Prediction of mortality in patients with major burns: clinical and biochemical factors.

OBJECTIVE: The plasma electric charge, in addition to clinical factors, was considered to improve the prediction of mortality in patients with major burns.
METHODS: A software called PICAL 5.0 was used to determinate the plasma electric charge in 143 patients with major burns from the intensive care burn unit-Unfallkrankenhaus Berlin (Germany). In addition, a retrospective study with these patients was developed involving: (1) biochemical variables in the first 48 hours: pH value, [albumin], [Ca(2+)], etc; (2) clinical aspects: age, total body surface area and full-thickness surface area burned, diagnosis of inhalation injury, etc. A mortality predictive equation was calculated from univariate and multivariate logistic regression analyses in a set of randomly chosen participants and applied to a validation set of 35 participants.
RESULTS: The importance of each ion and protein for the equilibrium in the plasma charge is determinant. In statistical multivariate analysis, age, total body surface area burned, pH value, and [Mg(2+)] were independently associated with mortality.
CONCLUSIONS: [Na(+)], [HCO(3)(-)] (bicarbonate), and [Cl(-)] are the ions contributing the most to the plasma charge equilibrium in patients with major burns; a loss of 50% of plasma proteins in the first 48 hours is equivalent to the loss of 1 mmol/L of HCO(3)(-). Moreover, the consideration of plasma biochemical parameters in the first 48 hours may improve the mortality predictive equation of mortality for burned victims.