High Frequency Oscillatory Ventilation - Essay Example

air in a single breath is known as the "tidal volume." Conventional ventilators can have a harmful effect on infants because normal tidal volumes may overstretch the lungs. HFOV is a highly effective alternative, which uses high frequency (10 - 15 breaths per second) and smaller tidal volumes, which reduces the risk of lung damage. The development of the positive pressure mechanical ventilator in the 1950s marked a significant achievement in the care of patients with respiratory failure, and was a cornerstone in the establishment of the discipline of critical care medicine.

Since then, although mechanical ventilation is often life saving, it can also be injurious, especially in patients suffering from Acute Respiratory Distress Syndrome (ARDS). ARDS is the prototypical disease of abnormal lung compliance, causing respiratory failure in both children and adults. ARDS refers to the syndrome of lung injury characterized by dyspnea, severe hypoxemia, decreased lung compliance, and diffuse bilateral pulmonary infiltrates (Udobi & Childs, 1). It can also result in refractory hypoxemia, which can often stimulate attempting nonconventional ventilation strategies such as using nitric oxide, recruitment maneuvers, or prone positioning.

High-Frequency Oscillatory Ventilation (HFOV) has emerged as one such rescue strategy for patients with ARDS. Moreover, given that it appears to injure the lung less than conventional modes of ventilation, it may also be ideally suited to use early in ARDS. HFOV utilizes oscillations generated by a piston pump or a diaphragm oscillator driven by a motor. It produces a sinusoidal or somewhat erratic pressure waveform that gives the expiratory phase its unique active characteristic. This component is created by the backward movement of the diaphragm or piston of the oscillator.

A constant distending airway pressure is applied, over which small tidal volumes are superimposed at a high respiratory frequency (Bouchat, Godard and Claris,