conditions test #2

october 13

first line of defense

physical/chemical barriers (skin, mucous membrane, secretions)

second line of defense

innate immune responses (inflammation, phagocytes)

third line of defense

adaptive immunity ( T and B lymphocytes, antibodies)

normal lines of defense 

these layers prevent or limit infection and tissue damage 

innate components of the immune system

skin, muscoa, neutrophils, macrophages, NK cells, complement and cytokines

adaptive components of the immune system

b-cells (antibodies), t-cells (CD4 helper, CD8 cytotoxic), memory cells

lymphoid organs: immune system

bone marrow, thymus, lymph nodes, spleen

inflammation

tissue response to injury or infection, characterized by redness, heat, swelling, pain, and loss of function 

acute inflammation 

rapid onset, short duration, neutrophil-predominant, aims to eliminate insult and repair 

chronic inflammation

persistent, macrophage/lymphocyte involvement, fibrosis, long term tissue damage

local effects of inflammation

redness, heat, swelling (edema), pain, loss of function

systemic effects of inflammation

fever, leukocytosis, increased acute phase reactants (CRP), malaise, possible sepsis if widespread infection/inflammation

primary intention healing

clean wound edges, approximated (surgical closure)

secondary intention healing 

wound edges separated; fills with granulation tissue, more scarring 

teritary intention healing (delayed primary)

wound left open then closed later to reduce infection risk

contracture

permanent shortening of tissue across a joint limiting motion

adhesion

fibrous bands binding tissues/organs that should be separate

hypertrophic scar/keloid 

excessive collagen- hypertrophic remains within wound boundary; keloid extends beyond 

wound dehiscence

partial/ complete separation of surgical incision

ulceration

loss of epidermis/dermis often due to ischemia or pressure

epidermis

outer waterproof barrier (keratinocytes)

dermis

vascular connective tissue with collagen, nerves, hair follicles and glands

hypodermis (subcutaneous tissue) 

fat and connective tissue for cushioning and thermoregulation 

burn

tissue damage caused by heat, chemical, electricity, radiation or friction

mechanisms of burns

thermal, chemical, electrical, radiation, and cold/frostbite

1st degree (superficial)

epidermis only, erythema, no blisters, painful

2nd degree (partial thickness) 

involves epidermis and part of the dermis; blistering, very painful 

3rd degree (full thickness)

destroys epidermis and dermis; may extend to subcutaneous tissue, less painful if nerve endings destroyed; requires grafting

eschar 

dry, leathery necrotic tissue (often black/brown) that can impede healing and may require debridement 

exudate

fluid emitted by wound (serous, sanguineous, purulent) indicates inflammation or infection level; amount and quality guide dressing choice

TBSA (total body surface area)

estimates percent of body burned to guide fluid resuscitation, metabolic needs and transfer criteria

Rule of Nines

quick adult TBSA estimate dividing body into 9% areas (head-9, each arm-9, each leg-18, anterior trunk-18, posterior trunk-18, perineum-1)

Lund-Browder

more accurate for children; adjusts proportions by age

edema 

excess interstital fluid 

pitting edema

Indentation remains after pressure; graded (1+ to 4+)

third spacing

fluid shifts into nonfunctional interstitial spaces (ex. abdominal cavity); reducing intravascular volume and cause hypotension

systemic effects of burns 

Hypovolemic shock from fluid loss, increased capillary permeability, risk of respiration compromise (inhalation injury, ARDS), high infection risk, severe pain, hypermetabolic state increasing caloric/protein needs, electrolyte imbalances

temporary wound coverings 

wet-to-dry dressing, biologic dressings (allograft and xenograft), synthetic temporary membranes used to protect, reduce fluid loss and allow time for definitive care 

permanent wound coverings

autografts (patient’s skin), cultured epithelial autografts, or durable synthetic grafts used for definitive closure

splinting and protective positioning 

prevent contractures, protect grafts, maintain joint alignment, control edema

Appropriate positioning for the neck

soft collar and slight extension to prevent chin to chest contracture

Appropriate positioning for the axilla

abduction positioning or axillary splint at ~90° abduction to prevent adduction contracture

appropriate positioning for the elbow 

near full extension splint (5-10° flexion) to prevent flexion contrature 

appropriate positioning for the wrist

wrist in 10-30° extension, MCPs 60-70° flexion, IPs extended for hand burns (intrinsic-plus when appropriate)

appropriate positioning for the hand

intrinsic plus position - wrist at 10-30 ° extension, MCPs flexed at 60-70*, IPs extended, thumb abducted to preserve webspace 

bacteria

prokaryotes (ex. Staph aureus, MRSA, VRE)

viruses

require host cells (ex. influenza, HIV, SARS-CoV-2)

fungi

yeasts and molds (ex. Candida) 

Protozoa

single celled eukaryotes (ex. giarida)

prions

misfolded proteins (rare, ex. CJD)

direct contact 

person to person touch 

indirect contact

via contaminated objects (fomites)

droplet

large respiratory droplets (within ~3 feet) from cough/sneeze

aerosol (airborne) 

small particles that remain suspended and travel longer distances 

vector-borne

via organism (mosquito, tick)

standard precautions for infection control

assume all blood/body fluids potentially infectious. use hand hygiene, gloves, mask/eye protection when indicated safe injection practices, respiratory hygiene, and proper environmental cleaning

contact precautions 

gown and gloves for patient contact and contaminated surfaces  

droplet precautions 

surgical mask within 3-6 feet of patient, plus standard precautions 

airborne precautions 

N95 or higher respirator, negative pressure room, limit transport 

multi drug resistant organisms (MDRO)

organisms resistant to multiple antibodies (ex. MRSA, VRE)

at risk for transmission by contact

high risk; hospitalized, recent antibotics, invasive devices, and immunocompromised

neutropenia and neutropenic precautions 

low neutrophil count increasing infection risk 

precautions: limit exposure to infectious contacts, strict hand hygiene, avoid fresh flowers/uncooked foods in some settings, prompt evaluation of fevers 

autoimmune disorders 

immune response directed against self tissues; mechanisms involves loss of tolerance, autoantibodies, autoreactive T-cells (ex. rheumatoid arthritis) 

immunodeficiency

primary (genetic) or secondary (HIV, chemo) results in impaired host defense and increased susceptibility to infections

epidemiology, body structures and possible barriers for superficial burns 

epidermis only- pain, transient functional limitation; OT focuses on education, ROM, early mobilization 

epidemiology, body structures and possible barriers for partial thickness burns 

more pain-blisters; OT focuses on dressing changes coordination, ROM, splinting, edema and scar prevention 

epidemiology, body structures and possible barriers for full thickness burns

often require grafting; OT: graft protection, aggressive splinting, scar management and ADL training 

epidemiology, body structures and possible barriers for nosocomial infections and hospital acquired PNAs 

isolation may limit therapy sessions; focus on graded activity, breathing techniques and infection control 

structures of the pulmonary system

nose, pharynx, larynx, trachea, bronchi, bronchioles, alveoli, lungs and pleura

functions of the pulmonary system

gas exchange (oxygen in and carbon dioxide out), regulation of blood pH, phonation and filtration of air

protective mechanisms of the pulmonary system

mucociliary escalator, cough reflex, alveolar macrophages, nasal hairs, immune response 

ventilation

movement of air into and out of the lungs; about airflow

perfusion

blood flow through pulmonary capillaries; about blood flow

spirometry/pulmonary function test

measures lung volumes and air flow limitation

bronchoscopy

visualizes airways and collects samples 

pulse oximetry

non invasive oxygen saturation

cultures

identifies infections from sputum/ bronchial washings

common symptoms of pulmonary disorders

cough, wheezing, stridor, rales(crackles), rhonchi, dyspena, cyanosis, clubbing and mucous secretions 

anoxia

complete lack of oxygen

hypoxemia

low oxygen in blood

hypoxia

low oxygen in tissues

respiratory arrest

complete cessation of breathing

respiratory failure 

inability to maintain oxygen and carbon dioxide balance 

obstructive lung disease 

difficulty exhaling due to narrowed airways (ex. COPD and asthma)

restrictive lung disease

difficulty inhaling due to stiff lungs/ chest wall (ex. pulmonary fibrosis)

oxygen delivery

nasal cannula, simple mask, non-rebreather, venturi mask

Invasive ventilation

endotracheal intubation, tracheostomy

pulmonary rehabilitation

exercise training, education, breathing techniques, nutritional counseling, psychosocial counseling

dyspena control postures 

sitting and leaning forward to ease breathing 

pursed lip-breathing

prevents airway collapse and improves exhalation

diaphragmatic breathing

improves ventilation efficiency

effective coughing

clears secretions

noninvasive ventilation

CPAP, BiPAP via mask

congestive heart failure (CHF) 

heart pump failure; common in the elderly; structures affected: heart and lungs; impact: fatigue, edema, dyspnea; biggest symptom: lethargy

chronic obstructive pulmonary disease (COPD)

progressive air flow limitation; impacts lungs and gas exchange; barriers: decreased endurance and ADL difficulties

emphysema

alveolar destruction, hyperinflation; barriers: activity tolerance; smoking is the primary cause, but there can be a genetic factor

chronic bronchitis

inflammation, mucous production; barriers: fatigue, frequent infection; progressive and irreversible damage the to the bronchi 

asthma 

airway inflammation; bronchospasm; barriers: exercise intolerance; two basic types: extrinsic:childhood and intrinsic: adulthood; can be acute or chronic 

bronchiectasis 

airway dilation, mucus pooling; barriers: infection risk 

cystic fibrosis (CF) 

genetic, thick secretions; barriers: fatigue and infection; malabsorption and malnutrition due to buildup of mucus in the pancreas