title: Endotracheal temperature and humidity measurements in laryngectomized patients: intra- and inter-patient variability.
abstract: 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.
authors.affiliation: Department of Head and Neck Oncology and Surgery, The Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands.
authors.forename: R J
authors.initials: RJ
authors.lastname: Scheenstra
authors.forename: S H
authors.initials: SH
authors.lastname: Muller
authors.forename: A
authors.initials: A
authors.lastname: Vincent
authors.forename: M
authors.initials: M
authors.lastname: Sinaasappel
authors.forename: J K
authors.initials: JK
authors.lastname: Zuur
authors.forename: Frans J M
authors.initials: FJ
authors.lastname: Hilgers
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006361:Heating / Q000379:methods; D006801:Humans; D006813:Humidity; D007825:Laryngectomy; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D015656:Respiratory Mechanics / Q000502:physiology; D013696:Temperature; D014132:Trachea / Q000503:physiopathology*