Background. The aim of this study was to assess the heat and moisture exchange (HME) capacity of the upper respiratory tract
and the effect of tracheotomy breathing on endotracheal climate in patients with head and neck cancer. Methods. We plotted
the subglottic temperature and humidity measurements in 10 patients with head and neck cancer with a temporary precautionary
tracheotomy during successive 10-minute periods of nose, mouth, and tracheotomy breathing in a randomized sequence. Results.
End-inspiratory temperatures of nose, mouth, and tracheotomy breathing were 31.1, 31.3, and 28.3 degrees C, respectively.
End-inspiratory humidity measurements of nose, mouth, and tracheotomy breathing were 29.3, 28.6, and 21.1 mgH(2)O/L, respectively.
There was a trend toward lower end-inspiratory humidity in patients with radiotherapy or with large surgery-induced oropharyngeal
mucosal defects, whereas temperatures were similar. Conclusion. This study gives objective information about the HME capacity
of the upper respiratory tract in patients with head and neck cancer with precautionary tracheotomy, and thus provides target
values for HMEs for laryngectomized and tracheotomized patients. (C) 2010 Wiley Periodicals, Inc. Head Neck 33: 117-124, 2011