The Importance of Mortality Risk Assessment: Validation of the Pediatric Index of Mortality 3 Score.

OBJECTIVE: To evaluate the performance of the newest version of the Pediatric Index of Mortality 3 score and compare it with the Pediatric Index of Mortality 2 in a multicenter national cohort of children admitted to PICU. DESIGN: Retrospective, prospective cohort study. SETTING: Seventeen Italian PICUs. PATIENTS: All children 0 to 15 years old admitted in PICU from January 2010 to October 2014. INTERVENTIONS: None. MEASUREMENT AND MAIN RESULTS: Eleven thousand one hundred nine children were enrolled in the study. The mean Pediatric Index of Mortality 2 and 3 values of 4.9 and 3.9, respectively, differed significantly (p < 0.05). Overall mortality rate was 3.9%, and the standardized mortality ratio was 0.80 for Pediatric Index of Mortality 2 and 0.98 for Pediatric Index of Mortality 3 (p < 0.05). The area under the curve of the receiver operating characteristic curves was similar for Pediatric Index of Mortality 2 and Pediatric Index of Mortality 3. The Hosmer-Lemeshow test was not significant for Pediatric Index of Mortality 3 (p = 0.21) but was highly significant for Pediatric Index of Mortality 2 (p < 0.001), which overestimated death mainly in high-risk categories. CONCLUSIONS: Mortality indices require validation in each country where it is used. The new Pediatric Index of Mortality 3 score performed well in an Italian population. Both calibration and discrimination were appropriate, and the score more accurately predicted the mortality risk than Pediatric Index of Mortality 2.

Immunodeficiency in Vici syndrome: a heterogeneous phenotype.

Vici syndrome is a rare congenital multisystem disorder characterized by agenesis of the corpus callosum, hypotonia, developmental delay, hypopigmentation, cataract, cardiomyopathy, and immunological abnormalities. Recurrent infections, mainly affecting the respiratory tract, have been reported in the majority of cases, representing an important risk factor for morbidity and mortality. The immunological phenotype of patients is extremely variable, ranging from a combined immunodeficiency to nearly normal immunity. We report on a new patient with Vici syndrome, in whom we have extensively investigated immunological features. Despite a mild impairment of the cellular compartment, a defect of humoral immunity was found, requiring treatment with intravenous immunoglobulin. A wider knowledge of immune system abnormalities of Vici syndrome will help to plan strategies for treatment and prevention of infections, such as immunoglobulin replacement and antimicrobial prophylaxis, resulting in improved survival rates.