Last reviewed: 5 Nov 2022
Last updated: 05 Jan 2022

Summary

Definition

History and exam

Key diagnostic factors

  • dyspnoea
  • cough
  • increased sputum purulence and volume
  • wheeze
  • chest tightness/chest pain
  • tachypnoea
  • tachycardia
  • risk factors
  • cor pulmonale

Other diagnostic factors

  • signs of respiratory failure
  • fever
  • gastro-oesophageal reflux and/or swallowing dysfunction

Risk factors

  • bacterial infection
  • gastro-oesophageal reflux and/or swallowing dysfunction
  • viral infection
  • pollutants
  • atypical bacterial infection
  • change in weather

Diagnostic investigations

1st investigations to order

  • arterial blood gas (in hospital)
  • pulse oximetry (in hospital and in the community)
  • ECG (in hospital and in the community if available)
  • FBC with platelets (in hospital)
  • urea, electrolytes, and creatinine (in hospital)
  • CRP (in hospital)
  • CXR (in hospital)
  • sputum microscopy, culture, and Gram stain (in hospital)
  • vitamin D (in hospital or in the community)

Investigations to consider

  • blood cultures
  • respiratory virus diagnostics
  • cardiac troponin
  • serum theophylline level
  • pro-brain natriuretic peptide (BNP)
  • CT scan of chest
  • spirometry

Emerging tests

  • procalcitonin
  • point-of-care CRP
  • eosinophil count

Treatment algorithm

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.

Richard Russell

Specialty Registrar in Respiratory Medicine

Glenfield Hospital

Leicester

UK

Disclosures

RJR received sponsorship from AstraZeneca to attend a conference, May 2018 (covering travel, accommodation, and conference fee).

Acknowledgements

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

Carolyn L. Rochester MD

Associate Professor

Yale University School of Medicine

New Haven

VA Connecticut Healthcare System

West Haven

CT

Richard A. Martinello MD

Associate Professor

Yale University School of Medicine

New Haven

Veterans Health Administration

Office of Public Health

West Haven

CT

Disclosures

CLR serves on the COPD scientific advisory board for GlaxoSmithKline Pharmaceuticals but has no competing interests pertaining to this publication. RAM declares that he has no competing interests.

Peer reviewers

Carlos Echevarria

Consultant Respiratory Physician

Royal Victoria Infirmary

Newcastle upon Tyne

UK

Disclosures

CE declares that he has no competing interests.

Editors

Emma Quigley

Section Editor, BMJ Best Practice

Disclosures

EQ declares that she has no competing interests.

Tannaz Aliabadi-Oglesby

Lead Section Editor, BMJ Best Practice

Disclosures

TAO declares that she has no competing interests.

Julie Costello

Comorbidities Editor, BMJ Best Practice

Disclosures

JC declares that she has no competing interests.

Adam Mitchell

Drug Editor, BMJ Best Practice

Disclosures

AM declares that he has no competing interests.

Expert advisers: comorbidities

Martyn Patel, BMBcH, FRCP, MA

Consultant, Older People's Medicine

Norfolk and Norwich University Hospitals

NHS Foundation Trust

Norwich

UK

Disclosures

MP is a contributor to the Oxford Textbook of Otolaryngology, Oxford University Press, 2021, having written a chapter about mental capacity law, for which he received no fee. MP is the NHS representative on the board for Norwich Institute for Healthy Ageing (unpaid role). MP has spoken at the International Forum on Quality and Safety in Healthcare, virtual conference in November 2020 for which he received no fee.

Andrew Lewington, BSc (Hons), MBBS, MEd, MD, FRCP

Consultant Renal Physician

Honorary Associate Professor

Nephrology Department

Leeds Teaching Hospitals NHS Trust

Head of MBChB

School of Medicine

University of Leeds

Leeds

UK

Disclosures

AL has been the principal applicant/co-applicant for a number of grants including: Engineering and Physical Sciences Research Council Research - Multiplexed AKI biomarker detection with a single molecule biosensor; Leeds Cares - A novel, non-invasive diagnostic approach to assess kidney transplant health through the targeted measurement of biomarkers of kidney injury and immune response in kidney transplant recipients at the Leeds Teaching Hospitals NHS Trust; Kidney Research Yorkshire - Use of enhanced technology to characterise haemodialysis treatment for acute kidney injury (AKI); Bringing It Home - Validation of a micro-sampling technique for measuring tacrolimus and creatinine remotely; and to fund a research nurse; British Renal Society - Renal function assessment with point of care creatinine in diverse populations (RAPID), and several NIHR grants including on a) Improving the quality of post-discharge care following AKI b) An investigation into the use of remote blood sample collection to reduce health inequalities in patients with mental health disorders c) A comparison of remote blood collection devices: a human factor use study d) Defining the characteristics for a novel automatic device to monitor urine output in catheterized patients e) Leeds Medtech and In-vitro Diagnostic Cooperative Grant Extension f) Surgical MedTech Co-operative for the 2019/20 proof-of-principle funding stream g) A pilot investigation into the use of beta-trace protein for residual renal function estimation in haemodialysis h) Application of functional MRI to improve assessment of chronic kidney disease (AFiRM study) i) SuperResPath-Renal: Quantitative super-resolution technology for a fast, decentralised clinical diagnosis of renal pathologies. AL is the co-author of a number of manuscripts including on extracorporeal treatments, AKI, kidney function testing prior to contrast-enhanced CT, plasma exchange and glucocorticoids in severe ANCA-associated vasculitis, COVID-19 rapid diagnostics, multimodal image-guided ablation on management of renal cancer in Von-Hippel-Lindau syndrome, and on a summary of NICE guidance on CKD. AL is the author of several book chapters on nephrology and AKI. AL has received expenses for accommodation and travel for conferences at which he has given lectures, other than those delivered virtually. AL was a member of the AKI Scientific Program Committee for the ISN World Congress of Nephrology 2020-2021 and Chair of this same committee in 2021-2022.

Martin Cowie, MD, MSc, FRCP, FRCP (Ed), FESC, FHFA, FACC

Professor of Cardiology

Imperial College London (Royal Brompton Hospital)

London

UK

Disclosures

MC is chair of the European Society of Cardiology Digital Health Committee and a trustee of the Atrial Fibrillation Society. He has previously been a non-executive director of the National Institute for Health and Care Excellence. MC provides consultancy advice to AstraZeneca, Servier, Abbott, Medtronic, Boston Scientific, & Genomics PLC. MC declares that none of these interests is directly related to topics advised on for this project.

Rachael Evans, MBChB, FRCP (UK), PhD

Associate Professor (Clinical)

University of Leicester

Honorary Consultant Respiratory Physician

Glenfield Hospital

Leicester

UK

Disclosures

RAE has given lectures for non-promotional industry-led sessions on long COVID and provided consultancy for GSK, AstraZenica, Boehringer, and Chiesi, for individual payment and travel expenses totalling <£4000.

Gerry Rayman, MD, FRCP

Consultant Physician and Head of Service

Diabetes and Endocrine Centre and the Diabetes Research Unit

Ipswich Hospitals NHS Trust

Ipswich

UK

Disclosures

GR has been paid for advisory board meetings with the following companies: Safoni Aventis, Abbott Diabetes UK, Lilly Diabetes, Bayer. GR has received lecture fees from Safoni Aventis, Abbott Diabetes UK, Lilly Diabetes, Novonordisk, Napp Pharmaceuticals Ltd.

Sotiris Posporelis, MD, MRCPsych

Consultant Liaison Neuropsychiatrist

King’s College Hospital

South London and Maudsley NHS Foundation Trust

Honorary Senior Clinical Lecturer

Institute of Psychiatry, Psychology & Neuroscience

King’s College London

London

UK

Disclosures

SP declares that he has no competing interests.

Hamish McAuley, MBBS, BSc, MRCP

Clinical Research Fellow

Specialist Registrar (ST5)

Department of Respiratory Sciences

University of Leicester

Respiratory Biomedical Research Unit

Glenfield Hospital

Leicester

UK

Disclosures

HM declares that he has no competing interests.

Asangaedem Akpan, MPH, FRC

Consultant Geriatrician

Liverpool University Hospitals NHS Foundation Trust

Visiting Professor

University of Cumbria

Carlisle

Honorary Clinical Associate Professor

University of Liverpool

Liverpool

UK

Disclosures

AA has received honorariums for giving lectures on behalf of Profile Pharma in 2021. AA is an expert committee member of the National Institute for Health and Care Excellence (NICE) quality standards committee on urinary tract infections in adults and Deputy chair of the British Geriatrics Society England Council and Ageing Specialty Research Lead CRN NWC. AA sits on advisory committees for the following research studies: VOICE2 (development and testing of communication skills training for hospital healthcare practitioners caring for people living with dementia), SWOP (social work in older people) and CFIN (cognitive frailty interdisciplinary network). AA has received research funding from the Liverpool CCG and Applied Research Collaborative. He is contributing to developing a heart failure pathway tool for the British Society for Heart Failure and has been invited to contribute to the European Union Geriatric Medicine conference (free conference registration) and British Society for Heart Failure conference (accommodation and travel expenses covered).

Peer reviewers: comorbidities

Martyn Patel, BMBcH, FRCP, MA

Consultant, Older People's Medicine

Norfolk and Norwich University Hospitals

NHS Foundation Trust

Norwich

UK

Disclosures

MP is a contributor to the Oxford Textbook of Otolaryngology, Oxford University Press, 2021, having written a chapter about mental capacity law, for which he received no fee. MP is the NHS representative on the board for Norwich Institute for Healthy Ageing (unpaid role). MP has spoken at the International Forum on Quality and Safety in Healthcare, virtual conference in November 2020 for which he received no fee.

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