PMID- 14757920
OWN - NLM
STAT- MEDLINE
DCOM- 20040422
LR  - 20061115
IS  - 0928-7329 (Print)
IS  - 0928-7329 (Linking)
VI  - 11
IP  - 6
DP  - 2003
TI  - Continuous monitoring of tracheal pressure including spot-check of endotracheal 
      tube resistance.
PG  - 413-24
AB  - During mechanical ventilation, the resistance of the endotracheal and 
      tracheostomy tube (ETT) highly influences analysis of respiratory system 
      mechanics and imposes additional work of breathing for the spontaneously 
      breathing patient which both can be circumvented by applying the automatic tube 
      compensation (ATC) mode. In the ATC mode, tracheal pressure (ptrach) is 
      continuously calculated on the basis of measured flow and airway pressure using 
      predetermined tube specific coefficients. However, as during long-term 
      ventilation the ETT might become partially obstructed by secretions or tube 
      kinking, the predetermined coefficients are no longer valid rendering calculation 
      of ptrach inaccurate. We propose an easy-to-handle maneuver for the bedside 
      determination of current tube coefficients in the tracheally intubated patient. 
      Based on check-spot measurement of ptrach, current tube coefficients are 
      determined by a least-squares fit procedure valid for the partially obstructed 
      ETT with the indwelling pressure-measuring catheter (PMC). To correct for the 
      removal of the PMC, the relationship between tube coefficients with and those 
      without indwelling PMC has been determined in a laboratory investigation. 
      Accuracy of the procedure was determined during artificial ETT obstruction by 
      comparing calculated with measured ptrach. Correspondence between calculated and 
      measured ptrach has been found excellent. We conclude that by adopting this 
      bedside procedure periodically, accurate calculation of ptrach is guaranteed and 
      the advantages of the ATC mode are ensured even in long-term ventilatory support.
FAU - Haberthur, Christoph
AU  - Haberthur C
AD  - Section of Surgical Intensive Care Medicine, Department of Anaesthesia, 
      Kantonsspital Luzern, Switzerland. christoph.haberthuer@ksl.ch
FAU - Lichtwarck-Aschoff, Michael
AU  - Lichtwarck-Aschoff M
FAU - Guttmann, Josef
AU  - Guttmann J
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - Netherlands
TA  - Technol Health Care
JT  - Technology and health care : official journal of the European Society for 
      Engineering and Medicine
JID - 9314590
SB  - IM
MH  - *Airway Resistance
MH  - Germany
MH  - Humans
MH  - *Intubation, Intratracheal
MH  - Monitoring, Physiologic/*statistics & numerical data
MH  - Trachea/*physiology
EDAT- 2004/02/06 05:00
MHDA- 2004/04/23 05:00
CRDT- 2004/02/06 05:00
PHST- 2004/02/06 05:00 [pubmed]
PHST- 2004/04/23 05:00 [medline]
PHST- 2004/02/06 05:00 [entrez]
PST - ppublish
SO  - Technol Health Care. 2003;11(6):413-24.