Effects Of Goal-directed Fluid Therapy On Systemic Perfusion,Cerebral Metabolism And Post-operative Rehabilitation In Patients Undergoing Meningioma Resection

ObjectivePatients with intracranial tumors are often accompanied by intracranial hypertension, local brain tissue hypoxia, edema and necrosis. Hypovolume or hypotension is prone to happen according to the long operation time, bleeding, prolonged fasting and dehydration. All of these can cause or worsen hypoxic-ischemic brain injury, imbalances of brain tissue oxygen supply and demand and barriers to energy metabolism. Appropriate fluid treatment can stabilize hemodynamic and maintain the cerebral perfusion pressure, which plays a great role in postoperative recovery by reducing the mortality and morbidity. There are still some conflicts on perioperative fluid management. We hope to mitigate and prevent cerebral edema by limiting the fluid volume, but which inversely may cause hypovolemia and instability hemodynamic. Recent years, the key of fluid management is not only to maintain the normal blood pressure, but also to cure the primary pathophysiological change at the same time. Goal-directed fluid therapy (GDFT) strategy has evolved to be the dominant trend for perioperative fluid management, which is treated according to the patient’s gender, age, weight, type of disease, preoperative systemic conditions. In a word, GDFT is to carry out individualized rehydration solutions by effective monitoring. First, GDFT can sustain the capacity of circulation. Second, it can protect the perioperative gastrointestinal function. Third, it can revise hemodynamic abnormalities and improve systemic tissue hypoxia.Implementation of GDFT depends on the monitoring methods and reliability guiding indicators. Intrathoracic blood volume (ITBV) can better describe the effective circulating blood volume and has been shown a good correlation with cardiac index (CI). At the same time, central venous oxygen saturation measurtment (ScvO2) is simple and clinically accessible as a surrogate for mixed venous oxygen saturation measurement (SvO2). ScvO2can be used for early detection of hypoxic-ischemic brain tissue, including the cerebral circulation, oxygen supply and demand balance.The value is related to cardiac output (CO), hemoglobin content, arterial oxygen pressure (PaO2), and arterial oxygen saturation (SaO2). And it can dynamically and accurately reflect the effective blood volume and CO. As a specific product of anaerobic glycolysis, blood lactate can reflect the status of tissue oxygenation metabolism, and can assess theseverity and prognosis of the disease. Combined with cycle indicators and microcirculation indicators is expected to be more comprehensive to assess the impact of GDFT on systemic perfusion and oxygen metabolism.In this study, we compared the effects of different fluid managements on perioperative systemic perfusion, cerebral metabolism and postoperative rehabilitation. We chose ITBV as a basic volume indicator to guide fluid management with PiCCO system, and considering the ScvO2and blood lactate as the secondary indicators as well. We also assessed the recovery indicators postoperative in those patients. All of these are confirmed to guide a better strategy for the basis of GDFT.Material and Method MaterialThe study was endorsed by the Hospital Medical Ethics Committee approved, and signed informed consent before surgery. We chose28patients with meningiomas who were undergoing meningioma resection in supine position. The age was arranged from18to60years, ASA I or II degree. The patients had no organs dysfunction, and the blood clotting was normal. And the hemoglobin (Hb) should more than100g·L-1, with hematocrit (Hct) not less than30%. The Glasgow scores were15points. Twenty-eight patients were randomly divided into routine fluid replacement group (group C, n=13) and GDFT group (group G, n=15).Anesthesia MethodRoutine monitorings were taken when patients entered the operation room. Pre-anesthesia drugs were carried out30mins before the induction. Drugs included antichloneride (0.01mg·kg-1), midazolume (0.04mg·kg-1) and Innovar (0.04ml·kg-1) were used to comfort the patients. A central venous catheter (Certofix(?)7F) was inserted into the right internal jugular vein under local anesthesia. A thermodilution femoral artery catherter (Pulsion Medical Systems, Germany) was inserted into the femoral artery under local anesthesia in the sedative patients. This catheter was connected to a PiCCO system (Pulsion Medical Systems, Germany) to monitor CI, intrathoracic blood volume index (ITBI), extravascular lung water index (ELWI) and pulmonary vascular permeability index (PVPI). Anesthesia was induced by TCI with a target of propofol3～3.5μug·ml-1and remifentanil2～4ng·ml-1and cisatracuronium0.15mg·kg-1. Anesthesia maintenance was achieved by TCI with a target of propofol2.5～3.5μg·ml-1and remifentanil2～4ng·ml-1and cisatracuronium0.05mg·kg-1·h-1. PETCO2was maintained from30to33mmHg. Narcotrend was maintained E0to E1the anesthesia.Monitoring1. Observation interavals:before induction of anesthesia (T1, baseline), intubation (T2), open dura instantly (T3),1hour after open the dura(T4), at the closure of dura (T5), the end of operation (T6),12hours after operation (T7) and24hours after operation (T8).2. Circulation blood volume parameters:to monitor CI, ITBI, ELWI and PVPI at all intervals with PiCCO plus system.3. Tissue perfusion indicators:blood samples were taken from artery and central venous for blood gas analysis. ScvO2and central venous-to-arterial carbon dioxide tension difference (Pcv-aCO2) were observed at all intervals.4. Cerebral metabolism indicators:blood samples were taken from artery and jugular venous bulb for blood gas analysis. We abserved saturation of internal jugular venous bulb blood oxygen (SjvO2), saturation of artery blood oxygen (SaO2), PaO2, internal jugular venous bulb blood tension (PJvO2), content of artery blood oxygen (CaO2), content of internal jugular venous bulb blood oxygen (CjvO2), content of artery-internal differences in oxygen (Ca-jvO2), cerebral extraction ratio oxygen (CERO2), jugular bulb lactate (jvLac), arterial blood lactate (aLac), the difference in arterial and jugular bulb blood lactate (jv-aLac) and cerebral lactate acid production rate (LacPR).5. Rehabilitation indicators:We abserved length of stay in intensive care unit (ICU), length of stay in hospital, the Fourth National Cerebrovascular Disease Academic Council righteous by patients with cerebral infarction clinical neurological function deficit scores standard at the time of postoperative12hours and24hours, Karnofsky’s performance status (KPS) score at the time of pre-operation and discharge.Method of GDFTMean artery pressure (MAP), hemoglobin (Hb) and hematocrit (Hct) should be maintain in normal values in both groups. Succinylated gelatin injection was infused till the end of the surgery as a background at a speed of5ml·kg-1·h-1. The fluid replacement regime in group C included five parts, they were physiological requirements, continued loss (4-2-1rule), extra supplement amount (4ml·kg-1), compensatory volume expansion and cumulative loss. Compensatory volume expansion was replaced before induction of anesthesia at a rate of5ml·kg-1within30minutes in group G. When ITBI lower800ml·m-2,6%hydroxyethyl starch130/0.4(Voluven(?), Fresenius Kabi, Louviers, France) was infused at5ml·kg-1within15minutes as volume expansion. Otherwise, we gave furosemide0.1mg·kg-1when ITBI was more than1000ml·m-2. This rule was carried out to maintain ITBI between800～1000ml·m-2. Furosemide shouldn’t be given if the hypervolume happened again in two hours.Dopamine (3～5μg·kg-1·min-1) or aramine (0.5～1mg per time) was used to maintain MAP between60～90mmHg, based on the appropriate depth of anesthesia. Heart rate was maintained between50～100per minute. Parameters were given up when arrhythmia occurred. Blood transfusion was performed to maintain the Hct above30%, and the Hbmore than90g·L-1, ScvO2no less than70%. If ScvO2could not reach70%, dobutamine (2.5～20μg·kg-1·min-1) was used. Worming machine was used to maintain the nasopharyngeal temperature between34～36℃.Statistical AnalysisAll statistical analysis was computed by SPSS13.0software. Unless stated, dates are express as mean±standard deviations (mean±SD). Groups within the different time points were analyzed with analysis of variance for repeated measurements and two samples test with LSD. Comparisons between two groups were made by two independent samples T-test. Differences were considered significanly at P<0.05.Results1. General information of the two groupsTwo patients withdrew from the study due to intracranial hemorrhage underwent secondary surgery in each group. The remaining26patients were successfully completed the surgery. There were no serious complications perioperative. The amount of crystals, combined with the total fluid intake and output, were higher in Group C (P<0.05). 2. Changes in systemic perfusion of the two groupsThe ITBI was concentrated in the value of735～862ml·m-2. In all,63.39%of the time intervals needed fluid challenge, while8.04%needed furosemide therapy.ITBI was different at all intervals (F=7.280, P=0.000). Compared with T1, ITBI was significantly higher at other intervals (T2～T8)(P<0.05). PVPI had a fall-off tendency during the surgery (F=3.810, P=0.001). ELWI had no significant changes at all intervals (F=1.099, P=0.351).CI was different at all intervals in both groups (P<0.05). CI was higher in group G with an upward trend than in group C (P<0.05).ScvO2and Pcv-aCO2were different at all intervals in both groups (P<0.05). Compared with T1, ScvO2was significantly higher in group G at T2, T3(P<0.05). Pcv-aCO2was significantly higher in group G at T4, T6(P<0.05). There were no differences between two groups in ScvO2and Pcv-aCO2(P>0.05).3. Changes in cerebral oxygen metabolism of the two groupsCJvO2, CaO2, aLac, jvLac, jv-aDLac and LacPR were different between two groups (P<0.05). Compared with T1, CJvO2, CaO2, jv-aDLac and LacPR were significantly lower, while jvLac and aLac were higher compared in both groups (P<0.05). There were no differences between or within two groups in Ca-jvO2and CERO2(P>0.05).4. Changes in postoperative rehabilitation of the two groupsNo significant difference in length of stay was found in neither ICU nor hospital (P>0.05). Neurological functional deficit score decreased in group G than that in group C [(15.21±4.64) vs (18.00±2.63)] in24hours post-operative (P<0.05). The KPS scores at discharge were lower than those of pre-operation in both groups (P<0.05), but had no difference between groups (P>0.05).Conclusion1. GDFT guided with ITBI in the lower value (735～862ml·m-2) can not only maintain the effective circulating blood volumeand systemic perfusion, but also reduce the total fluid exchange in intraoperation meningioma resection, without effecting ScvO2and Pcv-aCO2.2. GDFT guided with ITBI in the lower value (735～862ml·m-2) cansustain cerebral oxygen supply, reduce brain lactate production rate, and improve microcirculation, without affecting the cerebral oxygen metabolism in intraoperation meningioma resection.3. GDFT guided with ITBI in the lowere value (735～862ml·m-2) can decrease neurological functional deficit score24hours post operative, without affecting KPS scores in the early period post-operative in meningioma resection.