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CARDIOVASCULAR
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Volume 5, 2000, No 3 |
Normothermic
Cardiopulmonary Bypass
I. Birdi, N.
Chaudhuri, G. D. Angelini
Traditionally, the use of hypothermia during cardiopulmonary bypass (CPB) has been to provide cerebral protection and a degree of safety in the event of technical problems with the extracorporeal circuit. More recently, however, it has become apparent that the deleterious effects of CPB are mediated largely by the damaging effect of cooling the body. This perception has fuelled interest in normothermic techniques, which have been suggested to provide a more physiological environment for the perfusion of the major organs. The literature is confused, however, because of differences between definitions of normothermic CPB, and inconsistencies in cardioplegic protocols used in many of the studies investigating the effects of temperature practice. While normothermia may be advantageous with regard to indices such as improved haemodynamics, reduced blood product transfusion and shorter intubation times, there are real concerns regarding the limited degree of cerebral protection offered by this technique.
In the present article, a detailed review of the current knowledge of the effects of different systemic perfusion temperatures during CPB are discussed, the advantages and pitfalls of normothermia are highlighted, and suggestions for the use of moderate degrees of hypothermia during open heart surgery are advocated.
(CVE. 2000; 5 (3): 222-229)
Key words: cardiopulmonary bypass, hypothermia, normothermia, cardioplegia
Inderpaul
Birdi
Specialist Registrar in Cardiothoracic Surgery
Papworth Hospital
Papworth Everard
Cambridge, CB3 8RE
U.K.
E-mail: Inderuk@hotmail.com
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