Mind map

burns and acute inflammation

Hala Mesmar English

Map content

burns and burn management
- a burn is sever skin damage that cause the affected skin cells to die
  - causes
    - intense heat
    - electricity
    - UV radiation
    - chemicals
  - types
    - range from 1st degree to 4th degree burns
      - 1st
        damage to the epidermis
      - 2nd
        damage to the epidermis and part of the dermis
        partial-thickness
      - 3rd
        full-thickness burn
      - 4th
        hypodermis also damages, burn reaches muscle tissue
- management of burns
  - pre hospital
    - stop the burning
      - stop, drop, roll
    - cool the burned wound
    - give fluids
  - at the hospital
    - early fluid replacement
    - ensure the environment is sterile
    - find the degree of the burn
    - rule of nines
    - ABCDE assessment
      - airway
      - breathing
      - circulation
      - disability
      - exposure
skin layers and function
- skin layers
  - epidermis
    - stratum corneum
    - stratum lucidum
    - stratum granulosum
    - stratum spinosum
    - stratum basale
  - dermis
    - papillary layer
    - reticular layer
  - hypodermis /subcutaneous adipose tissue
- skin functions
  - covers the entire body an protects the internal organs
  - protection against pathogens
  - prevents dehydration and reserves water
  - temperature regulation
  - excretes waste
  - produces vitamin D via sun exposure
  - act as route of drug administration
  - aids in diagnosis of systemic diseases
acute inflammation
- a response against a pathogen that aims to protect the body against the invader and eliminate it
- main players
  - blood vessels
    - dilate to increase permeability and help the protective cells escape to the site of injury
      - leads to exudate formation
  - cells and proteins
    - predominant cells in acute inflammation are neutrophils
      - eliminate pathogens by phagocytosis
    - proteins and mediators like chemokines and cytokines work as signals that guide leukocytes to injury site
- exudate formation
- signs and symptoms
  - inflammation cardinal signs
    - redness
    - swelling
    - heat
    - pain
    - limited joint movement
  - systemic symptoms
    - fever
    - loss of appetite
    - headaches
    - generalized fatigue
    - an effect of pyrogens and leukotrienes released from mediator cells of inflammation
apoptosis vs necrosis
- necrosis
  - pathological
  - happens as a result of injury
  - also called a host cell reaction
  - reversible
- apoptosis
  - self programmed degradation of cells
    - physiological
  - happens because of the body's own decision
    - elimination of unwanted cells
  - the cell is degraded by its own enzymes
  - irreversible
- cellular level changes
signs of wound infection
- expanding redness around the wound
- yellow to green pus formation/cloudy wound drainage
- red streaking of the edges of the wound
- unpleasant odor
- increased inflammation of the wound
  - pain, tenderness, swelling, heat
  - loss of function and movement of the infected area
skin normal microbiota
- commensal bacteria that live and thrive on the skin feeding on substances the skin produces
- prevent colonization by pathogens by competing for attachment sites or for essential nutrients
- factors contributing to variation
- types of skin flora
  - staphylococcus epidermidis
  - staphylococcus aureus
  - corynebacteria
  - propionibacteria
    - cutibacterium acnes
  - B-proteobacteria
  - flavobacteria
  - streptococcus mitis
innate immunity
- physical and chemicals barriers that prevent pathogens from entering the body
  - eliminate pathogen before the engagement of the third line of defense
- cells of the innate immunity
  - neutrophils
    - phagocytes
  - eosinophils
  - mast cells
  - basophils
  - monocytes
    - macrophages
    - dendritic cells
- mechanism of immune response against infection
antibiotics
- any substance that inhibits the growth and replication of a bacterium or kills it outright
- classification according to mechanism of action
  - cell wall synthesis inhibitors
  - increase cell membrane permeability
  - protein synthesis inhibitors
  - interfere with RNA and DNA synthesis
  - antimetabolites
- penicillins
  - kill susceptible bacterial by inhibiting the synthesis of the bacterial peptidoglycan cell wall
  - types
    - natural penicillins
    - extended spectrum penicillins
    - antistaphylococcal penicillins
  - pharmacokinetics
    - low plasma binding protein affinity
    - bioavailability depends on type
    - short half life
    - kidney excretion
  - adverse reactions to penicillins
    - urticaria
    - fever
    - joint swelling
    - angioneurotic edema
    - pruritus
    - skin rashes
bacterial resistance
- is the resistance of bacteria against antibiotics, the bacteria develops tolerance to the antibiotic that used to affect it previously
  - how bacterial resistance happens
- mechanisms of resistance
- prevention
  - immunization
  - using antibiotics only when necessary and only to the targeted bacteria
- resistance gene transfer
antibiotic susceptibility test
- susceptibility is the inability of a pathogen to grow in the presence of an antimicrobial drug
- testing is done to determine if a bacteria is resistant or susceptible to a certain antibiotic as well as the effectiveness of this drug on the bacteria
  - done by culturing a specimen of bacteria taken from a subject and exposing it to the drug
- results
  - susceptible
    - likely to inhibit bacterial growth
      - right choice for treatment
  - intermediate
    - can be effective at a higher or more frequent dosage
    - may only be effective in some body parts
  - resistant
    - not effective at inhibiting bacterial growth
      - most likely not the appropriate choice for treatment
- methods
  - dilution
  - disk
  - E-test
  - automated antimicrobial susceptibility testing systems
process of wound healing
- homeostasis
  - blood escapes the broken capillaries
    - blood dries on the exposed surface of the wound and dries forming a scab
  - platelets migrate to the ijnury site
    - start the clotting process
- inflammation
  - macrophages and neutrophils fill the injury site and eliminate pathogens
    - with the help of increased permeability of blood vessels and the release of mediators
- proliferation
  - fibroblasts and myofibroblasts replace damaged tissue with collagen fibers
  - formation of granulation because of proliferative skin cells and revascularization of the area
- remodeling
  - happens lastly when the damaged cells are replaced with new ones as well as collagen fibers and intact blood vessels are present yet again
complications of burns and healing
- inadequate scar formation
  - the wound may split or reopen again
- excessive scar formation
  - keloid scar
    - regions of extreme overgrowth beyond the confines of the original wound area
  - hypertrophic scar
    - occur when the remodelling stage exists for a longer period of time and they are more cellular and more vascular than mature scars
- contracture formation
  - develop when normally elastic tissues such as muscles or tendons are replaced by inelastic tissues (fibrosis)
- burn patients are at risk of several physical and mental disturbances
  - physical
    - infections
    - sever fluid loss
    - reduced bone or muscle density
    - hypermetabolism leading to malnutrition
    - scarring
    - metabolic acidosis
  - mental
    - anxiety
    - stress
    - insecurity