Effect of low-dose norepinephrine combined with goal-directed fluid therapy on cerebral oxygen metabolism in patients undergoing intracranial tumor resection / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the effect of low-dose norepinephrine (NE) combined with goal-directed fluid therapy (GDFT) on cerebral oxygen metabolism in patients undergoing intracranial tumor resection.Methods Forty patients of American Society of Anesthesiologists physical status Ⅱ or Ⅲ,aged ≥ 18 yr,scheduled for elective intracranial tumor resection,were divided into 2 groups (n =20 each) using a random number table method:GDFT group (group G) and low-dose NE combined with GDFT group (group N).Fluid was replaced according to stroke volume variation (SVV) under the guidance of Flotrac-Vigileo system in both groups.When SVV ≤13％,fluid was replaced at 1-2 ml · kg-1 · h-1.When SVV＞ 13％ for more than 5 min,fluid replacement was enhanced to reduce it below 13％.In group N,NE was infused continuously via the central vein at 0.01-0.03 μg· kg-1 · min-1 after anesthesia induction,and mean arterial pressure (MAP) was maintained ≥ 65 mmHg.After anesthesia induction (T1),when the dura of brain was opened (T2),at 1 h after opening the dura (T3) and at the end of surgery (T4),the heart rate and MAP were recorded,and blood samples were collected from the internal jugular venous bulb and radial artery for blood gas analysis.The fluid input and output were recorded.Arterial oxygen content,jugular bulb venous oxygen content,arteriovenous oxygen content difference,cerebral oxygen extraction rate,cerebral lactic acid production rate and ratio of cerebral blood flowto cerebral oxygen metabolic rate were calculated.Results Compared with group G,MAP at T4 and cerebral oxygen extraction rate at T3,4 were significantly increased,the total volume of fluid and volume of crystalloid solution were decreased (P＜0.05),and no significant change wasfound in arterial oxygen content,jugular bulb venous oxygen content,arteriovenous oxygen content difference,ratio of cerebral blood flow to cerebral oxygen metabolic rate or cerebral lactic acid production rate in group N (P＞0.05).Conclusion Low-dose NE combined with GDFT can reduce the intraoperative volume of fluid infused and improve cerebral oxygen supply when applied to the patients undergoing intracranial tumor resection.