Measurement of end-expiratory lung volume in intubated children without interruption of mechanical ventilation

Abstract

Purpose: Monitoring end-expiratory lung volume (EELV) is a valuable tool to optimize respiratory settings that could be of particular importance in mechanically ventilated pediatric patients. We evaluated the feasibility and precision of an intensive care unit (ICU) ventilator with an in-built nitrogen washout/washin technique in mechanically ventilated pediatric patients. Methods: Duplicate EELV measurements were performed in 30 patients between 5 kg and 43 kg after cardiac surgery (age, median + range: 26, 3-141 months). All measurements were taken during pressure-controlled ventilation at 0 cm H 2O of positive end-expiratory pressure (PEEP). Results: Linear regression between duplicate measurements was excellent (R 2 = 0.99). Also, there was good agreement between duplicate measurements, bias ± SD: -0.3% (-1.5 mL) ± 5.9% (19.2 mL). Mean EELV ± SD was 19.6 ± 5.1 mL/kg at 0 cm H2O PEEP. EELV correlated with age (p < 0.001, r = 0.92, R 2 = 0.78), body weight (p < 0.001, r = 0.91, R 2 = 0.82) and height (p < 0.001, r = 0.94, R 2 = 0.75). Conclusion: This ICU ventilator with an in-built nitrogen washout/washin EELV technique can measure EELV with precision, and can easily be used for mechanically ventilated pediatric patients.