ABSTRACT
The respirators originally used for ventilating infants were machines in which volumes and frequencies had been designed for adult use. They proved less than satisfactory when adapted to the pediatric patient. More extended investigation of the hemodynamic effects of high-frequency ventilation is needed, particularly in the pulmonary vascular system. However, with advances in neonatal intensive care, the increasing use of ventilation for premature and low birth weight infants with immature lungs has resulted in the development of more chronic lung disease; this has been variously ascribed to the effects of positive pressure, inspired oxygen level, and the duration of ventilation. The conventional solution to lung failure associated with parenchymal lung disease is to apply positive pressure to the lung in order to provide bulk flow of gases. Some confusion exists over what constitutes high frequency ventilation (HFV), or when ventilation ceases to be conventional and can be classified as HFV.
