Hypovolemia

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Hypovolemia
Other namesOligemia, hypovolaemia, oligaemia, hypovolæmia, volume depletion
SpecialtyEmergency medicine
Symptomsheadache, fatigue, nausea, profuse sweating, dizziness

Hypovolemia, also known as volume depletion, is a state of decreased blood volume or diminished body fluid;[1] more specifically, decrease in volume of the liquid portion of blood.[2][3] Hypovolemia can also be thought of as a form of volume contraction. Hypovolemia is characterized by sodium depletion that can be caused by dehydration or decreased blood volume.[4]

Signs and symptoms[edit]

Symptoms may not be present until 10–20% of total whole-blood volume is lost. Headache, fatigue, nausea, profuse sweating, and dizziness may occur as the condition develops.

Causes[edit]

Common causes of hypovolemia are:[5]

Diagnosis[edit]

Hypovolemia can be recognized by a fast heart rate, low blood pressure,[9] and the absence of perfusion as assessed by skin signs (skin turning pale) and/or capillary refill on forehead, lips and nail beds. The patient may feel dizzy, faint, nauseated, or very thirsty. These signs are also characteristic of most types of shock.[10]

In children, compensation can result in an artificially high blood pressure despite hypovolemia (a decrease in blood volume). Children typically are able to compensate (maintain blood pressure despite hypovolemia) for a longer period than adults, but deteriorate rapidly and severely once they are unable to compensate (decompensate).[11] Consequently, any possibility of internal bleeding in children should be treated aggressively.[12][13]

Signs of external bleeding should be assessed, noting that individuals can bleed internally without external blood loss or otherwise apparent signs.[13]

There should be considered possible mechanisms of injury that may have caused internal bleeding, such as ruptured or bruised internal organs. If trained to do so and if the situation permits, there should be conducted a secondary survey and checked the chest and abdomen for pain, deformity, guarding, discoloration or swelling. Bleeding into the abdominal cavity can cause the classical bruising patterns of Grey Turner's sign (bruising along the sides) or Cullen's sign (around the navel).[14]

Stages[edit]

Usually referred to as a "class" of shock. Most sources state that there are 4 stages of hypovolemic shock;[15] however, a number of other systems exist with as many as 6 stages.[16]

The 4 stages are sometimes known as the "Tennis" staging of hypovolemic shock, as the stages of blood loss (under 15% of volume, 15–30% of volume, 30–40% of volume and above 40% of volume) mimic the scores in a game of tennis: 15, 15–30, 30–40 and 40.[17] It is basically the same as used in classifying bleeding by blood loss.

The signs and symptoms of the major stages of hypovolemic shock include:[18]

Stage 1 Stage 2 Stage 3 Stage 4
Blood loss Up to 15% (750 mL) 15–30% (750–1500 mL) 30–40% (1500–2000 mL) Over 40% (over 2000 mL)
Blood pressure Normal (Maintained
by vasoconstriction)
Increased diastolic BP Systolic BP < 100 Systolic BP < 70
Heart rate Normal Slight tachycardia (> 100 bpm) Tachycardia (> 120 bpm) Extreme tachycardia (> 140 bpm) with weak pulse
Respiratory rate Normal Increased (> 20) Tachypneic (> 30) Extreme tachypnea
Mental status Normal Slight anxiety, restless Altered, confused Decreased LOC, lethargy, coma
Skin Pallor Pale, cool, clammy Increased diaphoresis Extreme diaphoresis; mottling possible
Capillary refill Normal Delayed Delayed Absent
Urine output Normal 20–30 mL/h 20 mL/h Negligible

Investigation[edit]

In a hospital, physicians respond to a case of hypovolemic shock by conducting these investigations:

Treatment[edit]

Field care[edit]

The most important step in treatment of hypovolemic shock is to identify and control the source of bleeding.[19]

Medical personnel should immediately supply emergency oxygen to increase efficiency of the patient's remaining blood supply. This intervention can be life-saving.[20]

The use of intravenous fluids (IVs) may help compensate for lost fluid volume, but IV fluids cannot carry oxygen the way blood does—however, researchers are developing blood substitutes that can. Infusing colloid or crystalloid IV fluids also dilutes clotting factors in the blood, increasing the risk of bleeding. Current best practice allow permissive hypotension in patients suffering from hypovolemic shock,[21] both avoid overly diluting clotting factors and avoid artificially raising blood pressure to a point where it "blows off" clots that have formed.[22][23]

Hospital treatment[edit]

Fluid replacement is beneficial in hypovolemia of stage 2, and is necessary in stage 3 and 4.[18] See also the discussion of shock and the importance of treating reversible shock while it can still be countered.

The following interventions are carried out:

  • IV access
  • Oxygen as required
  • Fresh frozen plasma or blood transfusion
  • Surgical repair at sites of bleeding

Vasopressors (such as dopamine and noradrenaline) should generally be avoided, as they may result in further tissue ischemia and don't correct the primary problem. Fluids are the preferred choice of therapy.[24]

History[edit]

In cases where loss of blood volume is clearly attributable to bleeding (as opposed to, e.g., dehydration), most medical practitioners prefer the term exsanguination for its greater specificity and descriptiveness, with the effect that the latter term is now more common in the relevant context.[25]

See also[edit]

References[edit]

  1. ^ 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.
  2. ^ "Hypovolemia definition - MedicineNet - Health and Medical Information Produced by Doctors". Medterms.com. 2012-03-19. Retrieved 2015-11-01.
  3. ^ "Hypovolemia | definition of hypovolemia by Medical dictionary". Medical-dictionary.thefreedictionary.com. Retrieved 2015-11-01.
  4. ^ "Dehydration definition - MedicineNet - Health and Medical Information Produced by Doctors". Medterms.com. 2013-10-30. Retrieved 2015-11-01.
  5. ^ Sircar, S. Principles of Medical Physiology. Thieme Medical Pub. ISBN 9781588905727
  6. ^ Danic B, Gouézec H, Bigant E, Thomas T (June 2005). "[Incidents of blood donation]". Transfus Clin Biol (in French). 12 (2): 153–9. doi:10.1016/j.tracli.2005.04.003. PMID 15894504.
  7. ^ "Burn Shock / House Staff Manual". Total Burn Care. Retrieved 2015-11-01.
  8. ^ "Resuscitation in Hypovolaemic Shock. Information page | Patient". Patient.info. Retrieved 2015-11-01.
  9. ^ "Stage 3: Compensated Shock". Archived from the original on 2010-06-11.
  10. ^ Joseph S. Alpert; Gordon A. Ewy (2002). Manual of Cardiovascular Diagnosis and Therapy. Lippincott Williams & Wilkins. p. 101. ISBN 978-0-7817-2803-4.
  11. ^ Henry; Edward R. Stapleton (26 July 2011). EMT Prehospital Care. Jones & Bartlett Publishers. pp. 471–. ISBN 978-0-323-08533-5.
  12. ^ Assuma Beevi (31 August 2012). Pediatric Nursing Care Plans. JP Medical Ltd. pp. 47–. ISBN 978-93-5025-868-2.
  13. ^ a b Clement; I (20 May 2013). Textbook on First Aid and Emergency Nursing. Jaypee Brothers Publishers. pp. 113–. ISBN 978-93-5025-987-0.
  14. ^ Blaber, Amanda; Harris, Graham (1 October 2011). Assessment Skills For Paramedics. McGraw-Hill Education. pp. 83–. ISBN 978-0-335-24199-6.
  15. ^ Hudson, Kristi. "Hypovolemic Shock - 1 Nursing CE". Archived from the original on 2009-06-06.
  16. ^ "Stage 1: Anticipation stage (a new paradigm)". Archived from the original on 2010-01-16.
  17. ^ Greaves, Ian; Porter, Keith; Hodgetts, Timothy; et al., eds. (2006). Emergency Care: A Textbook for Paramedics. Elsevier Health Sciences. p. 229. ISBN 9780702025860.
  18. ^ a b Elizabeth D Agabegi; Agabegi, Steven S. (2008). Step-Up to Medicine (Step-Up Series). Hagerstwon, MD: Lippincott Williams & Wilkins. ISBN 978-0-7817-7153-5.
  19. ^ Bulger, E. M., Snyder, D., Schoelles, K., Gotschall, C., Dawson, D., Lang, E., ... & White, L. (2014). An evidence-based prehospital guideline for external hemorrhage control: American College of Surgeons Committee on Trauma. Prehospital Emergency Care, 18(2), 163-173.
  20. ^ Takasu A, Prueckner S, Tisherman SA, Stezoski SW, Stezoski J, Safar P. (2000), Effects of increased oxygen breathing in a volume controlled hemorrhagic shock outcome model in rats., PMID 10959021
  21. ^ "Permissive Hypotension". Trauma.Org. 1997-08-31. Retrieved 2015-11-01.
  22. ^ American Academy of Orthopaedic Surgeons (AAOS); AAOS; Mike Kennamer (30 September 2013). Intravenous Therapy for Prehospital Providers. Jones & Bartlett Publishers. pp. 63–. ISBN 978-1-4496-4204-4.
  23. ^ Roberto de Franchis; Alessandra Dell'Era (25 January 2014). Variceal Hemorrhage. Springer Science & Business Media. pp. 113–. ISBN 978-1-4939-0002-2.
  24. ^ "Failure of dobutamine to improve liver oxygenation during resuscitation with a crystalloid solution after experimental haemorrhagic shock". Pubmed-NCBI. 1996-08-31. Retrieved 2017-11-21.
  25. ^ L. Geeraedts Jr.; H. Kaasjager; A. van Vugt; J. Frölke (2009). "Exsanguination in trauma: A review of diagnostics and treatment options". Injury. 40 (1): 11–20. doi:10.1016/j.injury.2008.10.007. PMID 19135193.

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