Acid–base changes in meningococcal sepsis revealed by partitioning the base deficit

Base deficit (BD) quantifies a metabolic acidosis without defining aetiology. Factors contributing to a metabolic acidosis include lactic acid and unmeasured anions (together known as tissue acid), hyperchloraemia and plasma albumin concentration. An equation exists to quantify the effect of albumin on BD; we have recently derived a similar equation for the effect of chloride. After partitioning the BD for these factors, the residual BD should reflect the contribution from tissue acid.