As described in the previous blog, this blog also describes a procedure from practice in which jet ventilation was used. This example took place in an academic hospital in the Netherlands. In both cases, Superimposed High Frequency Jet ventilation was applied via a modified laryngoscope.
During these procedures, it is of great importance that the surgeon and anesthesiologist cooperate well with each other. After all, the ENT doctor uses the laryngoscope directly in the ventilation channel, which is the anesthesiologist’s field of work. If, for example, a problem arises with gas exchange, the positioning of the scope may have to be adjusted. Good communication between surgeon and anesthesiologist is essential.
Start of procedure
In the patients of the practical examples, the anesthesia is administered using a propofol and remifentanil pump. The relaxation of the patients is done by means of esmeron. In addition to standard monitoring, a TOF is also connected, BIS is used and CO₂ is measured transcutaneously. Because jet ventilation can contribute to cooling, the patients receive a warming blanket and the temperature is regularly measured via the ear. The patients also receive heated bias flow 20 L/min.
Laryngeal surgery in 46-year-old woman
Start jetting: HF 800, peep of 0.7 bar, and 1:1.5 i:e. The normoventilation/LF: 16x, peep 0.9 bar. O₂ of 80%. The measured pressures are nicely low: around 1 mbar. A CO₂ of 3.3 kPa. In this patient you do see SpO₂ fluctuations and the peep of the HF is increased in particular. The entrainment increases with it, and thus usually the SpO₂. The SpO₂ always remains within acceptable values.
Again, the communication between ENT and Anesthesia is optimal. For example, when the ENT doctor indicates “I am going to dilate, the jet may be turned off” and immediately afterwards: “can I dilate for 30 seconds, can the patient handle that in terms of saturation?”. Then: “I am finished dilating, the jet can be turned on again”.
The procedure lasts about 30 minutes, is successful and the patient wakes up well and can breathe independently to the recovery room.
Superimposed High Frequency Jet ventilation is frequently used in various Dutch (mostly academic) hospitals; the surgeon then has a completely clear view of the operating area and can therefore perform the operation optimally.
Various studies show that this form of jet ventilation is a safe way of ventilation with few complications and can be applied to almost every patient category.
