Effects of dry air and subsequent humidification on tracheal mucous velocity in dogs

J. A. Hirsch, J. L. Tokayer, M. J. Robinson, M. A. Sackner

Research output: Contribution to journalArticlepeer-review

69 Scopus citations


The impairment of mucociliary transport by dry air breathing and the restoration of function with subsequent humidification of inspired air were investigated in anesthetized dogs. Tracheal mucous velocity was measured by a cinebronchofiberscopic technique. The breathing of dry air through an uncuffed endotracheal tube produced almost complete cessation of the flow of tracheal mucus after 3 h. Subsequent breathing of air at 38°C with 100% relative humidity restored tracheal mucous velocity to control values by the end of an additional 3 h. Histologic examination of the trachea at the end of the 3 h dry air breathing period revealed focal areas of sloughing of the ciliated epithelium and submucosal inflammation. Although morphometry was not employed, the inflammatory changes appeared to have progressed during 3 h of breathing fully humidified air subsequent to the dry air breathing period. These findings were consistent with previous reports that the inflammatory response to injury of the tracheobronchial mucosa might be delayed and that the mucociliary transport system has a great deal of functional reserve. The authors found that an artificial heat and moisture exchanger placed on the proximal end of an endotracheal tube partially protects against the suppression of tracheal mucous velocity caused by dry air breathing.

Original languageEnglish (US)
Pages (from-to)242-246
Number of pages5
JournalJournal of applied physiology
Issue number2
StatePublished - Jan 1 1975

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)


Dive into the research topics of 'Effects of dry air and subsequent humidification on tracheal mucous velocity in dogs'. Together they form a unique fingerprint.

Cite this