Os efeitos do balanço hídrico positivo em lactentes menores de um ano com bronquiolite viral aguda submetidos à ventilação mecânica

Abstract

Objective : to evaluate the effects of positive fluid balance in infants under one year with bronchiolitis undergoing mechanical ventilation. Methodos : retrospective cohort study based on analysis of medical records of infants under one year admitted from April 2008 to September 2011 with bronchiolitis requiring mechanical ventilation in a tertiary Pediatric Intensive Care Unit (PICU) in southern of Brazil. We excluded patients with chronic lung disease, tracheostomy and previous use of mechanical ventilation due to acute pulmonary disease. We calculated the cumulative fluid balance within the first 3 days of the onset of mechanical ventilation. The outcomes assessed were ventilator-free days, length of stay in PICU, ventilator parameters used on the third day. Results : eighty-one patients were included in the study, 49 males (60.5%). The mean cumulative fluid balance on the third day of mechanical ventilation was 139 ± 68 ml/kg, the ventilator-free days was 19.7 ± 5.7 and the length of stay in PICU was 10.4 ± 5 6 days. In multivariate analysis, increasing cumulative fluid balance on the third day of mechanical ventilation was associated with a lower number of ventilatorfree days (&#946; -.03; 95% CI -.05, -.01; p <.001). The increasing cumulative fluid balance on the third day was also associated with higher PEEP and higher FiO2 used on the same day (&#946; .01; 95% CI.006, .019; p <.001 and &#946; .09; 95% CI .053, .136; p <.001 respectively). There was no relationship between cumulative fluid balance and length of stay in PICU (p = .950). Conclusion : cumulative fluid balance on the third day of mechanical ventilation is an independent risk factor for a lower number of ventilator-free days in infants under one year with bronchiolitis. There is also an association between higher cumulative fluid balance on the third day of mechanical ventilation and higher PEEP and higher FiO2 on the same day.