chapter four

Division 1Introduction to AdvancedPrehospital Care : Division 1Introduction to AdvancedPrehospital Care

Chapter 4General Principles of PathophysiologyPart I How Normal Body Processes Are Altered by Disease and Injury : Chapter 4General Principles of PathophysiologyPart I How Normal Body Processes Are Altered by Disease and Injury

Topics : Topics Disease Risk Hypoperfusion Shock Multiple Organ Dysfunction Syndrome

Pathophysiology : Pathophysiology The study of how diseases alter the normal physiological processes of the human body From the root “patho” meaning disease

How Cells Respond to Change and Injury : How Cells Respond to Change and Injury

Cellular Adaptation : Cellular Adaptation Cells, tissues, organs, and organ systems can adapt to both normal and injurious conditions. Adaptation to external stressors results in alteration of structure and function. Examples: Growth of the uterus during pregnancy, dilation of the left ventricle after an MI.

Types of Cellular Adaptations(1 of 2) : Types of Cellular Adaptations(1 of 2) Atrophy Decreased size resulting from a decreased workload Hypertrophy An increase in cell size resulting from an increased workload

Types of Cellular Adaptations(2 of 2) : Types of Cellular Adaptations(2 of 2) Hyperplasia An increase in the number of cells resulting from an increased workload Metaplasia Replacement of one type of cell by another type of cell that is not normal for that tissue Dysplasia A change in cell size, shape, or appearance caused by an external stressor

Cellular Injury : Cellular Injury Hypoxic Chemical Infectious Immunologic/Inflammatory Physical agents Nutritional balances Genetic factors

Manifestation of Cellular Injury : Manifestation of Cellular Injury When cells are injured metabolism is changed, causing substances to infiltrate or accumulate to an abnormal degree in cells.

Cellular Swelling : Cellular Swelling Results from a permeable or damaged cellular membrane Caused by an inability to maintain stable intra- and extracellular fluid and electrolyte levels

Fatty Change : Fatty Change Lipids invade the area of injury. Occurs most commonly in vascular organs, most frequently the liver. Causes a disruption of the cellular membrane and metabolism and interferes with the vital functions of the organ.

Signs and Symptoms of Cellular Change : Signs and Symptoms of Cellular Change Fatigue and malaise Altered appetite Fever Increased heart rate associated with fever Pain

Cell Death (1 of 3) : Cell Death (1 of 3) Apoptosis Injured cell releases enzymes that engulf and destroy the cell. Cells shrink. Eliminating damaged and dead cells allows tissues to repair and possibly regenerate.

Cell Death (2 of 3) : Cell Death (2 of 3) Necrosis A pathological process Cells swell and rupture Coagulative Liquefactive Caseous Fatty

Cell Death (3 of 3) : Cell Death (3 of 3) Gangrenous necrosis Cell death over a wide area Dry Wet Gas

Fluids and Fluid Imbalances : Fluids and Fluid Imbalances

Slide 18 : Water is the most abundant substance in the human body.

Where the Water Is Found : Where the Water Is Found Intracellular fluid—fluid inside the cells Extracellular fluid—all the fluid outside the body cells Intravascular fluid—fluid within the circulatory system Interstitial fluid—fluid outside of the cell membranes but not within the circulatory system

Edema : Edema Accumulation of water in the interstitial space due to disruption in the forces and mechanisms that normally keep net filtration at zero

Mechanisms That Cause Edema : Mechanisms That Cause Edema A decrease in plasma oncotic force An increase in hydrostatic pressure Increased capillary permeability Lymphatic channel obstruction

Edema (1 of 2) : Edema (1 of 2) Can be local or within a certain organ system Sprained ankle vs. pulmonary edema

Edema (2 of 2) : Edema (2 of 2) Water in interstitial spaces is not available for metabolic processes. Edema, therefore, can cause a relative condition of dehydration.

Intravenous Therapy : Intravenous Therapy

Slide 25 : Blood Components

Slide 26 : The percentage of the blood occupied by the red blood cells is termed the hematocrit.

Fluid Replacement : Fluid Replacement

Slide 28 : Transfusion reactions occur when there is a discrepancy between the blood type of the patient and the type of the blood being transfused. Transfusion Reactions

Signs and Symptoms of Transfusion Reactions : Signs and Symptoms of Transfusion Reactions Fever Chills Hives Hypotension Palpitations Tachycardia Flushing of the skin Headache Loss ofconsciousness Nausea Vomiting Shortness of breath

Treatment of Transfusion Reactions (1 of 2) : Treatment of Transfusion Reactions (1 of 2) IMMEDIATELY stop the transfusion. Save the substance being transfused. Rapid IV infusion.

Treatment of Transfusion Reactions (2 of 2) : Treatment of Transfusion Reactions (2 of 2) Assess the patient’s mental status. Administer oxygen. Contact medical direction. Be prepared to administer mannitol, diphenhydramine, or furosemide.

Intravenous Fluids : Intravenous Fluids

Hemoglobin-Based Oxygen-Carrying Solutions (HBOCs) : Hemoglobin-Based Oxygen-Carrying Solutions (HBOCs) Commonly referred to as “blood substitutes” Compatible with all blood types Do not require blood typing, testing, or cross-matching PolyHeme Hemopure

Colloids : Colloids Colloids remain in intravascular spaces for an extended period of time and have oncotic force. Plasma protein fraction (Plasmanate) Salt-poor albumin Dextran Hetastarch (Hespan)

Crystalloids : Crystalloids Crystalloid solutions are the primary compounds used in prehospital care. Isotonic solutions Hypertonic solutions Hypotonic solutions

Slide 36 : The effects of hypertonic, isotonic, and hypotonic solutions on red blood cells

Most Commonly Used Solutions in Prehospital Care : Most Commonly Used Solutions in Prehospital Care

Acid-Base Derangements : Acid-Base Derangements

Respiratory Acidosis : Caused by abnormal retention of CO2 from impaired ventilation due to problems occurring in the lungs or respiratory center of the brain. Respiratory Acidosis

Respiratory Alkalosis : Caused by increased respiration and excessive elimination of CO2. The CO2 level is decreased and the pH is increased. Respiratory Alkalosis

Metabolic Acidosis : Results from the production of metabolic acids such as lactic acid. These acids consume bicarbonate ions. Can be the result of dehydration, diabetes, or medication usage. Metabolic Acidosis

Slide 42 : Compensation for metabolic acidosis begins with an increase in respirations.

Metabolic Alkalosis : Metabolic Alkalosis The pH is increased and the CO2 level is normal. It is usually caused by administration of diuretics, loss of chloride ions associated with prolonged vomiting, and overzealous administration of sodium bicarbonate.

Slide 44 : Genetics and Other Causes of Disease

Many Factors Combine to Cause Disease (1 of 3) : Many Factors Combine to Cause Disease (1 of 3) Genetics Environment Lifestyle Age Gender

Many Factors Combine to Cause Disease (2 of 3) : Many Factors Combine to Cause Disease (2 of 3) Inherited traits are determined by molecules of deoxyribonucleic acid (DNA). Each somatic cell contains 46 chromosomes. Sex cells contain 23 chromosomes.

Many Factors Combine to Cause Disease (3 of 3) : Many Factors Combine to Cause Disease (3 of 3) An offspring receives 23 chromosomes from the mother and 23 chromosomes from the father. One or more chromosomes may be abnormal and may cause a congenital disease or a propensity toward acquiring a disease later in life.

Slide 48 : Most disease processes are multifactorial in origin.

Disease Effects on Individuals : Disease Effects on Individuals Host Agent Environment

Disease Effects on Populations : Disease Effects on Populations Incidence Prevalence Mortality

Family History and Associated Risk Factors : Family History and Associated Risk Factors

Immunologic Disorders : Immunologic Disorders A number of immunologic disorders are more prevalent among those with a family history of the disorder.

Cancer : Cancer Some types of cancer tend to cluster in families and seem to have a combination of genetic and environmental causes. Breast cancer Colorectal cancer

Endocrine Disorders : Endocrine Disorders The most common endocrine disorder is diabetes mellitus. Leading cause of: Blindness Heart disease Kidney failure Premature death Both Type I and Type II diabetes can be family related.

Hematological Disorders : Hematological Disorders There are many causes of hereditary hematological disorders such as gene alteration and histocompatibility (tissue interaction) dysfunctions. Hemophilia Hemochromatosis

Cardiovascular Disorders : Cardiovascular Disorders The cardiovascular system can be greatly affected by genetic disorders. Elongation of the QT interval Mitral valve prolapse Coronary artery disease Hypertension Cardiomyopathy

Renal Disorders : Renal Disorders Caused by a variety of factors, primarily hypertension. EMS is increasingly being called upon to deal with complications of dialysis including: Problems with vascular access devices Localized infection and sepsis Electrolyte imbalances

Rheumatic Disorders : Rheumatic Disorders Gout is a disorder both genetic and environmental characterized by the deposit of crystals in the joints, most commonly the great toe. The crystals form as a result of abnormally high levels of uric acid in the blood.

Gastrointestinal Disorders : Gastrointestinal Disorders Lactose intolerance Crohn’s disease Peptic ulcers Cholecystitis Obesity

Neuromuscular Disorders : Neuromuscular Disorders Diseases of the nervous and muscular systems include: Huntington’s disease Multiple sclerosis Alzheimer’s disease

Psychiatric Disorders : Psychiatric Disorders Genetic and biological causes of these disorders are being studied and increasingly understood. Schizophrenia Manic-depressive illness (bipolar disorder)

Hypoperfusion : Hypoperfusion

Slide 63 : Hypoperfusion (shock) is inadequate perfusion of body tissues.

Slide 64 : Progression of Shock

The Pathophysiology of Hypoperfusion : The Pathophysiology of Hypoperfusion

Causes of Hypoperfusion (1 of 3) : Causes of Hypoperfusion (1 of 3) Inadequate pump Inadequate preload Inadequate cardiac contractile strength Excessive afterload

Causes of Hypoperfusion (2 of 3) : Causes of Hypoperfusion (2 of 3) Inadequate fluid Hypovolemia

Causes of Hypoperfusion (3 of 3) : Causes of Hypoperfusion (3 of 3) Inadequate container Dilated container without change in fluid volume (inadequate systemic vascular resistance) Leak in the container

Shock at the Cellular Level : Shock at the Cellular Level Shock causes vary; however, the ultimate outcome is impairment of cellular metabolism.

Impaired Use of Oxygen : Impaired Use of Oxygen When cells don’t receive enough oxygen or cannot use it effectively, they change from aerobic to anaerobic metabolism.

Glucose Breakdown (1 of 2) : Glucose Breakdown (1 of 2) Stage one, glycolysis, is anaerobic (does not require oxygen). It yields pyruvic acid, with toxic by-products such as lactic acid, and very little energy.

Glucose Breakdown (2 of 2) : Stage two is aerobic (requires oxygen). In a process called the Krebs or citric acid cycle, pyruvic acid is degraded into carbon dioxide and water, which produces a much higher yield of energy. Glucose Breakdown (2 of 2)

Compensation and Decompensation : Compensation and Decompensation Usually the body is able to compensate for any changes. However, when the various compensatory mechanisms fail, shock develops and may progress.

Compensation Mechanisms : Compensation Mechanisms The catecholamines epinephrine and norepinephrine may be secreted. The renin-angiotensin system aids in maintaining blood pressure. Another endocrine response by the pituitary gland results in the secretion of anti-diuretic hormone (ADH).

Shock Variations (1 of 3) : Shock Variations (1 of 3) Compensated shock is the early stage of shock during which the body’s compensatory mechanisms are able to maintain normal perfusion.

Shock Variations (2 of 3) : Shock Variations (2 of 3) Decompensated shock is an advanced stage of shock that occurs when the body’s compensatory mechanisms no longer maintain normal perfusion.

Shock Variations (3 of 3) : Shock Variations (3 of 3) Irreversible shock is shock that has progressed so far that the body and medical intervention cannot correct it.

Types of Shock : Types of Shock Cardiogenic Hypovolemic Neurogenic Anaphylactic Septic

Cardiogenic Shock : Cardiogenic Shock The heart loses its ability to supply all body parts with blood. Usually the result of left ventricular failure secondary to acute myocardial infarction or CHF. Many patients will have normal blood pressures.

Cardiogenic Shock Evaluation : Cardiogenic Shock Evaluation The major difference between cardiogenic shock and other types of shock is the presence of pulmonary edema causing: Difficulty breathing. As fluid levels rise, wheezes or crackles (rales) may be heard. There may be a productive cough with white or pink-tinged foamy sputum. Cyanosis, altered mentation, and oliguria.

Cardiogenic Shock Treatment (1 of 2) : Cardiogenic Shock Treatment (1 of 2) Assure an open airway. Administer oxygen. Assist ventilations as necessary. Keep the patient warm.

Cardiogenic Shock Treatment (2 of 2) : Cardiogenic Shock Treatment (2 of 2) Elevate the patient’s head and shoulders. Establish IV access with minimal fluid administration. Monitor the heart rate. Dopamine or dobutamine may be administered.

Hypovolemic Shock : Hypovolemic Shock Shock due to loss of intravascular fluid Internal or external hemorrhage Trauma Long bones or open fractures Dehydration Plasma loss from burns Excessive sweating Diabetic ketoacidosis with resultant osmotic diuresis

Hypovolemic Shock Evaluation (1 of 2) : Hypovolemic Shock Evaluation (1 of 2) Altered level of consciousness. Pale, cool, clammy skin. Blood pressure may be normal, then fall.

Hypovolemic Shock Evaluation (2 of 2) : Hypovolemic Shock Evaluation (2 of 2) Pulse may be normal then become rapid, finally slowing and disappearing. Urination decreases. Cardiac dysrhythmias may occur.

Hypovolemic Shock Treatment : Hypovolemic Shock Treatment Airway control. Control severe bleeding. Keep the patient warm. Administer a bolus of crystalloid solution for fluid replacement. Non-trauma or no blood loss: Bolus crystalloid or colloid solutions Trauma or blood loss: “Permissive hypotension” – SBP of 70-85 mmHg PASG if part of local protocol.

Neurogenic Shock : Neurogenic Shock Results from injury to brain or spinal cord causing an interruption of nerve impulses to the arteries. The arteries dilate causing relative hypovolemia. Sympathetic impulses to the adrenal glands are lost, preventing the release of catecholamines with their compensatory effects.

Neurogenic Shock Evaluation : Neurogenic Shock Evaluation Warm, dry, red skin Low blood pressure Slow pulse

Neurogenic Shock Treatment : Neurogenic Shock Treatment Airway control. Maintain body temperature. Immobilization of patient. Consider other possible causes of shock. IV access and medications that increase peripheral vascular resistance.

Anaphylactic Shock : Anaphylactic Shock A severe immune response to a foreign substance. Signs and symptoms most often occur within a minute, but can take up to an hour. The most rapid reactions are in response to injected substances: Penicillin injections Bees, wasps, hornets

Anaphylactic Shock Evaluation : Anaphylactic Shock Evaluation Cardiovascular system: Vasodilation, increased heart rate, decreased blood pressure Gastrointestinal system: Nausea, vomiting, abdominal cramping, diarrhea Nervous system: Altered mental status, dizziness, headache, seizures, tearing

Anaphylactic Shock Treatment : Anaphylactic Shock Treatment Airway protection; may includeendotracheal intubation. Establish an IV of crystalloidsolution. Pharmacological intervention: Epinephrine, antihistamines, corticosteroids, vasopressors, inhaled beta agonists

Septic Shock : Septic Shock An infection that enters the bloodstream and is carried throughout the body. The toxins released overcome the compensatory mechanisms. Can cause the dysfunction of an organ system or result in multiple organ dysfunction syndrome.

Septic Shock Evaluation : Septic Shock Evaluation The signs and symptoms are progressive. Increased to low blood pressure High fever, no fever, or hypothermic Skin flushed, pale, or cyanotic Difficulty breathing and altered lung sounds Altered mental status

Septic Shock Treatment : Septic Shock Treatment Airway control. IV of crystalloid solution. Dopamine to support blood pressure. Monitor heart rhythm.

Multiple Organ Dysfunction Syndrome : Multiple Organ Dysfunction Syndrome MODS is the progressive impairment of two or more organ systems from an uncontrolled inflammatory response to a severe illness or injury.

Slide 97 : MODS Stages

Primary MODS : Primary MODS Organ damage results directly from a specific cause such as ischemia or inadequate tissue perfusion from shock, trauma, or major surgery. Stress and inflammatory responses may be mild and undetectable. During this response, neutrophils, macrophages, and mast cells are thought to be “primed” by cytokines.

Secondary MODS : Secondary MODS The next time there is an injury, ischemia, or infection, the “primed” cells are activated, producing an exaggerated inflammatory response. The inflammatory response enters a self-perpetuating cycle causing damage and vasodilation. An exaggerated neuroendocrine response is triggered causing further damage.

MODS 24 Hours after Resuscitation : MODS 24 Hours after Resuscitation Low grade fever Tachycardia Dyspnea Altered mental status General hypermetabolic, hyperdynamic state

MODS within 24 to 72 Hours : MODS within 24 to 72 Hours Pulmonary failure begins.

MODS within 7 to 10 Days : MODS within 7 to 10 Days Hepatic failure begins. Intestinal failure begins. Renal failure begins.

MODS within 14 to 21 Days : MODS within 14 to 21 Days Renal and hepatic failure intensify. Gastrointestinal collapse. Immune system collapse.

MODS after 21 Days : MODS after 21 Days Hematological failure begins. Myocardial failure begins. Altered mental status resulting from encephalopathy. Death.

Summary : Summary Disease Risk Hypoperfusion Shock Multiple Organ Dysfunction Syndrome