Mathematical modeling of buffers used in myocardial preservation

Jonathan R. Triana, Mark Yanagihashi, Douglas F Larson

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Objective. Buffers added to myocardial preservation solutions are considered to be critical for resisting myocardium pH changes from the accumulation of protons (H+). Our hypothesis is that mathematical modeling of three clinically used buffers will define their individual buffering capacities under simulated clinical conditions. Methods. The buffers, tromethamine (THAM), sodium bicarbonate (HCO3-), and L-histidine, were compared in terms of their buffering capacity (β) under specific temperatures and concentrations, using a mathematical model. Results. At 37°C, the maximal beta (βmax) occurred at pH 7.75 for THAM, pH 6.10 for HCO3-, and pH 5.89 for L-histidine at equimolar concentrations. A decrease in temperature moved βmax to a higher pH value for each buffer. At clinical concentrations, L-histidine provided the greatest buffering capacity followed by HCO3- and THAM, respectively. Discussion. This model permitted comparison of the above buffers under simulated clinical conditions. The assumption was that the magnitude of βmax at a given temperature determines which buffer(s) could be most effective for myocardial preservation. Also, the assumption was taken that these buffers are used in a closed system - where there is no continuous blood flow - and that the buffering ability of THAM and L-histidine were not influenced by the accumulation of CO2 as is HCO3-. THAM and L-histidine were more effective at hypothermic temperatures compared with HCO3-; however, HCO3- provided buffering at normothermic temperatures. Through the theoretical considerations of this study, we propose that combining HCO3 - with THAM or L-histidine could be most efficacious for myocardial preservation during open heart surgery or organ transplantation.

Original languageEnglish (US)
Pages (from-to)353-362
Number of pages10
JournalPerfusion
Volume22
Issue number5
DOIs
StatePublished - 2007

Fingerprint

mathematical modeling
Tromethamine
Histidine
Buffers
model comparison
Temperature
surgery
Sodium bicarbonate
Transplantation (surgical)
Theoretical Models
Surgery
ability
Sodium Bicarbonate
Protons
Blood
Organ Transplantation
Heart Transplantation
Mathematical models
Thoracic Surgery
Hydrogen

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine

Cite this

Mathematical modeling of buffers used in myocardial preservation. / Triana, Jonathan R.; Yanagihashi, Mark; Larson, Douglas F.

In: Perfusion, Vol. 22, No. 5, 2007, p. 353-362.

Research output: Contribution to journalArticle

Triana, Jonathan R. ; Yanagihashi, Mark ; Larson, Douglas F. / Mathematical modeling of buffers used in myocardial preservation. In: Perfusion. 2007 ; Vol. 22, No. 5. pp. 353-362.
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