Effect of closed endotracheal suction in high-frequency ventilated premature infants measured with electrical impedance tomography

OBJECTIVE: To determine the global and regional changes in lung volume during and after closed endotracheal tube (ETT) suction in high-frequency ventilated preterm infants with respiratory distress syndrome (RDS). DESIGN: Prospective observational clinical study. SETTING: Neonatal intensive care unit. PATIENTS: Eleven non-muscle relaxed preterm infants with RDS ventilated with open lung high-frequency ventilation (HFV). INTERVENTIONS: Closed ETT suction. MEASUREMENTS AND RESULTS: Changes in global and regional lung volume were measured with electrical impedance tomography. ETT suction resulted in an acute loss of lung volume followed by spontaneous recovery with a median residual loss of 3.3% of the maximum volume loss. The median stabilization time was 8 s. At the regional level, the lung volume changes during and after ETT suction were heterogeneous in nature. CONCLUSIONS: Closed ETT suction causes an acute, transient and heterogeneous loss of lung volume in premature infants with RDS treated with open lung HFV.