Open lung high frequency ventilation in preterm infants with respiratory distress syndrome: practical considerations and recommendations

In premature infants ventilated because of RDS the favorable effect of HFV OLV compared to conventional mechanical ventilation on the incidence of BPD remains a matter of debate. An important lack in published human studies is the clinical practice surrounding the thorough application of OLV with HFV from the acute stage of RDS through the weaning process until extubation.
Studies in this thesis demonstrate that applying a "full package" OLV from start to finish in respiratory failure with high frequency ventilation is feasible and safe in preterm infants with RDS. Lung hysteresis is present which stresses the importance to decrease the pressure after the recruitment maneuver. As surfactant therapy changes lung characteristics pressures should be adjusted timely after surfactant instillation to prevent overinflation. The need for these individualized adjustments is more time consuming but, when applied by trained medical staff the personnel resources can be reduced. Also the radiological evaluation of the chest is different especially with regard to the gradation of the severity of RDS. Classical radiological characteristics of RDS cannot be used as radiolucency is improved. Mild hyperinflation is found in only a minority of patients on chest X-ray. Finally, cross over from OLV HFV to conventional mechanical ventilation can be avoided as it is possible to wean and to extubate patients directly from HFV.