Hosptial Acquired Infections Flashcards
How is the nature of HAI changing?
Invasive procedure, prosthetic and implantable decises
Obesity
Diabetes
Extremes of age
Immunosuppression
Emerging organisms/ resistance
Scanning of EM or biofilm on vacs cath 24 hours post insertion
Why are organisms increasingly resistant?
Widespread prolonged used of broad spectrum abx Mrsa Vre/gre Esbl Multi resistant gram negatives
How does the environment effect transmission?
Environmental hygiene- c diff, norovirus, acinetbacter breakouts
Environmental sources- legionella in cooling towers, aspergillus in building works
Negative pressure isolation- TB, chicken pox and RSV
How many patients that come into UK experience hai?
10%
What is the most common HAI?
GI system- c diff, norovirus
UTI
Surgical site
What percentage of HAI do mrsa and c doff account for?
15%
What has driven reductions in mrsa and c diff?
Mandatory surveillance
Code of practice
Inspections
Not the same reductions in other avoidable HAI
What is the most common organism causing ha- UTI?
E. coli S saprophytic Proteus Kleb and other coli forms Enterococcus and pseudo
What are UTI coli forms?
Gram negative rods, commensals in colon
Lactose fermenting- E. coli, klebsiella, enterobacter, serratia, citrobacter
Non lactose fermenting- proteus, pseudomonas
What is the relationship between UTI and catheters?
Catheters become rapidly colonised 60% colonised within 96 hours Predispose to invasion Heavy bacterial load in bag Asymptomatic bacteruria in elderly Catheter infections- treat sepsis only
What resistant mechanisms are common with hai UTI?
Chromosomal, plasmid mediated
E. coli less than klebsiella, less than enterobacter
ESBl- enzymatic mechanism
What is the mechanism of resistance for carbapenem?
Hydrolysis of carbepenam Very transmissible Lots of resistance Prolonged carriage part of gut flora Meropenem use for esbl urosepsis
What key organisms have resistance?
E. coli, kleb, pseudo, strep pneumo
Carbopenemase producing enterobacteria- increased
What is the spectrum of activity for following bacteria? Flucloxacillin Co amxiclav Metro Pipeqcillin- tazobactem Amoxicillin Ciprofloxacin Gentamicin Meropenem Colistin
Flucloxacillin- gram positive, narrow
Co amxiclav- pos, neg, anaerobes, broad
Metro- anaerobes, narrow
Pipeqcillin- tazobactem- hosp neg, some pos, anaerobes, pseudo, broad
Amoxicillin- positive, negative, anaerobes, broader than co- amox
Ciprofloxacin- gram neg, pseudomonal, broad
Gentamicin- gram neg, narrow
Meropenem- hosp gram neg, gram positive, anaerobes, pseudo, broad
Colistin- hosp gram neg including carb resistant, broad
What are the contributors to SSI?
Host defence- pre op care
Wound environment- intra op care and skill
Pathogens- decontamination
What two factors relate to pathogens in SSI?
Innoculum- bacteria from skin tissue, intrinsic
Bacteria from air, instruments, HCW, extrinsic
Largest when site is heavily colonised
Small bowel less than right colon less than sigmoid
Intra operative contamination
Virulence- MSSA more than coag neg staph
What factors relate to the wound environment in SSI?
Haemoglobin
Necrotic tissue
Foreign bodies, absorbable sutures better than silk
Dead space
What factors relate to host defence in SSI?
Shock Hypoxia Hypothermia Glycemic control Chronic illness Immunosuppressive agents
What are the 7 high impact interventions?
Central venous catheter care Peripheral intravenous cannula care Renal dialysis catheter care Prevention of SSI Care for ventilated patients or tracheostomy Urinary catheter care Reducing risk of c diff
Who should undergo mrsa screening and decontamination?
All patients undergoing implant, cardiothoracic, orthopaedic and neuro procedures
Large bowel, small bowel, cholecystectomy, bile duct, liver and pancreatic surgery most common
Deep space infection 1/3
Organisms changing over time- s aureus falling, enterobacteria more prevalent
What percentage of HAI are preventable?
15-30%
What is c diff?
Gram positive spore forming anaerobes
Spores transmissible, contaminate environment, persist
Ingested spores germinate in gut
Gut flora disturbed by abx exposure to different extents
What are the virulen factor for c diff?
Toxins a and b, diarrhoea and colitis
Dehydration, pseudomembranous colitis, perforation
Worse in older, debilitated, abx treated
What is c diff management?
Recognise or suspect cases, test stool and isolate patient Stop abx for other infections Stop gi active drug Assess severity Fluid resus, electrolyte correction, nutrition review Metro for 2 weeks, vanco second line Severe- vanco oral, qds for 2 weeks Fidaxomicin- role in reducing recurrence
What is the management for severe and life threatening c diff?
Vanco- 500 mg oral qds
Plus minus iv metro
Iv immunoglobulin
Life threatening- colectomy, vanco, intracolonic vanco, iv metro, ivig
What is the management for recurrent c diff?
Relapse common, repeat treatment with same agent Prolonged taper oral vanco Pulsed dosing oral vanco Faecal transplant Ivig
What are novel approaches to manage c diff?
Faecal transfer- fresh faeces, healthy donor, in saline, filtered, administer NG
Tablets formulations of faeces becoming available
Reduction in recurrence
Administr Non-toxigenic c diff- non pathogenic, may occupy the niche of pathogenic types
How does Mrsa infection occur?
Preceded by colonisation
Skin breach- skin disease, chronic disease resulting in skin lesions
Invasive procedure, device
