An investigation on a trachea air flow pattern in an intubated patient : Airway edema case

In a respiratory failure patient, an artificial ventilation is commonly performed by using a mechanical ventilator particularly in an ICU ward. On such a case, an endotracheal tube (ETT) must be inserted into patient's airway and following by a balloon cuff blowing in order to fix and act as a sealed artificial airway for an artificial ventilation. However, those implementations adversely affect to tracheal tissue-epithelial layer and probably damaging a larynx and vocal cord zone. After a ventilator weaning and an extubating process, some patients always suffering with a larynx or tracheal edema symptom or postextubation stridor (PES) in which patient airway is narrowed or swelling due to a long term pressurization by the ETT balloon cuff. This mainly causes a difficulty in a spontaneous breathing. In general, a cuff leak test is a common medical maneuver used in order to predict a larynx or tracheal edema possibility after ETT was removed. Air volume different between an inspired volume (V
_Ti
) and an expired volume (V
_Te
) normally should be higher than 100 mL or 10%. In this paper, we propose an investigation of an airflow pattern on an intubated patient in the cuff leak test process in order to understand and support a prediction of the tracheal edema before perform an ETT extubation. The study was performed in an intubated trachea by using a simulation of an airflow pattern, air volume prediction in a normal intubated case and during cuff leak test process with no edema and edema case. Although, this simulation was intently implemented in a simple intubated trachea model, however the obtain results imply us a practical information and will be used as a basic implementation for a further study, especially in case of variety in the ETT intubation or cuff less ventilation even more complication case in the near future.