Endoscopy of Larynx and Trachea with Rigid Laryngo-Tracheoscopes Under Superimposed High-Frequency Jet Ventilation (SHFJV)
- Alexander Aloy, Matthaeus Grasl, Manuel García, Joseph Oertel
BACKGROUND Stenotic processes of the tracheobronchial system may lead to dyspnoea that can become lift-threatening. To restore sufficient function of the blocked airway, a silicone stent can be inserted. The anaesthesia techniques used for this intervention so far have been complicated. The object of this study was to determine whether the super-imposed high-frequency jet ventilation (SHFJV) via the jet laryngoscope originally designed for microlaryngeal surgery can be utilized for endoluminal stent insertion. METHODS In 12 patients with acute respiratory insufficiency (ASA 3-5) due to stenosis of the tracheobronchial system, an endoluminal silicone stent was inserted through the jet laryngoscope while the patient was ventilated using SHFJV: RESULTS A significant rise in paO2 readings prior to the jet ventilation and subsequent measurements was observed. The CO2 elimination was good (average paCO2 31.5 +/- 7.5-53.1 +/- 14 mmHg). Variably high paCO2 readings during stent insertion were related to the respective surgical phases. At the end of the surgical manipulation, all patients had sufficient spontaneous ventilation. CONCLUSIONS First clinical applications of the jet laryngoscope combined with superimposed jet ventilation for stent insertion demonstrated satisfactory results. Not only were the patients ventilated throughout the procedure, but CO2 elimination was also satisfactory. Superimposed jet ventilation provides a sufficient tidal volume with low ventilation pressures, and therefore oxygenation and CO2 elimination are unproblematic. SHFJV enables the anaesthetist to ventilate the patient nearly continuously with minimal phases of apnoea. The only apnoea phases, as with any other method, occur during surgical manipulation while inserting the stent and thus blocking the airway. We believe that the jet laryngoscope with SHFJV presents a distinct advantage for both anaesthetist and surgeon when inserting stents in the tracheobronchial system.