Pathophysiology Key Concepts

• These study notes cover key terms and concepts from a pathophysiology final exam blueprint, focusing on various disorders and imbalances within the body.

Introduction to Pathophysiology

• Idiopathic refers to a disease with an unknown cause.
• Iatrogenic refers to a disease caused by a treatment, procedure, or medical error.
• Predisposing risk factors indicate a high risk for developing a disease, but do not guarantee its development.
• Prophylaxis is a measure taken to preserve health and prevent disease spread.
• Prevention involves actions aimed at reducing disease development.
• Incidence indicates the number of new cases in a population during a specific time.
• Prevalence refers to the number of new and old cases within a specific population and time period.
• Epidemics occur when there's a higher-than-expected number of infectious disease cases in a given area.
• Pandemics involve higher numbers of cases across many regions of the globe.
• Atrophy is the decrease in cell size, resulting in reduced tissue mass.
• Hypertrophy is the increase in cell size, resulting in enlarged tissue mass.
• Hyperplasia is the increased number of cells, resulting in enlarged tissue mass.

Fluid, Electrolyte, and Acid-Base Imbalances

• Fluid intake and output should be equal to maintain a constant body level.
• Sensible losses are measurable, including urine, feces, emesis, and drainage from tubes.
• Insensible losses include fluid lost through skin or exhaled air, which cannot be measured.
• Intake should account for IV fluids, liquid medications, and enteral feedings.

Hormones in Fluid and Electrolyte Regulation

• ADH controls the amount of fluid leaving the body in urine by promoting water reabsorption into the blood from kidney tubules.
• Aldosterone determines the reabsorption of sodium and water from kidney tubules, conserving more fluid during deficits.
• Atrial natriuretic peptide (ANP) stimulates water and sodium elimination in urine to prevent salt-induced hypertension.

Edema

• Causes include increased capillary hydrostatic pressure, loss of plasma proteins, lymphatic obstruction, and increased capillary permeability.
• Assessment involves identifying location (legs, ankles, feet, eyes, lungs, abdomen), pitting vs. nonpitting, weight gain, decreased urine output, SOB, and lung crackles.
• Monitoring includes daily weights, I&O tracking, skin assessments, vital signs, and lab values.

Dehydration

• Causes include vomiting, diarrhea, excessive diaphoresis, diabetic ketoacidosis, and insufficient water intake.
• Effects and assessment findings include dry mucous membranes, decreased skin turgor, hypotension, weak pulse, fatigue, increased hematocrit, and confusion.
• Compensation mechanisms include increased thirst, tachycardia, vasoconstriction, and urinary retention.

Hyponatremia

• Hyponatremia is low sodium, below 135 mEq/L.
• Causes include excessive fluid losses, diuretics with low-salt diets, hormonal imbalances, early chronic renal failure, and excessive water intake.

Hypokalemia

• Hypokalemia is low potassium, less than 3.5 mEq/L.
• Causes include excessive losses, diuretics, excessive aldosterone or glucocorticoids, decreased dietary intake, and treatment of diabetic ketoacidosis with insulin.

Hyperkalemia

• Hyperkalemia is high potassium, greater than 5.0 mEq/L.
• Causes include renal failure, aldosterone deficit, potassium-sparing diuretics, and leakage of potassium into extracellular fluids.

Arterial Blood Gasses

• ABGs (Arterial Blood Gasses) is a blood test that measures the acidity (pH) and the levels of oxygen and carbon dioxide in the blood.

Infection

• Resident flora are harmless microorganisms inhabiting specific body areas.
• Nosocomial infections occur in healthcare facilities.
• Microbes, undiagnosed infectious diseases, shared environments, weakened immune systems from treatments, employees, and fomites contribute to nosocomial infections.
• Factors decreasing resistance (increasing risk) to infections: age extremes, pregnancy, genetics, immunodeficiency, malnutrition, chronic disease, stress, inflammation, and impaired inflammatory responses.

Immunity

• Anaphylaxis is a severe and life-threatening condition.
• Symptoms: dyspnea, wheezing, decreased BP, anxiety, tingling, hives, dizziness, loss of consciousness.
• Management prioritizes maintaining airway patency and oxygenation.
• Epinephrine, glucocorticoids, antihistamines, oxygen, and BP stabilization are key interventions.
• Immunodeficiency raises concerns about increased infection and cancer risks.
• Prophylactic antimicrobial drugs are used in management.
• Secondary infections in HIV/AIDS are primary causes of death.
• Increased cancer risk includes herpes simplex, candida, TB, pneumocystitis carnii, and non-Hodgkin lymphoma.

Hematological Disorders

• Pernicious anemia causes are autoimmune reactions to vitamin B12.
• Diagnosis includes serum B12, Schilling’s test, CBC, gastric analysis, and bone marrow biopsy.
• Treatment involves injectable vitamin B12, never oral due to lack of intrinsic factor.
• Iron deficiency anemia symptoms include pallor, weakness, fatigue, irritability, low hemoglobin, low hematocrit, and low erythrocytes.
• Pancytopenia is a decrease in all blood cell types.
• Normal RBC: 4.5 - 5.5 million
• Normal WBC: 4,500 - 11,000
• Normal Platelet count: 150,000 - 450,000
• Disseminated intravascular coagulation is increased platelet consumption, causing simultaneous bleeding and clotting.
• Symptoms include bleeding from multiple sites, bruising, and blood clots.
• Monitoring involves blood tests and assessing for bleeding.

Cardiovascular System Disorders

• Modifiable risk factors for coronary artery disease: lifestyle, diet, weight, smoking, type 2 diabetes, and hypertension.
• Nonmodifiable risk factors: age, gender, and genetics.
• Precipitating factors increase the heart's demands, such as exercise, anger, respiratory infection, weather extremes, pollution, or large meals.
• Emergency treatment for angina includes rest, ceasing activity, sitting upright, and administering sublingual nitroglycerin.
• Administer a second dose of nitroglycerin if the patient is known to have angina.
• Emergency medical aid is needed if the patient has no history of angina.
• Check vital signs and administer supplemental oxygen if necessary.

Diagnostic Tests in MI

• ECG (Electrocardiogram)
• Serum enzyme and isoenzyme levels
• Serum levels of myosin and troponin are elevated
• Leukocytosis, elevated CRP, and ESR are common.
• ABG may be altered.
• Pulmonary artery pressure measurements

EKG

• EKG (Electrocardiogram) is a test that checks for problems with the electrical activity of your heart.

Heart Failure

• Left-sided heart failure (Lungs)
• Right-sided heart failure (Rest of body)
• Paroxysmal nocturnal dyspnea
• Pulmonary congestion: cough, crackles, wheezes, blood-tinged sputum, tachypnea
• Orthopnea
• Exertional dyspnea
• Increased peripheral venous pressure
• Ascites
• Hepatomegaly and splenomegaly
• Distended jugular veins
• Weight gain
• Dependent edema

Hypertension Management

• Primary hypertension is idiopathic, with BP consistently above 140/90.
• Lifestyle changes, mild diuretics, ACE inhibitors, and antihypertensive drugs are used.
• Secondary hypertension results from an underlying trigger.
• The underlying problem must be treated.
• Emergency hypertension is uncontrollable, severe, and rapidly progressing.
• IV antihypertensive medications (ACE inhibitors, diuretics) are administered.

Respiratory System Disorders

• Kussmaul’s breathing involves deep, rapid respirations or "air hunger."
• A typical state of acidosis may follow strenuous exercise.
• Cheyne-Stokes respirations are periods of apnea alternating with regular series of respirations.
• Rate and depth will be irregular in pattern
• Influenza symptoms include sudden, acute onset of fever, fatigue, and myalgia.
• Treatment with -ivir drugs within the first 48 hours helps manage symptoms.
• Prevention includes seasonal vaccination, hand hygiene, and masks.

Nosocomial Pneumonia Prevention

• Hand hygiene
• Oral care for intubated patients
• Head of bed should be elevated
• Repositioning and turning to move lung secretions
• Aspiration symptoms include coughing, choking, stridor, wheezing, tachycardia, tachypnea, nasal flaring, chest retraction, and hypoxia.
• Management/treatment: airway management, positioning, supplemental oxygen, surgery, and Heimlich maneuver.

Pathophysiological Changes with Asthma

• Inflammation of mucosa with edema
• Bronchoconstriction of smooth muscle
• Increased secretion of thick mucus
• Status asthmaticus is a persistent severe asthma attack.
• Management: supplemental oxygen, inhaled bronchodilators (beta 2 adrenergic agent such as salbutamol).

Acute Asthma Drugs

• SABA (short acting beta agonists): albuterol

Chronic Asthma Treatment

• Zafirlukast (Accolate) and Montelukast (Singulair)
• Cromolym sodium daily

Pulmonary Emboli

• Risk factors: smoking, aging, obesity, immobility, surgery, oral contraceptives
• Symptoms: sudden SOB, tachypnea, chest pain, cyanosis, hypotension
• Management: preventative measures, oxygen, heparin, fibrinolytic agents to prevent further clots, mechanical ventilation, embolectomy
• Pneumothorax symptoms include tracheal deviation from the affected side, atelectasis, dyspnea, cough, chest pain, reduced breath sounds, hypoxia, and unequal chest expansion.

Endocrine System Disorders

• Diabetic ketoacidosis (DKA) symptoms include Kussmaul’s respirations (rapid and deep), acetone breath (sweet and fruity), lethargy, and decreased responsiveness.
• Treatment: fluids, insulin, electrolyte monitoring.
• Hyperosmolar hyperglycemic nonketotic coma (HHNK) symptoms include severe dehydration (increased hematocrit, poor skin turgor, tachycardia, tachypnea), neurologic deficits, muscle weakness, dysphasia, and abnormal reflexes.
• Treatment: fluids, insulin, electrolyte monitoring.

Chronic Complications of Diabetes

• Vascular problems - atherosclerosis
• Microangiopathy: retinopathy, nephropathy, neuropathy
• Macroangiopathy: R/F heart attacks, strokes, PVD, gangrene, amputation, slow healing ulcers