Hypovolemic shock

Hypovolemic shock
Hypovolemic shock
	A diagram showing the formation of interstitial fluid from the bloodstream
Specialty	Emergency care
Symptoms	Anxiety, confusion, decreased or no urine output, cool and clammy skin, sweating, weakness, pallor, rapid breathing, unconsciousness
Causes	Severe dehydration or blood loss
Treatment	Replacement of fluids, surgery to repair cause of bleeding

Hypovolemic shock is a form of shock caused by severe hypovolemia (insufficient blood volume or extracellular fluid in the body).^[1]^[2] It could be the result of severe dehydration through a variety of mechanisms or blood loss.^[3]^[2] Hypovolemic shock is a medical emergency; if left untreated, the insufficient blood flow can cause damage to organs, leading to multiple organ failure.^[4]

In treating hypovolemic shock, it is important to determine the cause of the underlying hypovolemia, which may be the result of bleeding or other fluid losses. To minimize ischemic damage to tissues, treatment involves quickly replacing lost blood or fluids, with consideration of both rate and the type of fluids used.^[4]

Tachycardia, a fast heart rate, is typically the first abnormal vital sign.^[3] When resulting from blood loss, trauma is the most common root cause, but severe blood loss can also happen in various body systems without clear traumatic injury.^[3] The body in hypovolemic shock prioritizes getting oxygen to the brain and heart, which reduces blood flow to nonvital organs and extremities, causing them to grow cold, look mottled, and exhibit delayed capillary refill.^[3] The lack of adequate oxygen delivery ultimately leads to a worsening increase in the acidity of the blood (acidosis).^[3] The "lethal triad" of ways trauma can lead to death is acidosis, hypothermia, and coagulopathy.^[3] It is possible for trauma to cause clotting problems even without resuscitation efforts.^[3]

Damage control resuscitation is based on three principles:

permissive hypotension: tries to balance temporary suboptimal perfusion to organs with conditions for halting blood loss by setting a goal of 90 mmHg systolic blood pressure ^[3]
hemostatic resuscitation: restoring blood volume in ways (with whole blood or equivalent) that interfere minimally with the natural process of stopping bleeding.^[5]
damage control surgery.^[3]

^ ^a ^b "Hypovolemic shock: MedlinePlus Medical Encyclopedia". MedlinePlus. 2019-01-28. Retrieved 2019-02-21.
^ ^a ^b McGee, Steven (2018). Evidence-based physical diagnosis. Philadelphia, PA: Elsevier. ISBN 978-0-323-39276-1. OCLC 959371826. The term hypovolemia refers collectively to two distinct disorders: (1) volume depletion, which describes the loss of sodium from the extracellular space (i.e., intravascular and interstitial fluid) that occurs during gastrointestinal hemorrhage, vomiting, diarrhea, and diuresis; and (2) dehydration, which refers to the loss of intracellular water (and total body water) that ultimately causes cellular desiccation and elevates the plasma sodium concentration and osmolality.
^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ Hooper, Nicholas; Armstrong, Tyler J. (2018-10-27). "Shock, Hemorrhagic". NCBI Bookshelf. PMID 29262047. Retrieved 2019-02-21.
^ ^a ^b Taghavi, S; Askari, R (2018), "article-28977", Hypovolemic Shock, Treasure Island (FL): StatPearls Publishing, PMID 30020669, retrieved 2019-02-20
^ Cap, Andrew P.; Gurney, Jennifer M.; Meledeo, Michael A. (2020). "Hemostatic Resuscitation". Damage Control Resuscitation. pp. 117–144. doi:10.1007/978-3-030-20820-2_7. ISBN 978-3-030-20819-6. S2CID 242142361.

[MedlinePlus_2019-1] "Hypovolemic shock: MedlinePlus Medical Encyclopedia". MedlinePlus. 2019-01-28. Retrieved 2019-02-21.

[McGee_2018-2] McGee, Steven (2018). Evidence-based physical diagnosis. Philadelphia, PA: Elsevier. ISBN 978-0-323-39276-1. OCLC 959371826. The term hypovolemia refers collectively to two distinct disorders: (1) volume depletion, which describes the loss of sodium from the extracellular space (i.e., intravascular and interstitial fluid) that occurs during gastrointestinal hemorrhage, vomiting, diarrhea, and diuresis; and (2) dehydration, which refers to the loss of intracellular water (and total body water) that ultimately causes cellular desiccation and elevates the plasma sodium concentration and osmolality.

[CC_2018-3] ^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ Hooper, Nicholas; Armstrong, Tyler J. (2018-10-27). "Shock, Hemorrhagic". NCBI Bookshelf. PMID 29262047. Retrieved 2019-02-21.

[CC-4] Taghavi, S; Askari, R (2018), "article-28977", Hypovolemic Shock, Treasure Island (FL): StatPearls Publishing, PMID 30020669, retrieved 2019-02-20

[5] Cap, Andrew P.; Gurney, Jennifer M.; Meledeo, Michael A. (2020). "Hemostatic Resuscitation". Damage Control Resuscitation. pp. 117–144. doi:10.1007/978-3-030-20820-2_7. ISBN 978-3-030-20819-6. S2CID 242142361.

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