OBSERVATIONS
OF
TOTAL
SERUM
BASE
IN
CHILDREN
AND
YOUNG
ADULTS
BY
A
CONDUCTIVITY
METHOD
By W. M. KELSEY, M.D., AND L. B. LEINBACH, B.S.
Winston-Salem, N.C.
D
ETERMINATION of total serum base has not been used extensively in clinicalmedicine because of the technical difficulty of the available methods. A simple
and inexpensive procedure has been presented by Sunderman.56 The purpose of this
study was to determine normal values for total serum base in children as measured by the
conductivity method.
PROCEDURE
The method and necessary equipment was described by Sunderman.’ Blood is drawn into clean
glassware and centrifuged. Serum which has been used for pH determinations may be utilized. About
0.75 cc. of serum is drawn into the conductivity cell and the resistance is measured with the cell in a water bath which is about 25#{176}C. With the cell constant which is known, the observed resistance of the serum and the total serum protein, the total base is read from a nomogram which is supplied with the instrument.* Corrections for temperature changes are made as described by Sunderman.’ Certain technical difficulties were encountered which were not emphasized by Sunderman. Precipitation
TABLE I
Serum Total Base mEq./I.
mM Na Added
per 0.5 cc. as NaCl
Calculated Total
Base mEq./l.
Experimentally
Ob-tamed Total Base mEq./l.
% Error
149.0 0.5cdH2O No NaC1
99.3 110.8 11.58
149.0 0.007 104.0 113.6 9.23
149.0 0.015 109.3 119.0 7.97
149.0 0.031 120.0 127.0 5.83
149.0 0.046 130.0 134.0 3.07
149.0 0.062 140.6 143.0 1.77
149:0 0.077 150.6 154.0 2.25
of serum protein in the conductivity cell could be prevented only i’f exceptional care was taken in
cleaning the cell after each determination. Serum proteins were determined by the method of Phillips and Van Slyke.7 The errors in this method were recognized and frequent checks of the serum protein level were made by the micro Kjeldahl method. All protein values below 5.0 gm./100 cc. were checked by the micro Kjeldahl method. If there is any question of hypoproteinemia the protein should be determined by the Kjeldahl method since the error in the determination is considerably greater when the total serum protein is below 5.0 gm./100 cc.
The accuracy of the Sunderman method was checked in 5 ways. 1. Known amounts of sodium chloride were added to serum. The observed values were compared with the calculated values and found to check closely in dilutions approaching that of serum. These figures are shown in Table I.
From the Department of Pediatrics of the Bowman Gray School of Medicine of Wake Forest College, Winston-Salem, NC.
(Received for publication Feb. 21, 1949.)
* A. H. Thomas, Philadelphia, Pa.
Serum Total Base mEq./1.
TABLE II
Total Amount of Sugar (Serum
Addition) mg. %
Resultant Total Base Reading
mEq./l.
H20 Correction1 Decrease Due of Reading
mEq./l.
148.0
148 .0
148.0
148.0
148 .0
148.0 148.0
148.0
to Sugar mEq.I.
Corrected Total Base
mEq./l.
53.0
133.3
220.0 303.3 386.6
553.3 720.0
1053.3
107.2
106.2
104.9
103.3
103.0
102.2
101.9
101.0
40.8
40.8 40.8
40.8
40.8
40.840.8
40.8
1.0
2.3
3.9
4.2
5.0 5.3
6.2
147 145.7
144.1
143.8
143.0
142 .7
141.8
806
W.
M.
KELSEY
AND
L.
B.
LEINBACH
CHART 1
When the concentration of total base was lower than that of normal serum, the observed values for total base by the conductivity method were 5.8 to 11.5% higher than the calculated values. This difference in conductivity method may be accounted for by a difference in ionic activity in the lower dilutions. 2. Sugar was added to serum in varying dilutions to find out the effect of the addition of sugar on conductance. These results are listed in Table II. The addition of sugar did not produce an appreciable error in the total base determination unless the concentration was high. The changes in column 3 of Table 11 are due to fluid addition and not to changes in sugar concentration. 3. Multiple determinations were made on 3 individuals who were well. These figures are listed in Table III.
J. E. had 12 determinations on consecutive days. W. M. K. had daily determinations for 3 periods of time. G. S. had ii determinations over a 4 mos.’ period of observation. 4. Duplicate
determina-TABLE III
J.E. 143 143 143 142.5 145 146 148.5 145 146.5 144 145 145.5
W.M.K. 146 149 150 - 153 153 153 153 - 148 149 148
G.S. 146 143 144 146 147 147 145.5 142.5 146.5 146.5 144 148.5
tions on single specimens were made on 50 consecutive samples. The deviations in these samples were never greater than 2 mEq./l. 5. The values obtained in the adults compared with those reported by Sunderman.’
RESU LTS
The values for total serum base in different age groups are shown in Chart 1. Almost all of the samples obtained in the pediatric age group were from well ambulatory children from an orphanage.
A few samples were obtained from convalescent poliomyelitis patients. The samples from adults were obtained from internes, nurses and laboratory workers. In no case was there any suspicion that the individual had a disease process known to affect electrolyte balance. Unfortunately it was not possible
to draw the blood under basal conditions. The adult values of 142 to 160.5 mEq./l. check closely
with those obtained by Sunderman.’ In children values of 143 to 160.5 mEq./l. were found to
compare with those of other workers using different methods. Darrow and Hartmann’ found
TABLE IV
Age in Yrs. 0-2 2-4 4-6 6-8 8-12 12-14
oi’r
No. of Determinations
Mean
Standard Deviation
7
152.9
±4.23
20
153.7 ±2.24
20
153.5 ±3.24
21
151.6
±4.68
28
153.2
±4.44
20 148.3
±5.39
53
146.84 ±2.12
values ranging from 147 to 15 mEq./l. in 10 children. This compared with values of 145 to 151 mEq./l. in 3 adults. The benzidirie method was used. Blackfan and Hamilton’ reported figures of 156 to 162 mEq./l. in 9 normal children. Hamilton’#{176} determined total serum base values in 13 children with various pathologic states. His values varied from 140 to 166 mEq./l.
A statistical study was made of the 169 normal determinations.* Standard deviations for each
group age are shown in Table IV. These deviations indicate that the range of values are within the expected limit of variation. Comparisons were. made between 4 age groups. The “t” value for
comparison between all values below the age of 12 and for the older group was 10.03. The ‘t” valu for comparison between all values below the age of 12 and all older than 14 yrs. was 10.66. This would indicate a highly significant difference in total base in the 2 age groups. Comparisons of
the 12 to 14 group and the older group gave a “t” value of 1.704 which is not significant. Comparison of the 8 to 12 group with the 12 to 14 group gave a “t” value of 3.387 which is highly significant.
The conclusion was that there was a statistically significant difference between the total base in
children below 12 yrs. of age and the older age groups. It is obvious that the 12 to 14 age group is transitional but is considerably closer to the adult group than the 10 to 12 age group. A review
of the literature failed to reveal a similar finding.
DiscussIoN
The principle behind this method has been generally accepted and Sunderman’s data
strongly suggest that the values obtained by this method check closely with those
ob-tamed by another method. Comparison to the total base with the total anions is difficult
because of the variability in theundetermined organic acids. The authors have attempted
to correlate the relative increase and decrease in cations and anions in a number of
persons and have found a satisfactory correlation. None
of
the
patients
in these
studies
had disease processes known to result in phosphate retention. The one patient with an
inability
.to
retain fixed base had normal serum phosphorus levels. Examples of these dataare given in Table V.
The advantages of this method are considerable. Since the serum is not altered by the
determination it may be used for other studies. This permits use of small quantities of
serum, and the determination may be run in a matter of minutes. Reproducible results
808 W. M. KELSEY AND L. B. LEINBACH
TABLE V
Patient CO2 C.P. mEq./l. Cl mEq./l. Urinary Ketones Total Serum Protein Gm./lOOcc. Total Base mEq./l.
Estimated Changes In
Cations Anions mEq./l. mEq./l. 1. B.H.2mos. Diarrhea 7.7 17.0 15.5 24.8 117.0 94.3 87.0 87.4 None None None None 6.8 4.8 6.1 6.6 154.3 138.3 135.3 143.7 -16.0 - 3.0 + 8.0 -17.4 - 4.8 + 9.7
2. F.P. 11 mos.
Renal Disease 8.2 12.2 12.6 22.0 17.6 20.3 106.0 109.0 107.6 96.0 98.0 100.0 None None None None None None 5.9 5.2 6.0 5.4 5.8 6.1 145.8 152.0 147.2 146.0 145.0 148.2 + 6.2 - 4.8 - 1.2 - 1.0 + 3.2 + 7.0 - 2.0 - 2.2 - 2.4 + 4.7
3. HE. 45 yrs. Normal 21 .0 27.0 21.0 21.0 22.0 21.0 25.5 103.0 93.0 90.0 99.0 95.0 94.0 90.0 None None None None None None None 5.7 5.8 7.3 6.5 5.5 5.9 5.1 143.0 143.0 145.0 148.5 146.5 145.0 145.5 0.0 + 2.0 + 3.5 - 2.0 - 1.5 + 0.5 - 2.0 - 6.5 + 7.0 - 5.0 - 2.0 - 0.5
have been obtained by relatively inexperienced technicians, and the equipment is not
expensive.
The
determination
has
been
used
as a rough
check
on
the
serum
sodium
level,
and
as
such has served as a guide in the diagnosis of diseases involving sodium metabolism. It
has been of aid in guiding therapy involving the use of sodium salts. In unusual
condi-tions involving electrolyte imbalances the determination of total base by this method
has served as a check on the sum of the anions. In many cases where routine
determina-tions of serum chloride and CO2 C. P. have been unusual the total base has aided in
checking these data, Patients with alkalosis associated with vomiting and achlorhydria
and hyperelectrolytemia serve as examples. The total base has not been the final answer but
has been a simple means for indicating the need for more exact studies. Examples of
such cases are given in Table V.
CONCLUSION
Values for total serum base in 96 normal children under 1 2 years of age as determined
by
the conductivity method fell. between 143 to 160.5 mEq./l. The mean was 153. Standard deviations for each age group are given.The
values
in 73 n#{224}rmalpersons
above
the
age
of
12 varied from 142 to 160.5 mEq./l.The
mean
was
147mEq./l.
A statistically
significant
difference
between
the
total
serum
base in children and adults was found.
REFERENCES
1. Peters, J. P., and Van Slyke, D. D., Quantitative Clinical Chemistry, Baltimore, Williams &
2. Keys, A., Determination of total base in blood and other biological fluids, J. Biol. Chem. 114:
449, 1936.
3. Polis, B. D., and Reinhold, J. G., Determination of total base of serum by ion exchange reactions of synthetic resins, J. Biol. Chem. 156:231, 1944.
4. Leva, E., and Guest, G. M., Method for determination of total base in blood, J. Biol. Chem.
130:777, 1939.
5. Sunderman, F. W., Studies in serum electrolytes: Estimation of total base in serum, J. Biol. Chem.
143:185, 1942.
6. Sunderman, F. W., Measurement of serum total base, Am. J. Clin. Path. 15:219, 1945.
7. Phillips, R. A., and others, Copper sulphate method for measuring specific gravities of whole blood and plasma, Bull. U. S. Army M. Dept. 17:66, 1943.
8. Darrow, D. C., and Hartmann, A. F., Comparison of calculated and determined osmolar con-centration of normal serum, Am. J. Dis. Child. 37:51, 1929.
9. Blackfan, K. D., and Hamilton, B., Study of inorganic constituents of serum in children with acute nephritis, Bull. Johns Hopkins Hosp. 41:322, 1927.
10. Hamilton, B., Comparison of concentrations of inorganic substances in serum and spinal fluid,
J. Biol. Chem. 65:101, 1925.
SPANISH ABSTRACT
Observaciones
de Base
de Suero
Total
en Nilios
y Adultos
J#{244}venespor
un
M#{233}todo
de Conductividad
Los valores de base de suero total en 96 niflos normales de menos de 12 aflos de edad determinados por el m#{233}todo de conductividad bajaron entre 143 a 160.5 mEq./1. El medio fu#{233}153. Se dan las desviaciones regulares de cada grupo de edad.
Los valores en 73 personas normales de mfls de 12 aflos de edad variaron de 142 a 160.5 mEq./1. El medio fu#{233}147 mEq./1. Se encontr#{243} una diferencia estadisticamente significativa entre la base de suero total en los niflos y en los adultos.
