Uric acid as a prognostic marker in critically ill patients

BACKGROUND: Elevated uric acid concentrations reflect adenosine triphosphate degradation and suggest poor prognosis since they indicate a cellular bioenergetic crisis. OBJECTIVE: To study uric acid concentrations as a prognostic marker of disease severity in critically ill children. PATIENTS AND METHODS: Seventy-eight patients admitted to our pediatric intensive care unit with different diseases were prospectively studied. Thirty-five patients with meningococcal infection were retrospectively studied. Data on uric acid concentrations, diagnosis, length of stay, age, weight, the therapeutic intervention scoring system (TISS) and the pediatric risk of mortality score (PRISM) were collected. In patients with meningococcal infection severity was evaluated by studying evolution (death and the presence of sequelae or otherwise). RESULTS: Uric acid concentrations on admission were significantly correlated with TISS on the first day (r 0.260; p 0.023) and with PRISM during the first 24 hours (r 0.277; p 0.015). In patients without craniocerebral trauma, correlations between uric acid concentrations and PRISM during the first 24 hours (r 0.524; p < 0.001) and correlations between uric acid concentrations with TISS on day 1 (r 0.483; p < 0.001) and day 2 (r 0.373; p 0.014) improved. In patients with craniocerebral trauma no significant correlations were found between uric acid and any of the other variables. In patients with meningococcal infection, uric acid concentrations on admission were closely related to evolution (uric acid concentrations were 13.20 8.2 mg/dl in patients who died, 8.01 1.77 mg/dl in those with sequelae and 4.72 1.84 mg/dl in in those without sequelae; p < 0.003). CONCLUSIONS: Serum uric acid concentrations can be considered as a marker of severity in critically ill patients without craniocerebral trauma and especially in patients with meningococcal infection.