Delivery of molecular versus particulate water in spontaneously breathing tracheotomized patients

Adequate humidification of inspired gas with active or passive humidifiers is a standard of care for tracheotomized patients. In this study, a comparison is made between the tracheal climate after tracheobronchial humidification either with molecular water (via a vaporizing humidifier) or particulate water (via spray) in spontaneously breathing tracheotomized patients.

We performed a randomized, 2-way crossover study on 10 tracheotomized patients. Tracheal humidity and temperature were measured prior to and after use of a vaporizing humidifier and aerosol spray, respectively.

After use of both the vaporizing humidifier and the aerosol spray, the end-inspiratory total water content and water gradient in the upper trachea increased significantly, compared with baseline values before application. After end of use of the vaporizing humidifier, the total water content and the water gradient decreased significantly faster than after application of the aerosol spray.

Delivery of both molecular and particulate water significantly increases the tracheal climate and conditioning in the tracheal airways. Because the tracheal humidity remained on a higher level after aerosol spray, we speculate that particulate water may be efficient on tracheal humidification for longer. However, the positive effect on tracheal humidity after prolonged application of the aerosol spray remains to be proven.