Blood volume

Source: Wikipedia, the free encyclopedia.

Blood volume (volemia) is the volume of blood (blood cells and plasma) in the circulatory system of any individual.

Humans

A typical adult has a blood volume of approximately 5 liters, with females and males having approximately the same blood percentage by weight (approx 7 to 8%)[1][2] Blood volume is regulated by the kidneys.

Blood volume (BV) can be calculated given the hematocrit (HC; the fraction of blood that is red blood cells) and plasma volume (PV), with the hematocrit being regulated via the blood oxygen content regulator:

Blood volume measurement may be used in people with

chronic hypertension, kidney failure
and critical care.

The use of relative blood volume changes during dialysis is of questionable utility.[3]

Total Blood Volume can be measured manually via the Dual Isotope or Dual Tracer Technique, a classic technique, available since the 1950s.[4] This technique requires double labeling of the blood; that is 2 injections and 2 standards (51Cr-RBC for tagging red blood cells and I-HAS for tagging plasma volume) as well as withdrawing and re-infusing patients with their own blood for blood volume analysis results. This method may take up to 6 hours for accurate results. The blood volume is 70 ml/kg body weight in adult males, 65 ml/kg in adult females and 70-75 ml/kg in children (1 year old and over).[5][6]

Semi-automated system

Blood volume may also be measured semi-automatically. The BVA-100, a product of Daxor Corporation, is an FDA-cleared diagnostic used at leading medical centers in the United States which consists of an automated

inversely proportional to the concentration of the indicator in the known volume; the larger the unknown volume, the lower the tracer concentration, thus the unknown volume can be calculated. The microhematocrit data along with the I-131 indicator data provide a normalized hematocrit number, more accurate than hematocrit or peripheral hematocrit measurements.[8] Measurements are taken 5 times at 6-minute intervals so that the BVA-100 can calculate the albumin transudation time to understand the flux of liquid through capillary membranes
.

Blood volumes have also been measured in humans using the non-radioactive, carbon monoxide (CO) rebreathing technique for more than 100 years. With this technique, a small volume of pure CO gas is inhaled and rebreathed for a few minutes. During rebreathing, CO binds to hemoglobin present in red blood cells. Based on the increase in blood CO after the rebreathing period, the volume of blood can be determined through the dilution principle (i.e. similar as the case for radioactive tracer methods). Although CO gas in large volumes is toxic to humans, the volume used to access blood volumes corresponds to what would be inhaled when smoking one cigarette. While researchers typically use custom-made rebreathing circuits, the Detalo Performance from Detalo Health has fully automated the procedure and made the measurement available to a larger group of users.[9]

Other animals

Animal Blood volume
(ml/kg)[10]
Cat 55 (47-66)
Cow
 55 (52-57)[11]
Dog 86 (79-90)
Ferret 75
Gerbil
 67
Goat 70
Guinea pig 75 (67-92)
Hamster 78
Horse 76
Human (male) 75
Human (female) 65
Monkey (rhesus)
 54
Mouse 79 (78-80)
Pig 65
Rabbit 56 (44-70)
Rat 64 (50-70)
Sheep 60
Marmoset 60-70[12]

The table at right shows circulating blood volumes, given as volume per kilogram, for healthy adults and some animals.[10] However, it can be 15% less in obese and old animals.[10]

See also

References

  1. ^ "How much blood is in the human body? What to know". June 2020.
  2. ^ Lee, LanNa (1998). Elert, Glenn (ed.). "Volume of blood in a human". The Physics Factbook. Retrieved 2019-03-23.
  3. PMID 22269777
    .
  4. ^
    S2CID 21290772
    .
  5. ^ "History of Changes for Study: NCT02972294".
  6. ^ "Maximum allowable blood loss | Iowa Head and Neck Protocols".
  7. PMID 17496003
    .
  8. ^ Park, Junki; Puri, Sonika; Mattoo, Aditya; Modersitzki, Frank; Goldfarb, David (2012). "Radioisotope Blood Volume Measurement in Hemodialysis Patients" (PDF).
  9. PMID 28663373
    .
  10. ^ a b c A Compendium of Drugs Used for Laboratory Animal Anesthesia, Analgesia, Tranquilization and Restraint Archived June 6, 2011, at the Wayback Machine at Drexel University College of Medicine. Retrieved April 2011
  11. ^ Reynolds, Monica; Plasma and Blood Volume in the Cow Using the T-1824 Hematocrit Method American Journal of Physiology - June 1953 vol. 173 no. 3 421-427 doi:10.1152/ajplegacy.1953.173.3.421
  12. ^ Wolfensohn & Lloyd, 2003, Handbook of Laboratory Animal Management and Welfare, 3rd Edition

External links

  • Klabunde, Richard E. (25 April 2014). "Blood Volume". Cardiovascular Physiology Concepts. Retrieved 4 July 2017.
Retrieved from "https://en.wikipedia.org/w/index.php?title=Blood_volume&oldid=1219247966"