Preparing for Surgery Flashcards
Define aseptic technique
A set of techniques and practices designed to prevent or minimise microbiological contamination of the surgical wound.
Why is there no such thing as “sterile”
Sterile implies an inanimate object- there will always be air and a patient to contaminate the surgical site
what does infection involve?
The hosts immune system
5 factors associated with infection
Bacterial numbers >105
Bacterial type
Host Resistance
Presence of Foreign Bodies
Interaction between host and bacteria
Define sepsis
the presence of pathogens, or their toxic products in the tissues of a patient
Define asepsis
absence of pathogenic microbes in living tissue
Define sterilization
destruction of all microbes and organisms, including spores (inanimate objects only) by physical or chemical means
Sterilization is the complete removal of all viable microbial forms including the vegetative forms of bacteria and spores
Define antisepsis
use of antimicrobial chemicals on living tissues
Define disinfectant
A germicidal chemical agent that kills microorganisms on inanimate objects
When do surgical infections usually occur?
30 days general
12 months orthopedic
What is the goal of successful surgery?
Prevention of surgical infection and to encourage wound healing
4 Golden rules of preparing for surgery
- STRICT ASEPTIC TECHNIQUE-
NO PATHOGEN HAS YET DEVELOPED RESISTANCE TO ASEPTIC TECHNIQUE! - Disruption of dermal integrity = access to inner tissues- everytime there is a cut, it allows stuff access
- Laws of the Operating Room
- Aseptic technique prevents cross contamination in surgery
4 sources if bacterial contamination
- The surgical personnel
- the patient (urogenital, respiratory, gastrointestinal)
- Operating theatre environment (need to work clean to dirty )
- Surgical instruments and implanted materials (biomaterials) inc. suture
4 aspects involved in aseptic techniques
- surgical site
- facilities and environment
- surgical team
- surgical equipment
Golden rule of antibiotics
Antibiotic coverage is NEVER a good substitute for appropriate precautions and good operative technique
5 signalments of patient selection and preparation when preventing surgical infections
History (age, food, cycle stage, previous surgery, medications, sensitivities, other disease processes)
Physical exam
CBC and Biochem
Urine SG
Treatment of underlying disease or remote infection
ASA 1
Minimal risk of normal healthy patient with no underlying disease
ASA 2
SLight risk of a slight to milk systemic disease. Neonate, geriatrics, obesity
ASA 3
Moderate risk, obvious systemic disease
Anemia, moderate dehydration, fever, low grade heart murmur or cardiac disease
ASA 4
High risk with severe, systemic, life threatening disease
severe dehydration, shock, uremia, toxemia, high fever, uncompensated heart disease, uncompensated diabetes, pulmonary disease, emaciation
ASA 5
Extreme risk, moribund (point of death), patient will probs die with or without surgery
Advanced cases of kidney, heart, liver or endocrine disease
Profound shock
severe trauma
pulmonary embolus
terminal malignancy
ASA E
Emergency
can be attached to each class in case of emergency surgery
6 characteristics of an ideal antiseptic agent
Non irritant to skin
Bactericidal
Broad spectrum
Long residual activity
Not inactivated in the face of organic material
Economical
3 chemical groups of antiseptic agents
Iodophors (povidone- iodine)
Bisbiguanide (chlorhexidine)
Alcohols
Iodine MOA
penetrates cell wall and displaces molecules with free iodine
Iodine persistent action
4-6 hours
Iodine toxicity
Thyroid dysfunction
Acute contact dermatitis
Activity decreases by organic material
Chlorhexidine MOA
Increase cell wall permeability
Precipitates cellular components
Chlorhexidine persistent action
> 6 hrs
Chlorhexidine residual action
upto 1-2 days
Chlorhexidine toxicity
Ototoxic
corneal toxic
neurotoxic
Alcohol MOA
Cell lysis, protein denaturation, metabolic interruption
Alcohol toxicity
Corneal toxicity
neurotoxic
Why are abraded areas problematic ?
Need to be minimised as they will lead to direct contact with surgery site regardless of how well you close the sight
What are skin and hair?
Bacterial reservoirs
Staphylococcus, streptococcus, micrococcus, clostridium and bacillus
What is the recommended technique for hair removal?
Clipping - appropriate area each side of proposed incision should be clipped
BUT NOT THE DAY BEFORE - increases risk of infection by 3 fold
Water soluble gel should be placed on open wounds prior to clipping- nicks and grazes act as a focus for bacterial contamination
is clipping or shaving better ?
Clipping - shaving increases infection rate
3 scrub method
LATHER and SCRUBBING IS IMPORTANT
Initial scrub –Antiseptic/Detergent mixture
Second scrub –Alcohol antiseptic scrub/wipe
Tertiary scrub –Antiseptic agent
Avoid overzealous force - increases irritation and bacterial liberation
Wear gloves
Initial prep should be done outside the operating room
4 sources of contamination from the surgeon to the patient ?
Hands (nails)
Mouth (breath)
Head (skin)
Hair
4 Barrier method components
Scrub suit
Surgical head covers
Shoes or shoe covers
Face masks
Purpose of scrub suit
Not impermeable barrier to micro-organisms
aim is to reduce particulate shedding in the operating theatre (should not be worn outside theatre or cover)
Purpose of surgical head covers
Hair is a source of bacterial contamination from the surgical team
purpose of shoes or shoe covers
Prevent external bacteria and hair being tracked into theatre
Also avoids tracking material from theatre around hospital
purpose of face masks
Aerosol droplets and direct to the sides (so forget ur manners if you need to cough)
Contains expelled microorganisms
3 aims of surgeon skin prep
Mechanical removal of gross dirt from hands and forearms
Reduction in the transient microbial count to as close to zero as possible
Prolonged depressant effect on the resident microflora of the hands ANDarms
Important points of gown (3)
Act as a barrier between patient and surgical team
-Gowns should be resistant to blood and aqueous fluids- Cloth gowns are cheaper but lose all barrier properties when wet
-Disposable single use gowns have superior barrier properties and decrease wound infection rates
important points of gloves (2)
Sterile gloves are mandatory to reduce contamination
25-30% of surgical gloves have tears at end of surgery
Operating team breaks in asepsis
Exposed hair
Active respiratory infection
Dermatitis
Loose fitting mask
Soiled scrub suit
Scrub procedure breaks in asepsis
Rings and bracelets left on
Long or dirty fingernails
Improper scrub technique
Gowning or gloving with wet hands
Advantages of disposable barrier materials
Excellent water repellent
Always in good condition
Labour saving - less laundry
Presterilised
Disadvantages of disposables
Expensive
May be less conforming
Large stock required
Advantages of reusable
Cheaper
Less waste
Disadvantages of reusable
Poor barrier to properties which lead to strike through
Labour intensive
Threads may detach and lint into wound
Reduced quality with repeat washing
4 quadrant method of draping
- side closest to surgeon (between patient and surgeon)
- Adjacent quadrant (left side)
- Quadrant opposite 2 (right side)
- Opposite surgeon
Secure with towel clamp
How many organisms fall into surgical wound in 1hr
75 000
Bacteria can be endogenous or exogenous
What is a nosocomial infection?
also called health-care-associated or hospital-acquired infections, are a subset of infectious diseases acquired in a health-care facility
More AB resistance with nosocomial infections
Animals acquire hospital organisms soon after admission and reservoirs established in the lower gitract, lower utand nasopharynx
7 requirements of an operating theatre
Located out of high traffic area
Only necessary personnel enter
All personnel correctly attired
Room not used to examine or treat animals
(Mild positive pressure laminar air flow so air flows out when door opened)
(Airflow should move from area of least to greatest contamination)
PRINCIPLES OF OPERATION AND CONDUCT
3 steps of routine cleaning procedure
Damp dust all surfaces at start of day
End of day vacuum and disinfect all surfaces and equipment
Once weekly thorough scrub of walls and floors
2 forms of sterilization
First, instruments must be cleaned (mechanically or chemically) then:
1: Physical- heat, filtration, radiation
2: Chemical- ethylene oxide, alcohols
What is the role of sterilisation indicators ?
Monitor the efficacy of sterilisation method
What is a sterilisation indicator ?
Chemical indicators undergo a colour change when exposed to a certain temperature
NOTE: do not indicate time of exposure or if items or sterile
2 classes of chemical indicators
1: Tape
2: Bowie-dick indicator strips
4 consequences of post surgical wound infection
There should be less than 5% chance of getting a wound infection from a clean surgical site
- wound breakdown or delayed healing
- septicaemia/ endotoxemia
- pain, morbidity
- Increased hospitalization
Why occurs during wound breakdown or delayed healing
Breakdown of viscera repair
Sepsis associated with implants
Haemorrhage associated with lysis around infected ligatures
Evisceration
hernia repair failure
True or false: al surgical wounds become contaminated even when strict asepsis is maintained
TRUE
When are peri-operative AB delivered ?
Prophylactic usage
After induction, before you start surgery
Want circulating therapeutic levels circulating in the tissues
Ideally be present at surgical site at time of potential contamination- ideally intravenously at least 20-30 mins before first cut, repeated at 60-90 minute intervals depending on selected antibiotic
When are post operative antibiotics delivered?
Therapeutic usage
Send patient home with them if there has been an identified:
-breech in sterility
- systemic disease/ comorbidities
Dependent on:
- owner compliance
- classification of surgery (risk to patient, risk of complication)
When are host tissues most susceptible to bacterial lodgement ?
Within first 3 hours of contamination
When are ABs more efficacious
when given pre-operative +/- repeat
Duration of therapy should be determined by the wound classification and individual patient assessment
4 classifications of surgical wounds
- Clean
- Clean Contaminated
- Contaminated
- Dirty
Class 1: Clean
An uninfected operative wound in which no inflammation is encountered
respiratory, alimentary, genital, or uninfected urinary tract is not entered.
primarily closed
if necessary, drained with closed drainage.
Operative incisional wounds that follow nonpenetrating (blunt) trauma should be included in this category if they meet the criteria.
Class 2: Clean contaminated
An operative wound in which the respiratory, alimentary, genital, or urinary tracts are entered under controlled conditions and without unusual contamination.
Specifically, operations involving the biliary tract, appendix, vagina, and oropharynx are included in this category, provided no evidence of infection or major break in technique is encountered.
Class 3: Contaminated
Open, fresh, accidental wounds.
Operations with major breaks in sterile technique (eg, open cardiac massage)
Or gross spillage from the gastrointestinal tract,
incisions in which acute, non-purulent inflammation is encountered
Class 4: Dirty- infected
Old traumatic wounds with retained devitalized tissue Wound that involve existing clinical infection or perforated viscera.
This definition suggests that the organisms causing postoperative infection were present in the operative field before the operation.
4 usages of the surgical wound classification
- Predicts level of bacterial contamination
- Predicts likelihood of infection
- Informs use of peri-operative antibiosis
- applies to non-surgical wound and helps to inform antibiotic usage and wound management
How much can wound ischemia (blocked blood flow/ arterial insufficiency) potentiate infection?
10 000 fold
What can some bacterial species do in a local wound environment?
secrete a bioslime or glycocalyx
What can surgical implants do in a local wound environment?
Act as nidus (focus of infection - a place where bacteria may multiply)
What does tissue trauma do?
Significantly affects the number of bacteria required to produce infection
6 Halsted Principles of Surgery
- Aseptic technique
- Sharp anatomic dissection
- Gentle tissue handling
- Careful haemostasis (preservation of blood supply)
- Avoid tension
- Obliteration of dead space (accurate tissue apposition)
Why bother with Halsted’s principles of surgery?
Reduced dehiscence
Rapid wound healing
Prevention infection
Number one way to reduce peri-operative errors?
Medical checklists
They act as a memory aid and guide users through accurate task completion
They specify each step, in order aiming to limit errors
4 stages on a surgical safety checklist
1: pre operative (prep room) inc anaesthesia choices, allergies, airway/ aspiration risk, blood loss risk, equipment test, surgical site
2: before incision (operating room) inc prophylactic AB’s, sponge count in, team members and role, anticipated critical events
3: Before leaving operating room inc spong count out, specimens labelled and accounted for, equipment issues, review of patient
4: after leaving operating room inc rectal sponges and purse string sutures out
3 ways to limit surgical complications
Consider checklist for atomisation of regular procedures
Maintain team communication
Be aware of environment and self
errors of omission are
under stimulated
errors of commission (doing something wrong)
overstimulated
Why are procedural skills perishable?
You still need adequate initial preparation and ongoing practice to maintain proficiency
5 ways to optimise zone of optimal personal function
Practice under pressure
Mental rehearsal
Team review
limit distractions
pause and review
5 components of the clinical audit
- Identify the audit topic
- Set the standard and design the method
- Collect the data
- Analyse the data
- Implement change
