Acute kidney injury with oxalate deposition in a patient with a high anion gap metabolic acidosis and a normal osmolal gap

Background. Anion gap (AG) has been proved to be associated with prognosis of many cardiovascular diseases. This study is aimed at exploring the association of AG with inhospital all-cause mortality and adverse clinical outcomes in coronary care unit (CCU) patients. Method. All data of this study was extracted from Medical Information Mart for Intensive Care III (MIMIC-III, version 1.4) database. All patients were divided into four groups according to AG quartiles. Primary outcome was inhospital all-cause mortality. Lowess smoothing curve was drawn to describe the overall trend of inhospital mortality. Binary logistic regression analysis was performed to determine the independent effect of AG on inhospital mortality. Result. A total of 3593 patients were enrolled in this study. In unadjusted model, as AG quartiles increased, inhospital mortality increased significantly, OR increased stepwise from quartile 2 (OR, 95% CI: 1.01, 0.74-1.38, P=0.958) to quartile 4 (OR, 95% CI: 2.72, 2.08-3.55, P<0.001). After adjusting for possible confounding variables, this association was attenuated, but still remained statistically significant (quartile 1 vs. quartile 4: OR, 95% CI: 1.02, 0.72-1.45 vs. 1.49, 1.07-2.09, P=0.019). Moreover, CCU mortality (P<0.001) and rate of acute kidney injury (P<0.001) were proved to be higher in the highest AG quartiles. Length of CCU (P<0.001) and hospital stay (P<0.001) prolonged significantly in higher AG quartiles. Maximum sequential organ failure assessment score (SOFA) (P<0.001) and simplified acute physiology score II (SAPSII) (P<0.001) increased significantly as AG quartiles increased. Moderate predictive ability of AG on inhospital (AUC: 0.6291), CCU mortality (AUC: 0.6355), and acute kidney injury (AUC: 0.6096) was confirmed. The interactions were proved to be significant in hypercholesterolemia, congestive heart failure, chronic lung disease, respiratory failure, oral anticoagulants, Beta-blocks, angiotensin-converting enzyme inhibitor (ACEI)/angiotensin receptor blocker (ARB), and vasopressin treatment subgroups. Conclusion. AG was an independent risk factor of inhospital all-cause mortality and was associated with adverse clinical outcomes in CCU patients.

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Metabolic acidosis in toluene sniffing

CJEM ◽

10.2310/8000.2013.130974 ◽

2013 ◽

Vol 15 (04) ◽

pp. 249-252 ◽

Cited By ~ 3

Author(s):

Jon Tuchscherer ◽

Habib Rehman

Keyword(s):

Metabolic Acidosis ◽

Renal Tubular Acidosis ◽

Excretion Rate ◽

Ammonia Excretion ◽

Distal Renal Tubular Acidosis ◽

Anion Gap ◽

Renal Tubular ◽

Conjugate Bases ◽

Osmolal Gap ◽

Ammonia Excretion Rate

ABSTRACT Toluene sniffing, frequently described under the generic category of “glue sniffing,” is a potential cause of normal anion gap metabolic acidosis due to distal renal tubular acidosis. Urine anion gap is used to diagnose metabolic acidosis of a normal anion gap variety; however, pitfalls exist when using urine anion gap in the setting of toluene sniffing. We present the case of a young woman who had a normal anion gap metabolic acidosis due to toluene sniffing and an unexpectedly low urine anion gap. In such a scenario, the urine anion gap will underestimate the rate of ammonia excretion when the conjugate bases of acids other than HCl are excreted in large quantities. Estimation of the urine osmolal gap will provide a more accurate ammonia excretion rate in these circumstances. The challenges in interpretation of the urine anion gap and ammonia excretion in the setting of distal renal tubular acidosis due to toluene toxicity are discussed.

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