EM · Shock
Shock states — the recognition and the approach
Also known as Circulatory shock · Acute circulatory failure · Tissue hypoperfusion
Shock — the definition (the inadequate tissue perfusion and the cellular hypoxia); the four patterns by the haemodynamics (the hypovolaemic, the distributive, the cardiogenic, the obstructive); the compensated vs the decompensated phases; the clinical signs (the compensatory tachycardia, the vasoconstriction, the tachypnoea that precede the hypotension); the lactate as the occult-shock marker; the bedside ultrasound (the IVC, the cardiac); and the management framework (the treat-the-cause, the fluid, the vasopressor, the transfusion, the targets). ACEM-primary, globally tagged.
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Shock is the emergency physician's bread and butter — the recognition of the tissue hypoperfusion before the blood pressure drops, the classification by the haemodynamic pattern, and the rapid correction with the fluid, the vasopressor and the treat-the-cause approach. The Fellowship candidate must know the four patterns, the compensated vs the decompensated phases, the role of the lactate, and the targets for the resuscitation, because the shock is the final common pathway of every acute presentation from the trauma to the sepsis to the MI.[1][2]
Definition
Shock is the state of inadequate cellular oxygen delivery — the oxygen supply to the tissues falls below the oxygen demand, producing the anaerobic metabolism, the lactate generation and, if untreated, the multi-organ failure and the death. The definition is haemodynamic: the cardiac output (the stroke volume times the heart rate) is insufficient to meet the tissue demand, whether because of the low preload (the hypovolaemic), the low contractility (the cardiogenic), the low systemic vascular resistance (the distributive), or the external obstruction to the flow (the obstructive).[1]
You have read the opening of this topic. The complete unit — every section and its primary-source references — is part of the Emergency Medicine fellowship atlas.
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- [1]Standl T, Annecke T, Cascorbi I, et al. The Nomenclature, Definition and Distinction of Types of Shock Dtsch Arztebl Int, 2018.PMID 30573009
- [2]Chioncel O, Parissis J, Mebazaa A, et al. Epidemiology, pathophysiology and contemporary management of cardiogenic shock - a position statement from the Heart Failure Association of the European Society of Cardiology Eur J Heart Fail, 2020.PMID 32469155
- [3]Rivers E, Nguyen B, Havstad S, et al. Early goal-directed therapy in the treatment of severe sepsis and septic shock N Engl J Med, 2001.PMID 11794169
- [4]Yealy DM, Kellum JA, Huang DT, et al. A randomized trial of protocol-based care for early septic shock N Engl J Med, 2014.PMID 24635773
- [5]Peake SL, Delaney A, Bailey M, et al. Goal-directed resuscitation for patients with early septic shock N Engl J Med, 2014.PMID 25272316
- [6]Mouncey PR, Osborn TM, Power GS, et al. Trial of early, goal-directed resuscitation for septic shock N Engl J Med, 2015.PMID 25776532
- [7]Perera P, Mailhot T, Riley D, Mandavia D. The RUSH exam: Rapid Ultrasound in SHock in the evaluation of the critically lll Emerg Med Clin North Am, 2010.PMID 19945597