While assisting ventilation during general anesthesia or other reasons, patients are often intubated with endotracheal tube to secure airway. Endotracheal tube can be placed trans-orally or trans-nasally according to surgical conditions, anatomical considerations and nursing needs. Except inadequate cuff pressure related complication, nasotracheal intubation can cause dysfunction of nasal mucosal cilia, injury and hemorrhage of nasal mucosa, turbinate avulsion, obstruction of nasal airway, sinusitis and compression and injury of nasal alar, resulting in local erythema, ischemia, pressure sore, necrosis, tissue damage and may affect appearance.~Previous studies focus on the process of nasal tracheal intubation, aim to reduce mucosal injury and hemorrhage via specific intubation tool, special endotracheal tube design, lubricant and so on. However, evidences in preventing nasal alar injury are limited, in which injuries are mostly prevented by self-made special endotracheal tube and artificial leather. In general, the etiology of tissue damage is compression pressure exceeding local capillary perfusion pressure, resulting in reduced perfusion, ischemia and necrosis. Clinically, health providers prevent the injury by standardized endotracheal tube fixation and/or artificial leather at sites with potential compression. But the extend of the effect of endotracheal tube to trachea mucosa varies, range of pressure affecting capillary perfusion pressure are not yet defined, and no routine monitoring for dermis compression. Thus, endotracheal tube related skin damage is an important clinical issue without best standard operating procedure.~In this study, the investigators will place a pressure sensor at the angle of nasotracheal tube, measure the actual pressure, define the sites of compression and its pressure, analyze the relationship of clinical signs and symptoms, pressure, and duration of nasotracheal intubation, and build up optimal clinical routines.
Nasotracheal intubation can cause injury and hemorrhage of nasal mucosa and nasal alar. The investigators measure the actual pressure at the angle between nasotracheal tube and nasal alar, analyze the relationship of clinical signs and symptoms to build up optimal clinical routines.