Variation in Positive End-Expiratory Pressure Levels for Mechanically Ventilated Extremely Low Birth Weight Infants

Objective To test the hypothesis that significant positive end-expiratory pressure (PEEP) level variation exists between neonatal centers. Study design We performed a secondary analysis cohort study of the Nasal Intermittent Positive-Pressure Ventilation trial. Our study population was extremely low birth weight infants requiring mechanical ventilation within 28 days of life. The exposure was neonatal center; 34 international centers participated in the trial. Subjects from centers with fewer than 5 eligible cases were excluded. The main outcome was the maximal PEEP level used during the first course of mechanical ventilation. Infant characteristics judged a priori to directly influence clinical PEEP level selection and all characteristics associated with PEEP at P <.05 in bivariable analyses were included with and without center in multivariable linear regression models. Variation in PEEP level use between centers following adjustment for infant characteristics was assessed. Results A total of 278 extremely low birth weight infants from 17 centers were included. Maximal PEEP ranged from 3 to 9 cm H2O, mean = 5.7 (SD = 0.9). Significant variation between centers remained despite adjustment for infant characteristics (P < .0001). Further, center alone explained a greater proportion of the PEEP level variation than all infant characteristics combined. Conclusions Marked variation in PEEP levels for extremely low birth weight infants exists between neonatal centers. Research providing evidence-based guidance for this important aspect of respiratory care in preterm infants at high risk of lung injury is needed.