Comparison of Effects of Normothermic and Hypothermic Cardiopulmonary Bypass on Cerebral Metabolism During Cardiac Surgery.
- Author:
Kwang Hyun CHO
1
;
Kyung Taek PARK
;
Keoung Heoun KIM
;
Seok Cheol CHOI
;
Kook Lyeol CHOI
;
Yoon Ho HWANG
Author Information
1. Department of Thoracic & Cardiovascular Surgery,Pusan Paik Hospital,College of Medicine,Inje University, Korea. ctsckh@ijnc.inje.ac.kr
- Publication Type:Original Article ; Randomized Controlled Trial
- Keywords:
Cardiopulmonary bypass;
Hypothermia;
Cerebral blood flow velocity;
Cerebral metabolism
- MeSH:
Adult;
Blood Gas Analysis;
Brain;
Cardiopulmonary Bypass*;
Cerebral Arteries;
Delirium;
Humans;
Hypothermia;
Incidence;
Metabolism*;
Operative Time;
Oxygen;
Prospective Studies;
Thoracic Surgery*
- From:The Korean Journal of Thoracic and Cardiovascular Surgery
2002;35(6):420-429
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
BACKGROUND: Moderate hypothermic cardiopulmonary bypass (CPB)has commonly been used in cardiac surgery.Several cardiac centers recently practice normothermic CPB in cardiac surgery.However,the clinical effect and safety of normothermic CPB on cerebral metabolism are not established and not fully understood.This study was prospectively designed to evaluate the clinical influence of normothermic CPB on brain metabolism and to compare it with that of moderate hypothermic CPB. MATERIAL AND METHOD: Thirty-six adult patients scheduled for elective cardiac surgery were randomized to receive normothermic(nasopharyngeal temperature>34.5 degrees C,n=18)or hypothermic (nasopharyngeal temperature 29~30 degrees C,n=18)CPB with nonpulsatile pump.Middle cerebral artery blood flow velocity(VMCA), cerebral arteriovenous oxygen content difference (CAVO2),cerebral oxygen extraction (COE),modified cerebral metabolic rate for oxygen (MCMRO2),cerebral oxygen transport (TEO2),cerebral venous desaturation (oxygen saturation in internal jugular bulb blood < or =50 %),and arterial and internal jugular bulb blood gas analysis were measured during six phases of the operation:Pre-CPB (control),CPB-10 min,Rewarm-1 (nasopharyngeal temperature 34 degrees Cin the hypothermic group),Rewarm-2 (nasopharyngeal temperature 37 degrees Cin the both groups),CPB-off and Post-CPB (skin closure after CPB-off). Postoperaitve neuropsychologic complications were observed in all patients.All variables were compared between the two groups. RESULT: VMCA at Rewarm-2 was higher in the hypothermic group (153.11 +/-8.98%)than in the normothermic group (131.18 +/-6.94%) (p<0.05).CAVO (2) (3.47 +/-0.21 vs 4.28 +/-0.29 mL/dL,p<0.05),COE (0.30 +/-0.02 vs 0.39 +/-0.02,p<0.05)and MCMRO (2) (4.71 +/-0.42 vs 5.36 +/-0.45,p<0.05)at CPB-10 min were lower in the hypothermic group than in the normothermic group.The hypothermic group had higher TEO (2) than the normothermic group at CPB-10 (1,527.60 +/-25.84 vs 1,368.74 +/-20.03, p<0.05),Rewarm-2 (1,757.50 +/-32.30 vs 1,478.60 +/-27.41,p<0.05)and Post-CPB (1,734.37 +/-41.45 vs 1,597.68 +/-27.50,p<0.05).Internal jugular bulb oxygen tension (40.96 +/-1.16 vs34.79 +/-2.18 mmHg,p<0.05),saturation (72.63 +/-2.68 vs 64.76 +/-2.49 %,p<0.05)and content (8.08 +/-0.34 vs 6.78 +/-0.43 mL/dL,p<0.05)at CPB-10 were higher in the hypothermic group than in the normothermic group.The hypothermic group had less incidence of postoperative neurologic complication (delirium)than the normothermic group (2 vs 4 patients,p<0.05). Lasting periods of postoperative delirium were shorter in the hypothermic group than in the normothermic group (60 vs160 hrs,p<0.01). CONCLUSION: These results indicate that normothermic CPB should not be routinely applied in all cardiac surgery,especially advanced age or the clinical situations that require prolonged operative time. Moderate hypothermic CPB may have beneficial influences relatively on brain metabolism and postoperative neuropsychologic outcomes when compared with normothermic CPB.
