Endotracheal temperature and humidity measurements in laryngectomized patients: intra- and inter-patient variability

Med Biol Eng Comput. 2009 Jul;47(7):773-82. doi: 10.1007/s11517-009-0496-2. Epub 2009 May 26.


This study assesses intra- and inter-patient variability in endotracheal climate (temperature and humidity) and effects of heat and moister exchangers (HME) in 16 laryngectomized individuals, measured repeatedly (N = 47). Inhalation Breath Length (IBL) was 1.35 s without HME and 1.05 s with HME (P < 0.0001). With HME, end-inspiratory (minimum) humidity values increased 5.8 mg H(2)O/L (P < 0.0001) and minimum temperature values decreased 1.6 degrees C (P < 0.0001). For the temperature and humidity minimums, the inter-patient variability was much smaller than the short- and long-term intra-patient variability. For exhalation breath length and full breath length, the opposite was the case.

Conclusions: (1) Because inter-patient variability is smaller than intra-patient variability, investigating endotracheal climate in a limited number of laryngectomized subjects is justified, provided repeated measurements per patient are accomplished; (2) main contributor to intra-patient variability is the positioning of the catheter tip in the trachea; (3) an HME leads to a shortened IBL which enhances the HME effect.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Female
  • Heating / methods
  • Humans
  • Humidity
  • Laryngectomy*
  • Male
  • Middle Aged
  • Reproducibility of Results
  • Respiratory Mechanics / physiology
  • Temperature
  • Trachea / physiopathology*