World Library  
Flag as Inappropriate
Email this Article

Distributive shock

Article Id: WHEBN0002930734
Reproduction Date:

Title: Distributive shock  
Author: World Heritage Encyclopedia
Language: English
Subject: Shock (circulatory), Sepsis, Septic shock, Critical Care Air Transport Team, Reference desk/Archives/Science/2009 June 30
Collection: Medical Emergencies
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Distributive shock

Distributive shock is a

  • Surviving Sepsis Campaign

External links

  1. ^ a b c Kanaparthi, Lalit K.; Klaus-Dieter, Lessnau; Peralta, Ruben (12 February 2013), Pinsky, Michael R., ed., "Distributive Shock: Overview: Background", Medscape Reference ( 
  2. ^ a b c d e f g Elbers, Paul W.G.; Ince, Can (19 July 2006). "Mechanisms of critical illness--classifying microcirculatory flow abnormalities in distributive shock".  
  3. ^ a b c d e Kanaparthi et al. 2013, Overview: Etiology.
  4. ^ a b c d e f Kanaparthi et al. 2013, Overview: Pathophysiology.
  5. ^ a b Ince, Can (25 August 2005). "The microcirculation is the motor of sepsis".  
  6. ^ Weaver, Lynne C.; Fleming, Jennifer C.; Mathias, Christopher J.; Krassioukov, Andrie V. (2012). "Ch. 13: Disordered Cardiovascular Control After Spinal Cord Injury". In Verhaagen, Joost; McDonald, John W. Handbook of Clinical Neurology 109. pp. 213–33.  
  7. ^ Kanaparthi et al. 2013, Treatment: Approach Considerations.
  8. ^ a b Kanaparthi et al. 2013, Treatment: Resuscitation.
  9. ^ Kanaparthi et al. 2013, Treatment: Corticosteroids.
  10. ^ Kanaparthi et al. 2013, Treatment: Antimicrobial Treatment.
  11. ^ Kanaparthi et al. 2013, Treatment: Surgical Control of Shock Sources.
  12. ^ Kanaparthi et al. 2013, Treatment: Treatment of Anaphylaxis.
  13. ^ Kinasewitz, Gary T.; Privalle, Christopher T.; Imm, Amy; Steingrub, Jay S.; et al. (July 2008). "Multicenter, randomized, placebo-controlled study of the nitric oxide scavenger pyridoxalated hemoglobin polyoxyethylene in distributive shock".  
  14. ^ Jang, D.H.; Nelson, L.S.; Hoffman, R.S. (September 2013). "Methylene blue for distributive shock: A potential new use of an old antidote".  

References

The choice of fluids for resuscitation remains an area of research, the Surviving Sepsis Campaign an international consortium of experts, did not find adequate evidence to support the superiority crystalloid fluids versus colloid fluids.[8] Drugs such as, pyridoxalated hemoglobin polyoxyethylene, which scavenge nitric oxide from the blood have been investigated.[13] As well as methylene blue which may inhibit the nitric oxide-cyclic guanosine monophosphate (NO-cGMP) pathway which has been suggested to play a significant role in distributive shock.[14]

Research Directions

Septic shock is associated with significant mortality and is the leading non cardiac cause of death in intensive care units (ICU's).[1]

Prognosis

Anaphylactic shock is treated with epinephrine.[12]

Patients with septic shock are treated with antimicrobial drugs to treat the causative infection.[10] Some sources of infection require surgical intervention including necrotizing fasciitis, cholangitis, abscess, intestinal ischemia, or infected medical devices.[11]

The main goals of treatment in distributive shock are to reverse the underlying cause and achieve hemodynamic stabilization.[7] Immediate treatment involves fluid resuscitation and the use of vasoactive drugs, both vasopressors and inotropes.[8] Hydrocortisone is used for patients whose hypotension does not respond to fluid resuscitation and vasopressors.[9] Opening and keeping open the microcirculation is a consideration in the treatment of distributive shock, as a result limiting the use of vasopressors has been suggested.[2] Control of inflammation, vascular function and coagulation to correct pathological differences in blood flow and microvascular shunting has been pointed to as a potentially important adjunct goal in the treatment of distributive shock.[2]

Treatment

  • Class I: all capillaries are stagnant when there is normal or sluggish venular flow.
  • Class II: there are empty capillaries next to capillaries that have flowing red blood cells.
  • Class III: there stagnant capillaries next to capillaries with normal blood flow.
  • Class IV: hyperdynamic flow in capillaries adjacent to capillaries that are stagnant.
  • Class V: widespread hyperdynamic flow in the microcirculatory system.[2]

Elbers and Ince have identified five classes of abnormal microcirculatory flow in distributive shock using side stream dark field microscopy.

Forms

Distributive shock associated with adrenal crisis results from inadequate steroid hormones.

Neurogenic shock is caused by the loss of vascular tone normally supported by the sympathetic nervous system due to injury to the central nervous system especially spinal cord injury.[4][6]

In anaphylactic shock low blood pressure is related to decreased systemic vascular resistance (SVR) triggered primarily by a massive release of histamine by mast cells activated by antigen-bound immunoglobulin E and also by increased production and release of prostaglandins.[4]

There are four types of distributive shock. The most common, septic shock, is caused by an infection, most frequently by bacteria, but viruses, fungi and parasites have been implicated.[3] Infection sites most likely to lead to septic shock are chest, abdomen and genitourinary tract.[3] In septic shock the blood flow in the microvasculature is abnormal with some capillaries under perfused and others with normal to high blood flow.[5] The endothelial cells lining the blood vessels become less responsive to vasocontrictive agents, lose their glycocalyx (normal coating) and negative ionic charge, become leaky and cause extensive over-expression of nitric oxide.[2] The coagulation cascade is also disrupted.[4] Tissue factor that initiates the clotting cascade is produced by activated monocytes and the endothelial cells lining the blood vessels while antithrombin and fibrinolysis are impaired.[4] Disseminated intravascular coagulation (DIC) can result from the thrombin produced in the inflammatory response.[4] The ability of red blood cells to change shape decreases and their tendency to clump together increases, inhibiting their flow through the microvasculature.[5]

The cause of inadequate tissue perfusion (blood delivery to tissues) in distributive shock is a lack of normal responsiveness of blood vessels to vasoconstrictive agents and direct vasodilation.[4]

Pathophysiology

In addition to sepsis, distributive shock can be caused by systemic inflammatory response syndrome (SIRS) due to conditions other than infection such as pancreatitis, burns or trauma.[3] Other causes include, toxic shock syndrome (TSS), anaphylaxis (a sudden, severe allergic reaction), adrenal insufficiency, reactions to drugs or toxins, heavy metal poisoning, hepatic (liver) insufficiency and damage to the central nervous system.[3] Causes of adrenal insufficiency leading to distributive shock include acute worsening of chronic adrenal insufficiency, destruction or removal of the adrenal glands, suppression of adrenal gland function due to exogenous steroids, hypopituitarism and metabolic failure of hormone production.[3]

Causes

Contents

  • Causes 1
  • Pathophysiology 2
  • Forms 3
  • Treatment 4
  • Prognosis 5
  • Research Directions 6
  • References 7
  • External links 8

[1], a condition that can be fatal.septic shock leading to type of distributive shock called sepsis The most common cause is [2] is at or above a normal level.output of the heart Distributive shock is different from the other three categories of shock in that it occurs even though the [2]

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.