Hospital Infection Control - Lecture no. 4 -Nosocomial Pneumonia + BSI

Hospital Infection Control
Lecture no. 4
Nosocomial Pneumonia
Nosocomial Bloodstream Infections
Other nosocomial infections


Nosocomial Pneumonia
Nosocomial Pneumonia
Lower respiratory tract infection
Develops during hospitalization
Not present or incubating at time of admission
Does not become manifest in the first 48-72 hours of admission
Epidemiology
13-18% of nosocomial infections
6-10 episodes/1000 hospitalizations
Leading cause of death from NI
Economic consequences
prolongation of hospital stay 8-9 days
Costs $1 billion/year
Nosocomial Pneumonia
Cumulative incidence = 1-3% per day of intubation
Early onset (first 3-4 days of mechanical ventilation)
Antibiotic sensitive, community organisms (S. pneumoniae, H. influenzae, S. aureus)
Late onset
Antibiotic resistant, nosocomial organisms (MRSA, Ps. aeruginosa, Acinetobacter spp, Enterobacter spp)



Predisposing factors
Endotracheal intubation
ICU
Antibiotics
Surgery
Chronic lung disease
Advanced age
Immunosuppression
Pathogenesis
Oropharyngeal colonization
- upper airway colonization affected by host factors, antibiotic use, gram negative adherence
- hospitalized patients have high rates of gram negative colonization
Gastric colonization
-increased gram negatives with high gastric pH
- retrograde colonization of the oropharynx
Multiresistant bacteria are a problem in VAP
MRSA Pneumonia: Infection-Related Mortality
Diagnosis and Treatment
Clinical diagnosis
- fever, change in O2, change in sputum, CXR
Microbiologic Confirmation
Suctioned Sputum sample
Bronchoscopy with brochoalveolar lavage
Empiric antibiotic- clinical acumen
- Rx based on previous cultures, usual hospital flora and susceptibilities
- sputum gram stain
- colonization vs. infection
Prevention
Pulmonary toilet
Change position q 2 hours
Elevate head to 30-45 degrees
Deep breathing, incentive spirometry
Frequent suctioning
Bronchoscopy to remove mucous plugging
Nosocomial Bloodstream Infections
Nosocomial Bacteremia
4th most frequent site of NI
Attributable mortality 20%
Primary
* IV access devices
* gram positives (S. aureus, Coagulase Negative staphylococci)
Secondary
* dissemination from a distant site
* gram negatives


PATHOGENESIS
Direct innoculation
* during catheter insertion
Retrograde migration
* skin?subcutaneous tunnel?fibrin sheath at vein
Contamination
* hub-catheter junction
* infusate


Risk Factors for Nosocomial BSIs
Heavy skin colonization at the insertion site
Internal jugular or femoral vein sites
Duration of placement
Contamination of the catheter hub
Nosocomial Bloodstream Infections
12-25% attributable mortality
Risk for bloodstream infection:
Nosocomial Bloodstream Infections, 1995-2002
Prevention of Nosocomial BSIs
Limit duration of use of intravascular catheters
No advantage to changing catheters routinely
Maximal barrier precautions for insertion
Sterile gloves, gown, mask, cap, full-size drape
Moderately strong supporting evidence
Chlorhexidine prep for catheter insertion
Significantly decreases catheter colonization; less clear evidence for BSI
Disadvantages: possibility of skin sensitivity to chlorhexidine, potential for chlorhexidine resistance



Skin and soft tissue infections:
Gastroenteritis
ENT & Eye infections