Mölström Simon, Nielsen Troels H, Andersen Claus, Nordström Carl H, Toft Palle
Department of Anesthesiology and Intensive Care, Odense University Hospital, Odense, Denmark.
Department of Neurosurgery, Odense University Hospital, Odense, Denmark.
J Cardiothorac Vasc Anesth. 2017 Aug;31(4):1166-1173. doi: 10.1053/j.jvca.2016.11.001. Epub 2016 Nov 2.
This study investigated whether the lactate-to-pyruvate (LP) ratio obtained by microdialysis (MD) of the cerebral venous outflow reflected a derangement of global cerebral energy state during cardiopulmonary bypass (CPB).
Interventional, prospective, randomized study.
Single-center, university teaching hospital.
The study included 10 patients undergoing primary, elective coronary artery bypass grafting.
Patients were randomized blindly to low mean arterial pressure (MAP) (40-60 mmHg; n = 5) or high MAP (60-80 mmHg; n = 5) during CPB. The MD catheters were positioned in a retrograde direction into the jugular bulb, and a reference catheter was inserted into the brachial artery. The correlations among LP ratio, MAP, data obtained from bifrontal near-infrared spectroscopy (NIRS), and postoperative neurologic outcome measures were assessed.
The correlated difference between pooled LP ratio (low and high MAP) of the jugular venous and the arterial blood was significant (LP 17 [15-20] v LP 26 [23-27]; p = 0.0001). No cerebral desaturations (decrease in rSO>20% from baseline) were observed in either group during CPB. In each group, 50% of the patients showed significant cognitive decline (mini-mental state examination, 3 points) 2 days after surgery.
The LP ratio of cerebral venous blood increased significantly during CPB, indicating compromised cerebral oxidative metabolism. Conventional monitoring of rSO by NIRS did not show a corresponding decrease in cerebral oxygenation. As the patients exhibited decreased cognitive functions after CPB, increases in jugular venous LP ratio may be a sensitive indicator of impending cerebral damage.
本研究调查通过脑静脉流出物的微透析（MD）获得的乳酸与丙酮酸（LP）比值是否反映了体外循环（CPB）期间全脑能量状态的紊乱。
干预性、前瞻性、随机研究。
单中心大学教学医院。
该研究纳入了10例行初次择期冠状动脉搭桥术的患者。
患者在CPB期间被随机分为低平均动脉压（MAP）组（40 - 60 mmHg；n = 5）或高MAP组（60 - 80 mmHg；n = 5）。MD导管逆行置于颈静脉球内，同时将一根参考导管插入肱动脉。评估LP比值、MAP、双额叶近红外光谱（NIRS）获得的数据与术后神经学结果指标之间的相关性。
颈静脉血与动脉血的合并LP比值（低MAP和高MAP）之间的相关差异具有显著性（LP 17 [15 - 20] 对比 LP 26 [23 - 27]；p = 0.0001）。CPB期间两组均未观察到脑去饱和（rSO₂较基线下降>20%）。每组中，50%的患者在术后2天出现显著的认知功能下降（简易精神状态检查，下降3分）。
CPB期间脑静脉血的LP比值显著升高，表明脑氧化代谢受损。通过NIRS对rSO₂的常规监测未显示脑氧合有相应下降。由于患者在CPB后出现认知功能下降，颈静脉LP比值升高可能是即将发生脑损伤的敏感指标。
