استهلاك الجسم للاوكسجين اثناء عملية التروية القلبية - الرئوية باستخدام ماكنة القلب والرئة الصناعية عند درجات الحرارة الاعتيادية والمنخفضة == Correction Of QT, QTp, And Tpte Intervals To Heart Rate
Author name:
همام عبد الرحمن ابراهيم العبيدي
Supervisor name:
نبا عبد اللطيف رشيد ناجي | احمد عبودي نعمة المحمودي
General topic:
Medicine
Specific topic:
Medical Physics
Degree:
Master
University:
Mustansiriyah University
Language:
English
University location:
Baghdad
First pages:
19T1163 - p.pdf
Abstract:
This study was conducted in pursuit of gaining a better understanding of the importance of hypothermia for cardiac surgery, and for CABG in particular. Most of the cardiac surgeons worldwide are accustomed to the use of mild hypothermia (32 - 35)°C for CABG procedures. Studies showed however that the risks of exposing the patient to mild hypothermia are similar to the risks endured during moderate hypothermia (28 - 32)°C. Objectives This study sought to weigh the benefits of mild hypothermia and moderate hypothermia against that of normothermia (35 - 37)°C concerning their impact on tissue oxygen consumption. Design This study is Prospective, randomized, comparative and purely observational and does not involve any intervention to the patient beyond the standard normal management. Setting At the department of physiology, college of medicine, Al - Mustansiriyah university in cooperation with the Iraqi Center for Heart Diseases and Ibn Al - Bitar Specialized Cardiac Surgery Center, in Baghdad, between December 2014 and April 2015. Patients, materials and methods Seventy patients, (55) males and (15) females, undergoing coronary artery bypass grafting surgery (CABG) were included in this study. Patients were allocated into three groups according to the surgeon's preferences; viz (normothermia, mild hypothermia and moderate hypothermia). Systemic complications associated with hypothermia were investigated via chemical analysis of the blood samples for renal and liver functions. Blood samples were collected two times during CPB from the arterial and venous ports of the oxygenator and were immediately analyzed to determine oxygen consumption and oxygen delivery. Results The decrease in the temperature for the hypothermic groups showed similar values of oxygen delivery (DO2) to that of normothermia (3537)°C at the same period during CPB. There were no noticeable changes between normothermia and mild hypothermia (32 - 35)°C. However, for moderate hypothermia (28 - 32)°C, there was a remarkable decrease in the oxygen consumption (VO2). The biochemical analysis for renal and liver functions in the normothermia and moderate hypothermia groups showed no significant differences between preoperative and postoperative results. However, in the group with mild hypothermia there was a significant change in results. Conclusion Moderate hypothermia rather than mild hypothermia proves to be of more benefit to the tissues when compared to normothermic conditions, as it significantly reduces tissue oxygen consumption. Moreover, even normothermia was found to be superior to mild hypothermia due to the latter's adverse effects on renal and liver functions while it maintains similar results with regards to oxygen consumption.
