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 Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Graffigna, A.C.L. Articles by Antolini, R. Search for Related Content PubMed PubMed Citation Articles by Graffigna, A.C.L. Articles by Antolini, R. Related Collections Myocardial protection

Eur J Cardiothorac Surg 2002;21:995-1001
© 2002 Elsevier Science NL

Continuous monitoring of myocardial acid–base status during intermittent warm blood cardioplegia

^a Cardiac Surgery Unit, S. Chiara Hospital, Largo Medaglie d'Oro, 38100 Trento, Italy
^b Department of Physics & ITC-IRST, University of Trento, Trento, Italy

Received 18 September 2001; received in revised form 9 January 2002; accepted 30 January 2002.

* Corresponding author. Tel.: +39-0461-903322; fax: +39-0461-903345
e-mail: graffigna{at}tn.aziendasanitaria.trentino.it

Objective: Intermittent warm blood cardioplegia (IWBC) is a well-established technique for myocardial protection during cardiac operations. According to standardized protocols, IWBC administration is currently performed every 15–20 min regardless of any individual variable and in the absence of any instrumental monitoring. We devised a new system for continuous measurement of the acid–base status of coronary sinus blood for on-line evaluation of myocardial oxygenation during IWBC. Methods: In 19 patients undergoing cardiac surgery for coronary artery bypass graft and/or valve surgery and receiving IWBC (34–37°C) by antegrade induction (3 min) and retrograde or antegrade maintenance (2 min) every 15 min, continuous monitoring of myocardial oxygenation and acid/base status was performed by means of a multiparameter PO₂, PCO₂, pH, and temperature sensor (Paratrend7 ®, Philips Medical System) inserted into the coronary sinus. Results: Mean cross-clamping time was 76±26 min; ischemic time was 13±0.2 min. pH decline was not linear, showing an initial fast decline, a point of flexus, and a progressive slow decline. After every ischemic period, the pH adaptation curve showed a complex pattern reaching step-by-step lower minimum levels (7.28±0.14 during the first ischemic period, to 7.16±0.19 during the third ischemic period – P=0.003). PO₂ decreased rapidly at 90% in 5.0±1.2 min after every reperfusion. During ischemia, PCO₂ increased steadily at 1.6±0.1 mmHg per minute, with progressively incomplete removal after successive reperfusion, and progressive increase of maximal level (42±12 mmHg during the first ischemic period, to 53±23 mmHg during the third ischemic period – P=0.05). Conclusions: Myocardial oxygen, carbon dioxide, and pH show marked changes after repeated IWBC. Myocardial ischemia is not completely reversed by standardized reperfusions, as reflected by steady deterioration of PCO₂ and pH after each reperfusion. Progressive increase of reperfusion durations or direct monitoring of myocardial oxygenation could be advisable in cases of prolonged cross-clamping time.

Key Words: Cardiac blood pH • Myocardial protection • Cardioplegia

This article has been cited by other articles:

				J W Mulholland The Great Britain and Ireland perspective: current perfusion safety issues, preparing for the future Perfusion, July 1, 2005; 20(4): 217 - 225. [Abstract] [PDF]

				C. Schmitz, O. Ashraf, W. Schiller, C. J. Preusse, B. Esmailzadeh, J. A. Likungu, R. Fimmers, and A. Welz Transit time flow measurement in on-pump and off-pump coronary artery surgery J. Thorac. Cardiovasc. Surg., September 1, 2003; 126(3): 645 - 650. [Abstract] [Full Text] [PDF]