Camp. Biochem. Physiol., 1975, Vol. SlA, pp. 821 to 822. Pergomon Press.
Printed in Great Britain
CHANGES IN pCOa AND pH IN BLOOD SAMPLES FROM GALLUS DOA4ES’TICUS HELD AT AMBIENT TEMPERATURE T. E. NIGHTINGALE*, M. R. FEDDE AND W. D. KUHLMANN Department
of Physiological
Sciences, Kansas State University,
Manhattan,
KS 66506, U.S.A.
25 April 1974)
(Received
Abstract-l.
Changes in pC0, and pH were determined in whole blood samples from Gullus held at ambient temperature (24--27°C) for 80 min. increased at a rate of 0+44 torr min-l. 3. pH decreased at a rate of 0.00049 units min-l. 4. These values can be used to correct measurements which cannot be made immediately after
domesticus 2. pCOa
blood withdrawal from the bird.
INTRODUCTION IT IS generally agreed that blood samples should be analyzed for pOB, pCOo and pH immediately after
being drawn, although multiple sampling often precludes this. While blood is in the sampling syringe, metabolic processes continue to produce changes in gas tensions and pH. Though storing blood samples at 0°C would slow metabolism, that is not always feasible; furthermore, glycolysis during cooling and rewarming periods may lead to errors (Severinghaus et al., 1956; Kelman & Nunn, 1966). Changes in gas tensions and pH during storage have been extensively studied in mammalian blood (Severinghaus et al., 1956; Siggaard Andersen, 1964; Eldridge 8c Fretwell, 1965; Lenfant & Aucutt, 1965 ; Kelman & Nunn, 1966; Rhodes & Moser, 1966), but they have not been determined for avian blood. Besch (1966) found that oxygen uptake of avian blood cells was constant at a given temperature between 25 and 40°C for as long as 2.5 hr; thus, for a similar time and temperature, changes in blood pCOa and pH should also occur. Because it is often necessary to hold blood samples until pCOl and pH determinations can be made, we conducted a series of trials to ascertain changes in those parameters as a function of storage time at room temperature in chicken blood. MATERIALS
AND METHODS
Arterial blood samples from twenty adult, anesthetized, male, White Leghorn-type chickens (Babcock strain) were drawn into IO-ml, gas-tight, plastic syringes using an attached three-way stopcock. The dead space of each syringe previously had been tilled with heparinixed saline. At 5- to 7-min intervals during the next 80 min, aliquots * Present address: U.S. Department of Agriculture, A.R.S., Poultry Research Laboratory, RD 2, Box 600, Georgetown, DE 19947, U.S.A.
821
of the blood were analyzed in duplicate for pCOa and pH at 40°C using an Instrumentation Laboratory blood gas system (Models 123 and 127). Between analyses, the syringe containing the remaining blood was placed on the laboratory bench at room temperature (24-27°C). Simple linear regression analyses were used to determine regression of pC0, and pH as a function of time (Fryer, 1966). RESULTS AND DISCUSSION Changes in pCOp and pH were determined on 43 normal, freshly drawn, blood samples stored anaerobically up to 80 min at room temperature. A total of 260 determinations were made to defme those relationships in the range of pC0, from 20 to 45 torr (Figs. 1 and 2). Changes in slopes of regression lines relating ApCO, to time and A pH to time were found to be independent of initial&O,, as well as of room temperatures between 24 and 27°C. Changes in pCOa and pH as a function of storage time were:
A pCOz = 0.044X,
A pH = - O.o0049X,
where X was storage time in minutes. Thus, to correct a measured value for a change in pCOB with time, it is necessary to subtract the factor calculated with the equation from the observed value. The change in pH with time after withdrawal, calculated from the equation, must be added to the observed value to obtain the true pH at withdrawal time. The magnitude of changes in pCOB in chicken blood after withdrawal was similar to that reported by Lenfant & Aucutt (1965), Kelman 8c Nunn (1966) and Siggaard Andersen (1961) for human blood stored at 20-24% (i.e. ApCOB = O-074, O-066 and 0.042 torr min-I, respectively). The similarity of pCOl changes in avian and mammalian blood during storage support the conclusion of Cape1 et al. (1965) that CO* production
T. E. NIGHTINGALE,M. R. FEDDEAND W. D. KUHLMANN
822
in stored blood is independent of oxygen consumption since the latter is known to be some ten times higher in avian blood than in mammalian blood (Hunter & Hunter, 1957; Besch, 1966; Lutz et al., 1973). The rather small changes in pCOz and pH during short-term storage indicate that, for most purposes, no corrections are necessary if measurements are made within a few minutes of withdrawal. The measurements should be corrected, however, if the blood must be stored for longer periods. Acknowledgement-Contribution No, 128, Department of Physiological Sciences, K.A.E.S., Kansas State University, Manhattan, Kansas 66506. This work was supported, in part, by a grant-in-aid from the Kansas Heart Association. 20
40
REFERENCES
60
Time (min)
Fig. 1. Relationship between carbon dioxide tension changes in normoxic whole chicken blood and time of storage at room temperature. Solid line is the calculated regression line. Dashed lines are the 95 per cent confidence limits. (N = 260.)
;
-005
-007
BEXH E. L. (1966) Respiratory activity of avian blood cells. J. ceI1.Physiol. 67, 301-306. CAPEL L. H., FLETCHERE. C. & NUNN J. F. (1965) Carbon dioxide production of whole blood in vitro. Nature, Lond. 208, 82. ELDRIDGE F. & FRETWELL L. K. (1965) Change in oxygen tension of shed blood at various temperatures. J. appl. Physiol. 20, 790-792. FRYER H. C. (1966) Concepts and Methods of Experimental Statistics. Allyn & Bacon, Boston. HUNTER A. S. & HUNTER F. R. (1957) A comparative study of erythrocyte metabolism. J. cell. camp. Physiol. 49,479-502. KELMAN G. R. & NUNN J. F. (1966) Nomograms for correction of blood PO,, PC02, pH and base excess for time and temperature. J. appl. Physiof. 21. 14841490. LENFANTC. & Aucurr C. (1965) Oxygen uptake and change in carbon dioxide tension in human blood stored at 37C. J. appl. Physiol. 20, 503-508. LUTZ P. L., LONGMUIRI. S., T~X-IXEJ. V. & SCHMIDTNIELSENK. (1973) Dissociation curve of bird blood and effect of red cell oxygen consumption. Resp. Physiol. 17, 269-275. RHODESP. G. & MOSERK. M. (1966) Sources of error in oxygen tension measurement. J. appf. Physiol. 21, 729-734. SEVERINGHAUSJ. W., STUPFEL M. & BRADLEYA. F. (1956) Accuracy of blood pH and PCO, determinations. J. appl. Physiol. 9, 189-196. SIGGAARDANDERSEN0. (1961) Sampling and storing of blood for determination of acid-base status. Stand. J. c/in. Lab. Invest. 13, 196-204. SIGGAARDANDERSEN0. (1964) The Acid-Base Status of the Blood, 2nd Edn. Williams & Wilkins, Baltimore.
--._ .--._ .%_ ...-. .-. --._ F npH.-Q.000,9
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.
.
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Fig. 2. Relationship between pH changes in normoxic whole chicken blood and time of storage at room temperature. Solid line is the calculated regression line. Dashed lines are the 95 per cent confidence limits. (N = 260.)
Key Word Index-Avian blood; blood gases; blood metabolism; blood storage; CO2 production; Gal/w domesticus; oxygen consumption; temperature effect.