Principles of Pathophysiology I

Principles Of Pathophysiology I : 

Principles Of Pathophysiology I Mike Ziem, A.S., EMT-P April 2008

Pathophysiology : 

Pathophysiology Patho = Abnormal Physiology = Function

Cell Adaptation : 

Cell Adaptation

Cell Adaptation : 

Cell Adaptation Cells adapt to change to their environment to protect themselves from injury and/or death

Atrophy : 

Atrophy Decrease in cell size due to a decrease in workload

Hypertrophy : 

Hypertrophy Increase in cell size due to an increase in workload

Hyperplasia : 

Hyperplasia Increase in cell numbers due to an increased workload

Metaplasia : 

Metaplasia Reversible conversion of one kind epithelial cell into another type of epithelial cell Example: Respiratory tract replacing damaged ciliated columnar epithelium with stratified squamous epithelium

Dysplasia : 

Dysplasia Abnormal change in cell size, shape and appearance due to external stressor Changes result from chronic irritation and inflammation of the cell Massive cell proliferation to protect

Neoplasia : 

Neoplasia New and abnormal development of cells in a tissue or organ. AKA: Tumor May be benign or malignant

Cellular Death : 

Cellular Death

Cellular Death : 

Cellular Death Occurs when cells no longer adapt to the agents that have injured them. Hypoxic Injury Immunological Injury Physical Agents Chemical Injury Genetic Factors Infectious Injury Nutritional Imbalance

Apoptosis : 

Apoptosis Genetically programmed cell death Cellular Suicide The "decision" for apoptosis can come from the cell itself, from the surrounding tissue, or from a cell that is part of the immune system. The processes of disposal of the cellular debris does not damage the organism which differentiates apoptosis from necrosis

Necrosis/Gangrene : 

Necrosis/Gangrene Accidental death of cells and living tissue Disorderly death generally does not send signals telling phagocytes to engulf the dying cell Unlike apoptosis, cells that die by necrosis may release harmful chemicals that damage other cells

Necrosis : 

Necrosis 11 year old boy bitten by a snake 2 weeks earlier and only treated with antibiotics

Blood Components : 

Blood Components

Blood ComponentsFormed Elements : 

Blood ComponentsFormed Elements Erythrocytes Red blood cells 99% of all cells No nucleus Transport oxygen

Blood ComponentsFormed Elements : 

Blood ComponentsFormed Elements Leukocytes White blood cells Provides protection against pathogens and antigens

Blood ComponentsFormed Elements : 

Blood ComponentsFormed Elements Platelets Cell fragments Vital for blood clotting Aspirin and NSAID’s block their function

Blood Components : 

Blood Components Plasma Blood matrix 92% water Contains plasma proteins, salts, metals, gases, wastes Transports cells, fat-soluble vitamins, hormones

Hemoglobin : 

Hemoglobin Protein in the RBC’s that contain iron and transport oxygen

Hematocrit : 

Hematocrit Percentage of RBC’s in a sample of whole blood.

Hemoglobin/Hematocrit – “H & H” : 

Hemoglobin/Hematocrit – “H & H” Viscosity is the interaction of molecules and suspended materials in a liquid Low H&H = Low viscosity. Blood is too thin and too few cells High H&H = High viscosity. Blood is too thick

Electrolytes, Cations & Anions : 

Electrolytes, Cations & Anions

Electrolytes : 

Electrolytes Substance whose molecules dissociate into electrically charged particles (ions) when dissolved in water

Electrolytes - Cations : 

Electrolytes - Cations Sodium Na+ #1 ECF cation Maintains osmotic balance of ECF Potassium K+ #1 ICF cation Maintains osmotic balance of ICF Magnesium Mg++ Activator in many enzymatic reactions Assists in the production and use of ATP Calcium Ca++ Builds bone Muscle contraction

Electrolytes - Anions : 

Electrolytes - Anions Chloride Cl- #1 ECF anion Bicarbonate HCO3- Used by the carbonic acid - bicarbonate buffer system

Extracellular vs. Intracellular : 

Extracellular vs. Intracellular K+ K+ K+ K+ K+ K+ K+ K+ K+ K+ K+ Na+ Na+ Na+ Na+ Na+ Na+ Na+ Na+ Na+ Na+ Na+ Na+ Na+ Na+ Na+ K+ K+ K+ Extracellular Intracellular Cl- Cl- Cl- Cl- Cl- Cl- Cl- Cl- Cl- Cl- Cl- Cl- Cl- Cl-

Slide 30: 

Water Balance

Fluid Compartments : 

Fluid Compartments Intracellular

Fluid Compartments : 

Fluid Compartments Interstitial

Fluid Compartments : 

Fluid Compartments Intravascular (mostly plasma)

Water Balance : 

Water Balance 75% of all water is intercellular 25% is extracellular Interstitial Intravascular

Fluid Intake/Output – “I&O” : 

Fluid Intake/Output – “I&O” Intake Food – 1200 mL Liquids – 1000 mL Metabolic Sources – 300 mL Output Water Vapor – 400 mL Urine – 1500 mL Perspiration – 400 mL Feces – 200 mL Intake Food – 1200 mL Liquids – 1000 mL Metabolic Sources – 300 mL Output Water Vapor – 400 mL Urine – 1500 mL Perspiration – 400 mL Feces – 200 mL

Water Balance : 

Water Balance Over hydration Dehydration

Osmosis, Diffusion & Active Transport : 

Osmosis, Diffusion & Active Transport

Osmotic Gradient : 

Osmotic Gradient Difference in the concentration of molecules on opposites sides of a semipermeable membrane

Osmosis : 

Osmosis H2O Occurs when an osmotic gradient exists. Water moves from a lower solute concentration to a higher solute concentration.

Concept check : 

This solution has become more _________ Concept check This solution has become more __________ concentrated dilute

Diffusion : 

Diffusion Movement of molecule/solutes/particles across a cell membrane from an area of high concentration to and area of low. Inhalation

Diffusion : 

Exhalation Diffusion Movement of molecule/solutes/particles across a cell membrane from an area of high concentration to and area of low.

Active Transport : 

Active Transport The movement of particles/solutes/molecules from an area of low concentration to an area of high. K+ K+ K+ K+ K+ K+ K+ K+ K+ K+ K+ K+ K+ K+ K+ K+ K+ K+ K+ K+ K+ Na+ Na+ Na+ Na+ Na+ Na+ Na+ Na+ Na+ Na+ Na+ Na+ Na+ Na+ Na+ Na+ Na+ Na+ ATP

Isotonic Solutions : 

Isotonic Solutions Solutions on either side of a semipermeable membrane are equal in concentration Examples : 0.9% sodium chloride, Ringers Lactate, and blood plasma

Hypertonic Solution : 

Hypertonic Solution More particles in a solution in relation to another solution Examples: D50, sodium bicarbonate, sea water Will cause water to diffuse out of the cells and interstitial space Hypertonic Solution

Hypotonic Solution : 

Hypotonic Solution Less particles in a solution in relation to another solution Example: 0.45% sodium chloride, D5W, distilled water Will cause water to diffuse into the cells and interstitial space Hypotonic Solution

Crystalloid Solutions : 

Crystalloid Solutions Contains crystals dissolved in water which can diffuse through a semipermeable membrane Classified according to their tonicity Isotonic Hypertonic Hypotonic

Colloid Solution : 

Colloid Solution Contain large molecules too large to diffuse through a semipermeable membrane Stay in the vascular space longer and pull water into the vasculature

Crystalloid Uses : 

Crystalloid Uses D5W Not used much in EMS Glucose transported into cells, water follows glucose Ringer’s Lactate Fluid of choice for shock Well balanced electrolyte solution Normal Saline Suitable for shock

Balance : 

Acid Base Balance

Acid-Base Balance : 

Acid-Base Balance The condition when the rate at which the body produces acids and bases equals the rate at which they are excreted The body operates very poorly in acidic conditions and actually prefers to be relatively alkalotic

Acid-Base Balance : 

Acid-Base Balance Acid – Substance that freely gives off hydrogen ions when dissociated in a solution Base – Substance that freely receives hydrogen ions when dissociated in a solution

Acid-Base Balance : 

pH – abbreviation for potential of hydrogen pH is the degree of acidity or alkalinity of a substance Acid-Base Balance

Acid-Base Balance : 

A change of 1 pH unit reflects a 10-fold difference in the actual hydrogen ion concentration Example: A solution with a pH of 6 is 10X more acidic than a solution with a pH of 7 Acid-Base Balance

Acid-Base Balance : 

Normal blood pH is 7.35 – 7.45, slightly alkalotic. Cell function is seriously impaired when the body’s pH falls below 7.2 or raises above 7.55 Acid-Base Balance

Acid-Base Balance : 

Acidosis CNS depressant Depressed cardiac function Peripheral vasodilatation and pooling Alkalosis Neurons become more excitable Acid-Base Balance

Acid-Base Balance : 

To maintain normal serum pH, the body utilizes 3 buffer systems: Carbonic acid – bicarbonate buffer system Protein buffer system Renal buffer system Acid-Base Balance

Carbonic Acid – Bicarbonate Buffer : 

Fastest of all buffer systems Major buffer of the ECF Consists of 2 components Carbonic Acid (H2CO3) Bicarbonate (HCO3) CO2 + H2O H2CO3 H+ + HCO3- Carbonic Acid – Bicarbonate Buffer

CO2 + H2O H2CO3 H+ + HCO3- : 

CO2 + H2O H2CO3 H+ + HCO3- CO2 is a potential acid As CO2 levels rise, so does the level of hydrogen The lungs can quickly eliminate excess CO2, therefore , a change in respiratory rate is the first visible sign of compensation in the patient

Protein Buffer : 

Amino acids accept or release hydrogen ions as needed. Alkalosis causes the dissociation of amino acids and the release of hydrogen ions Acidosis causes the amino group to accept additional hydrogen ions Protein Buffer

Protein Buffer : 

Protein Buffer N C C R H O OH H H

Protein Buffer : 

Protein Buffer N C C R H O O- H H H+

Protein Buffer : 

Protein Buffer N C C R H O OH H H H

Renal Buffer System : 

Renal Buffer System The kidneys will secrete or retain hydrogen or bicarbonate as needed. Slowest of all systems May take hours to days to work

Acid-Base Disorders : 

Acid-base disorders are classified according to the problem which created them Acidosis is serum pH less than 7.35 Alkalosis is serum pH greater then 7.45 Acid-Base Disorders

Acid-Base Disorders : 

Respiratory disorders are due to abnormally high or low CO2 levels in the body Metabolic disorders are caused by the generation of organic acids (lactic acid) or conditions which alter the concentration of bicarbonate ions in the body Acid-Base Disorders

Respiratory Acidosis : 

A rise in CO2 levels in the blood stream due to a decrease in respiratory rate, decrease in tidal volume, FBAO, or the inability to exchange gases at the alveoli Causes: COPD Drugs Pneumonia Bronchospasm Respiratory Acidosis

Respiratory Alkalosis : 

An abnormal drop in the blood CO2 levels Causes: Hyperventilation Panic/anxiety attack Fever Pain Chronic hypoxia Adaptation to high altitudes Respiratory Alkalosis

Metabolic Acidosis : 

Caused by the increase of hydrogen ions or the loss of bicarbonate ions Causes: Respiratory failure (after respiratory acidosis) Shock Chronic kidney failure DKA Ingestion of acids (ASA) Metabolic Acidosis

Metabolic Alkalosis : 

Metabolic Alkalosis Caused by a loss of hydrogen ions or an increase in bicarbonate ions Causes: Excessive vomiting Antacid ingestion IV bicarbonate

What’s My Diagnosis? : 

Cardiac Arrest, no spontaneous respirations or pulse What’s My Diagnosis? Initially respiratory acidosis. Leading into metabolic acidosis.

What’s My Diagnosis? : 

Multi-trauma patient, bled out, tension pneumothorax, cyanotic What’s My Diagnosis? Respiratory acidosis from the tension pneumothorax. Metabolic acidosis from blood loss.

What’s My Diagnosis? : 

Hysterical young woman, just broke up with her boyfriend What’s My Diagnosis? Respiratory Alkalosis

What’s My Diagnosis? : 

Depressed woman, broke up with her boyfriend , swallowed 1 bottle of aspirin What’s My Diagnosis? Metabolic Acidosis

What’s My Diagnosis? : 

Type I diabetic, out of insulin, sick with the flu What’s My Diagnosis? Metabolic Acidosis

What’s My Diagnosis? : 

Elderly man, severe COPD, who developed pneumonia What’s My Diagnosis? Respiratory Acidosis

QUESTIONS? : 

QUESTIONS?