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96 terms

Med Surg

STUDY
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Pathophysiology
involves the study of functional or physiologic change in the body from disease processes. As a disease develops, the changes in the normal anatomy &/or physiology may be obvious or may be hidden, occurring at the cellular level. As such, pathophysiology includes some aspects of pathology.
Medical History
Essential to identify any impact health care activities might have on a patient's condition, or how a patient's illness might complicate care.
Common cellular adaptations
a) atrophy, b) hypertrophy, c) hyperplasia, d) metaplasia, e) dysplasia, f) anaplasia, g) neoplasm
Atrophy
decrease in size. **CAUSES: reduced use, insufficient nutrition, decreased neurological or hormonal stimulation, and aging.
Hypertrophy
Increase in size. **CAUSES: additional work by tissue (EX enlarged heart), consistent exercise on skeletal muscle, and excessive hormonal stimulation.
Hyperplasia
Increased number. **CAUSES: compensatory mechanism, hormonal imbalance, increased risk of cancer possibility
Metaplasia
One mature cell type replaced by different mature cell type. **CAUSES: Vitamin A deficiency, adaptive mechanism
Dysplasia
Cells vary in size and shape, large nuclei, and rate of mitosis increased. **CAUSES: chronic irritation or infection, possibly pre-cancerous.
Anaplasia
Cells are undifferentiated, have variable nuclei and cell structure, and numerous mitotic figures. **CAUSES: associated with malignancy, or cancer, tumor grades.
Neoplasm
"New growth" tumor (benign, malignant) malignant=cancer.
Causes of cell damage
a) ischemia, b) physical agents, c) mechanical damage, d) chemical toxins, e) microorganisms, f) abnormal metabolites, g) nutritional deficits, h) fluid/electrolyte imbalance
Necrosis
death of a group of cells
Gangrene
Area of necrotic tissue that has been invaded by bacteria.
Defense mechanisms
Used by the body to protect itself from anj injurous agent. may be specific or non-specific.
1st Line of defense
Skin or mucous membrane
2nd Line of defense
Phagocytosis and inflammation (non-specific)
3rd Line of defense
Immune system (specific)
Ischemia
Lack of oxygen
Physical Agents
Excessive temperature or radiation
Mechanical damage
Pressure/tearing tissue
Microorganisms
Bacteria, viruses, and parasites
Inflammation
Normal defense mechanism a) Localizes and removes injurous agent, b) removes cellular debris, c) initiates healing process, d) Allows restoration of structure and function, e) regeneration of damaged tissue must occur to have complete restoration of function.
Systemic affects of inflammation
a) mild fever, b) malaise, c) headache, d) anorexia
Chronic inflammation
May follow an acute inflammation who's cause has not been completely sured OR a chronic irritation (smoking)
Acute inflammation
Develops immediately and lasts a short time
Cardinal Signs and Symptoms of Inflammation
a) erythema, b) heat, c) sweling, d) pain
Inflammatory response
1) Damaged tissues release histamines, increasing blood flow to the area. 2) Histamines cause cappillaries to leak, releasing phagocytes and clotting factors into the wound. 3) Phagocytes engulf bacteria, dead cells, and cellular debris. 4) Platelets move out of the cappillary to seal the wounded area.
Inflammation as it relates to PT
Plays a vital role in the healing process. PTA should support the healing process and encourage pts to do the same.
Healing by 1st intention
suture (faster)
Healing by 2nd intention
large open wound (slower)
Regeneration
Healing process that occurs in damaged tissue in which cells are capable of mitosis. Damaged tissue is replaced.
Repair
1) Begins with blood clot, then inflammation. 2) After 3-4 days phagocytes, monocytes and macrophages have removed debris. 3) Granulation tissue grows in the gap. 4) Epithelial cells undergo mitosis extending across the wound. 5)Fibroblasts produce collagen (scar tissue).
Scar Tissue
Fills the defect or gap in tissue. Overgrowth of scar tissue can cause a) loss of ROM, b) contracture (fixation and deformity of joint), c) adhesions (band of scar tissue joining 2 surfaces that are normally separated), d) hypertrophy and ulceration.
Factors that affect tissue healing
1) growth factors, 2) health, 3) presence of comorbidalities, 4) tobacco and caffeine, 5) nutrition, 6) type of tissue, 7) local or systemic infection, 8) medical treatment
Effect of prolonged immobilization
Tissue dehydrates and becomes less elastic, less plastic, and more brittle. Capsular structures (ligaments) become stiff and weak.
Immune response
1) specific defense, 2) Responds to specific substances, cells, toxins, or proteins, 3) Detects and destroys unknown material, 4) Demonstrates tolerance by ignoring self cells, 5) Recognizes specific antigens as foreign (develops specific response and stores response in memory for future reference).
Immunology
Covers the study of all aspects of the immune system. a) physiological, b) immunological disorders, c) characteristics and components of immune system
Benefits of a properly working Immune system
decreases risk of infection, provides protection, reduces susceptibility to common everyday infectious agents
Active Immunity
Person's own body develops antibodies, or T cells, in response to specific antigen introduced into body.
active natural immunity
direct antigen exposure **memory
active artificial immunity
vaccine **memory
Passive Immunity
Antibodies transferred from one person to another.
Passive natural immunity
invitro and breast milk **no memory
Passive artificial immunity
Rabies or anti-venom, immunoglobulin ** no memory
Skin
1st line of defense. Acts as barrier.
Tissue transplant rejection causes
Occurs when the immune system is responding to the foreign tissue resulting in destruction of the organ.
Tissue transplant rejection treatment
Involves immunosuppression techniques that reduce the immune response and prevent rejection. -drug intervention
Type I- Hypersensitivity
Allergic reactions, hay fever, food allergies, atopic dermatitis (eczema), asthma
Type II- Cytotoxic Hypersensitivity
Reaction to different blood type (Rh factor)
Type III- Immune Complex Hypersensitivity
Glomerulnephritis, rheumatoid arthritis
Type IV- Cell-mediated or Delayed Hypersensitivity
TB test, contact dermatitis, allergic skin rash
anaphylaxis
Severe life-threatening. Hypersensitivity reaction resulting in: 1) decreased BP, 2) airway obstruction, 3) severe hypoxia.
Anaphylaxis EFFECTS
itching, tingling, coughing, difficulty in breathing, weakness, dizziness, fainting, fear/panic, edema in eyes, lips, tongue, hands, feet, hives, loss of conciousness
Autoimmune disorders
Occur when individuals develop antibodies to their own cells or cellular material and these antibodies then attack the individual's tissues (EX lupus)
HIV risk in healthcare professions
Great concern over, but little evidence of, transmission to healthcare workers from infected patients other than by accidental injury or the presence of open skin lesions. Should assume risk of some infection from contact with bodily fluids and follow universal precautions.
AIDS
chronic infectious disease caused by HIV which destroys helper T-cell lymphocytes, causeing loss of the immune response and increase susceptibility to secondary infection and cancer. Prolonged latent period followed by period of active infection.
Fluid distribution
Fluids entering should equal fluids exiting to maintain balance
Extracellular Compartment (ECF)
1) intravascular fluid (IVF) - blood, 2) interstitial fluid (ISF) - inside cell, 3) cerebrospinal fluid (CSF), 4) transcellular fluid - pericardium or synovial joint cavities
Intracellular Compartment (ICF)
fluid inside the cell
Edema Causes
1) increased capillary hydrostatic pressure (blood volume. 2) Loss pf plasma proteins, 3) Obstruction of lymphatic circulation, 4) Increased capillary permeability **Occurs in extracellular compartment
Dehydration Causes
1) vomiting/diarrhea, 2) excessive sweating, 3) diabetic ketoacidosis with loss of fluid, electrolytes, and glucose in urine
Dehydration Effects
1) decrease in interstitial and intravascular fluids causing dry mucous membrane, lower BP, increased hematocrit. 2) Increase in thirst, 3)increased HR, 4)pale cool skin due to constricted blood vessels, 5) decreased urine output.
Hyponatremia
Low Sodium Levels
Hyponatremia Causes
1) Direct sodium loss or excess fluid in the extracellular compartment dilluting sodium content 2) diarrhea 3) vomiting 4) diuretic
Hyponatremia Effects
1) Muscle twitching, weakness 2) Lethargy, seizures, coma, confusion 3) Bypotension, tachycardia, 4) nausea and vomiting 5) oliguria or anuria
Hypernatremia
High sodium levels
Hypernatremia Causes
1) High sodium intake 2) Loss of water faster than loss of sodium 3) Loss of thirst mechanism 4) watery diarrhea 5) Prolonged periods of rapid respiration
Hypernatremia Effects
1) Agitation 2) Pitting edema, hypertension, 3) Thirst 4) dyspnea, respiratory arrest , death
Hypokalemia
lowpotassium levels
Hypokalemia Causes
1) diarrhea, diuresis 2) excessive aldosterone or glucocorticoids 3) decreased dietary intake, 4) insulin to treat ketoacidosis
Hypokalemia Effects
1) arrhytmia, cardiac arrest 2) anorexia, nausea, constipation 3) fatigue, muscle twitch, weakness, leg cramps 4) shallow respiration, 5) postural hypotension, polyuria, mocturia
Hyperkalemia
high potassium levels
Hyperkalemia Causes
1) renal failure, 2) aldosterone deficit, 3) diuretics 4) displacement of potassium from cells by prolonged or severe acidosis.
Hyperkalemia Effects
1) arrhythmia, 2) nausea, diarrhea, leg cramps 3) muscle weakness, flacid paralysis
Hypocalcemia
low calcium levels
Hypocalcemia Causes
1) hypoparathyroidism 2) malabsorption 3) deficient serum albumin 4) increased serum pH
Hypocalcemia Effects
1) tetany, tingling fingers 2) confusion, irritability 3) arrhythmia
Hypercalcemia
High calcium levels
Hypercalcemia Causes
1) uncontrolled release of calcium ions from the bones due to neoplasms 2) hyperparathyroidism 3) immobility 4) increased calcium intake 5) milk-alkalai syndrome
Hypercalcemia Effects
1) apathy, lethargy 2) anorexia, nausea, constipation 3) polyuria, thirst 4) kidney stones 5) arrhythmia, increased BP
Importance of acid -base balance
Cell enzymes can only function in a very narrow pH range
Respiratory acidosis
CAUSE: shallow respiration and respiratory congestion
Metabloic acidosis
CAUSE: Shock, diabetic ketoacidosis, renal failure, diarrhea
Acidosis EFFECTS
headache, lethargy, weakness, confusion. Leads to coma and death
Respiratory Alkylosis
CAUSE: hyperventilation
Metaboli Alkylosis
CAUSE: vomiting and excessive antacid intake
Alkylosis EFFECTS
restlessness, muscle twitching, tingling and numbness of fingers, tetany, seizures and coma
Acid-base imbalance treatment
Underlying cause of imbalance should be diagnosed and removed. Add/remove fluid or electrolytes
Hematocrit
M 45-52% F 37-48%
Hemoglobin
M 13.5-18 g/100mL F 12-16 g/100mL
Sodium (Na+)
135-142 mEq/L
Potassium (Ka)
3.8-5 mEq/L
Blood glucose (fasting)
70-110
WBC
4500-10500 /mm3
O2 saturation (SaO2)
96-98%
Prothrombin (PT/INR)
1.5-2.5 sec.