PMID- 38478728
OWN - NLM
STAT- Publisher
LR  - 20240313
IS  - 2737-5935 (Electronic)
IS  - 0037-5675 (Linking)
DP  - 2024 Mar 13
TI  - Diagnostic threshold and performance of anion gap in screening for high anion gap 
      metabolic acidosis.
LID - 10.4103/singaporemedj.SMJ-2023-009 [doi]
AB  - INTRODUCTION: The anion gap (AG) is commonly used to screen for acid-base 
      disorders. It was proposed that the cut-off for high anion gap metabolic acidosis 
      (HAGMA) may be lower with current laboratory techniques, although modern 
      laboratory equipment are still calibrated to familiar reference ranges 
      established with earlier techniques. The appropriate cut-off for HAGMA is 
      unclear. This study aimed to assess the performance of AG as a screening test for 
      HAGMA and to determine the optimal diagnostic threshold of AG for HAGMA. METHODS: 
      This was a retrospective analysis of a large, anonymised dataset extracted by 
      computerised protocol from 2017 to 2019. All inpatients with blood samples taken 
      for organic acids (lactate, ketone or salicylate) paired with a metabolic panel 
      were included. The target condition was HAGMA secondary to elevated blood 
      lactate, ketone and/or salicylate. Sensitivity for HAGMA was explored at various 
      AG cut-off levels. RESULTS: Of 16,475 patients, 2,621 had organic acidosis. 
      Median age was 65 years, and median estimated glomerular filtration rate was 70 
      mL/min/1.73 m2. With organic acidosis, the median AG was 23 (interquartile range 
      [IQR] 20-29) mEq/L, while without organic acidosis, the median AG was 16 (IQR 
      14-19) mEq/L. The area under the curve-receiver operating characteristic of AG 
      for HAGMA was 0.873. Desired sensitivity for HAGMA was set at >/=95%, and this was 
      found with an AG threshold of >/=15 mEq/L (sensitivity 98.1%, specificity 34.0%). 
      CONCLUSION: The recommended AG threshold value is >/=15 mEq/L with a high 
      sensitivity for HAGMA. The AG should always be interpreted with the clinical 
      context, and it should be repeated as the clinical picture evolves.
CI  - Copyright (c) 2024 Copyright: (c) 2024 Singapore Medical Journal.
FAU - Chionh, Chang Yin
AU  - Chionh CY
AD  - Department of Renal Medicine, Changi General Hospital, Singapore.
FAU - Tien, Carolyn Shan-Yeu
AU  - Tien CS
AD  - Department of Renal Medicine, Changi General Hospital, Singapore.
AD  - Renal Medicine, SingHealth Residency, Singapore.
FAU - Yeon, Wenxiang
AU  - Yeon W
AD  - Department of Renal Medicine, Changi General Hospital, Singapore.
CN  - Changi REnal MEdicine REsearch (CREMERE) Group
LA  - eng
PT  - Journal Article
DEP - 20240313
PL  - India
TA  - Singapore Med J
JT  - Singapore medical journal
JID - 0404516
SB  - IM
EDAT- 2024/03/13 18:47
MHDA- 2024/03/13 18:47
CRDT- 2024/03/13 14:32
PHST- 2022/12/27 00:00 [received]
PHST- 2023/04/05 00:00 [accepted]
PHST- 2024/03/13 18:47 [medline]
PHST- 2024/03/13 18:47 [pubmed]
PHST- 2024/03/13 14:32 [entrez]
AID - 00077293-990000000-00105 [pii]
AID - 10.4103/singaporemedj.SMJ-2023-009 [doi]
PST - aheadofprint
SO  - Singapore Med J. 2024 Mar 13. doi: 10.4103/singaporemedj.SMJ-2023-009.