Ten patients, who are supplied with a tracheostomy stent (placeholder) for reinsertions after long term ventilation will be treated for a short time during the day with the nasal high flow system AIRVO at different flow rates (15, 30, 45L/min) to estimate possible long term implications of high flow treatment.
Respiration is measured by impedance plethysmography with a calibrated belt system (Respitrace, VIASYS). Pressure and end tidal CO2 concentration is measured inside of the placeholder.
The order of the high flow rates (15, 30, 45L/min) is randomized; each flow rate is measured for 15 minutes. A wash out time of ten minutes is planned after each phase. In this time the patient breathes his individual oxygen flow rate with attention to the oxygen saturation, which should not exceed 96%. Transcutaneous PCO2 and SpO2 is monitored with TOSCA during the study.
