Shock is a life-threatening condition that needs urgent intervention, often in a critical care setting.
The patient with shock will look unwell and often have symptoms specific to the underlying cause (e.g., fever, chest pain, shortness of breath, or abdominal pain). This may be difficult to recognise in practice.
Use an ABCDE approach to diagnose shock in order to treat empirically.
Rapidly identify and treat the underlying cause as soon as possible to reduce mortality.
The term ‘shock’ describes a pathophysiological state with many different causes and is not a specific diagnosis. It may be due to decreased blood perfusion of tissues, inadequate blood oxygen saturation, or increased oxygen demand from the tissues that results in decreased end-organ oxygenation and dysfunction. If left untreated, shock results in sustained multiple organ dysfunction, and end-organ damage with possible death. Tissue hypoperfusion may be present without systemic hypotension, but at the bedside shock is commonly diagnosed when both are present (arterial hypotension and organ dysfunction).
History and exam
Key diagnostic factors
- skin changes
- mental state changes
- presence of risk factors
- chest pain
Other diagnostic factors
- abdominal pain
- peripheral oedema
- raised jugular venous pressure (JVP)
- muffled or quiet heart sounds
- petechial rash
- urticarial rash
- reduced breath sounds on one side of the chest
- tracheal deviation
- distended bladder
- flaccid paralysis of the limbs
- increasing age
- myocardial infarction
- heart valve disease
- gastrointestinal bleeding
- ruptured abdominal aortic aneurysm
- burns/heat stroke
- gastrointestinal losses: diarrhoea and vomiting
- spinal or brainstem injury
- endocrine disease
- pulmonary embolism
- cardiac tamponade
- medication induced
1st investigations to order
- lactate (from arterial blood gas)
- venous blood gas (VBG) or arterial blood gas (ABG)
- full blood count
- urea and electrolytes
- coagulation studies
- C-reactive protein
Investigations to consider
- chest x-ray
- urinalysis and urine pregnancy test
- infection screen
- point-of-care ultrasound
- CT chest, abdomen, and pelvis
- computed tomographic pulmonary angiography (CTPA)
- x-ray long bones
- x-ray spine
Alexander Alexiou, MBBS, BSc, DCH, FRCEM, Dip IMC RCSEd
Emergency Medicine Consultant
Barts Health NHS Trust
Physician Response Unit Consultant
London’s Air Ambulance
Royal London Hospital
AA declares that he has no competing interests.
Clovis Rau, MBBS, BSc, FRCEM DipIMC
ST6 Emergency Medicine
Royal Free NHS Foundation Trust
CR declares that he has no competing interests.
BMJ Best Practice would like to gratefully acknowledge the previous expert contributor, whose work has been retained in parts of the content:
Samuel J. Stratton MD, MPH
Fielding School of Public Health
David Geffen School of Medicine at UCLA
Deputy Health Officer
Orange County Health Care Agency
Health Disaster Management/Emergency Medical Services
SJS declares that he has no competing interests.
Centre for Medical Education
School of Medicine
Honorary Consultant in Intensive Care Medicine
University Hospital of Wales
PF declares that he has no competing interests.
Michael Toolis, MBBS, FCICM, GDipClinUS
MT declares that he has no competing interests.
Section Editor, BMJ Best Practice
AS declares that she has no competing interests.
Lead Section Editor, BMJ Best Practice
TAO declares that she has no competing interests.
Head of Research and Development, BMJ
Comorbidities Editor, BMJ Best Practice
JC declares that she has no competing interests.
Drug Editor, BMJ Best Practice
AM declares that he has no competing interests.
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