Skip Navigation

This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow E-Letters: Submit a response to the article
Right arrow Alert me when this article is cited
Right arrow Alert me when E-letters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (3)
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Larsen, P. D.
Right arrow Articles by Galletly, D. C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Larsen, P. D.
Right arrow Articles by Galletly, D. C.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

British Journal of Anaesthesia, 2003, Vol. 91, No. 2 184-189
© 2003 The Board of Management and Trustees of the British Journal of Anaesthesia

Clinical Investigations

Quantal ventilatory variability during spontaneous breathing anaesthesia

P. D. Larsen*, Y. C. Tzeng and D. C. Galletly

Department of Surgery and Anaesthesia, Wellington School of Medicine, PO Box 7343, Wellington, New Zealand

Corresponding author. E-mail: peter.larsen@wnmeds.ac.nz
{dagger}LMA® is the property of Intavent Limited.

Background. Cardioventilatory coupling is the triggering of inspiratory onset by preceding cardiac activity. We have observed two forms of coupling with a bimodal (‘quantal’) variation of respiratory period.

Methods. We investigated the variables of inspiratory duration (TI), expiratory duration (TE), and tidal volume (VT) where respiratory period variation was bimodal. In 25 anaesthetized spontaneously breathing subjects we took 11 samples of recording where the variation of respiratory period was quantal.

Results. In eight of these epochs the variation in respiratory period was associated with fluctuations in the number of heart beats per breath (entrainment ratio) with a constant time interval between inspiration and the immediately preceding heart beat (coupling interval), which we define as pattern II coupling. During pattern II coupling, the quantal variations in respiratory period were entirely caused by variation in TE, with no associated changes in either TI or VT. The other three epochs with quantal variations in respiratory period were observed in pattern III coupling, where an alternating fluctuation in both entrainment ratio and coupling interval occurs. During pattern III coupling, quantal fluctuations were observed in TE, TI, and VT.

Implications. Cross correlation analysis suggested that when pattern III was present, TI was dependent upon the preceding TE, which differs markedly from traditional views on the interaction between inspiratory and expiratory duration. VT was linearly related to TI, and so could also be determined by the preceding TE during this type of coupling.

Br J Anaesth 2003; 91: 184–9


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
Y. C. Tzeng, P. D. Larsen, and D. C. Galletly
Effects of hypercapnia and hypoxemia on respiratory sinus arrhythmia in conscious humans during spontaneous respiration
Am J Physiol Heart Circ Physiol, May 1, 2007; 292(5): H2397 - H2407.
[Abstract] [Full Text] [PDF]


Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.