muscles

change the size of the cavity.

(32)

The Cardiopulmonary System

• Respiratory System Dysfunction



Disruption of pressure

• Lungs are attached to the chest with two

membranes.

• Parietal pleura on the chest wall

• Visceral pleura on the lung

• _{Pleural space}

-

May accumulate blood and air

(33)

The Cardiopulmonary System

• Respiratory System Dysfunction



Disruption of pressure

• Expanded chest cavity creates negative

pressure and lets air in.

• _{Relaxed chest cavity creates positive}

pressure and forces air out.

• Hole in the chest wall affects the changes

in pressure.

• Blood or air in the pleural space creates a

hemothorax or a pneumothorax.

(34)

The Cardiopulmonary System

• Respiratory System Dysfunction



Disruption of lung tissue.

• Damage to lung tissue reduces ability for

gas exchange.

• Trauma

• Pneumonia

• _Infection

• _{Reduced oxygen levels and increased}

(35)

The Cardiopulmonary System

• Respiratory System Compensation



Brain monitors carbon dioxide levels in

blood.

(36)

The Cardiopulmonary System

• Cardiovascular System



Blood

• Transport system of the body

• Insufficient quantity leads to poor

circulation.

(37)

The Cardiopulmonary System

• Cardiovascular System



Blood vessels are pathways.

• Arteries

• _{Carries oxygenated blood away from the}

heart

• Veins

• Carries deoxygenated blood to the heart

(38)

The Cardiopulmonary System

• Cardiovascular System



Blood vessels are pathways.

• Arterioles

• _{Feeds oxygenated blood to the capillaries}

• Capillaries

• Offloads oxygen and picks up carbon

dioxide

(39)

The Cardiopulmonary System

• Cardiovascular System



Blood vessels are pathways.

• Pulmonary arteries

• _{Carries deoxygenated blood from the}

heart to the lungs

• Pulmonary veins

• Carries oxygenated blood from the lungs

to the heart

(40)

The Cardiopulmonary System

• Cardiovascular System



Blood pressure

• Created by the beating heart to move

blood around the body

(41)

The Cardiopulmonary System

• Cardiovascular System



Blood pressure

• Diameter of blood vessels and volume of

blood directly affects amount of pressure.

• Dilated vessels and blood loss decreases

pressure.

-

Hypotensive

(42)

The Cardiopulmonary System

• Cardiovascular System



Blood pressure

• Diameter of blood vessels and volume of

blood directly affects amount of pressure.

• Constricted vessels or increased fluid in

the blood increases pressure.

-

Hypertensive

(43)

The Cardiopulmonary System

• Cardiovascular System



Heart

• 4 chambered pump designed to move

blood

• Stroke volume

• Volume of blood ejected from the heart in

one contraction

(44)

The Cardiopulmonary System

• Cardiovascular System



Heart

• Cardiac output

• _{Amount of blood ejected from the heart in}

one minute

• _{Increased heart rate leads to increased}

CO.

• If rate is too fast, output actually

decreases.

-

>180 bpm in adults

(45)

The Cardiopulmonary System

• Cardiovascular System



Heart

• Cardiac output

• _{Autonomic nervous system response}

adjusts cardiac output.

-

Sympathetic "fight or flight" response

-

Parasympathetic response

(46)

The Cardiopulmonary System

• Cardiovascular System



Heart failure

• Electrical failure

• Tachycardia

• Bradycardia

• Ventricular fibrillation

• Mechanical failure

• _Trauma

• _{Squeezing of the heart muscle}

(47)

Think About It

• The best way to assess a patient's tidal

volume is to watch the chest rise and

fall while counting the ventilations per

minute.

• Hypoxia leads to cell death.



Getting your patient on oxygen can

delay the change to anaerobic

metabolism.

(48)

Think About It

• Low blood pressure can lead to hypoxia

(49)

(50)

Hypoperfusion and Shock

• Perfusion



Delivery of oxygen and nutrients and

removal of waste to every cell and

organ

(51)

Hypoperfusion and Shock

• Perfusion



All components of the cardiopulmonary

system must be functioning.

• Oxygen delivered all the way to the

alveoli and carbon dioxide transported all

the way out

• Enough available blood, a functioning

(52)

Hypoperfusion and Shock

• Hypoperfusion and Shock



Shock occurs when perfusion fails.

• Hypoperfusion



Cells become hypoxic without perfusion

of adequate oxygen.

• Switch to anaerobic metabolism

• Lactic acid and waste products build up.

• Cells eventually die.

(53)

Hypoperfusion and Shock

• Compensation



Sympathetic nervous system compensates

for hypoperfusion.

• Vessels constrict.

• Heart rate increases.

• _{Pupils dilate.}

• Skin sweats.

• Brain responds to increased levels of carbon

dioxide.

(54)

Hypoperfusion and Shock

• Pediatric Compensation



One of the leading causes of death in

pediatric patients.



Children compensate differently than

adults.



Increased heart rate is the main

mechanism.

(55)

Hypoperfusion and Shock

• Pediatric Compensation



Vasoconstriction allows them to

maintain blood pressure with significant

volume loss.

• Blood pressure is an unreliable factor

during assessment.



Higher metabolism rates burn off

(56)

Think About It

• Recognizing compensation is an

important element in the assessment of

a patient because it can rapidly identify

the patient in shock.

• EMRs should always be on the lookout

for telltale signs of shock such as

increased heart rate, decreased blood

pressure, and abnormal respiratory

(57)

(58)

Summary

• Understanding pathophysiology helps

you understand the basic and most

important functions of the body and

their critical dysfunctions.

• Delicate balance of fluid in the body



Levels must be appropriate in the major

spaces and balanced constantly to

maintain life.

(59)

Summary

• Aerobic metabolism



The normal way the body converts

glucose into energy

• Anaerobic metabolism



Not as efficient, and it creates

significantly more waste product

(60)

Summary

• Perfusion



Combined function of the respiratory

and cardiovascular systems.



All functions needed to order to deliver

oxygenated blood to the cells

• Oxygen is introduced into the body

from the ambient air.



Respiratory system moves air in and out

of the lungs.

(61)

Summary

• Inspired air pairs with circulating blood

for perfusion.



_{Appropriate quantities ensure adequate}

delivery of oxygen to the cells.

(62)

Summary

• The cardiovascular system



Transport mechanism for oxygen,

carbon dioxide, and nutrients for the

cells



Requires the presence of appropriate

elements of blood, pressure within the

system, and a functioning pump

(63)

Summary

• Cellular metabolism



Relies upon a constant supply of glucose

and oxygen

• Normal metabolism relies upon perfusion

and the successful operation of the

(64)

(65)

Review Questions

1. How is the process of aerobic

metabolism different from the process

of anaerobic metabolism?

2. What is perfusion and what are the

components necessary to maintain it?

3. How do changes in respiratory function

affect ventilation?

(66)

Review Questions

4. How are oxygen and carbon dioxide

transported in the blood?

5. What are the factors that affect

cardiac output?

(67)

Review Questions

6. What are the two ways the heart can

fail and result in decreased cardiac

output?

7. What are the responses by the body

(68)

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