Lúcio Flávio Peixoto de Lima

Low blood thiamine concentrations in children upon admission to the intensive care unit: risk factors and prognostic significance

BACKGROUND Thiamine deficiency has been associated with poorer clinical outcomes. Early recognition of thiamine deficiency is difficult in critically ill patients because clinical signs are nonspecific. OBJECTIVE We determined the prevalence of and identified risk factors associated with low blood thiamine concentrations upon admission of children to a pediatric intensive care unit and evaluated this condition as a predictor of clinical outcomes. DESIGN A prospective cohort study was conducted in 202 children who had whole-blood thiamin concentrations assessed by HPLC upon admission to the intensive care unit. The following independent variables for thiamine deficiency were analyzed: age, sex, nutritional status, clinical severity scores upon admission (ie, the revised Pediatric Index of Mortality and Pediatric Logistic Organ Dysfunction score), systemic inflammatory response measured by C-reactive protein serum concentrations, severe sepsis or septic shock, heart failure, and cardiac surgery. The dependent variables in the outcome analyses were mortality, length of stay, and time on mechanical ventilation. RESULTS Low blood thiamine concentrations upon admission were detected in 57 patients (28.2%) and were shown to be independently associated with C-reactive protein concentrations >20 mg/dL (odds ratio: 2.17; 95% CI: 1.13, 4.17; P = 0.02) but not with malnutrition. No significant association was shown between low blood thiamine concentrations upon admission and outcome variables. CONCLUSIONS The incidence of low blood thiamine concentrations upon admission was high. Of the risk factors examined, only the magnitude of the systemic inflammatory response showed an independent association with this event. The association between thiamine deficiency upon admission and prognosis requires further investigation.

Malnutrition May Worsen the Prognosis of Critically Ill Children With Hyperglycemia and Hypoglycemia

OBJECTIVES To determine whether hyperglycemia and hypoglycemia are associated with higher mortality, longer length of intensive care unit (ICU) stay, and fewer ventilator-free days in critically ill children while taking into account the clinical severity and nutrition status. PATIENTS AND METHODS A prospective observational cohort study was conducted on 221 children admitted to the ICU. Blood glucose levels were analyzed in the first 72 hours. Potential exposure variables for adverse prognosis included hyperglycemia (blood glucose >150 mg/dL), hypoglycemia (blood glucose ≤60 mg/dL), age <1 year, sex, nutrition status, the revised Pediatric Index of Mortality (PIM 2), and the Pediatric Logistic Organ Dysfunction (PELOD). RESULTS Of the patients, 47.1% were malnourished. Controlling for nutrition status, both hyperglycemia and hypoglycemia increased the risk of mortality in the malnourished patients compared with the well-nourished ones. Adjusting for clinical severity, the odds ratio of mortality was higher in malnourished patients with hyperglycemia (odds ratio [OR], 3.98; 95% confidence interval [CI], 1.14-13.94; P = .03), whereas no significant associations were detected in the well-nourished patients. After controlling for nutrition status, hypoglycemia was associated with longer length of ICU stay (OR, 6.5; 95% CI, 1.30-32.57; P < .01) and fewer ventilator-free days (OR, 4.11; 95% CI, 1.26-13.40; P < .01) only in the malnourished group of patients. CONCLUSIONS Compared with the well nourished, malnourished patients with hyperglycemia are at a greater risk of mortality, independent of clinical severity. Hypoglycemia was shown to be associated with mortality, longer length of ICU stay, and fewer ventilator-free days only in malnourished patients.

Effect of blood thiamine concentrations on mortality: Influence of nutritional status

OBJECTIVE To test the hypothesis that low blood thiamine concentrations in malnourished critically ill children are associated with higher risk of 30-d mortality. METHODS Prospective cohort study in 202 consecutively admitted children who had whole blood thiamine concentrations assessed on admission and on days 5 and 10 of intensive care unit (ICU) stay. The primary outcome variable was 30-d mortality. Mean blood thiamine concentrations within the first 10 d of ICU stay, age, sex, malnutrition, C-reactive protein concentration, Pediatric Index of Mortality 2 score, and severe sepsis/septic shock were the main potential exposure variables for outcome. RESULTS Thiamine deficiency was detected in 61 patients within the first 10 d of ICU stay, 57 cases being diagnosed on admission and 4 new cases on the 5th d. C-reactive protein concentration during ICU stay was independently associated with decreased blood thiamine concentrations (P = 0.003). There was a significant statistical interaction between mean blood thiamine concentrations and malnutrition on the risk of 30-d mortality (P = 0.002). In an adjusted analysis, mean blood thiamine concentrations were associated with a decrease in the mortality risk in malnourished patients (odds ratio = 0.85; 95% confidence interval [CI]: 0.73-0.98; P = 0.029), whereas no effect was noted for well-nourished patients (odds ratio: 1.03; 95% CI: 0.94-1.13; P = 0.46). CONCLUSIONS Blood thiamine concentration probably has a protective effect on the risk of 30-d mortality in malnourished patients but not in those who were well nourished.

825 Hypoalbuminemia is Independently Associated with Morbidity and Mortality in Critically ill Children

Background and Aim Although hypoalbuminemia has been recognized as a marker of poor outcome in adult patients, this association has not been demonstrated in a general population of pediatric critically ill children, and studies have not considered non-nutritional factors that may influence albumin concentrations. This study aimed to determine whether hypoalbuminemia is associated with mortality and morbidity of critically ill children while considering the clinical severity of the patients. Methods This was a prospective study involving 178 children admitted to the ICU. The outcome variables studied were ICU mortality, severity of organ dysfunction, free-ventilator days and free-ICU days. The outcome variables were as follows: nutritional status, Pediatric Index of Mortality (PIM 2), serum albumin, C Reactive Protein and lactate concentrations. Children with liver failure and chronic kidney disease were excluded. Results Mean serum albumin concentration upon admission among survivors was 3.16+/–0.66 versus 2.63+/–0.67 in non-survivors (p=0.015). The mortality rate was 6.4% (11/178). In a multiple logistic regression model, adjusting for PIM 2 score, lower albumin concentrations were independently associated with increased organ dysfunction (OR: 0.18, 95% CI: 0.06–0.53; p=0.002) and mortality (OR: 0.22, 95% CI: 0.07–0.76; p=0.017). In a multiple linear regression model, adjusted for PIM2, malnutrition and other potential confounders, lower albumin concentrations were associated with fewer free-ventilator days (p=0.024) and free-ICU days (p=0.028). Conclusions Children with hypoalbuminemia at admission are at a greater risk of organ dysfunction and mortality, and longer time of mechanical ventilation and length of ICU stay, independent of clinical severity and nutritional status.