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

• Published in: Medical & biological engineering & computing Vol. 47; no. 7; pp. 773 - 782
• Main Authors: Scheenstra, R. J, Muller, S. H, Vincent, A, Sinaasappel, M, Zuur, J. K, Hilgers, Frans J. M
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Berlin/Heidelberg : Springer-Verlag 01.07.2009; Springer-Verlag; Springer Nature B.V
• Subjects: Aged; Aged, 80 and over; Biomedical and Life Sciences; Biomedical Engineering and Bioengineering; Biomedicine; Cancer; Catheters; Computer Applications; Equilibrium; Female; Heat; Heating - methods; Human Physiology; Humans; Humidity; Imaging; Laryngectomy; Male; Measurement techniques; Medical technology; Middle Aged; Original; Original Article; Ostomy; Otolaryngology; Patients; Radiology; Reproducibility of Results; Respiration; Respiratory Mechanics - physiology; Sensors; Studies; Temperature; Throat; Trachea - physiopathology; Total laryngectomy; Tracheal climate; Temperature and humidity
• ISSN: 0140-0118; 1741-0444
• DOI: 10.1007/s11517-009-0496-2

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 H₂O/L (P < 0.0001) and minimum temperature values decreased 1.6°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.