Agreement of simplified Fencl-Stewart with Figge-Stewart method in diagnosing metabolic acidosis in critically ill children

  • Rotua Sinaga
  • Abdurachman Sukadi
  • Dadang Hudaya Somasetia
Keywords: simplified Fencl-Stewart, Figge Stewart, metabolic acidosis, critically ill


Background The traditional Henderson-Hasselbalch approach has
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
Kappa calculations.
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.

Author Biographies

Rotua Sinaga
Department of Child Health, Medical School, Padjadjaran
University, Bandung, Indonesia.
Abdurachman Sukadi
Department of Child Health, Medical School, Padjadjaran
University, Bandung, Indonesia.
Dadang Hudaya Somasetia
Department of Child Health, Medical School, Padjadjaran
University, Bandung, Indonesia.


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How to Cite
Sinaga R, Sukadi A, Somasetia D. Agreement of simplified Fencl-Stewart with Figge-Stewart method in diagnosing metabolic acidosis in critically ill children. PI [Internet]. 31Aug.2007 [cited 15Jul.2024];47(4):144-. Available from:
Received 2016-08-27
Accepted 2016-08-27
Published 2007-08-31