Introduction to Surgery Flashcards
What were Halsted’s Principles of Surgery?
- Handle tissues gently
- Control haemorrhage carefully
- Preserve blood supply to tissues
- Observe strict aseptic technique
- Apply minimum tension to tissue
- Ensure tissues correctly apposed
- Eliminate dead space
What are the historical perspective of asepsis?
1867: Lister = Principles of Asepsis => remove necrotic tissue/dirt, apply disinfectant to doctor and wound (carbolic acid)
1886: Steam sterilization
1891: Aseptic ritual
1910: Aseptic principle fully accepted in America
1913: Halsted uses surgeon’s gloves
Late 1940s: Aseptic veterinary surgery common
1960s: All surgeons wearing hats, masks, sterile gowns and gloves
What are the sources of contamination?
Surgeon. Animal. Instruments. Environment
What are the results of minimizing contamination?
Improved wound healing, surgical success, decreased mortality, repeatable animal models, narrower standard errors
How do you eliminated the surgeon as a source of infection?
- Wear sterile gowns, remove jewelry
- Sterile gloves, scrubbing hands
- Maintenance of sterility
How do you eliminated the animal as a source of infection?
- Clipping and shaving fur
- Disinfecting surgical site (not ethanol)
- Draping site to prevent contamination
- Maintaining sterility
How do you eliminate the instruments as a source of infection?
- Remove organic material (washing), then sterilise by chemical/heat techniques
- Dry heat/autoclave/gamma radiation/beads
- Hot bead sterilisation = batches of animals
- Sharp and well-maintained
How do you eliminate the environment as a source of infection?
- Clean dust-free environment that can be cleaned appropriately
- Good lighting and circulation space
Availability of equipment to ensure aseptic technique, anaesthesia, monitoring, heating - Easily cleanable surfaces
- Enough space to maneuver
Where did the myth that rodents don’t get post-operative infection come from?
No obvious signs (pus, wound breakdown, death), but still other symptoms (malaise, behavioural changes, pyrexia, weight loss)
What are the stages of wound healing?
- Inflammatory phase = Haemorrhage, Inflammation, Primary Wound Contracture
- Reparatory Phase = Epithelialization, Granulation, Contracture, Maturation
What happens during haemorrhage of the inflammatory phase?
- Vessels constrict
- Thrombus forms
- Vessels relax, cell mediators released = clot formed = elements of repair if undisturbed
What happens during inflammation of the inflammatory phase?
- Mediators from damaged cells = accumulation of inflam cells and blood factors
=> Ensure process = localised - Clear up inefective debris and secrete growth factors for healing
What happens during primary wound contracture of the inflammatory phase?
- Local fibroblasts contract to decrease wound surface area
What happens during epithelialisation of the reparatory phase?
- Cells in bottom layer of skin at wound edge migrate under scab to cover defect
What happens during granulation of the reparatory phase?
- Capillaries and fibroblasts beneath epithelial layer multiply and migrate inward = granulation tissue (firm, pink, resistant to infection)
- Tissue bed supplies O2, collagen, aids in contraction
