Unmasking a Case of Pseudo-metabolic Alkalosis: Analytical Interference Leading to a Misleading Biochemical Profile

Analytical interferences in automated chemistry analyzers can produce misleading results with potential clinical implications.We report a serum sample showing falsely elevated bicarbonate value associated with markedly increased lactate dehydrogenase (LDH) activity on the Beckman Coulter DxC 700 AU analyzer.Serum bicarbonate exceeded 45 mmol/L with a dilution flag, inconsistent with other analytical methods.The spurious elevation was most probably due to LDH interference affecting the NADH-dependent enzymatic reaction used in the bicarbonate assay.Awareness of this interference pattern is essential to prevent misinterpretation and unnecessary clinical concern.