Patients after laryngectomy are subject to a high incidence of chest complaints. In attempting to reduce these a number of 'new nose' stoma filters have recently been introduced which claim to humidify and warm air, filter particulate matter and, by increasing tracheal airway resistance, to improve lung function.
Our study defines the normal tracheal temperature, humidity and resistance values which were obtained from 16 patients with a normal upper respiratory tract. These parameters will allow the available filters to be evaluated objectively and may lead to the development of a more physiological 'new nose'.
The physiological airflow resistance from the anterior nares to the upper trachea has recently been documented. This resistance is thought to be important in preventing alveolar collapse and in maintaining the optimum lung ventilation: perfusion ratio. 2This resistance is lost in laryngectomees who may have a subsequent decline in lung function and arterial oxygen saturation. A stoma filter with a resistance approximating to that of the normal upper airway has been developed and laryngectomees who wear this device demonstrate a rapid increase in tissue oxygen saturation (median increase: 1.4 kPa, P = 0.0087) without significantly altering tissue carbon dioxide saturation. This finding will have a major impact on the future rehabilitation of laryngectomees and those with a temporary tracheostomy.
