ECP 2 Flashcards
Define:
Sepsis
Asepsis
Antisepsis
- Sepsis: The presence of pathogens (or their toxins) in the tissues.
- Asepsis: The absence of pathogenic microorganisms in living tissue.
- Antisepsis: Prevention of sepsis by the destruction or inhibition of microorganisms.
Define antiseptic, disinfectant and sterilization
- Antiseptic: A chemical agent that either kills pathogenic microorganisms or inhibits their growth. (Applied to patient)
- Disinfectant: A germicidal chemical substance that kills microorganisms on inanimate objects. The term disinfectant is reserved for agents that are not applied to the body. Not as effective as sterilization.
- Sterilization: Is the complete elimination of microbial viability, including vegetative forms of bacteria and spores
post-operative infections what is the new challenge and main problems
- New challenges - Methicillin-resistant Staphylococcus aureus (MRSA), Methicillin-resistant Pseudintermedius (MRSP)
- Increases the morbidity of procedure outcomes, prolongs hospitalisation times and increases costs to the client.
- Particularly for orthopaedic procedures -> increased time for surgery and recovery
- Adverse publicity -> can ruin a clinic
What are the 4 sources of contamination during surgery
- The patient – main source
a. Skin
b. Haematogenous - The surgical equipment and implanted biomaterials (sutures, plates, screws etc)
- Surgical personnel
- The operating theatre environment, including airborne particles.
What are the 4 non-sterile barriers and 3 sterile barriers
NON-STERILE BARRIERS 1. Scrub suits 2. Surgical head covers 3. Face masks 4. Shoes and shoes covers STERILE BARRIERS 1. Surgical gown 2. Sterile gloves - susceptible to tearing and punctures 3. Sterile drapes
What are the 2 different types of surgical gowns and drapes
1) Reusable:
○ Typically woven 50/50 Polyester/cotton -> woven so have larger holes for bacteria
○ Holes need to be repaired via a heat sealed patch.
○ Should be treated to make them waterproof
2) Single use: - BEST OPTION
○ Synthetic - Non-woven
○ The use of disposable gowns decreases contamination and infection rates.
What is the goal of surgical site preparation and the 6 considerations for a good antiseptic solution
- Whilst it isn’t physically possible to sterilize the skin of the patient, the intention should be to remove organic material and reduce bacterial contamination to as close to zero as possible and eliminate transient bacteria.
- Broad spectrum
- Ability to reduce growth on transient and resident microorganisms
- Be rapid and cumulative
- It should not create skin irritation
- It should have residual/persistent action
- TGA approved
What are the 3 common antiseptics for skin preparation and their characteristics
1) Chlorhexidine gluconate
- G+/G- bacteria, viruses and fungi NOT sporicidal
- residual action (6 hours), not inactivated by organic materal, diluted in wounds 0.05%
- not compatible with iodine
2) Povidone-iodine
- bactericidal, fungicidal, virucidal may be sporicidal
- low residual activity, inactivated by organic material
- high incidence of skin reactions
3) alcohols
- ○ Most RAPID and effective antibacterial antiseptic (including MRSA & MRSP)
○ Bactericidal, fungicidal, variable against viruses and ineffective against spores.
○ Most effective at 70%
○ Evaporates very quickly - minimal residual effect so never used ALONE
○ Tissue necrosis in open wounds
Hair removal for surgery preparation what is important
- skin trauma increases bacterial counts
- size 40 clippers
- hair removed in wide margins
- with the grain and then against
What are the 3 key steps
- Pre-Wash (using a detergent based antiseptic) - chlorhexidine or Povidone-iodine
- Removal of the detergent (using 70% alcohol)
- Application of an approved surgical skin antiseptic product.
What are the 3 main aims of surgical hand scrub
- To remove dirt, flaking skin, oil and microorganisms from the hands and lower arms (below the elbow).
- To reduce the microbial count (residential & transient) to as close to zero as possible.
- To provide a prolonged inhibitory effect on the resident micro flora.
What are the 2 types of hand scrubs and what is considered the best
- Traditional Water Based Hand Scrub
- ALCOHOL BASED HAND RUB (ABHR)
- Considered gold standard in surgical hand hygiene
- Applied to clean, dry hands and arms.
What is the sterile zone on a gown and what is the only thing that can touch it
- The sterile zone
○ Mid chest level to waist level
○ From finger tips to elbows
Gloved hands should only touch the sterile zone!!!!
Draping what is teh sequence and how to drape a limb
- Near, top, tail and far sequence, followed by the large cover drape (fenestrated or nonfenestrated) - learn order
- Free draping
○ When whole limb is required to be within the sterile field
○ Paw bandaged and suspended
○ Paw bandage wrapped with:
§ Sterile Vetrap and waterproof glove
§ Sterile waterproof drape
What is the most important thing in terms of theatre etiquette and the order to process and sterilise instruments
- Direct correlation between the number of people, their movements and the number of airborne bacteria in the operating theatre.
- Work flow should encourage separate processing, from cleaning dirty instruments, instrument packaging, sterilizing, then storage.
sealing and labelling instruments before autoclaving what is involved
- Sealing: ○ Autoclave tape ○ Heat sealing: for paper bags and laminates - Labelling ○ Not ball point pens ○ Not on paper packaging ○ Include the following information: § Date of sterilization § Expiry date § Instrument type Staff member initials
List 6 methods of sterilization
- Gas Plasma - Hydrogen peroxide vapour and low temperature (42°C) – aka “Sterrad” system
- Gamma irradiation - Radioactive isotope Cobalt 60
- Ethylene oxide gas
- Peracetic acid aka Steris System
- Elevated temperature in dry heat oven (160-180°C)
- Steam under pressure - Autoclave (common in veterinary practice)
Autoclaves why used, and how works
- Steam sterilizers are cheap to run, non-toxic, safe and simple to use.
- Pressure vessels (autoclaves or steam sterilizers) are used to achieve high temperatures with dry saturated steam.
○ Dry saturated steam refers to steam that doesn’t produce water droplets and the condensate is in equal balance with evaporation.
What is shelf life related to
- Shelf life is dependent on external events that compromise the integrity of the protective barrier of the sterilized item, such as choice of packaging material, correct sterilization process, handling and storage, rather than a given time frame. Therefore, shelf life is event related not time related.
What is the most common towel clamp, what used for and is it used at melbourne uni
- Used to secure linen drapes to patient skin.
- Backhaus towel clamps most common.
- Not used for single use, disposable drapes so not used at Melbourne
What are the 6 suture material characteristics
- Tensile strength – load at which suture fails
- Capillarity - wicking of fluid along structure
- Mechanical creep/stress relaxation – slowly deforms under constant stress
- Plasticity - deformation under load, then reverts
- Pliability – ability of suture to change shape
- Suture pull out value – load required to pull suture out of tissue
Monofilament vs multifilament what are the advantages and disadvantages and which is preferred
Monofilament: preferred - Less pliable - Poorer handling, increased memory - Less tissue drag - Less knot security, more knots required. Multifilament: - Greater strength and pliability - Improved handling compared to monofilament - Increased capillarity - Increased tendency for bacterial colonization - Avoid in contaminated environments - Greater tissue drag - Increased knot security
What makes a suture absorable and what is the purpose of sutures
Absorbable are those that absorb within body tissue under 120 days and do not require removal, whilst nonabsorbable sutures retain their strength until they are removed.
- The common purpose of sutures; are to stop bleeding and/or to pull together wound edges to allow healing of damaged tissue.
- An additional purpose in modern day surgery is the “stay suture”.
What are the 2 most common monofilament and 1 multifilament sutures and their properties
PDS, PDS II – synthetic, absorbable, general closure, significant memory - GO TO MOST COMMON Monocryl – synthetic absorbable, similar to Biosyn.
Multifilament
1. Catgut – absorbable, excessive tissue reaction. Better suture available.
Suture size what is it measured in, the reference range, what choose for small patients and which thicker and thiner diameter
- United State pharmacopeia (USP)
○ 11/0 to 7
○ For small animal patients, typically sizes 4/0 (finer) to 0 (thicker diameter)
○ USP most commonly used in Australia - Metric
○ suture diameter expressed in 10th’s of a millimeter
Suture needles what makes the ideal ne and the 2 types with properties
- Ideal surgical needle – sharp enough to penetrate with minimal resistance, slim without compromising strength, resistant to bending but flexible enough to resist breaking
1) Eyed - resusable, increased tissue damage (blunt needle) - not recommended
2) swaged on - USE THIS ONE, single use, cause less tissue trauma (shrap needle), essential for suturing delicate tissue
What are the 4 different needle shapes
- Straight - Placed by hand in skin
- Curved - defined by fraction, ½, 3/8, ¼
- Half curved – used to be very popular
- Half circle – currently the most popular shape for many circumstances (available in a multitude of sizes)
Suture needle points what are the 2 main ones, what used for and 3 types within
1) Blunt & Taper Point (round bodied) - Used in friable and delicate tissue (GIT, liver, muscle)
2) Cutting - Used in tough tissue (e.g. skin, periosteum, fascia)
1. Conventional cutting
○ Cutting surface on concave surface
○ Increased risk of cut out so need larger suture diameter
2. Reverse cutting
○ Cutting surface on convex side § Preferred as less cut out
3) Tapercut
○ Compromise between round and cutting needle
○ Fine point: used in delicate tissue
○ Reverse cutting tip and tapered body
○ Greater penetration compared with taper but less cutting compared with reverse cutting
What are the 4 main considerations when selecting a suture material
1) suture as strong as tissue placed within
2) rate at which suture lose strength and tissue heals compatible
- For rapidly healing tissues like bladder or stomach, a short acting absorbable is appropriate.
- For slow healing tissues e.g. fascia (poor blood supply) a long acting absorbable is appropriate.
3) biological effect of suture not abraided in GIT
4) appropriate size commensurate with the tissue
What occurs in terms of wound strength after surgery and tensile strength
- Wound strength reliant on sutures for first 3-5 days - CONFINED FOR 7 DAYS
- The most rapid gain in wound strength is between 7 and 14 days after injury
- Wounds never attain the tensile strength of normal tissue - at maximum strength a scar is only 70% to 80% as strong as normal tissue.
What are the 5 main knots and how long should tags be in syntehetic and catgut
- Simple - 1 throw
- Square knot - 2 throws, revising direction with each throw
- Surgeons knot - only when tissue won’t come together easily
- Granny knot - DON’T WANT, 2 single throws without reversing direction
- Sliding (slip) knot - uneven tension applied to square knot
Tags should be 3mm long for synthetic and 6mm for catgut
Interupted and continuous suture patterns contrast and the 2 main types of each
INTERRUPTED SUTURE PATTERNS
- Allow more precise wound margin apposition and adjustment of tension
- Closure security improved
- Slower, more foreign material
- Skin sutures should not be tied too tightly
Types
1) Appositional patterns
2) Simple interrupted
CONTINUOUS SUTURE PATTERNS
- Quicker
- Greater suture economy
- Distribute tension more evenly – appositional
- Reduced closure security c/w interrupted
Types
1) Simple continuous - appositional
2) Ford interlocking (blanket stitch) - greater tissue stability than simple continuous
What are 4 main problems with haemorrhage
- Severe haemorrhage leads to hypotensive shock
- Bleeding obscures the operative field
- Blood within the operative field irritates tissue, prevents tissue apposition, delays healing and potentiates infection
- Blood on instruments, drapes and tissues is an ideal medium for bacterial growth
What are the 4 main methods of haemostasis and describe
- Pressure/Tamponade - use a gauze swab, for definitive haemostasis need to hold for 4 mins
- Hypothermia – causes vasoconstriction
- Ligation - use of suture materials - increased application time
- Electrosurgery - electric prongs (electrocoagulation) - can lead to a fire risk
○ Leads to damage so shouldn’t be used close to vital structures, longer healing times
○ Vessel sealing devices -> used up to 1mm arteries and 2mm veins
What does contrast studies provide and what are positive and negative contrast agents
- provides additional morphologic and functional information to assist diagnosis and treatment planning
Positive contrast agents are radiopaque (white)
Negative contrast agents are radiolucent (dark)
What are some examples of negative contrast agents and what are they used for
Negative contrast agents are room air, carbon dioxide, or nitrous oxide
- Negative contrast agents are used to inflate hollow organs
