Diagnosis and features of hospital-acquired pneumonia: a retrospective cohort study

C D Russell, O Koch, I F Laurenson, D T O'Shea, R Sutherland, C L Mackintosh

Research output: Contribution to journalArticlepeer-review

Abstract / Description of output

BACKGROUND: Hospital-acquired pneumonia (HAP) is defined as radiologically confirmed pneumonia occurring ≥48h after hospitalization, in non-intubated patients. Empirical treatment regimens use broad-spectrum antimicrobials.

AIM: To evaluate the accuracy of the diagnosis of HAP and to describe the demographic and microbiological features of patients with HAP.

METHODS: Medical and surgical inpatients receiving intravenous antimicrobials for a clinical diagnosis of HAP at a UK tertiary care hospital between April 2013 and 2014 were identified. Demographic and clinical details were recorded.

FINDINGS: A total of 166 adult patients with a clinical diagnosis of HAP were identified. Broad-spectrum antimicrobials were prescribed, primarily piperacillin-tazobactam (57.2%) and co-amoxiclav (12.5%). Sputum from 24.7% of patients was obtained for culture. Sixty-five percent of patients had radiological evidence of new/progressive infiltrate at the time of HAP treatment, therefore meeting HAP diagnostic criteria (2005 American Thoracic Society/Infectious Diseases Society of America guidelines). Radiologically confirmed HAP was associated with higher levels of inflammatory markers and sputum culture positivity. Previous surgery and/or endotracheal intubation were associated with radiologically confirmed HAP. A bacterial pathogen was identified from 17/35 sputum samples from radiologically confirmed HAP patients. These were Gram-negative bacilli (N = 11) or Staphylococcus aureus (N = 6). Gram-negative bacteria tended to be resistant to co-amoxiclav, but susceptible to ciprofloxacin, piperacillin-tazobactam and meropenem. Five of the six S. aureus isolates were meticillin susceptible and all were susceptible to doxycycline.

CONCLUSION: In ward-level hospital practice 'HAP' is an over-used diagnosis that may be inaccurate in 35% of cases when objective radiological criteria are applied. Radiologically confirmed HAP represents a distinct clinical and microbiological phenotype. Potential risk factors were identified that could represent targets for preventive interventions.

Original languageEnglish
Pages (from-to)273-9
Number of pages7
JournalJournal of Hospital Infection
Issue number3
Publication statusPublished - Mar 2016

Keywords / Materials (for Non-textual outputs)

  • Aged
  • Aged, 80 and over
  • Cross Infection
  • Diagnostic Tests, Routine
  • Female
  • Humans
  • Lung
  • Male
  • Pneumonia
  • Radiography, Thoracic
  • Retrospective Studies
  • Tertiary Care Centers
  • United Kingdom
  • Journal Article
  • Observational Study


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