Luis Estremadoyro

Factors associated with mortality in acute renal failure (ARF) in children

Objective: To assess the factors that affect the mortality in acute renal failure (ARF) in children. Patients and methods: We studied 149 patients with ARF and described the findings by age, gender, pathophysiological mechanism of renal damage, and type of renal damage, which can be oligoanuric and/or septic. We used multiple logistic analysis, Cox analysis for survival, and Kaplan–Meier curves. Results: The male/female ratio was 91/58. The most affected age groups were newborns (44.3%) and infants (37.6%). The ARF mechanism was ischemic in 87 cases (58%) and the most frequent clinical type was nonoliguric in 118 cases (79.2%). In the multiple logistic regression analysis, only oliguria (P=0.07) and age group (P=0.049) were associated with mortality. In the survival analysis using the Cox method, oliguria (P=0.003) and sepsis (P=0.03) were associated with mortality. The survival curves showed that the cumulative probability of dying in the first 10, 20, or 40 days after the event was 75, 70, and 45% respectively. When oliguria was present, the survival at day 10 was 47% and when sepsis was present it was 68%. Conclusion: Oliguria, age, and sepsis are factors associated with mortality in children with ARF.

Validation of the salivary urea test as a method to diagnose chronic kidney disease.

BACKGROUND Serum urea correlates very well to salivary urea, which can be used as a low-cost, easily accessible and noninvasive diagnostic method for screening patients in early stages of kidney disease, especially in developing countries where resources are limited, giving the possibility of establishing secondary prevention programs later. METHODS One hundred and one people were enrolled: 11 with creatinine clearance (CrCl) less than 10 ml/min per 1.73 m(2); 10 with CrCl of 11-20 ml/min per 1.73 m(2); 12 with CrCl of 21-50 ml/min per 1.73 m(2); 26 with CrCl of 51-80 ml/min per 1.73 m(2) and 42 with CrCl of 81-170 ml/min per 1.73 m(2), to analyze salivary urea test accuracy through construction of a receiver operating characteristic curve. RESULTS Salivary urea cutoff point of 20 mg/dL and a CrCl of 80 ml/min per 1.73 m(2) showed sensitivity (S) of 0.98, specificity (SP) of 0.29, pretest probability (PPT) of 0.58, positive predictive value (PPV) of 0.66, negative predictive value (NPV) of 0.92, posttest positive probability (PTPP) of 0.66 and posttest negative probability (PTNP) of 0.09. A cutoff point of 40 mg/dL and a CrCl of 80 ml/min per 1.73 m(2) showed S=0.80, SP=0.71, PPT=0.58, PPV=0.80, NPV=0.71, PTPP=0.79 and PTNP=0.28. A cutoff point of 100 mg/dL and a CrCl of 80 ml/min per 1.73 m(2) showed S=0.22, SP=1, PPT=0.58, PPV=1, NPV=0.48, PTPP=1 and PTNP=0.52. Receiver operating characteristic curve analysis showed that the best cutoff point for salivary urea was 40 mg/dL. CONCLUSION The salivary urea test has a great capacity to discriminate patients with chronic kidney disease from healthy people, and it was shown that the best cutoff point is 40 mg/dL.