Roles of cerebral metabolic rate for oxygen in evaluating the prognosis of cerebral function after cardiopulmonary resuscitation / 中华急诊医学杂志

Objective To investigate the roles of cerebral metabolic rate for oxygen (CMRO2) monitoring in the evaluation of cerebral function after cardiopulmonary resuscitation (CPR) through transcranial doppler (TCD) and SjvO2. Methods In this prospective/retrospective analysis, we included 46 cases admitted to the general intensive care unit (GICU) of the Second Affiliated Hospital of Soochow University from January 2012 to December 2014. Upon admission, TCD and SjvO2 were performed,and the patients' characteristics were recorded. Based on the CPC score upon GICU discharge, the patients were divided into two groups with satisfactory cerebral function and poor cerebral function, respectively. Then the clinical symptoms, cerebral blood flow (CBF), a-vDO2, SjvO2 and CMRO2 were analyzed, followed by investigating their correlation with the prognosis of cerebral function. The measurement data that were normally distributed were presented by mean ± standard deviation. Student's t test was utilized for the inter-group comparison. Correlation analysis was performed. ROC was plotted, followed by evaluating roles of each index in the specificity and sensitivity of nervous prognosis. Results No statistical differences were noted in the gender, age, initial monitoring indicators, ICU duration and initial GCS between the two groups (P>0.05). The CA-ROSC time and APACHE II score in the satisfactory cerebral function group were significantly shorter than those of the poor cerebral function group (P<0.05). The SjvO2 in the satisfactory cerebral function group was significantly lower than that of the poor function group (67.33±10.30 vs. 76.89±13.08, t=-3.579, P<0.05). The Vs and Vd as revealed by TCD in the satisfactory function group were higher than those of the poor function group, together with the CBF. Significant decrease was noted in the PI and RI in the satisfactory function group compared with that of the poor function group (P<0.05). Besides, the CMRO2 and a-vDO2 in the satisfactory function group showed significant increase compared with those of the poor function group (P<0.05). ROC indicated that CMRO2, CBF, a-vDO2 and SjvO2 could be utilized for the evaluation of cerebral function, among which CMRO2 showed the highest accuracy for the cerebral function prognosis. Conclusions CMRO2, CBF, a-vDO2 and SjvO2 were associated with cerebral function prognosis. CMRO2 was the most appropriate parameter to evaluate the oxygen metabolism in brain tissues, which could evaluate the prognosis of cerebral function.

Vasopressin ameliorates hypotension induced by beach chair positioning in a dose-dependent manner in patients undergoing arthroscopic shoulder surgery under general anesthesia / 대한마취과학회지

BACKGROUND: The beach chair position (BCP) is associated with hypotension that may lead to cerebral ischemia. Arginine vasopressin (AVP), a potent vasoconstrictor, has been shown to prevent hypotension in BCP. It also improves cerebral oxygenation in different animal models. The present study examined the effect of escalating doses of AVP on systemic hemodynamics and cerebral oxygenation during surgery in BCP under general anesthesia. METHODS: Sixty patients undergoing arthroscopic shoulder surgery in BCP under general anesthesia were randomly allocated to receive either saline (control, n = 15) or three different doses of AVP (0.025, 0.05, or 0.075 U/kg; n = 15 each) 2 minutes before BCP. Mean arterial pressure (MAP), heart rate (HR), regional cerebral oxygen saturation (SctO2), and jugular venous oxygen saturation (SjvO2) were measured after induction of anesthesia and before (presitting in supine position) and after BCP. RESULTS: AVP per se given before BCP increased MAP, and decreased SjvO2, SctO2, and HR in all patients (P 20% SctO2 decrease from the baseline value) with no differences in SjvO2 and the incidence of SjvO2 < 50% or SjvO2 < 40% among the groups. CONCLUSIONS: AVP ameliorates hypotension associated with BCP in a dose-dependent manner in patients undergoing shoulder surgery under general anesthesia. However, AVP may have negative effects on SctO2 before and after BCP and on SjvO2 before BCP.

The impact of lung-protective mechanical ventilation on cerebral perfusion pressure and cerebral oxygen metabolism in patients with severe cerebral injury combined with respiratory failure / 中华急诊医学杂志

Objective To explore the impact of lung-protective mechanical ventilation (low tidal volume and optimal positive end-expiratory pressure (PEEP) on cerebral perfusion pressure (CPP) and cerebral oxygen metabolism.Methods Forty patients with severe cerebral injury along with respiratory failure were randomly assigned into two groups:lung-protective ventilation group A and conventional ventilation group B.Group A was planned to prescribe tidal volume 6 ～ 8 mL/kg,initial FiO240％,PEEP gradually increasing from 2 cmH2O to matched with FiO2 elevation,but the FiO2 was kept at permissive lower level.Group B was formulated with tidal volume 8 ～ 12 mL/kg,PEEP stepwise increasing from 0 2 cmH2O to match with FiO2 elevation,but PEEP was kept at permissive lower pressure.The intracranial pressure (ICP),mean arterial pressure (MAP),CPP,arterial and jugular venous blood gas were monitored.Results PEEP (8.2±3.32 cmH2O),ICP (19.7 ±3.6 mmHg),PaCO2 (54±7.3 mmHg),jugular venous carbon dioxide partial pressure (PjV CO2,56.7 ± 9.6 mmHg) in group A were higher than those (5.7±2.3 cmH2O,16.9±3.8 mmHg,41 ±5.2 mmHg,49.8 ±6.9 mmHg) in group B (P＜ 0.05 or P ＜ 0.01).VT,FiO2 in the group A were lower than those in the group B.There were no differences in PaO2/FiO2,jugular venous oxygen saturation (SjVO2),MAP,and CPP between two groups.PaCO2 were significantly correlated with CPP (r =0.368,P =0.019) while there was no correlation with ICP,PaO2,SjVO2,PjVCO2 (all P ＞0.05).CPP (69.7 ± 12.3 mmHg) was higher in case of PaCO2 (46 ～60mmHg) than those (61.5 ±9.1 mmHg) in case of PaCO2 (35 ～45 mmHg).There was correlation between PEEP and ICP (r =0.436,P =0.005).When PEEP was divided into three groups:≤52 cmH2O,6 ～ 102 cmH2O and ＞ 102 cmH2O,ICPs were different one another among three groups.When PEEP ＞ 102 cmH2O,it had a distinguished negative correlation with CPP (r =-0.395,P =0.017),while PEEP ≤ 102 cmH2O,CPP presented decreasing tendency.SjVO2 correlated with PaO2 (r =0.403,P =0.014) and PjVCO2 (r =-0.502,P =0.001) respectively.There were no significant relationships between SjVO2 and CPP,ICP,MAP,PEEP,respectively.Conclusions Lung-protective mechanical ventilation was relatively safer in patients with severe cerebral injury compared with conventional mechanical ventilation.Mild PaCO2 elevation (46 ～ 60 mmHg) combined with higher PEEP (＜ 102 cmH2O) did not decrease CPP.There was no difference in SjVO2 between the two modes of mechanical ventilation,suggesting no changes in cerebral metabolism occurred.

Changes in Jugular Venous Oxygen Saturation during Liver Transplantation / 대한마취과학회지

BACKGROUND: Marked changes in systemic hemodynamics during liver transplantation may lead to changes in cerebral hemodynamics and metabolism. Therefore, continuous monitoring of the jugular venous oxygen saturation (SjvO2) may help the anesthetic management of liver transplantation. METHODS: We observed changes in SjvO2 using a double lumen oximetry catheter for continuous monitoring and analyzed the correlation between SjvO2 and hemodynamic measurements in thirty patients undergoing liver transplantation. RESULTS: There were no significant changes in SjvO2 compared to initial SjvO2 during liver transplantation. SjvO2, however, increased from 72.5 to 79.6 % (P < 0.05), before and after reperfusion. There was a weak correlation between changes in SjvO2 and cardiac output (r = 0.38, P < 0.05), whereas no correlation was found among changes in SjvO2 and arterial carbon dioxide tension, mean arterial pressure, central venous pressure, or mixed venous oxygen saturation before and after reperfusion. CONCLUSIONS: SjvO2 that reflects changes in cerebral oxygen demand-supply balance was well maintained during liver transplantation except the reperfusion period. Continuous monitoring of changes in SjvO2 at this period may provide further insight to understand physiology of cerebral oxygenation during liver transplantation and merits further studies.

Effect of Combined Hyperventilation and Mannitol on Cerebral Blood Flow and Cerebral O2 Metabolism during a Craniectomy / 대한마취과학회지

BACKGROUND: There are therapies to lower intracranial pressure (ICP) including head elevation, hyperventilation, diuretics injection, intravenous mannitol, hypothermia, cerebrospinal fluid drainage, and cerebral resection in neurosurgical patients. However in recent reports, hyperventilation followed by mannitol administration may lead to cerebral ischemia. Therefore, we investigated the effect of 0.5-1.0 g/kg mannitol administration on jugular venous oxygen saturation (SjVO2) and cerebral arterial- jugular venous oxygen content difference (AVDO2) at PaCO2 25-30 mmHg and 35-40 mmHg in patients undergoing neurosurgery. METHODS: We studied 17 patients undergoing neurosurgery in the Ajou University Hospital. Anesthesia was induced with fentanyl, midazolam, thiopental, and vecuronium, and maintained with O2-Air-Isoflorane, a continuous infusion of fentanyl, and vecuronium. Patients were divided into two groups. Group 1 (n = 10) which is PaCO2 25-30 mmHg and Group 2 (n = 7) which is PaCO2 35-40 mmHg by controlling ventilator. Measurements of SjVO2 and AVDO2 in following time intervals: I = preinjection of mannitol, II = postinjection 20 minutes of mannitol, III = postinjection 40 minutes of mannitol were obtained for each group. 0.5-1.0 g/kg mannitol was administered intravenously just at duramater opening. RESULTS: Hemodynamics and hematologics were not significantly different among the two groups. SjVO2 of each group are as follows; Group 1; I (70.3+/-8.1%), II (66.3+/-6.9%), III (69.1+/-7.9%) and Group 2; I (78.6+/-7.4%), II (75.1+/-8.1%), III (76.0+/-11.2%). Hyperventilation significantly decreased SjVO2. AVDO2 was not significantly different but SjVO2 in II was significantly decreased compared with I and III in Group 1 (20% patients). CONCLUSIONS: Mannitol produced a change of SjVO2 and AVDO2 during hyperventilation. Therefore, intravenous mannitol during hyperventilation should be given cautiously according to the patients status because it may cause cerebral ischemia in critical patients.

Anesthesia for Liver Transplantation in Patients with Fulminant Hepatic Failure under Intracranial Pressure and Jugular Venous Oxygen Saturation Monitoring / 대한마취과학회지

BACKGROUND: Fulminant hepatic failure is characterized by rapid progressive liver failure with the onset of encephalopathy within a few weeks of the appearance of jaundice. This illness is frequently complicated by hemodynamic instability, multiple organ dysfunction and intracranial hypertension associated with cerebral edema, which is the most common cause of death in this condition. We reviewed 8 cases of liver transplantation with fulminant hepatic failure with respect to anesthetic management and neurologic monitoring. METHODS: We analyzed anesthetic management, intracranial pressure (ICP), cerebral perfusion pressure (CPP), jugular venous oxygen saturation (SjvO2) and hemodynamics retrospectively during liver transplantation in 8 patients with fulminant hepatic failure. Intracranial hypertension was defined as an ICP >or= 20 mmHg for at least 5 minutes. The goal of management is to keep the CPP above 40 - 50 mmHg and ICP below 30 - 40 mmHg. There were 3 cases of hepatorenal syndrome and continous veno-venous hemodiafiltration (CVVHD) was used in 2 cases. RESULTS: All patients showed characteristic hyperdynamic circulation with severe vasodilation and vasopressive drugs were needed to maintain CPP. The episodes of intracranial hypertension occurred in all patients during transplantation. To decrease ICP, medical therapy with mannitol, furosemide and thiopental infusion were required. Intracranial hemorrhagic complications occurred in 3 cases. SjvO2 decreased transiently below 60% in 3 cases. However, it was improved with an increase of PaCO2 by hypoventilation and maintained above 60 - 80% in all cases. CONCLUSIONS: This data suggests that there is a risk of brain injury secondary to elevated ICP and low CPP during liver transplantation. ICP, CPP and SjvO2 monitoring in patients with fulminant hepatic failure can be useful for the prompt recognition of intracranial hypertension and for guiding therapy. However, correction of the coagulopathy before placement of the ICP tranducer must be performed to prevent hemorragic complications.

Jugular Bulb Venous Oxygen Saturation Monitoring in Brain Surgery / 대한마취과학회지

BACKGROUND: During intracranial brain surgery, numerous factors may alter cerebral blood flow and the oxygen supply-demend balance. Continuous monitoring of the jugular bulb venous oxygen saturation (SjvO2) may help in the anesthetic management of such procedures. METHODS: Fiberoptic SjvO2 was continuously monitored and recorded 1, 3 and 5 min after the skin incision, skull bone craniotomy, dura open and dura closure in 20 patients. RESULTS: The SjvO2 was increased after the skin (scalp) incision at 1, 3 and 5 minutes and also after endotracheal suctioning for removal of secretions. CONCLUSIONS: Although the accuracy of Fibroptic SjvO2 determination is limited, it allows the detection of cerebral blood flow and oxygen supply-demend imbalance during brain surgery. The frequent occurance of SjvO2 elevations is suggestive of reactive hyperemia mechaniams.

The Effects of Intravenous Thiopental Injection on Jugular Venous Oxygen Saturation (SjVO2) during Cerebral Aneurysm Surgery / 대한마취과학회지

BACKGROUND: Thiopental has a profound impact on the cardiovascular system. The effects of hemody namics after intravenous thiopental on the balance of cerebral metabolism with cerebral blood flow is unknown. The purpose of this study was to monitor hemodynamic change, cerebral arterial-jugular venous oxygen content difference (AVDO2) and jugular venous oxygen saturation (SjVO2) after a thiopental injection for brain protection during cerebral aneurysm surgery. METHODS: Twenty patients received a standard anesthetic consisting of isoflurane, vecuronium and fentanyl with a PaCO2 of 30 35 mmHg. Hemodynamics, arterial and jugular venous blood gases were measured at 3 time points:I; Just before thiopental injection; II; Electroencephalographic (EEG) burst suppression after a 4 5 mg/kg intravenous thiopental injection; and III; EEG recovery. RESULTS: Intravenous thiopental (4 5 mg/kg) induced an EEG burst suppression for 6.5 +/- 1.7 minutes. Hemodynamics and arterial blood gas analysis were not significantly different among the different time points, but mean arterial pressure (68.4 +/- 7.2 mmHg) and systemic vascular resistance (1027.0 +/- 300.9 dynes sec/cm5) in II were significantly (P < 0.05) decreased compared with I (84.3 +/- 9.6, 1169.1 +/- 304.5) and III (89.1 +/- 10.6, 1288.6 +/- 426.1). SjVO2 (71.6 +/- 11.8%) was significantly (p < 0.05) decreased within the normal value compared with I (75.1 +/- 5.6) and III (76.1 +/- 10.1), but AVDO2 was not significantly different among the 3 time points. There was no evidence of cerebral ischemia or infarction in computed tomographic (CT) findings of the 20 patients after surgery. CONCLUSIONS: Hemodynamics after 4 5 mg/kg intravenous thiopental do not modify the balance ofcerebral oxygen metabolism with cerebral blood flow in patients undergoing cerebral aneurysm surgery.

Continuous Monitoring of Jugular Venous Oxygen Saturation in Severe Head-injured Patients

The continuous measurement of jugular venous oxygen saturation(SjvO2) with a fibroptic catheter is evaluated as a method of detecting cerebral ischemia after head injury. Fifty patients admitted to the hospital who were unconscious after severe head injuries had continuous and simultaneous monitoring of SjvO2, intracranial pressure, arterial oxygen saturation, arterial blood pressure. Whenever SjvO2 dropped to less than 50%, a standardized protocol was followed to confirm the validity of the desaturation and to elucidate its cause. A total of 72 episodes of jugular venous oxygen desaturation occurred in 45 patients, possibly due to intracranial hypertension in 39 episodes, arterial hypoxia in 13, combinations of the above in 9, systemic hypotension in 7, and anemia in 4. Two episodes of hyp-eremia, SjvO2 more than 90%, occurred in 2 patients with carotid-cavernous fistula. The incidence of jugular venous oxygen desaturation found in this study suggests that continuous monitoring of SjvO2 may be of clinical value in patients with head injury.