Post-operative infection Flashcards
Learning outcomes
- List the six common infection sites that occur after operative surgery, explaining how each may arise
- Outline pre-operative, intra-operative and post-operative measures taken to prevent post operative infection
- Demonstrate an understanding of the rationale and use of perioperative prophylactic antimicrobials to prevent surgical site infection
- Identify and suggest suitable treatments for wound infections
- Describe the mode of action and spectrum of activity for three commonly prescribed antimicrobials: flucloxacillin, co-amoxiclav and vancomycin
6 common infection sites
- Superficial surgical site infection
- Deep surgical site infection
- Respiratory tract infection
- Venous access site infection
5.Urinary tract infection
(which may be associated with urinary catheters) - Gastrointestinal tract infection, specifically Clostridium difficile
- Superficial surgical site infection
Early onset versus late onset
-Commensal bacteria of the skin can become pathogenic
-Staphylococcus aureus the prime pathogen
-Contamination by the healthcare worker or environment may lead to a wider variety of organisms
MRSA possibly
-Foreign bodies get contaminated, the colonised, then possibly infected
- Deep surgical site infection
-The deep tissues manipulated, the organ space
-Sterile versus non sterile organ sites
-Clean (e.g bones, brain, peritoneal cavity etc) versus ‘Clean-contaminated’ surgery
-Skin organisms and organisms from the organ space microbiome
-Staph aureus, and GI or resp. tract microbiome
-Deep placed foreign bodies a specific risk:
Prosthetic joints
Prosthetic heart valves
- Respiratory tract infection
- Drugs to render you unconscious, pain free and to relax muscles
- Suppress respiratory funciton
- Pooling of secretions providing a nutritious environment for organisms
- Chest physiotherapy and breathing work important
- Organisms change over time in hospital
- Strep pneumo and H. Influenzae early, enterobacteriaceae and others later
- Venous access site infection
-Venous access a mainstay of patient care in perioperative period
-Peripheral Venous Cannulae (PVC) the commonest inserted devices used in Healthcare
-Staph aureus the commonest pathogen
-Foreign body infection:
Biofilm formation
Device removal
- UTI (may be associated with catheterisation)
-Urinary flow key to preventing overgrowth and ascension of bacteria from the perineum to the bladder and urethra
-Catheters used to manage the urinary tract, and sometimes to monitor fluid output
-Perineal bacteria contaminate, then colonise catheters. -Infection may result:
E. coli, other enterobacteriacaeae
Catheter removal ASAP
- GI Tract infection (specifically C.diff)
-Anyone in a hospital can acquire Clostridium difficile ( C. diff) infection
-Gram positive, Anaerobic, spore forming rod
-Other bacterial causes of hospital associated GI infections rare
Norovirus is a viral risk
-Antibiotics a key risk for this C diff infection
-Surgical cases often given antibiotics
-Perioperative antibiotic prophylaxis
Pre, intra and post operative measures taken to prevent post operative infection
Pre: -Screening for resistant organisms
-MRSA: may be given suppressive antibiotic/ antiseptic body wash
-Hair removal at the incision site on the day of surgery
-Clippers not razors
-Peri-operative prophylaxis
-Optimising nutrition and skin health
Intra- Ventilated operating rooms
-Negative pressure to the corridor and rapid air changes
-Sterile drapes, PPE and instruments
-Sterile: absolutely free from organisms including viruses and bacterial spores
-Skin preparation
-70% alcohol with Chlorhexidine/ Iodine
-Normothermia and tight glycaemic control
Post:-Wound care
-Antiseptic impregnated dressings
-Vacuum assisted wound closure
-Aseptic Non-Touch Technique ‘ANTT’
-Patient not to touch the wound
-Follow up for suture removal
-Many procedures use dissolvable closure material
Preoperative prophylaxis to prevent post-operative infection
-A prophylactic is intended to prevent the disease.
-Having a therapeutic level of antibiotic present within the tissues surrounding the surgical incision reduces the likelihood of post-operative surgical site infection
Clean (hernia, breast hip knee etc):
-Prophylaxis only if you are leaving something behind in the patient
Clean-contaminated (Cholecystectomy, bowel resection):
-Involving non-sterile sites without disruption: give prophylaxis
Contaminated (Gross contamination/spillage of GI tract, trauma wound):
-Give prophylaxis
Dirty/ infected (infected surgery, diverticulitis or empyema):
-Give Treatment rather than prophylaxis
Suitable treatments for wound infections
-Wound infections generally obvious clinically
-If suspected: samples please prior to antibiotics
-Not all SSI, or other wounds, need antibiotics
-Primary management is cleaning and dressing wounds
Silver dressings, antiseptics, honey, larvae etc
-Optimise skin and soft tissue health
-First sample, and dress appropriately
-If antibiotics needed treat empirically
Empirical: based on our knowledge of what commonly causes infection at a given site
-Staphylococcus aureus
-Always cover Staph aureus in wound infection
-Organ specific microbiome
-GI particularly. Organisms from the deep surgical site can cause superficial SSI
Flucoxacillin
-The drug: amended penicillin molecule to be stable against the staphylococcal beta-lactamase
-A ‘daughter’ drug of Meticillin which was first developed in 1950s
-Meticillin not used now, but MRSA named after it
-Different but similar drugs used in USA and Europe/Asia
In the UK this Flucloxacillin is the default choice for many non-severe skin infections, including superficial SSI, as long as there is no evidence the patient is colonised with MRSA.
* Staphylococcus Aureus
LECTURE 5 MSK FOR Tables
How flucoxacillin is used in practice
It has to be given 6 hourly at it has a relatively short half-life.
Patients at home taking PO antibiotic are not likely to take the drug every 6 hours overnight- as it would mean a midnight and 6am dose. The risk is prolonged intervals between dosing. This leads to a small amount of circulating antibiotic in the patient at certain times of the day: not enough to treat an infection, but possibly enough to encourage some drug resistance. We sometimes refer to ‘sub-lethal’ dosing of antibiotics and this is one of the ways that happens.
-Active against Staphylococcus aureus
-Per Oral or Intravenous (PO/ IV): Skin and soft tissue infection, including SSI Bone and joint infection Device related infection Endocarditis
Co-amoxiclav
-A combination of 2 drugs: a beta-lactam and a beta-lactamase inhibitor (increases spectrum of action)
-Amoxicillin and Clavulanic acid
-The beta-lactamase inhibitor makes the drugs Broader Spectrum
-Very commonly prescribed
“the antibiotic of choice for people who don’t like to think about antibiotics”
* streptococcus pneumoniae
How co-amoxiclav is used in practice
- Broad spectrum, can be given orally, safe
- PO/ IV
- Intra-abdominal infection (both aerobic and anaerobic gram-negative activity)
- Used for perioperative prophylaxis in clean-contaminated surgery
- Complicated ear/ nose/ throat/ paranasal sinus infections
