Nosocomial Pneumonia

OVERVIEW

Nosocomial or hospital-acquired pneumonia (HAP) is defined as pneumonia that is not incubating at the time of admission to hospital and develops in a patient hospitalised for >48 hours.

  • common and has significant mortality
  • results primarily from  micro-aspiration of oropharyngeal and upper GI bacteria

CAUSATIVE ORGANISMS

The spectrum of potential pathogens associated with HAP differs from that of community-acquired pneumonia (CAP) — reflects organisms that colonise the oropharynx of hospitalised patients

  • aerobic Gram negative bacilli – ESCAPPM, Klebsiella
  • Legionella
  • MDR organism – MRSA, Enterobacteriaceae, Pseudomonas aeruginosa, Acinetobacter, Stenotrophomonas maltophila
  • viruses – influenza, RSV, adenovirus, parainfluenza
  • Aspergillus (e.g. aerosols from building works at hospital leading to contamination of air with soil)

RISK FACTORS

  • intubation
  • COPD
  • ARDS
  • low albumin
  • mechanical ventilation > 3 days
  • those requiring ICP monitoring
  • coma or decreased LOC
  • burns
  • trauma
  • high APACHE score
  • H2 blockers or antacids
  • previous antibiotics
  • use drugs that are markers of severe disease (inotropes, sedation, paralysis)
  • re-intubation
  • bronchoscopy
  • NG tube
  • transport

Risk factors for Legionella

  • diabetes
  • immunosuppression
  • high-dose corticosteroid therapy
  • malignancy
  • end-stage renal failure
  • history of smoking
  • excessive alcohol use
  • known local prevalence of hospital-acquired disease

CLINICAL FEATURES

  • crackles or dullness to percussion and any of the following:
  • purulent sputum
  • organism from blood cultures
  • CXR signs: infiltrate, consolidation, cavitation, effusion
  • virus in sputum
  • IgM antibody +ve
  • 4 fold increase in IgG titre
  • histopathology +ve for pneumonia

DIAGNOSIS

Reliable diagnosis of HAP is difficult and there are no universally accepted clinical or laboratory criteria that have sufficient diagnostic sensitivity and specificity

  • The presence of bacteria in expectorated sputum or endotracheal aspirate cultures usually represents colonisation only, and does not itself justify a diagnosis of HAP
  • Most postoperative patients with shadowing on chest X-ray do not have pneumonia, they have atelectasis

ASSESSMENT

Clinical

  • focal chest signs
  • purulent sputum
  • fever

Laboratory

  • inflammatory marker elevation
  • positive cultures (sputum or blood)
  • 4 fold increase in antibody titres
  • histopathology consistent with pneumonia

Radiological

  • infiltrate
  • consolidation
  • cavitation
  • pleural effusion

MANAGEMENT

Principles of antibiotic therapy

  • start empirically
    -> scale back at day 2 if patient improved
  • know local biograms
  • failure to control –
    > re-evaluation of antibiotic therapy
  • treat organism grown

Risk stratify patients:

(1) low risk of MDR organism – standard ward, < 5 days in hospital

  • cover Pneumococcus and non-MDR GNBs

-> mild: augmentin or benzylpenicillin + gentamicin
-> moderate/severe: ceftriaxone or cefotaxime or tazocin or timentin

(2) high risk of MDR organism – ICU/HDU or area with known MDR problem for 5 or more days

  • cover MDR organisms
  • stop antibiotics for VAP at 6-8 days (evidence that longer courses lead to colonisation with MROs)
  • treat Pseudomonas aeruginosa, Acinetobacter species or Stenotrophomonas maltophilia for 15 days

-> tazocin or timentin or cefepime
-> if suspected MRSA add in vancomycin (pre-existing longterm lines, prior MRSA, in hospital > 7day or recent admission <3 months)
-> add gentamicin if critically ill (ventilated) to cover MDR organisms (use ciprofloxacin if age >65y, GFR <50 or recently on gentamicin)
-> add teichoplanin if VRE colonized


References and Links

  • Masterton RG, Galloway A, French G, Street M, Armstrong J, Brown E, et al. Guidelines for the management of hospital-acquired pneumonia in the UK: report of the working party on hospital-acquired pneumonia of the British Society for Antimicrobial Chemotherapy. J Antimicrob Chemother 2008;62(1):5-34. [PubMed]

CCC 700 6

Critical Care

Compendium

Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also the Innovation Lead for the Australian Centre for Health Innovation at Alfred Health and Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.

After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.

He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE.  He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.

His one great achievement is being the father of two amazing children.

On Twitter, he is @precordialthump.

| INTENSIVE | RAGE | Resuscitology | SMACC

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