Avaliação do sódio sérico como preditor de mortalidade em lista de espera para transplante hepático

Abstract

The allocation of patients in waiting list for liver transplantation in Brazil follows an urgency criteria, definied by MELD score. This score, however, is failing as mortality predictor in some groups of patients, especially those with hyponatremia. Studies suggested that the incorporation of serum sodium into MELD score, proposing a new score, the MELD-Na. The objective of this study is to evaluate the serum sodium, the MELD, the MELD-Na and the severe hyponatremia as mortality predictors in patients in waiting list for liver transplantation in the State of Ceara in the years of 2007 and 2008. The promptuaries of 145 patients that were in the waiting list were, retrospectively, evaluated, with 85 patients that were transplanted, and 60 who have died. Serum sodium data were collected and MELD and MELD-Na scores were calculated on basis on the last evaluation of these patients before the outcome (transplantation or death), and the statistical analysis of these variables comparing the group that was transplanted with the group that have died, in the general and by blood group. Hyponatremia was definied when serum sodium value was under 135 mmol/L, and severe hyponatremia when serum sodium value was under 125 mmol/L. In the transplanted group, the mean values of MELD, of MELD-Na, of serum sodium and the percentage of the number of patients with severe hyponatremia were, respectively, 20,88; 22,75; 136,33 mmol/L and 0%; and in the group that have died, these values were, respectively, 19,65; 23,23; 132,2 mmol/L and 100%, with statistical significance between the groups in the variables serum sodium and presence of severe hyponatremia. Hyponatremia was clearly, and independently, associated with death in the waiting list, especially in the “O” and “A” blood groups. The conclusion is that MELD-Na score was superior to MELD score as mortality predictor in some groups of cirrhotic patients; and that hyponatremia and, mainly, severe hyponatremia are important as mortality predictors in cirrhotic patients in waiting list for liver transplantation.