Research in Veterinary Science 76 (2004) 121–127
www.elsevier.com/locate/rvsc
Effect of time delay and storage temperature on blood gas
and acid–base values of bovine venous blood
Gurbuz Gokce
a
a,*
, Mehmet Citil a, Vehbi Gunes a, Gultekin Atalan
b
Department of Internal Medicine, Faculty of Veterinary Medicine, University of Kafkas, Kars 36100, Turkey
b
Department of Surgery, Faculty of Veterinary Medicine, University of Kafkas, Kars 36100, Turkey
Accepted 12 August 2003
Abstract
The aim of this study was to investigate possible changes in the gas composition and acid–base values of bovine venous blood
samples stored at different temperatures (+4, 22 and 37 °C) for up to 48 h. Five healthy cattle were used in the study. A total of 15
blood samples collected from the animals were allocated into three groups, which were, respectively, then stored in a refrigerator
adjusted to +4 °C (Group I, n ¼ 5), at a room temperature of about 22 °C (Group II, n ¼ 5) and in an incubator adjusted to 37 °C
(Group III; n ¼ 5) for up to 48 h. Blood gas and acid–base values were analysed at 0 (baseline), 1, 2, 3, 4, 5, 6, 12, 24, 36 and 48 h of
storage. A significant decrease (p < 0:001) was found, in the pH of the refrigerated blood after 5 h and its maximum decrease was
recorded at 48 h as 0.04 unit. There were also significant alterations (p < 0:001) in the blood pH of the samples stored at room
temperature and in the incubator after 2 and 3 h, respectively. The maximum mean alteration in pCO2 value for Group I was )0.72
kPa during the assessment, while for groups II and III, maximum alterations in pCO2 were detected as +2.68 and +4.16 kPa, respectively. Mean pO2 values increased significantly (p < 0:001) for Group I after 24 h and for Group II after 6 h, while a significant
decrease was recorded for Group III after 24 h (p < 0:001). Base excess (BE) and bicarbonate (HCO3 ) fractions decreased significantly for all the groups during the study, compared to their baseline values. In conclusion, acid–base values of the samples
stored at 22 and +4 °C were found to be within normal range and could be used for clinical purposes for up to 12 and 48 h,
respectively, although there were small statistically significant alterations.
Ó 2003 Elsevier Ltd. All rights reserved.
Keywords: pO2 ; pCO2 ; Acid base parameters; Storage temperature time; Bovine
1. Introduction
Various metabolic and respiratory diseases effect venous blood gas composition and acid–base values of
cattle (Radostits et al., 1994; Carlson, 1996). Therefore,
accurate measurement of these blood values is of great
importance for veterinary clinicians and research workers. Human (Paerregaard et al., 1987; Muller-Plathe and
Heyduck, 1992; Beaulieu et al., 1999) and cattle (Poulsen
and Surynek, 1977; Szenci and Besser, 1990; Szenci et al.,
1991) blood gas composition and acid–base values may
change depending on the type of syringe used for sampling, delays in measurement time and variations in
*
Corresponding author. Tel.: +90-474-242-6800; fax: +90-474-2426853.
E-mail address: [email protected] (G. Gokce).
0034-5288/$ - see front matter Ó 2003 Elsevier Ltd. All rights reserved.
doi:10.1016/j.rvsc.2003.08.009
storage temperature. Continuous anaerobic and aerobic
metabolism between the drawing of the blood sample and
its analysis intervals may effect blood acid–base values in
humans (Boink et al., 1991; Liss and Payne, 1993), cattle
(Jagos et al., 1977; Krokavec et al., 1987; Szenci and
Besser, 1990) and dogs (Haskins, 1977). In vitro blood
metabolism includes both aerobic metabolism with production of carbon dioxide and anaerobic glycolysis with
production of non-gaseous acids such as lactic acid. Oxygen consumption depends on the enzymatic activity of
the citric acid and cytocrome systems in leucocytes
and reticulocytes and will vary with the concentration of
these cell types. Glycolysis is the predominant metabolic
process in mature red blood cells. These processes are
largely responsible for the rising of pCO2 in the stored
blood of dogs (Haskins, 1977), and cattle (Poulsen and
Surynek, 1977). These metabolic changes are temperature
122
G. Gokce et al. / Research in Veterinary Science 76 (2004) 121–127
dependent (Liss and Payne, 1993). Additionally, severe
leucocytosis (Schimidt and Plathe, 1992; Liss and Payne,
1993) and anaemia (Haskins, 1977) can lead to alterations
in acid–base values.
Since it is difficult to measure the acid–base and gas
values of blood under field conditions in a short period
of time its necessary to store blood (Szenci and Besser,
1990). Several authors have investigated the alterations
in acid–base variables during the storage of blood
samples from humans (Paerregaard et al., 1987; Schimidt and Plathe, 1992; Beaulieu et al., 1999), cattle
(Jagos et al., 1977; Poulsen and Surynek, 1977; Krokavec et al., 1987; Szenci and Besser, 1990; Szenci et al.,
1991, 1994) and dogs (Haskins, 1977). It would be useful
to determine the extent to which changes in blood acid–
base values and gas composition depend on the duration
and temperature of storage. To our knowledge, there is
no precise information available as to whether or not
clinically significant changes occur when bovine venous
blood is stored at 22 or at 37 °C for long periods.
Therefore, this study was carried out to detect the
changes in gas composition and acid–base values in
bovine venous blood samples stored at different temperatures (+4, 22 and 37 °C) for up to 48 h.
2. Materials and methods
matically performed on a blood gas analyser (Chiron
diagnostics, Rapidlab 248, UK) prior to the study.
Blood samples from the five cattle were analysed for
blood gas and acid base values four times each within 15
min to determine the imprecision of parameters, which
emerged as follows: pH 0.01%; pCO2 1.9%; pO2 3.52%;
ActHCO3 1.74%; StdHCO3 1.34%, BEact 1.98%, BEstd
1.02%, O2 SAT 0.39% and O2 CT 1.8% on the basis of
variation co efficiency. Control of accuracy was carried
out using a commercial accuracy control solution
(Complete, Bayer, East Walpole, USA). Control values
were within the normal range as described by the manufacturer. Calculated variables were automatically performed by blood gas analyser according to equations 1
programed to device by manufacterer (Chiron diagnostics, Rapidlab 248, UK) The values of pH, pCO2 and
pO2 were automatically adjusted to the animalÕs rectal
temperatures.
2.3. Haematological analyses
For the initial haematological examinations, peripheral blood samples were collected from jugular vein into
ethylenediaminetetraaceticacid (EDTA) treated tubes.
These blood samples were used to manually establish
total white blood cells (WBCs), total red blood cells
(RBCs) and haemoglobin concentration (Hb), as described by Coles (1980).
2.1. Animals and sampling
2.4. Statistical analyses
Five clinically healthy, 1–3 years old, crossbreed
cattle were used in the study. Following rectal temperature measurement, three jugular venous blood samples
were drawn from each animal into 10 ml plastic syringes
the dead space (0.08 ml) of which was filled with heparin
(LiquemineÒ -Roche, Istanbul, Turkey). The needle tips
were closed with a rubber stopper after the removal of
air bubbles from the samples. The samples were placed
in a bed of crushed ice, taken immediately to the laboratory and analysed within 15 min. Following the first
(0) hourÕs laboratory analysis, a total of 15 blood samples were collected from the animals, allocated into three
groups and then stored, respectively, in a refrigerator set
to +4 °C (Group I, n ¼ 5), at a room temperature of
about 22 °C (Group II, n ¼ 5) and in an incubator adjusted to 37 °C (Group III, n ¼ 5), for up to 48 h. Blood
gas and acid–base values were analysed at 0, 1, 2, 3, 4, 5,
6, 12, 24, 36 and 48 h of storage for all the groups.
2.2. Acid–base and blood gas analyses
The measurement of pH, pO2 , pCO2 and the calculation of standard Base excess (BEstd), actual base excess (BEact), standard bicarbonate (stHCO3 ), actual
bicarbonate (actHCO3 ) concentrations, oxygen saturation (O2 SAT) and oxygen content (O2 CT) were auto-
The effect of temperature on blood gas and acid base
values was tested by analysis of variance using SPSS for
Windows 6.0. The effects of time on the repeated measurements within each group were also examined using
two-way variance analysis (Kirkwood, 1988). The data
is presented as mean SE.
3. Results
The mean initial haematological values of the animals
used in the study were detected as 115 0.6 g/l for Hb,
5.9 0.5 1012 cell/l for RBC and 6.5 1.9 109 cell/l
for WBC. The mean rectal temperature of the animals
was 38.5 0.2 °C.
1
ActHCO3 ¼ pH þ logðpCO2 0:0307Þ 6:105; StdHCO3 ¼ 24:5þ
0:9A þ ðA 2:9Þ2 ð2:65 þ 0:31ctHbÞ=1000.
A ¼ BEstd 0:2½ctHb
½100 O2 SAT=100;
BEact ¼ cHCO3 24:8 þ 1:62ðpH 7:40Þ.
BEstd ¼ ð1 0:014 ctHbÞ½ðcHCO3 24:8Þ þ ð1:43 ctHb þ 7:7Þ
ðpH 7:40Þ.
N 4 15N 3 þ 2045N 2 þ 2000N
O2 SAT ¼ 4
100:
N 15N 3 þ 2400N 2 31100N þ 2:4 106
N ¼ pO2 þ 10½0:48ðpH7:4Þ0:0013BEstd and BEstd is calculated assuming
100% O2 SAT; O2 CT ¼ O2 SAT 1:39 ctHb þ 0:00314 pO2 .
Table 1
Effect of storage time on pCO2 and pO2 of bovine venous blood samples stored at +4 °C (Group I), 22 °C (Group II) and 37 °C (Group III) (n ¼ 5) (mean SE)
Parameter
Group
pCO2
(kPa)
I
Time (h)
II
III
0
1
2
3
4
5
6
12
24
36
48
P1
6.59 0.11
ab
6.59 0.11
f
6.59 0.11
e
5.95 0.09
e
6.34 0.14
f
6.20 0.15
e
5.94 0.10
B,e
6.60 0.16
A,f
6.41 0.15
A,e
5.87 0.12
B,e
6.59 0.12
A,f
6.61 0.12
A,e
6.04 0.10
B,de
6.81 0.14
A,e
7.01 0.16
A,d
6.01 0.11
C,e
6.88 0.10
B,e
7.37 0.18
A,c
6.17 0.10
C,cde
7.34 0.12
B,c
9.01 0.26
A,b
5.86 0.11
C,e
7.07 0.13
B,d
8.88 0.29
A,b
6.34 0.12
C,bcd
8.06 0.16
B,b
10.75 0.32 A,a
6.40 0.12
B,bc
8.82 0.19
A,a
9.29 0.19
A,b
6.90 0.10
B,a
9.27 0.47
A,a
9.05 0.34
A,b
p < 0:001
p < 0:05
p < 0:01
p < 0:001
p < 0:001
p < 0:001
p < 0:001
p < 0:001
p < 0:001
p < 0:001
4.47 0.15
d
4.41 0.15
d
4.33 0.10
a
4.55 0.15
cd
4.64 0.11
c
4.38 0.12
a
4.54 0.16
d
4.57 0.10
d
4.32 0.11
a
4.67 0.17
bcd
4.56 0.11
d
4.31 0.12
a
4.77 0.16
bcd
4.70 0.11
c
4.31 0.15
a
4.77 0.18
A,bcd
4.91 0.11
A,b
4.08 0.15
B,a
5.24 0.24
A,ab
5.00 0.10
A,a
0.86 0.13
B,c
5.12 0.24
A,abc
4.98 0.12
A,a
1.43 0.41
B,b
5.42 0.24
A,a
5.06 0.07
A,a
0.69 0.04
B,c
p < 0:01
p < 0:001
p < 0:001
p < 0:001
P2
4.26 0.10
d
4.26 0.10
d
4.26 0.10
a
I
II
III
4.27 0.16
d
4.25 0.10
d
4.32 0.09
a
P2
p < 0:001
p < 0:001
p < 0:001
p < 0:001
P1, significant differences within group compared to baseline value (a,b,c,d,e,f), (p < 0:001); P2, in each column different letters (A, B, C) indicated significant between groups (p < 0:01),
(p < 0:001); pCO2 , partial pressure of carbondioxide (kPa); pO2 , partial pressure of oxygen (kPa).
Table 2
Effect of storage time on O2 SAT and O2 ct of bovine venous blood samples stored at +4 °C (Group I), 22 °C (Group II) and 37 °C (Group III) (n ¼ 5) (mean SE)
Parameter
O2 SAT
Group
I
II
III
Time (h)
0
1
2
3
4
5
6
12
24
36
48
P1
62.32 1.20
d
62.32 1.20
62.80 2.46
cd
61.82 1.02
63.28 2.16
cd
61.33 1.69
64.36 2.04
bcd
64.42 0.34
63.78 2.24
cd
62.44 1.01
61.10 1.42
b
60.16 1.55
b
59.30 1.70
b
57.48 1.82
b
66.62 2.09
A,abcd
62.76 1.18
A
51.82 2.30
B,c
66.56 2.27
A,abcd
65.60 1.32
A
45.54 2.71
B,d
71.52 2.72
A,ab
63.88 1.34
B
32.22 0.41
C,e
69.82 2.89
A,abc
60.70 1.88
B
8.17 3.38
C,f
72.78 2.00
A,a
61.75 0.35
B
1.85 0.05
C,f
p < 0:05
62.32 1.20
a
65.46 2.19
A,bcd
62.06 1.21
A
55.58 2.00
B,c
p < 0:01
p < 0:001
p < 0:001
p < 0:001
p < 0:001
p < 0:001
10.66 0.34
A,c
10.12 0.35
AB
9.08 0.39
B,b
10.84 0.36
A,c
10.22 0.35
A
8.44 0.46
B,c
10.86 0.37
A,c
10.70 0.39
A
7.44 0.50
B,c
11.66 0.51
A,b
10.44 0.39
B
0.48 0.11
C,d
11.16 0.40
A,c
9.92 0.49
A
1.40 0.60
B,d
12.00 0.30
A,a
10.45 0.05
B
0.3 0.00
C,d
p < 0:05
p < 0:01
p < 0:001
p < 0:001
p < 0:001
p < 0:001
P2
O2 CT
(mmol/l)
I
II
III
P2
10.16 0.30
c
10.16 0.30
10.50 0.44
c
10.08 0.32
10.30 0.36
c
10.15 0.42
10.46 0.35
c
10.50 0.39
10.38 0.38
c
10.18 0.33
10.16 0.30
a
9.92 0.24
a
9.80 0.38
a
9.66 0.33
a
9.38 0.42
b
p > 0:333
p < 0:001
G. Gokce et al. / Research in Veterinary Science 76 (2004) 121–127
pO2 (kPa)
p < 0:001
p < 0:05
p > 0:954
p < 0:001
123
P1, significant differences within group compared to baseline value (a,b,c,d,e,f), (p < 0:05, p < 0:001); P2, in each column different letters (A, B, C) indicated significant between groups (p < 0:05,
p < 0:01, p < 0:001); O2 SAT, oxyhaemoglobin saturation (%); O2 CT, oxygen content (mmol/l).
124
Table 3
Effect of storage time on ActHCO3 and StdHCO3 of bovine venous blood samples stored at +4 °C (Group I), 22 °C (Group II) and 37 °C (Group III) (n ¼ 5) (mean SE)
Parameter
Group
ActHCO3
(mmol/l)
I
II
III
Time (h)
0
1
2
3
4
5
6
12
24
36
48
P1
31.38 0.35
a
31.38 0.35
29.04 0.27
B,c
30.32 0.37
A
28.94 0.26
B,c
28.00 0.30
B,cde
30.38 0.30
A
28.88 0.32
B,c
27.62 0.40
B,de
29.94 0.49
A
28.48 0.39
B,d
28.12 0.34
B,cd
30.00 0.35
A
29.02 0.37
AB,c
27.88 0.33
C,cde
30.00 0.20
A
29.00 0.35
B,c
28.42 0.43
B,cd
30.88 0.63
A
31.44 0.48
A,a
26.90 0.31
e
29.44 0.40
28.74 0.31
B,cd
31.20 0.52
A
29.80 0.36
B,b
28.56 0.54
B,cd
30.24 0.29
A
27.57 0.15
B,e
30.20 0.29
A,b
30.55 0.35
B
26.85 0.85
B,e
p < 0:001
p < 0:05
p < 0:001
p < 0:01
p < 0:01
p < 0:01
p < 0:01
p < 0:001
p < 0:01
p < 0:01
26.42 0.97
cd
28.28 0.27
b
27.46 0.31
b
26.40 0.26
B,cd
28.15 0.15
A,b
26.68 0.28
B,c
26.32 0.27
B,cd
27.80 0.40
A,c
26.18 0.28
B,c
26.88 0.20
A,bc
27.54 0.26
A,c
26.08 0.31
B,c
26.40 0.22
B,cd
27.46 0.15
A,c
26.36 0.44
B,c
26.80 0.36
bcd
27.88 0.52
c
26.58 0.27
c
25.58 0.20
A,d
27.74 0.38
A,c
23.24 0.28
B,d
27.00 0.24
A,bc
27.36 0.51
A,c
22.60 0.20
B,e
27.30 0.20
A,bc
25.70 0.38
B,d
21.67 0.23
C,f
27.78 0.29
A,b
25.55 0.75
A,d
21.05 0.75
B,f
p < 0:01
p < 0:01
p < 0:01
p < 0:05
p < 0:001
p < 0:001
p < 0:001
p < 0:001
31.38 0.35
a
P2
I
II
III
29.24 0.29
a
29.24 0.29
a
29.24 0.29
a
P2
p < 0:001
p < 0:001
n.s
p < 0:001
P1, significant differences within group compared to baseline value (a,b,c,d,e,f), (p < 0:05, p < 0:01, p < 0:001); P2, in each column different letters (A, B, C) indicated significant between groups
(p < 0:05, p < 0:01, p < 0:001); ActHCO3 , actual bicarbonate concentrations (mmol/l); StdHCO3 , standard bicarbonate concentrations (mmol/l).
Table 4
Effect of storage time on BEact and BEstd of bovine venous blood samples stored at +4 °C (Group I), 22 °C (Group II) and 37 °C (Group III) (n ¼ 5) (mean SE)
Parameter
BEact
(mmol/l)
Group
I
II
III
Time (h)
0
1
2
3
4
5
6
12
24
36
48
P1
7.04 0.39
a
7.04 0.39
a
7.04 0.39
a
4.74 0.32
B,bc
5.90 0.36
A,b
4.44 0.22
B,c
3.58 0.35
B,cd
5.83 0.22
A,b
4.14 0.31
B,c
3.2 00.42
B,de
5.30 0.52
A,c
3.46 0.43
B,c
3.64 0.36
B,cd
5.14 0.35
A,c
3.68 0.36
B,c
3.32 0.35
B,de
5.04 0.23
A,c
3.30 0.33
B,c
3.86 0.49
cd
5.70 0.70
b
4.94 0.44
b
2.24 0.31
A,e
4.16 0.45
A,d
0.88 0.39
B,e
4.06 0.31
A,cd
5.34 0.61
A,c
1.64 0.39
B,d
3.76 0.57
A,cd
3.58 0.46
A,d
)0.13 0.32
B,f
5.24 0.34
A,b
3.65 0.75
A,d
)0.85 0.85
B,f
p < 0:001
p < 0:05
p < 0:01
p < 0:05
p < 0:05
p < 0:01
p < 0:001
p < 0:001
p < 0:01
p < 0:001
4.16 0.26
B,bc
5.10 0.31
A,b
3.86 0.16
B,b
3.24 0.25
B,bcd
4.95 0.14
A,b
3.42 0.30
B,c
2.84 0.34
B,de
4.50 0.45
A,c
2.78 0.36
B,d
3.16 0.31
B,cd
4.44 0.38
A,c
2.78 0.33
B,d
2.90 0.32
B,de
4.18 0.18
A,c
2.40 0.27
B,d
1.98 0.29
B,e
3.28 0.4
A,d
)0.30 0.30
C,e
3.46 0.27
A,bcd
4.00 0.56
A,c
)0.02 0.30
B,e
3.14 0.50
A,cd
2.14 0.44
A,d
)1.58 0.35
B,f
4.28 0.32
A,b
2.05 0.85
B,d
)1.95 0.85
C,f
p < 0:05
p < 0:01
p < 0:05
p < 0:05
p < 0:01
p < 0:001
p < 0:001
p < 0:001
p < 0:001
P2
BEstd
(mmol/l)
I
II
III
P2
6.12 0.34
a
6.12 0.34
a
6.12 0.34
a
3.32 0.43
bcd
4.58 0.59
c
3.42 0.34
c
p < 0:001
p < 0:001
p < 0:001
p < 0:001
p < 0:001
P1, significant differences within group compared to baseline value (a,b,c,d,e,f), (p < 0:001); P2, in each column different letters (A, B, C) indicated significant between groups (p < 0:01, p < 0:05,
p < 0:001); BEact, extracelluler base excess (mmol/l); BEstd, blood base excess (mmol/l).
G. Gokce et al. / Research in Veterinary Science 76 (2004) 121–127
StdHCO3
(mmol/l)
28.08 0.39
e
p > 0:056
G. Gokce et al. / Research in Veterinary Science 76 (2004) 121–127
Blood acid–base and blood gas values are summarised
in Tables 1–4 and Fig. 1. The pH values of the samples
kept at different temperatures tended to decrease significantly with time in all groups (p < 0:001) (Fig. 1).
Compared to initial values, pH values were found to
decrease significantly after 5, 3 and 2 h (p < 0:001) for the
samples stored at +4, 22 and 37 °C, respectively.
Alterations in pCO2 and pO2 values are summarised
in Table 1. The mean pCO2 values of the samples stored
at +4 °C decreased significantly between 1 and 24 h, but
later increased again to their initial levels. Moreover, the
pCO2 values of the samples kept at 22 and 37 °C increased significantly (p < 0:001) after the fourth hour
and continued to increase until the end of the study
(Table 1). The maximum mean alteration in pCO2 value
for Group I was )0.72 kPa during the assessment, while
for groups II and III maximum alterations for pCO2
were detected as +2.68 and +4.16 kPa, respectively. The
pO2 values of the samples kept at +4 and 22 °C increased with time (p < 0:001). However, a significant
decrease was recorded after 24 h for the samples kept at
37 °C (p < 0:001). Values of O2 SAT in group I increased
(p < 0:05) after 24 h storage, on the other hand it was
significantly decreased in group III after 5 h (p < 0:001)
and there were no changes in group II (p > 0:333) (Table
2). The O2 CT values were significantly increased
(p < 0:05) after 24 h of storage at +4 °C, but significantly decreased after 4 h of storage at 37 °C (p < 0:001)
(Table 2). However, no significant alterations were observed in the O2 CT values of the samples stored at
22 °C. BE and HCO3 concentrations decreased signifi-
125
cantly for all three groups during the study compared to
their baseline values. The most prominent decrease in
BE and HCO3 concentrations was recorded for the
samples kept at 37 °C (Tables 3 and 4).
4. Discussion
The effects of storage time and temperature on blood
gases and acid–base values in humans (Mahoney et al.,
1991; Liss and Payne, 1993; Beaulieu et al., 1999; Lenfant and Aucutt, 1965) and in cattle (Poulsen and
Surynek, 1977; Szenci and Besser, 1990; Szenci et al.,
1991) have been investigated intensively. Previous
studies have revealed that the blood gas and acid–base
values of human blood samples usually stabilised between 15 min and 2 h (Paerregaard et al., 1987; Mahoney et al., 1991; Beaulieu et al., 1999). The effect of
storage temperature and storage time on blood gas and
acid–base values in cattle are disputed (Poulsen and
Surynek, 1977; Szenci and Besser, 1990; Szenci et al.,
1991). Szenci and Besser (1990) reported that cattle venous blood acid–base values could be used for diagnostic purposes up to 24 h. On the other hand, the pH
values of blood samples taken from cattle and stored at
+4 °C stabilised after for 5–6 h (Poulsen and Surynek,
1977). In the present study, the pH values of the blood
samples stored at +4 °C were found to be suitable for
clinical usage up to 48 h (Fig. 1). Furthermore, storage
time and temperature were found to significantly alter
the blood pH and bicarbonate values of all groups.
7,45
7,4
a
a
a
7,35
a
ab
ab
ab
abc
bc
pH
7,3
A,ab
A,bc
B,cd
A,abc
B ,cd
C,de
**
***
7,25
A,bc
B,cde
C,e
A,bc
B,de
C,f
***
Group I
7,2
***
Group II
Group III
A,bcd
B,e
C,g
A,bcd
B,f
C,h
***
7,15
***
A.cd
B,g
C,h
A,d
B,g
C,h
***
***
***
***
***
7,1
7,05
0
1
2
3
4
5
6
12
24
36
48
Fig. 1. Effects of storage time on the pH of bovine venous blood samples stored at +4 °C (Group I), 22 °C (Group II) and 37 °C (group III) (n ¼ 5)
(mean SE). a,b,c,d,e,f,g,h: significant differences within group compared to baseline (0 h), ***(p < 0:001). A,B,C: significant differences between
group **(p < 0:01), ***(p < 0:001).
126
G. Gokce et al. / Research in Veterinary Science 76 (2004) 121–127
Particularly, rapid and significant decreases in blood pH
(p < 0:001) were observed for those samples stored at
37 °C, compared to the other groups (Groups I and II)
(Fig. 1). Metabolism of in vitro blood samples continues
during storage. Oxygen consumption occurs due to anaerobic metabolism and CO2 generation in the tricarboxylic acid cycles (TCA). Additionally, lactic acid is
accumulated via glycolysis depending on anaerobic
metabolism. These metabolic activities cause a decrease
in blood pH (Andersen, 1961; Szenci and Besser, 1990;
Boink et al., 1991; Liss and Payne, 1993). Since sampling
error was reduced to a minimal level in the present study
the decrease in blood pH and HCO3 was attributed to
the formation of lactic acid due to glycolysis and to an
increase in the level of pCO2 . Moreover, the much
greater decrease in the pH of the blood samples stored at
37 °C may be attributed to lactic acid generation due to
rapid anaerobic metabolism as a result of the high
storage temperature (Liss and Payne, 1993).
In the present study, increases in the pCO2 values of
the blood samples kept at 37 °C and at room temperature and a decrease in those of the samples stored at
+4 °C were recorded as compared to their baseline
values. Researchers have reported that in vitro blood
pCO2 value rises depending on aerobic and anaerobic
metabolism in blood cells (Sandhagen et al., 1988;
Szenci and Besser, 1990; Beaulieu et al., 1999). Unlike
O2 , CO2 does not influx through plastic syringe walls
(Mahoney et al., 1991), and therefore the significant
rises of pCO2 in groups II and III may be the result of
high cell metabolic activities at +22 and 37 °C (Foster
and Terry, 1967). Moreover the most prominent increase in pCO2 was observed in the sample stored at
37 °C. The significant decrease in the pCO2 values of
the samples stored at +4 °C may be due to the blood
being transferred to a lower than body temperature
medium (Mahoney et al., 1991).
In the case of blood samples stored over time, the
type of syringe used for sampling (Mahoney et al., 1991;
Beaulieu et al., 1999) and the aerobic metabolism of
leucocytes (Poulsen and Surynek, 1977; Haskins, 1977)
in the blood have been determined to influence alterations in the levels of pO2 . It has been revealed that pO2
in plastic syringes increases by the diffusion of oxygen
through the plastic wall of the syringe (Paerregaard et
al., 1987; Beaulieu et al., 1999). Leucocytes are responsible for most of the aerobic metabolism in the blood
(Liss and Payne, 1993) and cause O2 consumption in
blood samples stored under in vitro anaerobic conditions (Sandhagen et al., 1988; Szenci and Besser, 1990).
A decrease in pO2 values has been found in blood
samples with high leucocyte counts (Schimidt and
Plathe, 1992) and in samples with anaemia (Haskins,
1977). Since the initial mean leucocyte and erythrocyte
numbers and haemoglobin concentrations of the blood
samples were within normal range in the present study,
the significant decrease (p < 0:001) in pO2 level found in
the blood samples stored at 37 °C after 24 h may be
attributed to an increase in aerobic metabolism and O2
consumption by leucocytes due to the high storage
temperature (Liss and Payne, 1993). A significant increase in the level of pO2 was detected after 6 h in the
samples stored at room temperature and in the refrigerated samples. This may have been due to the release of
O2 from haemoglobin as a result of the reduction in
blood pH (Szenci and Besser, 1990) and to the diffusion
of O2 through the plastic syringe wall (Beaulieu et al.,
1999; Mahoney et al., 1991) although oxygen consumption occurs during aerobic cell metabolism.
Moreover, this finding reflects the fact that aerobic
metabolism of leucocyte was lower at room temperature
and under +4 °C in vitro conditions than at 37 °C.
The SAT O2 value also decreased together with pH in
the blood samples kept at 37 °C. This can be explained
by the shifting of the haemoglobin–O2 dissociation
curve to the right (Bohr effect) due to decrease in blood
pH (Szenci and Besser, 1990; Carlson, 1996). The O2 CT
and O2 SAT value displayed the least alteration within
the parameters for the blood samples kept at room
temperature and at +4 °C, which is consisted the findings of Beaulieu et al. (1999) in a study carried out on
human blood. Therefore, we suggest that the O2 CT and
O2 SAT value should be taken into consideration for
blood samples stored at room temperature when assessing blood O2 .
In conclusion, the acid–base values of the samples
stored at 22 and 37 °C changed significantly when
compared to the samples stored at +4 °C. However, the
acid–base values of the samples stored at 22 and +4 °C
were within normal range and could be used for clinical
purposes for up to 12 and 48 h, respectively.
References
Andersen, O.S., 1961. Sampling and storing of blood for determination of acid–base status. Scandinavian Journal of Clinical Laboratory Investigation 13, 196–204.
Beaulieu, M., Lapointe, Y., Vinet, B., 1999. Stability of pO2 , pCO2 and
pH in fresh blood samples stored in a plastic syringe with low
heparin in relation to various blood-gas and hematological
parameters. Clinical Biochemistry 32, 101–107.
Boink, A.B.T.J., Buckley, B.M., Christiansen, T.F., Conington, A.K.,
Maas, A.H.J., Muller-Plathe, O., Andersen, O.S., 1991. Recomendation on sampling, transport and storage for the determination of
the concentration of ionized calcium in whole blood, plasma and
serum. Annual Biological Clinics 49, 234–438.
Carlson, G.P., 1996. Clinical chemistry tests (acid–base imbalance). In:
Smith, B.P. (Ed.), Large Animal Internal Medicine. Mosby-Year
Book, London, pp. 456–460.
Coles, E.H., 1980. Veterinary Clinical Pathology. third ed. London,
pp. 15–122.
Foster, J.M., Terry, M.L., 1967. Studies on the energy metabolism of
human leucocytes. I. Oxidative phosphorylation by human leucocyte mitochondria. Blood 30, 168–175.
G. Gokce et al. / Research in Veterinary Science 76 (2004) 121–127
Haskins, S.C., 1977. Sampling and storage of blood for pH and blood
gas analysis. Journal of American Veterinary Medical Association
170, 429–433.
Jagos, P., Bouda, J., Priklylova, J., 1977. Dynamics of acid–base
changes in the venous blood of cattle in vitro with time. Veterinary
Medicine (Prague) 22, 257–262.
Kirkwood, B.R., 1988. Essentials of Medical Statistics. Blackwell
Scientific Publications, Oxford, USA.
Krokavec, M., S_ımo, K., Mart_ınko, A., 1987. Changes in the acid–base
equlibrium in cattle in relation to the time intervals between
sampling and study under field conditions. Veterinary Medicine
(Praha) 32 (3), 145–150.
Lenfant, C., Aucutt, C., 1965. Oxygen uptake and change in
carbondioxide tension in human blood stored at 37 °C. Journal
Applied Phsiology 20, 503–508.
Liss, H., Payne, C.P., 1993. Stability of blood gases in ice and at room
temperature. Chest 103, 1120–1122.
Mahoney, J.J., Harvey, J.A., Wong, R.J., Kessel, L.V., 1991. Changes
in oxygen measurements when whole blood is stored in iced plastic
or glass syringes. Clinical Chemistry 37, 1244–1248.
Muller-Plathe, O., Heyduck, S., 1992. Stability of blood gases,
electrolytes and haemoglobin in heparinized whole blood samples:
Influence of the type of syringe. European Journal of Clinical
Chemistry and Clinical Biochemistry 30, 349–355.
Paerregaard, A., Nickelsen, C.N.A., Brandi, L., Andersen, G.E., 1987.
The influence of sampling site and time upon umbilical cord blood
127
acid–base status and pO2 in the newborn infant. Journal of
Perinatal Medicine 15, 559–563.
Poulsen, J.S.D., Surynek, J., 1977. Acid–base status of cattle blood.
Nordisk Veterinaer Medicin 29, 271–283.
Radostits, O.M., Blood, D.C., Gay, C.G., 1994. Veterinary Medicine,
eighth ed. Bailliere Tindall, London. pp. 66–86.
Sandhagen, C.F.H., Verdier, C.H., Eriksson, L., 1988. Distrubution of
blood gases, glucose and lactate within stored blood units. Vox
Sanguinis 55, 139–142.
Schimidt, C., Plathe, O.M., 1992. Stability of pO2 , pCO2 and pH in
heparinized whole blood samples: Influence of storage temperature with regard to leucocyte count and syringe material. European Journal of Clinical Chemistry and Clinical Biochemistry 30,
767–773.
Szenci, O., Besser, T., 1990. Changes in blood gas and acid–base values
of bovine venous blood during storage. Journal of American
Veterinary Medical Association 197, 471–474.
Szenci, O., Brydl, E., Bajcsy, C.A., 1991. Effect of storage on
measurement of ionized calcium and acid–base variables in equine,
bovine, ovine, and canine venous blood. Journal of American
Veterinary Medical Association 199, 1167–1169.
Szenci, O., Nemeth, F., Stollar, Z., Brydl, E., 1994. Effect of
storage time and temperature on ionized calcium concentration
in bovine and ovine blood, plasma and serum. Journal of
American Veterinary Medical Association 204 (8), 1242–
1244.