Medicine:Blood volume
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:
- [math]\displaystyle{ BV = \frac{PV}{1-HC} }[/math]
Blood volume measurement may be used in people with congestive heart failure, 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 well counter interfaced with a computer.[7] It is able to report with 98% accuracy within 60 minutes the Total Blood Volume (TBV), Plasma Volume (PV) and Red Cell Volume (RCV) using the indicator dilution principle, microhematocrit centrifugation and the Ideal Height and Weight Method.[4] The indicator, or tracer, is an I-131 albumin injection. An equal amount of the tracer is injected into a known and unknown volume. Clinically, the unknown volume is the patient's blood volume, with the tracer having been injected into the patient's blood stream and tagged to the blood plasma. Once the tracer is injected a technician takes five blood samples which undergo microhematocrit centrifugation to extrapolate true blood volume at time 0. The concentration of the I-131 in the blood is determined from the blood radioactivity against the standard, which has a known I-131 dilution in a known volume. The unknown volume is 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
- Volume status
- Hypovolemia
- Hypervolemia
References
- ↑ "How much blood is in the human body? What to know". June 2020. https://www.medicalnewstoday.com/articles/321122.
- ↑ Lee, LanNa (1998). "Volume of blood in a human". in Elert, Glenn. https://hypertextbook.com/facts/1998/LanNaLee.shtml.
- ↑ Dasselaar, JJ; van der Sande, FM; Franssen, CF (2012). "Critical evaluation of blood volume measurements during hemodialysis.". Blood Purification 33 (1–3): 177–82. doi:10.1159/000334142. PMID 22269777.
- ↑ 4.0 4.1 Yu, Mihae (2011). "A Prospective Randomized Trial Using Blood Volume Analysis in Addition to Pulmonary Artery Catheter, Compared with Pulmonary Catheter Alone, to Guide Shock Resuscitation in Critically Ill Surgical Patients". Shock 35 (3): 220–228. doi:10.1097/shk.0b013e3181fc9178. PMID 20926981.
- ↑ "History of Changes for Study: NCT02972294". https://clinicaltrials.gov/ct2/history/NCT02972294?V_6=View.
- ↑ "Maximum allowable blood loss | Iowa Head and Neck Protocols". https://medicine.uiowa.edu/iowaprotocols/maximum-allowable-blood-loss.
- ↑ Manzone, T. A.; Dam, H. Q.; Soltis, D.; Sagar, V. V. (11 May 2007). "Blood Volume Analysis: A New Technique and New Clinical Interest Reinvigorate a Classic Study". Journal of Nuclear Medicine Technology 35 (2): 55–63. doi:10.2967/jnmt.106.035972. PMID 17496003.
- ↑ Park, Junki; Puri, Sonika; Mattoo, Aditya; Modersitzki, Frank; Goldfarb, David (2012). "Radioisotope Blood Volume Measurement in Hemodialysis Patients". http://www.daxor.com/pdfs/ASN2012_Park_Radioisotope.pdf.
- ↑ Siebenmann, Christoph; Keiser, Stefanie; Robach, Paul; Lundby, Carsten (29 June 2017). "CORP: The assessment of total hemoglobin mass by carbon monoxide rebreathing". Journal of Applied Physiology 123 (3): 645–654. doi:10.1152/japplphysiol.00185.2017. ISSN 8750-7587. PMID 28663373.
- ↑ 10.0 10.1 10.2 A Compendium of Drugs Used for Laboratory Animal Anesthesia, Analgesia, Tranquilization and Restraint at Drexel University College of Medicine. Retrieved April 2011
- ↑ 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
- ↑ Wolfensohn & Lloyd, 2003, Handbook of Laboratory Animal Management and Welfare, 3rd Edition
External links
- Klabunde, Richard E. (25 April 2014). "Blood Volume". http://www.cvphysiology.com/Blood%20Pressure/BP025.
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