SHFJV. Jet-adapter for application of superimposed high-frequency jet ventilation (SHFJV) via a tube in intensive care: a new technique

Abstract

Despite advances and technical developments in the area of intensive care medicine it has not been possible to lower the mortality of patients with pulmonary insufficiency. Therefore, alternative ventilation strategies have been developed and applied. One of these ventilation techniques is superimposed high-frequency jet ventilation (SHFJV). For optimal application of SHFJV we designed a special jet-adapter. This jet-adapter made of plastic consists of a T-piece and four central, small-bore cannulas and can be connected to any commercially available endotracheal tube. Therefore, it does not require reintubation with an endotracheal jet tube when beginning SHFJV. The simultaneous high-frequency and low-frequency jet ventilation is performed over two jet-nozzles that have been designed according to optimal flow dynamic measurements. Two further cannulas are used for continuous airway pressure monitoring and humidification of the applied gases. A pre-warmed and humidified bias flow with exactly defined oxygen concentration is led through the cross-part of the T-piece for gas entrainment. Additionally, the cross-part contains a port that can be opened for endotracheal suctioning or bronchoscopy and makes disconnection of the jet adapter from the endotracheal tube for either purpose unnecessary. The jet adapter can be used: (1) to apply SHFJV; (2) to measure airway pressures continuously; (3) to humidify and warm inspired gases; (4) to administer medications or add nitrous oxide by the inspiratory route, enabling combination with new therapeutic possibilities in the management of patients with severe ARDS.