Pathophysiology part 5 paramedic

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Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Paramedic Care: Principles & Practice
Volume 1, 5e
Pathophysiology
Part 5

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Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Part 5
Disease at the Organ Level

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Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Disease at the Organ Level
• Genetic and Other Causes of Disease
– Inherited traits determined by deoxyribonucleic acid
(DNA).
– Inherit genetic structure from parents.
– Every one of person's somatic cells contains 46
chromosomes.
– Sex cells contain 23 chromosomes.
– 23 chromosomes from father; 23 chromosomes from
mother.

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Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Disease at the Organ Level
• Genetic and Other Causes of Disease
– Some diseases purely genetic.
– Multifactorial disorders: diseases caused by
combination of genetic and environmental factors.
– Clinical practitioners and epidemiologists study
disease.
 Effects on individuals
 Effects on populations

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Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Disease at the Organ Level
• Diseases Involving Genetic and Other Risk
Factors
– Immunologic disorders
– Cancer
– Endocrine disorders
– Hematologic disorders
– Cardiovascular disorders

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Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Disease at the Organ Level
• Diseases Involving Genetic and Other Risk
Factors
– Renal disorders
– Rheumatic disorders
– Gastrointestinal disorders
– Neuromuscular disorders
– Psychiatric disorders

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Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Disease at the Organ Level
• Hypoperfusion
– Hypoperfusion (shock): condition that is progressive
and fatal if not corrected.
– All forms of shock have same underlying
pathophysiology at cellular and tissue levels.
– Perfusion: constant, necessary passage of blood
through body's tissues.

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Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Disease at the Organ Level
• Hypoperfusion
– Inadequate perfusion of body tissues: hypoperfusion
(shock).
– Perfusion dependent on functioning and intact
circulatory system.
 The pump (heart)
 The fluid (blood)
 The container (blood vessels)

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Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Figure 12-83 Components of the circulatory system.

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Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Disease at the Organ Level
• Hypoperfusion
– Heart: pump of cardiovascular system.
– Factors affecting stroke volume:
 Preload
 Cardiac contractile force
 Afterload
– Preload: amount of blood delivered to heart during
diastole.

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Richard A. Cherry
Robert S. Porter
Disease at the Organ Level
• Hypoperfusion
– Preload affects cardiac contractile force.
– Greater volume of preload, the more ventricles
stretched.
– Catecholamines enhance cardiac contractile strength.
– Afterload: resistance against which ventricle must
contract.

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Richard A. Cherry
Robert S. Porter
Disease at the Organ Level
• Hypoperfusion
– Cardiac output: amount of blood pumped by heart in 1
minute.
– Stroke volume × heart rate = cardiac output.
– Blood pressure: dependent on cardiac output;
peripheral vascular resistance.
– Peripheral vascular resistance: pressure against which
heart must pump.

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Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Disease at the Organ Level
• Hypoperfusion
– Body strives to keep blood pressure constant by
compensatory mechanisms and negative feedback
loops.
– Blood: fluid of cardiovascular system; viscous fluid.
– Consists of plasma and formed elements (red cells,
white cells, platelets).

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Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Disease at the Organ Level
• Hypoperfusion
– Blood transports oxygen, carbon dioxide, nutrients,
hormones, metabolic waste products, heat.
– Adequate amount of blood required for perfusion.
– Natriuretic peptides (NPs): long-term regulation of
sodium and water balance, blood volume, arterial
pressure.

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Richard A. Cherry
Robert S. Porter
Disease at the Organ Level
• Hypoperfusion
– Atrial natriuretic peptide (ANP); brain natriuretic peptide
(BNP).
– Blood vessels (arteries, arterioles, capillaries, venules,
veins) serve as container of cardiovascular system.
– Blood flow through vessels regulated by peripheral
vascular resistance and pressure within system.

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Richard A. Cherry
Robert S. Porter
Disease at the Organ Level
• Hypoperfusion
– Oxygen brought into body via respiratory system.
– Oxygen from alveoli diffuses across alveolar-capillary
membrane and into bloodstream.
– Red blood cells "pick up" this oxygen.
– Oxygen-enriched blood then circulates back to heart.

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Richard A. Cherry
Robert S. Porter
Disease at the Organ Level
• Movement and Utilization of Oxygen (Fick
principle)
– Adequate inspired oxygen.
– Appropriate movement of oxygen across alveolar-
capillary membrane into arterial bloodstream.
– Adequate number of red blood cells.
– Proper tissue perfusion.
– Off-loading of oxygen at tissue level.

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Alveolar Gas Exchange Animation
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Richard A. Cherry
Robert S. Porter
Disease at the Organ Level
• Hypoperfusion
– Waste products of cellular metabolism carried away by
blood.
– Carbon dioxide leaves bloodstream during oxygen-
carbon dioxide exchange.
– Wastes expelled into lymphatic system.
– Wastes cleansed from blood by kidneys and excreted
as urine.

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Understanding ARDS Video
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Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Disease at the Organ Level
• The Pathophysiology of Hypoperfusion
– Inadequate pump
– Inadequate fluid
– Inadequate container
 Underlying causes: infection, trauma and hemorrhage, loss of
plasma through burns, severe cardiac arrhythmia, central
nervous system dysfunction.

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Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Disease at the Organ Level
• The Pathophysiology of Hypoperfusion
– Ultimate outcome of shock: impairment of cellular
metabolism.
– Cells not receiving enough oxygen or are unable to use
it effectively.
– Change from aerobic metabolism to anaerobic
metabolism.
– Primary energy source for cells: glucose.

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Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Disease at the Organ Level
• The Pathophysiology of Hypoperfusion
– Without oxygen, when glucose breakdown stops after
glycolysis, cellular stores of ATP used up much faster
than can be replaced; cellular metabolism gravely
impaired.
– Sodium-potassium pumping mechanism fails.
– Cell membrane ruptures; cellular death soon follows.

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Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Disease at the Organ Level
• The Pathophysiology of Hypoperfusion
– Same factors that reduce delivery of oxygen to cells
reduce delivery of glucose to cells.
– Glucose prevented from entering cells remains in blood
(hyperglycemia).
– Depletion of proteins in gluconeogenesis causes organ
failure.

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Education, Inc. All Rights Reserved.
Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Disease at the Organ Level
• The Pathophysiology of Hypoperfusion
– Impaired use of oxygen and glucose leads to cellular
death.
– Cellular death will lead to tissue death.
– Tissue death will lead to organ failure.
– Organ failure will lead to death of individual.

26. Copyright © 2017, 2013, 2009 Pearson
Education, Inc. All Rights Reserved.
Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Disease at the Organ Level
• The Pathophysiology of Hypoperfusion
– Compensation: in shock, fall in cardiac output, detected
as decrease in arterial blood pressure by
baroreceptors, activates body systems that attempt to
reestablish normal blood pressure.
– Renin-angiotensin system: aids body in maintaining
adequate blood pressure.

27. Copyright © 2017, 2013, 2009 Pearson
Education, Inc. All Rights Reserved.
Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Disease at the Organ Level
• The Pathophysiology of Hypoperfusion
– Compensated shock: to restore normal circulatory
volume; if excessive bleeding managed and shock
state has not progressed too far.
– Decompensated shock: if conditions causing shock too
serious, or progress too rapidly, compensatory
mechanisms may not be able to restore normal
function.

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Education, Inc. All Rights Reserved.
Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Disease at the Organ Level
• The Pathophysiology of Hypoperfusion
– Irreversible shock: shock state may progress to
condition where correction is no longer possible.
– Cardiac depression: critical factor in downward spiral of
decompensation.
– Depression of vasomotor center of brain: consequence
of reduced blood pressure.

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Education, Inc. All Rights Reserved.
Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Disease at the Organ Level
• The Pathophysiology of Hypoperfusion
– Metabolic wastes released into slower-flowing blood.
– Capillary cells suffer from lack of oxygen and nutrients,
and acidosis.
– Cellular deterioration progresses to tissue
deterioration, which progresses to organ failure.

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Richard A. Cherry
Robert S. Porter
Disease at the Organ Level
• Types of Shock
– Shock classified according to cause.
 Cardiogenic shock: inability of heart to pump enough blood to
supply all body parts.
 Usually result of severe left ventricular failure , acute
myocardial infarction or congestive heart failure.
 Presence of pulmonary edema, altered mentation, oliguria.

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Richard A. Cherry
Robert S. Porter
Disease at the Organ Level
• Types of Shock
– Hypovolemic shock: loss of intravascular fluid volume.
 Internal or external hemorrhage
 Traumatic injury; long bone or open fractures
 Severe dehydration
 Plasma loss from burns
 Excessive sweating
 Diabetic ketoacidosis

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Richard A. Cherry
Robert S. Porter
Disease at the Organ Level
• Types of Shock
– Hypovolemic shock:
 "Classic" signs of shock
 Mental status altered
 Skin becomes pale
 Blood pressure normal; then falls
 Pulse rapid, slowing and disappearing
 Urination decreases
 Cardiac arrhythmias may develop

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Richard A. Cherry
Robert S. Porter
Disease at the Organ Level
• Types of Shock
– Neurogenic shock: injury to brain or spinal cord.
– Cause of neurogenic shock: central nervous system
injury.
– Treatment same as for other types of shock: support of
airway, oxygenation, ventilation, maintenance of body
temperature, intravenous access.

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Disease at the Organ Level
• Types of Shock
– Anaphylactic shock: severe allergic response; occurs
very rapidly.
– Death can occur before patient can get to hospital;
prompt intervention critical.
– Signs and symptoms can affect: skin, respiratory,
cardiovascular, gastrointestinal, nervous systems.
– Treatment is pharmacological.

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Richard A. Cherry
Robert S. Porter
Disease at the Organ Level
• Types of Shock
– Septic shock: begins with septicemia (sepsis); infection
enters bloodstream and is carried throughout body.
– Dysfunction of more than one organ system (multiple
organ dysfunction syndrome).
– Signs and symptoms progressive; most susceptible:
lungs and respiratory system.

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Richard A. Cherry
Robert S. Porter
Disease at the Organ Level
• Multiple Organ Dysfunction Syndrome
– MODS: progressive impairment of two or more organ
systems resulting from uncontrolled inflammatory
response to severe illness or injury.
– Sepsis and septic shock most common causes.
– Any severe disease or injury that triggers massive
systemic inflammatory response.

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Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Disease at the Organ Level
• Multiple Organ Dysfunction Syndrome
– Primary MODS: organ damage results from specific
cause resulting from episode of shock, trauma, surgery.
– Secondary MODS: next time there is insult, primed
cells activated, producing exaggerated inflammatory
response.
– Inflammatory response enters self-perpetuating cycle.

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Richard A. Cherry
Robert S. Porter
Disease at the Organ Level
• Multiple Organ Dysfunction Syndrome
– Secondary insult triggers exaggerated neuroendocrine
response.
– As result of release of inflammatory mediators and
toxins and plasma protein cascades, a massive
immune/inflammatory and coagulation response
develops.

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Richard A. Cherry
Robert S. Porter
Disease at the Organ Level
• Multiple Organ Dysfunction Syndrome
– Effects of MODS at cellular and tissue levels cause
breakdown of organ systems.
– Does not occur in one intense crisis; develops over
weeks.
– No specific therapy.
– Early recognition; supportive measures.