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proven to be imprecise in critically ill patients. Stewart’s approach
can detect metabolic acidosis missed by traditional approach,
including acidosis caused by increased unmeasured agreement
(UA). The complexity of Stewart’s method leads to development
of simpler modifications, simplified Fencl-Stewart and Figge-
Stewart method. Agreement between both modifications is
Objective This study aimed to measure the agreement of simplified
Fencl-Stewart with Figge-Stewart method in diagnosing metabolic
acidosis in critically ill children.
Methods The was performed in Hasan Sadikin General Hospital,
Bandung from July to August 2006, involving <14 year-old critically
ill children. Blood samples for gas analysis, sodium, potassium,
chloride and albumin measurement were taken simultaneously. Test
result was analyzed with simplified Fencl-Stewart and Figge-Stewart
method and recorded with Excell spreadsheet. PASS was used for
interim analysis and DAG_Stat for raw agreement indices and
Results Forty-five (31 males, 14 females) children were enrolled.
Acid base disturbances based on Stewart’s method were identified
in 10 subjects with normal base excess and nine with normal
bicarbonate. Significant increase of UA was detected in 11 of 45
subjects with simplified Fencl-Stewart method, compared to that
of 12 subjects with Figge-Stewart method. Raw agreement indices
showed 95.65% and 98.51% agreement for positive and negative
result, Kappa was 0.94 (P=0.0000).
Conclusions Excellent agreement is shown between simplified
Fencl-Stewart and Figge-Stewart method in diagnosing metabolic
acidosis in critically ill children. Increased UA can be assessed
with both methods.
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acid-base primer for biology and medicine. Internet edi-
tion. Cited 2004 August. Available from: url: http://
2. Constable PD. Clinical assessment of acid-base status: com-
parison of the Henderson-Hasselbalch and strong ion ap-
proaches. Vet Clin Pathol 2000;29:115-28.
3. Kellum JA. Metabolic acidosis in the critically ill: lessons
from physical chemistry. Kidney Int 1998;56:81-6.
4. Fencl V, Jabor A, Kazda A, Figge J. Diagnosis of metabolic
acid-base disturbances in critically ill patients. Am J Respir
Crit Care Med 2000;162:2246-51.
5. Story DA, Morimatsu H, Bellomo R. Strong ions, weak ac-
ids and base excess: a simplified Fencl-Stewart approach to
clinical acid-base disorders. Br J Anesth 2004;92:54-60.
6. Story DA, Poustie S, Bellomo R. Quantitative physical chem-
istry analysis of acid-base disorders in critically ill patients.
7. Balasubramanyan N, Havens PL, Hoffman GM. Unmeasured
anions identified by the Fencl-Stewart method predict mor-
tality better than base excess, anion gap, and lactate in pa-
tients in the pediatric intensive care unit. Crit Care Med
8. Durward A, Mayer A, Skellett S, Taylor D, Hanna S, Tibby
AM, et al. Hypoalbuminemia in critically ill children: inci-
dence, prognosis, and influence on the anion gap. Arch Dis
9. Hatherill M, Wagie Z, Purves L, Reynolds L, Argent A.
Correction of the anion gap for albumin in order to de-
tect occult tissue anion in shock. Arch Dis Child
10. Schlichtig R, Grogono AW, Severinghaus JW. Human PaCO 2
and standard base excess compensation for acid-base imbal-
ance. Crit Care Med 1998;26:113-9.
11. Kushartono H. Analisis gangguan asam basa pada pasien ICU
anak: perbandingan cara tradisional dan Stewart [thesis].
Jakarta: Universitas Indonesia; 2005.
12. Fencl V, Leith DE. Stewart’s quantitative acid-base chemis-
try: application in biology and medicine (review). Respir
13. Gilfix BM, Bique M, Magder S. A physical chemical approach
to the analysis of acid-base balance in the clinical setting. J
Crit Care 1993;8:187-97.
14. Figge J, Jabor A, Kazda A, Fencl V. Anion gap and hypoalbu-
minemia. Crit Care Med 1998;26:1807-10.
15. Kleinbaum DG, Kupper LL, Morgenstern H. Epidemiologic
research: principles and quantitative methods. New York:
van Nostrand Reinhold Company; 1982.
16. Macnab AJ, Wensley DF. The rationale for paediatric inten-
sive care. In: Macnab AJ, Macrae, DJ, Henning R, editors.
Care of the critically ill child. London: Churchill Livingstone;
1999. p. 1-5.
17. Seidel J, Knapp JF. Preparedness for pediatric emergencies.
In: Gausche-Hill M, Fuchs S, Yamamoto L, editors. The pe-
diatric emergency medicine resource, 4 th ed. Boston: Jones
and Bartlett Publishers; 2004. p. 3-19.
18. Ross BC. Arterial line insertion. In: Singh NC, editor. Manual
of pediatric critical care. Philadelphia: W.B. Saunders Com-
pany; 1997. p. 366-8.
19. Hazinski MF. Manual of pediatric critical care. St Louis:
20. Carpenter TC, Dobyns EL, Lane J, Mourani P, Robinson A,
Ferguson M, et al. Critical care. In: Hay WW, Hayward AR,
Levin MJ, Sondheimer JM, editors. Current pediatric diag-
nosis and treatment, 16 th ed. Boston: McGraw-Hill; 2003.
21. Williams AJ. ABC of oxygen: assessing and interpreting arterial
blood gases and acid-base balance. BMJ 1998;317:1213-36.
22. Uebersax J. Raw agreement indices. Cited 2006 May. Avail-
able from: url: http://ourworld.compuserve.com/homepages/
23. Bishop YMM, Fienberg SE, Holland PW, Light RJ, Mosteller
F. Discrete multivariate analysis: theory and practice. Cam-
bridge: MIT Press; 1975.
24. Mackinnon A. How to use DAG_Stat. 2000. Cited 2006
May 10. Available from: url: http://www.mhri.edu.au/biostats/
25. NCSS, PASS, and GESS: statistics, graphics, power analy-
sis, sample size, & microarray analysis. Cited 2006 July. Avail-
able from: url: http://www.ncss.com
26. GWU Biostatistics Center. Statistical Consideration. 2001.
Cited 2006 July 7. Available from: url: http://www.bsc.gwu.edu/
27. Neligan PJ, Deutschman CS. Acid base balance in critical
care medicine. 2005. Cited 2005 August 22. Available from:
url: http://www.ccmtutorials.com/renal/Acid Base Balance in
Critical Care Medicine-NELIGAN.pdf.
28. Brandis K. Acid-base physiology. 2002. Cited 2004 August.
Available from: url: http://www/qlanaesthesia.com.
29. Dawson B, Trapp RG. Basic and clinical biostatistics. 3 rd ed.
Boston: McGraw-Hill; 2001.
30. Sterns RH. Fluid, electrolyte, and acid-base disturbances. J
Am Soc Nephrol 2003;2:1-33.
31. Brill SA, Stewart TR, Brundage SI, Schreiber MA. Base deficit
does not predict mortality when secondary to hyperchloremic
acidosis. Shock 2002;17:459-62.
32. Skellett S, Mayer A, Durward A, Tibby SM, Murdoch IA. Chas-
ing the base deficit: hyperchloremic acidosis following 0.9% sa-
line fluid resuscitation. Arch Dis Child 2000;83:514-6.
33. Nicholson JP, Wolmarans MR, Park GR. The role of albu-
min in critical illness. Brit J Anaesth 2000;85:599-610.
34. O’Dell E, Tibby SM, Durward A, Aspell J, Murdoch IA. Vali-
dation of a method to partition the base deficit in meningo-
coccal sepsis: a retrospective study. Crit Care 2005;9:464-70.
35. Forsythe SM, Schmidt GA. Sodium bicarbonate for the treat-
ment of lactic acidosis. Chest 2000;117:260-7.
36. Goonasekera C, Wilkins B, Dillon M. Renal disease and dis-
turbances of water and electrolytes. In: Macnab AJ, Macrae
DJ, Henning R, editors. Care of the critically ill child. Lon-
don: Churchill Livingstone; 1999. p. 249-65.
37. Gunnerson KJ, Saul M, He S, Kellum JA. Lactate versus non-
lactate metabolic acidosis: a retrospective outcome evalua-
tion of critically ill patients. Crit Care 2006;10:R22.
38. Simon S. StATS: Steve’s Attempts to Teach Statistics. 2006.
Cited 2006 July 26. Available from: url: http://www.children-