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): Joseph A. Dearani Trevor C. Axford Manisha A. Patel Shukri F. Khuri Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Dearani, J. A. Articles by Khuri, S. F. Search for Related Content PubMed PubMed Citation Articles by Dearani, J. A. Articles by Khuri, S. F. Related Collections Myocardial protection

Ann Thorac Surg 2001;72:S2235-S2243
© 2001 The Society of Thoracic Surgeons

---

Supplement: Monitoring and improving patient safety during and following cardiac surgery

Role of myocardial temperature measurement in monitoring the adequacy of myocardial protection during cardiac surgery

^a Division of Cardiovascular Surgery, Mayo Clinic, Rochester, Minnesota, USA
^b Department of Surgery, VA Boston Healthcare System, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, USA
^c Boston Biostatistics Research Foundation, Newton, Massachusetts, USA

* Address reprint requests to Dr Khuri, Surgical Service (112), VA Boston Healthcare System, 1400 VFW Parkway, West Roxbury, MA 02132, USA
e-mail: shukri.khuri{at}med.va.gov

Presented at Monitoring and Improving Patient Safety During and Following Cardiac Surgery, San Diego, CA, May 5, 2001.

Abstract

Inadequate myocardial protection continues to be encountered despite improved methods of cardioplegia delivery. Although myocardial temperature is commonly monitored to assess the adequacy of cardioplegia delivery, its relationship to the metabolic status of the myocardium has not been investigated. We prospectively reviewed patients who underwent valvular heart surgery with blood (n = 47) or crystalloid (n = 48) cardioplegia and continuous measurement of intraoperative myocardial tissue pH and temperature. We previously demonstrated a high correlation (r = 0.99) between extracellular myocardial pH, levels of intracellular hydrogen ion concentration, and a lowering of tissue ATP during coronary occlusion. Clinically, optimal metabolic protection was defined as the absence of myocardial tissue acidosis during the period of aortic occlusion as quantified by a temperature-corrected integrated mean pH of 6.8 or greater, which has been shown to be predictive of a favorable postoperative outcome. Age, bypass time, myocardial temperature, myocardial tissue pH at the onset of aortic occlusion, cross-clamp time, and volume of cardioplegia were not significantly different between blood and crystalloid groups. Linear regression analysis demonstrated no significant correlation between mean myocardial tissue pH and the corresponding mean myocardial temperature in either group during aortic occlusion. There was also no correlation between the mean myocardial tissue pH and volume of cardioplegia delivered in both groups. These data demonstrate wide intercardiac and intracardiac variability in the degree of regional tissue acidosis encountered during of hypothermic cardioplegia. Cardioplegia delivery guided by measurement of myocardial temperature or by standardized protocol did not prevent the occurrence of tissue acidosis and thus, did not ensure optimal metabolic protection of the heart. In 95 patients undergoing valvular heart surgery with cold blood or crystalloid cardioplegia, there was no correlation between myocardial tissue pH and mycardial temperature or between myocardial tissue pH and volume of cardioplegia administered. Temperature is a poor indicator of the metabolic state of the myocardium.

This article has been cited by other articles:

				E. Gongora and T. M. Sundt III Myocardial Revascularization with Cardiopulmonary Bypass Card. Surg. Adult, January 1, 2008; 3(2008): 599 - 632. [Full Text]

				S. F. Khuri, N. A. Healey, M. Hossain, V. Birjiniuk, M. D. Crittenden, M. Josa, P. R. Treanor, S. F. Najjar, D. J. Kumbhani, and W. G. Henderson Intraoperative regional myocardial acidosis and reduction in long-term survival after cardiac surgery J. Thorac. Cardiovasc. Surg., February 1, 2005; 129(2): 372 - 381. [Abstract] [Full Text] [PDF]

				Y. J. Woo and T. J. Gardner Myocardial Revascularization with Cardiopulmonary Bypass Card. Surg. Adult, January 1, 2003; 2(2003): 581 - 607. [Full Text]