NURS220: Patho/Pharm 1 - Stress & Adaptation

pathophysiology

• study of abnormal physiological processes that cause/associated with disease/injury

• how the body/systems work when diseased/injured

• common/classic presentation: general prediction of clinical progression, treatment, identification of cause

• dynamic/conceptual: explain relationships of pathologies

concepts of pathophysiology

etiology, pathogenesis, clinical manifestations, treatment/outcome

etiology

• study of causes/reasons for disease: causal factors that provoke disease/injury

• etiological classification system: schemes to categorize etiologies of disease

  • intrinsic

  • extrinsic

  • idiopathic

  • iatrogenic

intrinsic

malfunction/change within the body

extrinsic

caused by external factors (infectious agent/behavior)

idiopathic

unknown cause for disease

iatrogenic

of or relating to illness caused by medical examination/treatment/intervention (chemo)

risk factor

when present, increases probability of disease

causative agent

factor causes disease, disease cannot occur if factor not present

pathogenesis

• way in which a disease develops —> changes

• period from etiology to clinical manifestations: acute, chronic, or recurrent

• cellular level: intracellular pathways control physiological function —> effects on systems manifest clinically

clinical manifestations

signs and symptoms of disease/injury

sign

• objective evidence of illness/ disease state: observable/measurable by affected individual and others

• EX: history, biochemical analysis, imaging, labs, vomit - BP, HR, Temp, O2

symptoms

• subjective indication of illness/disease

• experience reported by individual affected

• EX: pain, headache, itching, nasea

syndrome

collection of signs and symptoms indicative of a specific disease/disorder

pallative care

treating signs/symptoms of disease

differential diagnosis

• differentiating between two/more conditions which share similar signs/symptoms

• possible diagnosis leaning towards based on evidence —> definitive diagnosis though tests

screening: procedure

• current H & P (health history & physical - head to toe)

• - hemodynamics: BP/HR

• Fluid tests: urine, blood, saliva, sputum, stool, CSF

• radiographic imaging: X ray, CAT, PET, MRI

• tissue sample, genetic testing, metabolic tests

• electrical activity: heart, brain, muscle

screening features

reliability, validity, sensitivity, specificity, gold standard

reliability

ability to give the same results in repeated measurements (consistency)

validity

measures what it is supposed to measure (accuracy)

sensitivity

• ability to detect the presence of X even at low levels (high: low false negative rate, low: false negatives likely to occur)

• ability to identify individuals who have a disease (minimize false negatives)

• probability a test will be positive when applied to a person with the condition

• highly sensitive test: most ppl with disease test positive, minimizing the number of missed cases (false negatives)

specificity

• ability to test for specified substance (low: false positive)

• how well a test can correctly identify individuals who do not have the disease

• a highly specific test means that most people without the disease will test negative, minimizing the number of false positive results

• probability a test will be negative when applied to a person without the condition 

gold standard

• 100% sensitivity and specificity - best test under reasonable conditions (not always available)

• EX: stroke (want CAT Scan with IV contrast)

stages of disease

• subclinical: patient functioning, disease processes underway (safety margin)

  • exposure (determine severity), latent (incubation- no s/s)

• clinical:

  • prodromal: first sign/symptoms-nonspecific

  • acute: max severity

  • convalescence: recovery period (not for chronic)

acute

• short duration

• signs/symptoms may be severe

• hours, days, weeks

chronic

• lasts months/years

• signs/symptoms may be subtle

• months, years

sequela

• that which follows (consequence)

• condition that is the consequence of a previous disease or injury

• EX: inflammation —> scarring, diabetic foot injury —> infection —> antibiotics —> GI upset —> infection

exacterbation

acute development of increased severity of signs/symptoms

• EX: asthma (environmental trigger)

remission

decline or disappearance of signs/symptoms (NOT cure/end)

treatment options

considerations: evidence-based practice (data), risk v benefit (side effects), availability, individual choice 

normal - statistical model

• estimate of diseases in a normal population: bell shaped curve

  • 95% pop falls within normal range, 5% fall outside normal

• used as standard to determine abnormal values - clinical findings to determine —> normal, normal variation, abnormality (disease)

  • comparison: ensure population sample taken from reflects pt - changes in age/gender

factors that influence normality

culture, age, gender, situation, time

factors that influence normality: culture

culture defines health/illness in a manner that reflects their experience 

factors that influence normality: age

normal value for a person at one age may not be normal for that person at a different age - organs shrink, sensory loss, less receptors/sensors

factors that influence normality: gender

relevant in both health/disease - hb lower in wome

factors that influence normality: situation

determine whether a derivation from normal should be considered abnormal or an adaptation mechanism - altitude causes higher RBC count (acclimatization

factors that influence normality: time

impact how body responds from day/night (diurinal), or at varying times of year

epidemiology

• study of disease patterns within a population

• factors that influence patterns of disease:

  • age: children/infants developing immune system - increases susceptibility

  • behavior

  • gender: women likely to have rheumatoid arthritis

  • geographic location: frostbite, malnutrition, mosquitos

  • social determination of health (access to safe drinking water, sanitary conditions, healthcare)

endemic

constantly present in a population or region with relatively low spread (COVID)

epidemic

sudden increase in cases spreading through a large pop (bird flu)

pandemic

sudden increase in cases across several countries/continents in the world

health

• physical, mental, social well-being

• not only the absence of disease

public health model for disease prevention

primary prevention, secondary prevention, tertiary prevention

• best to not get sick in first place!

primary prevention (public health model for disease prevention)

• well population: helth promotion and addressing risk factors - soical/genetic

• prevent disease/injury before it occurs by preventing exposures to hazards, altering unhealthy/unsafe behaviors that can lead to disease/injury

• EX: legislation/enforcement, education(high school education programs), immunization, nutrition, sanitization, housing

secondary prevention (public health model for disease prevention)

• reducing impact of disease already occurred

• early detection, screening, management of disease

• encourage personal strategies to prevent reinjury/recurrence

• implement programs to return people to original health/function to prevent long-term issues (smokers, sex workers)

• ex: regular exams/screenings, diet/exercise programs, pharmaceuticals, work modification, amnioscentesis

tertiary prevention (public health model for disease prevention)

• soften impact of ongoing illness/injury that has lasting effects by helping people manage long term complex health issues to improve as much as possible their ability to function/quality of life/life expectancy 

• people with a health problem: rehab, prevent complications, improve quality. of life

• supportive care, alleviate disability, restore function

• EX: cardiac/stroke rehab program, chronic disease management program, support group, vocational rehabilitation

homeostasis (homeo:same)

• dynamic, steady state in which all systems are in balance at the ideal set point

• maintaining a stable internal environment (@ set point) despite changing external conditions

• Continual regulation of vital body functions: temp, glucose, HR, o2, ph

allostasis (allo:variable)

• process by which the body responds to stressors through change in order to regain homeostasis

• ability of the body to adjust in order to maintain stability in the face of changing conditions

• Continual regulation of vital body functions become more variable based on specific demands

stress

• physical, chemical, emotional factor resulting in tension of body/mind

• real/perceived threat to homeostasis (triggers allostatic mechanism)

• stress response: attempt to restore the balance - meant to be helpful, becomes damaging when repeatedly activated/does not cease

• seyle: diff stressor to rats —> same response ‘stress response’

stressor

anything that throws the body out of an allostatic balance

general adaptation system (GAS) - seyle

three stages of general stress response:

• alarm: fight/flight

  • sympathetic-adrenal medullary manifestations: epi, norepi, endorphin

    • promote energy production for fight/flight/repair

• resistance/adaptation: allostasis (return to homeostasis)

  • hypothalamic pituitary adrenal axis: cytokines, aldosterone, cortisol

    • mobilize resources for repairs/maintenance of allostais

• exhaustion: allostatic overload - body unable to return to homeostasis

alarm (first stage of GAS)

• sympathetic-adrenal medullary manifestations: triggers fight/flight

  • real/perceived threat disrupts the balance of homeostasis —> triggers the hypothalamus to activate GAS

    • hypothalamus activates the SNS

    • secretion of ACH: stimulates adrenal medulla —> release catecholamines

      • epinephrine

      • norepinephrine

      • endorphins/enkephalins

• promote energy production for fight/flight/repair process

sympathetic adrenal medullary system: epinephrine effects (catecholamine)

• increased CO/VR: blood vol pumped

• increased myocardial contractility: increased HR

• bronchodilator: relaxes smooth muscle

• glycogenolysis: release glucose from the liver

• lipolysis: free glycerol for gluconeogenesis

• suppressed insulin secretion: elevate blood glucose lvl

• coagulation

sympathetic adrenal medullary system: norepinephrine effects (catecholamine)

• vasoconstriction: regulate blood flow, maintain BP

• reduced gastric secretions

• pupil dilation

• inhibit insulin production

sympathetic adrenal medullary system: endorphone/enkephalins

• raise pain threshold

• euphoria

• sedation

resistance/adaptation: second stage of gas

• hypothalamic-pituitary adrenal axis:

  • real/perceived threat disrupts the balance of homeostasis —> triggers the hypothalamus to activate GAS

    • hypothalamus secretes CRH

    • anterior pituitary secretes ACTH

    • adrenal cortex: glucocorticoids

      • cortisol

      • aldosterone

      • immune cytokines

• mobilize resources to make repair and maintain allostasis

  • immune boost

  • raise pain threshold

  • stimulate appetite

  • hemodynamic regulation

hypothalamic-pituitary adrenal axis: cortisol

• increases glucose levels-gluconeogenesis:

• protein metabolism: free amino acids for gluconeogenesis

• stimulates appetite: increases glucose

• anti-inflammatory: inhibits cytokines (suppress overactivity)

• release sugars: catabolic effect in skeletal muscle, lymphoid tissue, adipose, skin/bone —> release free FA/glycerols

hypothalamic-pituitary axis: aldosterone

• promote sodium conservation: sodium reabsorption in distal collecting duct, excrete potassium

• RAAS: renin-angiotensin-aldosterone system - renin secreted by kidney when BP low, angiotensin —> angiotensin 2, release of aldosterone from kidney

• increase blood volume: increase BP

hypothalamic-pituitary axis: immune cytokines

• enhance the immune response

resistance/adaptation

allostasis

• Mobilizing resources to make repairs and maintain allostasis - stress hormones decreae, which allows resources (energy) to be directed to repair

• Immune system boost, raise in pain threshold, stimulate appetite, hemodynamic regulation

• EX: frustration, irritable, poor concentration

exhaustion

allostatic overload

• Effects: inadequate adaptation leads to disease/eventual death

  • Related to excessive production of glucocorticoids/catecholamines 

• EX: depression, anxiety, physiological manifestations

adaptation

biopsychosocial process of adjusting physiology, morphology, behavior in response to a new or altered circumstance in the environment

distress

inability to cope with physiological or psychological stressor - activates release of HPA and SNS → exacerbate allostatic load 

allostatic overload

• cause: multiple stressors, repeated exposures, inability to adapt, chronic stress

• circulation of glucocorticoids/catchecolamines: linked to hypertension, athlerosclerosis, myocardial infarction, cardio vascular diseases/death

• chronic overactivity of brain: atrophy of nerve cells —> memory impairment

• cause depressive illness, PTSD, obesity (cortisol-increased hunger), inflammation

stress effect on nervous system

tics, fatigue, loss of motivation, anxiety, overeating, depression, insomnia

stress effect on cardiovascular system

irregular HR, hypertension, stroke, CAD

stress effect on GI system

gastritis, IBS, diarrhea, nausea/vomiting, UC

stress effect on genitourinary system

diuresis, irritable bladder, sexual dysfunction, menstrual irregularity

stress effect on integumentary system

eczema, psoriasis, acne, hair loss

stress effect on respiratory system

increased respiration, asthma, hay fever

stress effect on immune system

immunodeficiency/suppression, autoimmune

stress effect on endocrine system

hyperglycemia, diabetes mellitus

stress effect on musculoskeletal system

headache, contraction, arthritis, inflammation of CT