Hospital Acquired Infection and Surgical Site infection Flashcards
What is a hospital associated infection?
- Direct result of treatment or contact in a hospital or healthcare settin
- As a result of healthcare delivered in community
- Outside a healthcare setting but are brought in by patients, staff, or visitors and transmitted to others
How common are hospital acquired infections?
7-25% of hospital admission are complicated by a noscoiomal infection
What can make people at risk of hospital acquired infections?
- Has been given broad-spectrum antibiotics (e.g. antibiotic resistant organisms, C.diff colitis)
- Is unwell/immunocompromised (opportunistic infection)
- Has compromised barriers (indwelling catheter/line, ventilation, surgery)
What is the most common associated HAI?
catheter associated UTI (19%)
What is another route of infection route in HAI?
- Infections associated with the use of intravascular access devices:
- Includes peripheral, central venous and arterial catheters
- > 60% of bloodstream infections are associated with intravascular devices
What organisms are related to intravascular access devices?
- Staphyloccous epidermis
- Staphylococcus aureus and MRSA
- Candidia species
- Enterococci
How common is ventilator associated pneumonia (VAP)?
up to 20% of patients admitted to ICU
Why does VAP happen?
occurs as endotracheal tube interferes with protective upper airway reflexes and facilitates micro aspiration
What organisms are involved in VAP?
- Pseudomonas aeruginosa
- Enterobacterieacia
- Staph aureus
When should you suspect VAP?
if new/persistent infiltrates of CXR plus two or more of purulent sputum, leucocytosis, leukopenia and temperature
How can you prevent VAP?
- reducing colonization (mouthwash, sliver lined endotracheal tubes)
- nurses at 45 degrees to decrease aspiration risk 3. wean off vent asap
How common and lethal are surgical site infections?
- Affects 5% of patients undergoing surgical procedures
- Contributes to >1/3 of post-op deaths
What are the common organisms in surgical site infection?
- Staph aureus
- Strep pyogenes
- Enterobacteriaceacae when surgery involves entry to hollow viscera
What are the preventative methods for surgical site infection?
- Hand hygiene
- Strict asepsis
- MRSA screening and decolonization
- Hair removal
- Peri-operative normothermia
- Minimally disturbed low adherence/transparent dressings
What is c.diff?
Gram positive anaerobic bacillus and most common healthcare-associated pathogen
How common is C diff?
Part of colonic flora in 2-5% of healthy adults and 20-40% of hospitalised adults
What does c.diff cause disease?
when it converts to a vegetative growth state with production of enterotoxins A and B causing colitis
how do antibiotics cause c.diff?
Happens when inhibition by competing colonic flora is lost due to antibiotics exposure
What is the presentation for c.diff?
- Watery diarrhoea
- Mild to fulminant colitis (pseudomembranous colitis)
- Ileus
- Toxic megacolon
When do you need to consider c.diff?
in all diarrhoea associated with antibiotic use, esp in marked neutrophilia
What is needed for diagnosis of c.diff?
- Immunoassay for glutamate dehydrogenase (common antigen) detects all strains of C.diff
- Detection of toxin (toxin immunoassay, toxic gene nucleic acid amplification) distinguishes infection for carriage
How do you check for c.diff eradicated?
urea breath test
What is the conservative management for c.diff?
SIGHT Suspect Isolate Gloves and aprons Hand wash with soap Test immediately
How do you medicate mild/moderate c.diff?
metronidazole PO
How do you medicate severe c.diff WCC>15x10^9/L, or AKI or colitis or temp>38.5) ?
vancomycin PO or fidaxomicin
How do you treat non repsonders for c.diff?
high dose vancomycin PO + IV metronidazole, fidaxomicin, IV immunoglobulin (no RCT data)
How do you treat reccurent c diff?
- (weaning) vancomycin
- fidaxomicin
- faecal transplantation
