6 Effect of low tidal volumes vs conventional tidal volumes on outcomes of acute respiratory distress syndrome in critically ill children

Background: Adult data have shown low tidal volume strategy to be beneficial to the outcome of acute respiratory distress syndrome (ARDS). There are little data regarding the effect of different tidal volume strategies on outcomes in children with ARDS. Aims and Objectives: The aim of this study was to learn the differences in outcomes from ARDS in children using low vs conventional tidal volumes. Methods: All patients with ARDS (aged 1 month to 16 years) admitted to the pediatric intensive care unit from March 98 to June 2004 were studied. Prospective data for low expired tidal volumes (6-8ml/kg) were collected from Jan 2001 to June 2004 (group 1). ARDS patients during March 1998 to December 2000, receiving conventional tidal volumes (10-15 ml/kg) were used as retrospective control (group 2). Etiologies, PRISMIII scores, interventions, and outcomes data were recorded. Standard supportive therapy for ARDS was used in all children using conventional mechanical ventilation. Results: A total of 153 (4.67%) patients had ARDS as defined by standard criteria. Groups 1 and 2 had 78 and 65 patients, respectively, with comparable PRISMIII scores. Mortality was 23% (group 1) vs 36.9% (group 2) (P< 0.005). The mean duration of ventilation and hospitalization in group 1 was significantly lower when compared with group 2 (11 +/- 1 vs 18 +/- 2 days; P< 0.005) and group 1 (19 +/- 2 vs 26 +/- 3 days; P< 0.005), respectively. Incidence of pneumothorax was 5% (group 1) as compared with 12% (group 2) (P< 0.01). Long-term follow-up for incidence of chronic lung disease could not be studied. Common etiologies of ARDS included pneumonia, sepsis, dengue shock syndrome, falciparum malaria, and fulminant hepatic failure. Conclusions: Low tidal volume strategy was found to be associated with significantly lower duration of ventilation, hospitalization, incidence of pneumothorax, and mortality when compared with conventional tidal volume strategy in children with ARDS.