Post-op infections Flashcards
Define surgical site infection
A type of healthcare associated infection which occurs after an invasive surgical procedure.
Name 2 other healthcare associated infections that affect surgical patients
Post-op respiratory infection
Urinary tract infection
Bacteraemia
ABX-related diarrhoea
What are the 2 commonest causes of surgical site infection?
Patients own flora:
Skin - Staph aura, staph epidermidis
Viscera - E. coli (GI), Pseudomonas (biliary)
Name 4 sources of surgical infection
Patient's own flora Indirect contact Direct inoculation Airborne contamination Haematogenous spread Food and water Faecal-oral Insect bourne
What are the consequences of surgical site infection?
Increased morbidity and mortality
Extended hospitalisation
Cost
Name 2 pre-op measures to reduce surgical site infections
Patient shower before surgery
Hair removal using clippers
ABX prophylaxis when indicated
What are the indications for antibiotic prophylaxis in surgery?
Clean surgery involving insertion of prosthesis
Clean-contaminated surgery
Contaminated surgery
Name 2 intra-op measures to reduce surgical site infections
Antiseptic skin preparation
Hand decontamination and sterile gowns/gloves
Wound dressing
Name 2 post-op measures to reduce surgical site infections
Avoid unnecessary contact with wound for 48-72hr
Ensure clean hands and PPE
Involve tissue viability team if poor wound healing or infection
ABX if wound infected
Name 5 general risk factors for wound infection
Age Malnutrition Obesity Smoking Immunosuppression Diabetes mellitus Alcoholism Jaundice Chronic kidney disease Hypoxia and anaemia
Name 3 local risk factors for wound infection
Type of surgery Length of surgery Necrotic tissue Residual local malignancy Foreign body Ischaemia, haematoma
Name 2 microbiological risk factor for wound infection
Lack of ABX prophylaxis
Infectious organism
Name the 4 types of surgery
Clean
Clean contaminated
Contaminated
Dirty
What is the rate of surgical site infection for clean surgery?
<2%
What is the rate of surgical site infection for clean contaminated surgery?
<10%
What is the rate of surgical site infection for contaminated surgery?
15-20%
What is the rate of surgical site infection for dirty surgery?
> 40%
Name 3 of the commonest bacteria seen with surgical site infections
Coagulase -ve staph e.g. Staph epidermidis (25%) Enterococci (11.5%) Staph aureus (9%) Candida albicans (6.5%) E. coli (6.3%) Pseudomonas aeruginosa (6%)
Define clean surgery
An uninfected operative wound
No inflammation
Respiratory, GI, biliary, or genitourinary tract not entered
Define clean-contaminated surgery
Operative wound
Respiratory, GI, biliary, or genitourinary tract entered under controlled conditions
No unusual contamination
Define contaminated surgery
Open, fresh, or accidental wounds (<4hr)
Operations with major breaks in sterile technique or gross spillage from GI tract
Acute, non-purulent inflammation
Define dirty surgery
Old (>4hr) traumatic wounds with retained devitalised tissue, and those that involve existing clinical purulent infection
What are the 3 types of surgical site infection?
Superficial
Deep
Organ space
Define wound dehiscence
A surgical complication in which a wound ruptures along a surgical incision.
What is a complication of wound dehiscence of the abdomen?
Evisceration - viscera protrude through the wound
What is the commonest cause of wound dehiscence?
Secondary to surgical site infection
Outline the management of wound dehiscence
Initial: dress any exposed viscera, IV ABX if infected, drain pus
Superficial: regular lavage and dressing, consider vacuum-assisted closure
Deep: re-suture, vacuum-assisted closure
What are the symptoms of surgical site infection?
Pain and discharge in wound
Malaise, anorexia, fever
What are the signs of surgical site infection?
Fever, tachycardia
Red, swollen, tender wound
May be discharging pus
What factors increase the risk of post-op sepsis?
Immunosuppressed patient
ABX-resistant organism
What investigations should be sent in surgical site infection?
MCS of pus
FBC (Hb, WCC)
Blood cultures
What is the initial management of surgical site infections?
Appropriate ABX guided by microbiologist
Why are post-op respiratory infection common?
General anaesthetic irritates the respiratory tract.
Opioid analgesia inhibits cough reflex
Wound pain makes breathing and coughing more difficult
How are post-op respiratory infections treated?
Good analgesia post-op
Chest physiotherapy
Antibiotics
What is the most likely cause of post-op UTIs?
Catheter insertion
How long should a catheter remain in a patient?
Up to 4-5 days
How are post-op UTIs prevented?
Avoiding unnecessary catheterisation
Good aseptic technique
Remove at earliest time
What is the role of catheters during/after a surgical procedure?
Monitor fluid output to ensure adequate hydration and removal of metabolites.
What is the target urine output for the average patient?
0.5 ml/kg/hr
Which organism is associated with antibiotic-related diarrhoea
Clostridium difficile
Name 3 risk factors for C. difficile infection
Current or recent ABX use Over 65 Recurrent or prolonged admission Nursing home Serious co-morbidites Immunosuppression
Outline the management of C. difficile infection
Isolation Fluids and electrolytes Monitor daily Stop causative ABX Avoid work/school for 48hr after last episode
Mild: no specific ABX Tx
Mild-moderate: Metronidazole 500mg TDS for 10-14 days
Severe/recurrent: Vancomycin
