Aspiration pneumonia

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Last reviewed: 2 Aug 2025
Last updated: 24 Aug 2023

Summary

Definition

History and exam

Key diagnostic factors

  • presence of risk factors
  • cough
  • breathlessness
Full details

Other diagnostic factors

  • history of vomiting
  • tachypnoea
  • foul-smelling breath
  • crepitations
  • frothy or purulent sputum
  • fever
  • pleuritic chest pain
  • delirium
  • reduced appetite
  • reduced mobility
  • general debilitation
Full details

Risk factors

  • swallowing dysfunction
  • impaired conscious level
  • gastrointestinal disease
  • general anaesthetic or oropharyngeal procedures
  • older age
  • poor cough
  • presence of a feeding tube
  • head and neck cancers
  • polytrauma
  • recumbent position during enteral feeding
  • poor oral hygiene
  • learning disability
Full details

Diagnostic investigations

1st investigations to order

  • chest x-ray
  • full blood count
  • urea and electrolytes
  • liver function tests (LFTs)
  • C-reactive protein (CRP)
  • sputum Gram stain
  • sputum culture
Full details

Investigations to consider

  • arterial blood gas
  • bronchoscopy
Full details

Treatment algorithm

ACUTE

all patients

Contributors

Expert advisers

Jonathan Bennett, MD

Honorary Professor of Respiratory Sciences

University of Leicester

Respiratory Consultant

Glenfield Hospital

Leicester

UK

Biography

JB is Chair of the British Thoracic Society (BTS). He is also deputy medical director RCP Invited service Reviews, and speaker at National Society (eg., BTS), Primary Care respiratory Society, Society Cardiothoracic Surgeons meetings.

Disclosures

JB declares that he has no competing interests.

Claire Vella, MD, MRCP

Clinical Fellow Lung Cancer and Interventional Pulmonology

Glenfield Hospital

Leicester

UK

Disclosures

CV declares that she has no competing interests.

Acknowledgements

BMJ Best Practice would like to gratefully acknowledge the previous expert contributor, whose work has been retained in parts of the content:

Michael J. Lanspa, MD

Adjunct Associate Professor

Division of Pulmonary and Critical Care Medicine

Intermountain Medical Center

University of Utah

Salt Lake City

UT

Disclosures

MJL declares that he has no competing interests.

Peer reviewers

David G. Smithard, BSc, MB, MD, FRCP, FRCSLT (Hon)

Visiting Professor

University of Greenwich

Consultant in Elderly Medicine

Queen Elizabeth Hospital

Lewisham and Greenwich NHS Trust

Greenwich

UK

Disclosures

DGS declares that he has no competing interests.

Peer reviewer acknowledgements

BMJ Best Practice topics are updated on a rolling basis in line with developments in evidence and guidance. The peer reviewers listed here have reviewed the content at least once during the history of the topic.

Disclosures

Peer reviewer affiliations and disclosures pertain to the time of the review.

References

Our in-house evidence and editorial teams collaborate with international expert contributors and peer reviewers to ensure that we provide access to the most clinically relevant information possible.

Key articles

Simpson AJ, Allen JL, Chatwin M, et al. BTS clinical statement on aspiration pneumonia. Thorax. 2023 Feb;78(suppl 1):s3-21.Full text  Abstract

National Institute for Health and Care Excellence. Stroke and transient ischaemic attack in over 16s: diagnosis and initial management. April 2022 [internet publication].Full text

National Institute for Health and Care Excellence. Pneumonia (community-acquired): antimicrobial prescribing. September 2019 [internet publication].Full text

National Institute for Health and Care Excellence. Pneumonia (hospital-acquired): antimicrobial prescribing. September 2019 [internet publication].Full text

Reference articles

A full list of sources referenced in this topic is available to users with access to all of BMJ Best Practice.
  • Aspiration pneumonia images
  • Differentials

    • Community-acquired pneumonia (CAP)
    • Hospital-acquired pneumonia (HAP)
    • Pulmonary oedema
    More Differentials
  • Guidelines

    • Pneumonia (community-acquired): antimicrobial prescribing
    • Pneumonia (hospital-acquired): antimicrobial prescribing
    More Guidelines
  • Calculators

    CURB-65 pneumonia severity score

    More Calculators
  • Patient information

    Pneumonia

    More Patient information
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