Lecture 40: Post Operative Complications: Healthcare Associated Infections Flashcards
Fever, tachycardia and low BP are common signs post surgery of….
Healthcare associated
infection!
Remember in surgery there is both the skin level and organ level surgical stiches and change both
What does the significance of a urine sample from a catheter with >1000 million WBC/L have?
A urinary catheter if left in long enough will develop into pyuria.
So this can be ignored if it’s been in a while, look to see if there is somehing more suspicious going on (eg; fecal peritonitis from a ruptured bowel)
What is CA-UTI
an ILLNESS caused by bacterial infection associated with urinary catheter.
- presence of bacteria in the urine is very common (NB 3x risk of DEATH compared with people without bacteruria)
- prevalence: approx 10% patients with catheters
- approx, 100 (10% of inpatients) in ACH have an IDC in situ
- Risk factors: female, duration of catheterisation, poor care
- this is also a reflection of how unwell the patients are! There are many other factors!
- If you put a catheter in for long enough ANYONE WILL get an infection
- catheter bag never on bed so the urine can’t slosh back into patient!!
How do you recognise and identify a CA-UTI??
Specific symptoms may be lacking: fever, confusion, lethargy, flank pain
The presence of pyuria alone IS NOT DIAGNOSTIC: absence of pyuria however suggests an alternate diagnosis
The presence/absence of smelly/cloudy urine IS NOT DIAGNOSTIC:
Cultures usually show 1 bacterial species eg; E.coli
if no WBC you can relax!
What strategies might reduce CA-UTI??
- avoid catheters: use non-invasive condom devices instead of urethral device
What is the significance of Candida albicans as a pathogen?
The usual cause of thursh, but can also cause more invasive infections, usually only in the presence of catheters!
- one of ~150 candida yeasts
- but C. albicans is the most common cause of human illness (90%), nine species cause almost all human disease
- Found as part of human flora, in soil, on animals, hospital environments
- Unprovoked illness is RARE: usually due to some other illness/issue/medication in the host
- VERY RARE in healthy people and represents colonisation and in neonates it might represent candidaemia
What medical devices cause Infections and to what extent?
- Bladder catheter → 95% of UTIs
- Indwelling vascular catheter → 87% of blood stream infections
- Mechanical ventilation → 86% of pneumonia
How common are device-associated infections
How do these bacteria actually cause the infection?
- They make a Biofilm
- a microbial community of cells that attach to a substrate or interface to each other, embedded in a matrix of extracellular polymeric substance
- single bacteria; cells float through bloodstream and start to make a gooey protein material
- This starts to stick to things, eg; metal, teeth etc and start to build a thick structure that is many layers of bacteria.
- The top layer can come apart and end up once again as single bacteria in the blood stream, re infecting other surfaces
What are the factors that contibute to pathogenesis of device-associated infections
- Host
- Device
- Bacteria
If someone has the presence of C.albicans in the catheter do they require treatment??
- If there’s a belly infection and there’s something else going on then no
- If there’s no other problems but there’s fever, chills etc: removal of the catheter should be enough. Maybe take a sample after to be sure.
Problems with biofil-associated bacteria
Staph aureus is a very common cause of
skin and soft tissue infections and a common cause of indwelling catheters
Likely source and mode of transmission of this infection??
- Clostridium difficile is part of the normalflora of the GI tract
- Carriage rates; 5% in community and 20% in hospital
- Spread from person to person within hospital ward
- diarrhoea; contiminates environment
- long-lived bacterial endospores