|  | Conditions Treatments | Medical Conditions

Parts of High Frequency Jet Ventilators

High-frequency jet ventilation utilizes a type of mechanical ventilator that provides a jet gas pulse to the airway via a small-lumen catheter within the endotracheal tube, which is placed in the patient's airway. Breaths are given at a rate between 100 and 200 pulses per minute. The high-frequency oscillator is also a type of high-frequency ventilator, which cycles at a rate of 60 to 3,000 times per minute. Both of these ventilators provide high-frequency ventilation.

  1. Definition

    • High-frequency jet ventilation utilizes considerably higher respiratory rates in tandem with lower than normal tidal volumes. A normal respiratory rate for an adult is 12 to 15 breaths per minute and a normal spontaneous tidal volume is 7 to 9 milliliters per kilogram (mL/kg) of ideal body weight. Your tidal volume refers to the volume of air you take into your lungs with each normal breath.

    Process

    • The operational principle behind high-frequency jet ventilation (HFJV) is the delivery of short breaths or pulsations under pressure through a small lumen tube at high rates. The airway is intermittently pressurized with either 100 percent oxygen or a mixture of air and oxygen, at about 60 to 110 breaths per minute. The negatives for HFJV include the fact that short inspiratory times and high rates can prevent the patient from receiving adequate tidal volumes. HFJV gives air enough time to enter the lungs, but sometimes not enough time to exit the lungs resulting in air trapping. Both of these concerns can cause lung injury.

    HFJV Device

    • Parts of a high-frequency jet ventilator include the mechanical ventilator, which is connected to a power supply and a gas source. The ventilator has a pneumatic valve assembly, which consists of an inspiratory line that connects to a 14 to 18-gauge cannula found within the jet device. Additional oxygen may be fed into this line from the gas source. The device also has an expiratory line, which allows for active or passive expiration and a humidification system to prevent the airway from drying out. This entire device connects to an endotracheal tube that has been placed in the patient's airway.

    Types

    • Types of high-frequency ventilators include the high-frequency positive-pressure ventilator (HFPPVZ), the high-frequency-jet ventilator (HFJV), a high-frequency flow interrupter (HFFI) or a high-frequency oscillatory ventilator (HFOV). All of these ventilators provide high-frequency ventilation. Examples include the Life Pulse HFJV designed for infant ventilation, which provides passive exhalation to minimize lung injury; Infrasonics' Puritan Bennett Infant Star ventilator, which primarily supports pressure control ventilation but can also support high-frequency ventilation, and the Sensormedics 3100B HFOV.

Medical Conditions - Related Articles