The blood volume in man and animals
In general two methods have been used for the determination of blood volume in man and animals. These are, the CO method which measures plasma volume directly. Total blood volume in each case is calculated from the cell to plasma ratio give by the central venous or arterial haematocrit. Both methods...
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University of Oxford
1948
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| Online Access: | http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.729044 |
| Summary: | In general two methods have been used for the determination of blood volume in man and animals. These are, the CO method which measures plasma volume directly. Total blood volume in each case is calculated from the cell to plasma ratio give by the central venous or arterial haematocrit. Both methods have been subject to criticism; the CO method on the grounds of technical difficulties in CO in blood analyses and the fact that it may include an unknown quantity of muscle myoglobin in addition to circulating haemoglobin; the dye method because injected dye substances disappear from teh circulation and degree of dilution in the plasmas is calculated by extrapolation of the disappearance curve. In addition, the assumption that the central venous haematocrit is truely representative of the ratio of the body's total red cell volume to plasma volume has been questioned. If 'body' haematocrit and the central venous haematocrit are identical, simultaneous determinations of total blood volume by the CO method and the dye method should give equal values. |
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