Summary
Definition
History and exam
Key diagnostic factors
- direct trauma to the thorax and neck
- dyspnea
- confusion
- tachypnea
- accessory breathing muscle use
- stridor
- inability to speak
- retraction of intercostal spaces
- cyanosis
- loss of airway/gag reflex
Other diagnostic factors
- anxiety
- headache
- hypoventilation
- cardiac rhythm disturbances
- underlying neuromuscular disorder
- drug use
- seizure
- coma
- asterixis
- papilledema
Risk factors
- cigarette smoking
- young age
- older age
- pulmonary infection
- chronic lung disease
- upper airway obstruction
- lower airway obstruction
- alveolar abnormalities
- perfusion abnormalities
- cardiac failure
- peripheral nerve abnormalities
- muscle system abnormalities
- opioid and sedative medications
- toxic fumes and gases
- traumatic spinal injury
- traumatic thoracic injury
- central nervous system (CNS) disorders
- acute vascular occlusion
- pulmonary effusion
- pneumothorax
- hypercoagulable states
Diagnostic tests
1st tests to order
- pulse oximetry
- arterial blood gases
Tests to consider
- CBC
- D-dimer
- serum bicarbonate (HCO₃)
- Cardiac troponin I and/or T
- ECG
- chest x-ray
- pulmonary function tests
- Urine or serum toxicology
- chest CT
- CT pulmonary angiography (CTPA)
- ventilation/perfusion lung scan
- capnometry
- cardiothoracic ultrasound
Emerging tests
- transcutaneous CO₂ monitoring
Treatment algorithm
airway obstruction
no acute upper airway obstruction: stable
no acute upper airway obstruction: unstable
Contributors
Authors
Samuel J. Stratton, MD, MPH

Professor
Fielding School of Public Health
David Geffen School of Medicine at UCLA
Los Angeles
Deputy Health Officer
Orange County Health Care Agency
Health Disaster Management/Emergency Medical Services
Santa Ana
CA
Disclosures
SJS declares that he has no competing interests.
Peer reviewers
C. Michael Roberts, MA, MD, FRCP
Consultant Physician
Barts Health
London
UK
Declarações
CMR declares that he has no competing interests.
Ken Miller, MD, PhD
University of California
Irvine and Orange County Fire Authority
Irvine
CA
Declarações
KM declares that he has no competing interests.
Christopher Kahn, MD, MPH
Assistant Professor of Clinical Emergency Medicine
Department of Emergency Medicine
University of California
Irvine and Orange County Fire Authority
Irvine
CA
Declarações
CK 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.
Referências
Principais artigos
Rochwerg B, Brochard L, Elliott MW, et al. Official ERS/ATS clinical practice guidelines: noninvasive ventilation for acute respiratory failure. Eur Respir J. 2017 Aug 31;50(2):1602426.Texto completo Resumo
Davidson C, Banham S, Elliott, et al. British Thoracic Society/Intensive Care Society guideline for the ventilatory management of acute hypercapnic respiratory failure in adults. BMJ Open Respir Res. 2016 Mar 14;3(1):e000133.Texto completo Resumo
Artigos de referência
Uma lista completa das fontes referenciadas neste tópico está disponível para os usuários com acesso total ao BMJ Best Practice.
Diagnósticos diferenciais
- Hyperventilation secondary to metabolic acidosis
- Hyperventilation secondary to anxiety
- Sleep apnea
Mais Diagnósticos diferenciaisDiretrizes
- Symptom assessment for mechanically ventilated patients: principles and priorities
- ERS clinical practice guidelines: high-flow nasal cannula in acute respiratory failure
Mais DiretrizesFolhetos informativos para os pacientes
Asthma in adults: what is it?
Asthma in adults: what are the treament options?
Mais Folhetos informativos para os pacientesVideos
Radial artery puncture animated demonstration
Femoral artery puncture animated demonstration
Mais vídeosConectar-se ou assinar para acessar todo o BMJ Best Practice
O uso deste conteúdo está sujeito ao nosso aviso legal