HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Igor E. Konstantinov Andrew N. Redington Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Li, J. Articles by Redington, A. N. Search for Related Content PubMed PubMed Citation Articles by Li, J. Articles by Redington, A. N. Related Collections Extracorporeal circulation

Ann Thorac Surg 2004;77:1671-1677
© 2004 The Society of Thoracic Surgeons

---

Original article: cardiovascular

Continuous measurement of oxygen consumption during cardiopulmonary bypass: description of the method and in vivo observations

^a Division of Cardiology, Toronto, Ontario, Canada
^b Division of Perfusion, Toronto, Ontario, Canada
^c Division of Cardiovascular Surgery, The Hospital for Sick Children, Toronto, Ontario, Canada
^d Division of Cardiovascular Medicine, Addenbrookes Hospital, Cambridge University, Cambridge, United Kingdom

Accepted for publication October 2, 2003.

^* Address reprint requests to Prof Redington, Division of Cardiology, The Hospital for Sick Children, 555 University Ave, Toronto, ON, Canada M5G 1X 8
e-mail: andrew.redington{at}sickkids.ca

BACKGROUND: Systemic oxygen consumption is not routinely measured during cardiopulmonary bypass, despite its potential benefits. We aimed to develop a noninvasive method to continuously measure oxygen consumption using respiratory mass spectrometry during hypothermic cardiopulmonary bypass in pigs.

METHODS: Nine pigs weighing 18.5 (1.6) kg underwent hypothermic (32°C) cardiopulmonary bypass for 180 minutes with 120 minutes of aortic cross clamping. An AMIS 2000 mass spectrometer (Innovision A/S, Odense, Denmark) was adapted for the on-line measurement of oxygen consumption by sampling the inlet and outlet gases of the membrane oxygenator together with measurement of the "expired" gas volume.

RESULTS: Active cooling for 60 minutes reduced the venous blood temperature by 2.9 (0.8) °C and VO₂ by 0.70 (0.33) mL/kg/min. The 40-minute active rewarming restored the venous blood temperature by 4.4 (0.4) °C and oxygen consumption increased by 1.36 (0.33) mL/kg/min. There was wide interanimal variability, however, particularly at higher venous blood temperatures. Immediately after the release of aortic cross clamp, there was a noticeably acute increase in oxygen consumption in all the pigs (0.64 [0.21] mL/kg/min).

CONCLUSIONS: A simple and safe adaptation of mass spectrometry allows continuous measurement of oxygen consumption during hypothermic cardiopulmonary bypass. The wide interindividual variations observed in this pilot study underscore the need to more accurately describe changes in oxygen consumption and how they are affected by temperature, oxygen delivery, and other interventions during cardiopulmonary bypass. As such, the technique may have an important role in clinical research and management of oxygen transport in patients undergoing cardiac surgery.

This article has been cited by other articles:

				J. Li, J. Stokoe, I. E Konstantinov, R. K Kharbanda, and A. N Redington Evidence for a significant myocardial contribution to total metabolic burden during hypothermic cardiopulmonary bypass: a study of continuously measured oxygen consumption and arterial lactate levels in pigs Perfusion, September 1, 2005; 20(5): 277 - 283. [Abstract] [PDF]