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Sudden Cardiac Arrest and Cardiopulmonary Resuscitation (CPR)

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  1. Introduction to sudden cardiac arrest and resuscitation
    4 Chapters
  2. Resuscitation physiology and mechanisms
    2 Chapters
  3. Causes of sudden cardiac arrest and death
    2 Chapters
  4. Cardiopulmonary Resuscitation
    10 Chapters
  5. Special Circumstances
    11 Chapters
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Hyperthermia and malignant hyperthermia

Hyperthermia is characterized by a body temperature exceeding the typical range of 36.5-37.6°C (97.7-99.7°F). It arises when heat production or acquisition surpasses the body’s capacity for heat elimination.

Hyperthermia can induce an inflammatory state similar to the Systemic Inflammatory Response Syndrome (SIRS). Body temperatures surpassing 40°C (104°F) are potentially hazardous and may precipitate cardiac arrest. The classification of hyperthermia is delineated in Table 1 below.

SeverityClinical presentationTreatment
Mild hyperthermiaThirst. Weakness.Cold environment.
Passive cooling.
Cold oral fluids.
Heat syncopeDiscomfort, anxiety, dizziness, syncope.Cold environment.
Cold intravenous fluids (1-2 L crystalloid, with rate 500 ml/h).
Cold shower.
Ice packs.
Heat stroke (>40°C)Neurological symptoms, confusion, convulsion, tachycardia, hypotension, coma.As above but with lower temperatures.
Electrolyte replacement.
Large infusions of fluids are typically needed.
Table 1. Grading of hyperthermia.

Body temperature should decrease at a rate of 0.1°C/min during the cooling process.

Malignant hyperthermia

Malignant hyperthermia may manifest under two primary circumstances:

  • Due to a genetic mutation in the RYR1 receptor, resulting in persistent muscle contraction upon administration of halogenated anesthetic agents.
  • As an idiosyncratic response to substances such as MDMA (ecstasy) or amphetamines.

In either scenario, there is sustained muscle activation, leading to marked heat generation, acidosis, and the subsequent development of hyperkalemia. This condition is potentially fatal and necessitates prompt intervention, including sedation and the administration of Dantrolene.


DeBehnke DJ, Hilander SJ, Dobler DW, Wickman LL, Swart GL. The hemodynamic and arterial blood gas response to asphyxiation: a canine model of pulseless electrical activity. Resuscitation 1995;30:16975.

Safar P, Paradis NA, Weil MH. Asphyxial cardiac arrest. In: Paradis NA, Halperin HR, Kern KB, Wenzel V, Chamberlain DA, editors. Cardiac arrest—the science and practice of resuscitation medicine.

Kitamura T, Kiyohara K, Sakai T, et al. Epidemiology and outcome of adult out-of-hospital cardiac arrest of non-cardiac origin in Osaka: a population-based study. BMJ Open 2014;4:e006462.

Deasy C, Bray J, Smith K, et al. Hanging-associated out-of-hospital cardiac arrests in Melbourne, Australia. Emerg Med 2013;30:3842.

Luna GK, Pavlin EG, Kirkman T, Copass MK, Rice CL. Hemodynamic effects of external cardiac massage in trauma shock. J Trauma 1989;29:1430-3.

Jeffcoach DR, Gallegos JJ, Jesty SA, et al. Use of CPR in hemorrhagic shock, a dog model. J Trauma Acute Care Surg 2016;81:27-33.

Watts S, Smith JE, Gwyther R, Kirkman E. Closed chest compressions reduce survival in an animal model of hemorrhage-induced traumatic cardiac arrest. Resuscitation 2019;140: 37-42.

Endo A, Kojima M, Hong ZJ, Otomo Y, Coimbra R. Open-chest versus closed-chest cardiopulmonary resuscitation in trauma patients with signs of life upon hospital arrival: a retrospective multicenter study. Crit Care 2020;24:541.

Ebo DG, Clarke RC, Mertes PM, et al. Molecular mechanisms and pathophysiology of perioperative hypersensitivity and anaphylaxis: a narrative review. Br J Anaesth 2019;123:e3849.

Wallmuller C, Meron G, Kurkciyan I, et al. Causes of in-hospital cardiac arrest and influence on outcome. Resuscitation 2012;83:120611.

Wang CH, Huang CH, Chang WT, et al. The effects of calcium and sodium bicarbonate on severe hyperkalaemia during cardiopulmonary resuscitation: a retrospective cohort study of adult in-hospital cardiac arrest. Resuscitation 2016;98:10511.

Saarinen S, Nurmi J, Toivio T, et al. Does appropriate treatment of the primary underlying cause of PEA during resuscitation improve patients’ survival? Resuscitation 2012;83:81922.

Mroczek T, Gladki M, Skalski J. Successful resuscitation from accidental hypothermia of 11.8 degrees C: where is the lower bound for human beings? Eur J Cardiothorac Surg 2020;58:10912.

Stephen CR, Dent SJ, Hall KD, Smith WW. Physiologic reactions during profound hypothermia with cardioplegia. Anesthesiology 1961;22:87381.

Frei C, Darocha T, Debaty G, et al. Clinical characteristics and outcomes of witnessed hypothermic cardiac arrest: a systematic review on rescue collapse. Resuscitation 2019;137:418.

Wood S. Interactions between hypoxia and hypothermia. Annu Rev Physiol 1991;53:7185.

Podsiadlo P, Darocha T, Svendsen OS, et al. Outcomes of patients suffering unwitnessed hypothermic cardiac arrest rewarmed with extracorporeal life support: a systematic review. Artif Organs 2020.

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