[The influence of poor nutrition on the necessity of mechanical ventilation among children admitted to the Pediatric Intensive Care Unit].

OBJECTIVE To determine the relation between children's nutritional status when they are admitted to the Pediatric Intensive Care Unit, the necessity and length of mechanical ventilation and the mortality rate. METHODS A cohort study was conducted between July 1st, 1995 and June 30th, 1996. This study involved all children (28 days old to 48 months old) admitted to the pediatric intensive care unit of Hospital São Lucas, who stayed there longer than 8 hours. Exclusion criteria were complex cardiac disease, admission to the pediatric intensive care unit for elective procedure (regardless of pediatric intensive care unit admission criteria) or elective mechanical ventilation (cardiac, thoracic or other postoperative period). The staff responsible for the daily data collection were not involved with patient care or assistance decisions. On the day of admission to the pediatric intensive care unit, patients were evaluated regarding their nutritional status through the z score and the severity of the disease using the Pediatric Risk Mortality score. Demographic data, necessity and length of mechanical ventilation as well as main diagnosis and evolution of each patient were evaluated every day. RESULTS Malnourishment increased significantly the need for mechanical ventilation, especially when associated with (a) age under one year old (RR=2.4; 1.4-3.8); (b) children admitted to the pediatric intensive care unit with low Pediatric Risk Mortality score (less than 10) (RR=2.5; 1.3-4.7); (c) presence of respiratory disease (RR=2.1; 1.3-4.7). Otherwise, malnourishment did not show any influence on the mortality rate. CONCLUSION In our study, we could demonstrate that malnourishment in children under 4 years old admitted to the pediatric intensive care unit represented a decisive factor on evolution, increasing significantly the necessity and the length of mechanical ventilation as well as the length of stay at the pediatric intensive care unit.