An overlooked aspect on metabolic acidosis at birth: blood gas analyzers calculate base deficit differently.
Background: Metabolic acidosis (MA) at birth is commonly defined as umbilical cord arterial pH <7.0 plus base deficit (BD) ≥12.0 mmol/L. BD is not a measured entity but calculated from pH and pCO(2) values, with the hemoglobin (Hb) concentration included in the calculation algorithm as a fixed or actual value. Various blood gas analyzers use different algorithms, indicating variations in the MA di
