When jet ventilation is applied for longer than 30 minutes, there is a risk of the mucosa in the airways drying out. This is a complication that you will naturally want to avoid. It is therefore recommended to apply humidification. Humidification is always recommended for children due to the increased risk of dehydration.
Due to the high flows of jet ventilation, the mucous membranes around the surgical area will (partially) dry out. On the one hand, this can sometimes be a desired effect, for example, to stop bleeding. On the other hand, you want to prevent mucosal damage due to dehydration.
With the TwinStream in combination with a humidifier, mucosal damage during jet ventilation can be effectively prevented.
A flow can be supplied to a humidifier via the existing bypass system (Bias Flow) of the TwinStream. After this, heated and humidified air is added to the jet stream.
The image below shows the location where the humidified and heated air is administered. It may be desirable to insulate the hose from the humidifier to the patient. Due to downflow from the plenum, the heated air in the humidifier can cool down again. As a result, the alarm will also sound more often due to precipitation in the humidifier.
The Bias Flow (port on the rear of the device) has the same FIO2 as the jet stream delivered by the TwinStream™. The Bias Flow can be set at flow rates of 20, 40 or 55 L/min. The Bias Flow can be used in any mode. The Bias Flow is heated by the humidifier to approximately 35 to 37 degrees Celsius.
The Bias Flow and Jet flows are both stopped when a high-pressure alarm is activated. Both are also restarted after the cause of the high-pressure alarm has been resolved and RESET has been pressed.
Regular monitoring of the patient’s body temperature is required during the procedure. Measures must also be available and/or applied to maintain body temperature. After the operation, it is also recommended to humidify the postoperatively administered oxygen. This is standard in the Netherlands.
An additional advantage of using a humidifier is that the extra flow offered increases entrainment. This in turn has a positive influence on the patient’s gas exchange.
