Evidence Based Communications Research Articles

Approach to Risk Management of Perioperative Stroke

Aim of review: Perioperative stroke is a rare, but potentially devastating complication. This review is performed to draw attention of perioperative care providers to this complication and improve their understanding on the risk factors for perioperative stroke so that better management of patients with risk factors can be achieved.Method: Literature was searched and reviewed to identify articles on risk factors of perioperative stroke and management of these risk factors. Recent findings: Stroke rates are as high as 6% after cardiac, neurosurgical, and vascular surgery, and are lower (<1%) after general surgery. Perioperative stroke is mostly ischemic. Risk factors that are not modifiable include increasing age and female gender. Morbidities that increase the risk for perioperative stroke include renal failure, history of stroke or transient ischemic attack, diabetes mellitus, atrial fibrillation, congestive heart failure, smoking status, emergency surgery, carotid stenosis, and valvular cardiac disease. Modifiable factors for perioperative stroke during perioperative period include judicious use of antithrombotic therapy and beta-blockers, avoidance of hypotension and maintenance of normal blood glucose levels. Summary: Many risk factors for perioperative stroke have been revealed. Careful management of the modifiable risk factors may reduce the occurrence of perioperative stroke. Citation: Sunny S. Chiao, Zhi-Yi Zuo. Approach to risk management of perioperative stroke. J Anesth Perioper Med 2015; 2: 268-76. doi: 10.24015/JAPM.2015.0036This is an open-access article, published by Evidence Based Communications (EBC). This work is licensed under the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium or format for any lawful purpose. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

The Protective Effects of Myocardial Ischemic Postconditioning on Cardiac Surgry: A Systematic Review and Meta-Analysis of Rats and Clinical Trials

Background: Ischemic postconditioning (IPC) is a potent protective strategy implemented in animal myocardial ischemic-reperfusion (IR) models, while it has not yet been translated universally into clinical practice. We performed a unique systematic review and meta-analysis of animal and clinical studies respectively, to assess the protective effects of myocardial IPC and provide a new perspective for clinical practice.Methods: PubMed and Web of Science were searched for relevant researches. Trials met our inclusion criteria were selected and reviewed, and the meta-analyses were performed via Review Manager.Results: 44 trials were included in the meta-analysis. In animal studies, IPC demonstrated a decrease in size of myocardial infarction (standardized mean difference [SMD] -3.21, 95% confidence interval [CI] -3.89 to -2.52, P<0.00001), however, subgroup analysis showed that the protective effects of IPC disappeared in diabetic rats and hyperlipidemia rats (SMD -0.10, 95% CI -1.32 to 1.12, P=0.05; SMD -2.02, 95% CI -4.29 to 0.26, P=0.08, respectively). IPC reduced apoptosis index significantly (SMD -2.56, 95% CI -3.56 to -1.55, P<0.00001), while subgroup analysis indicted that IPC had no effect on decrease in level of myocardium apoptosis in hyperlipidemia rats (SMD -0.31, 95% CI -1.13 to 0.50, P=0.46). In clinical trials, no differences were noted in mortality between IPC and IR patients (SMD 0.44, 95% CI 0.07 to 2.85, P=0.41). IPC decreased the level of cardiac troponin I (cTnI) (SMD -1.74, 95% CI -2.71 to -0.78, P=0.0004), reduced the inotrope score (SMD -2.31, 95% CI -2.85 to -1.76, P<0.00001), shortened the time of ventilation and intensive care unit (ICU) stay (SMD -0.57, 95% CI -0.87 to -0.26, P=0.0002; SMD -0.57, 95% CI -0.84 to -0.30, P<0.0001, respectively).Conclusions: Myocardial IPC provided efficient protective effects for healthy rats rather than diabetic or hyperlipidemia rats. In clinical trials, IPC appeared to be beneficial to cardiac function and cardiac surgery prognosis, but had no effect on postoperative cardiac death. Citation: Bin Zhou, Zhong-Yuan Xia, Ming Guo. The protective effects of myocardial ischemic postconditioning on cardiac surgry: a systematic review and meta-analysis of rats and clinical trials. J Anesth Perioper Med 2015; 2: 256-67. doi: 10.24015/JAPM.2015.0035This is an open-access article, published by Evidence Based Communications (EBC). This work is licensed under the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium or format for any lawful purpose. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

The Synergism of Dexmedetomidine and Ketamine

Background: The study was designed to investigate the anesthetic effect of the combination of dexmedetomidine (Dex) and ketamine (Ket). Methods: Hot-plate test, acetic acid-induced writhing test, righting reflex test, acquisition test, JY-2410 digital brain atlas instrument, RM6240 multi-channel physiological signal acquisition and processing system and sequential method were used to observe the combination of Dex and Ket on the analgesia, hypnosis, anterograde amnesia, δ-band power percentage of quantitative pharmaco-electroencephalogram (QPEEG), heart rate (HR), mean arterial pressure (MAP), respiratory rate (RR) and 50% lethal dose (LD50) values respectively. Atipamezole (Ati) was used to analyse whether α2-adrenergic receptor could mediate the effect of combination of Ket and Dex.Results: Compared with single group, the pain threshold of mice was markedly increased in hot-plate test (P 0.05).Conclusions: The combination of Dex and Ket had a synergistic effect of anesthesia which was mediated by α2-adrenergic receptor. Dex can stabilize fluctuations of MAP and HR as well as possibly decreasing the toxicity of Ket. Citation: Su-Pei Song, Hong Wang, Hui-Ming Cai, Pan Li, Ti-Jun Dai. The synergism of dexmedetomidine and ketamine. J Anesth Perioper Med 2015; 2: 183-91. doi: 10.24015/JAPM.2015.0025This is an open-access article, published by Evidence Based Communications (EBC). This work is licensed under the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium or format for any lawful purpose. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Utility of Transesophageal Echocardiography in Valvular Heart Surgery

A comprehensive examination for the valvular lesions before CPB, a timely assessment of the repaired or replaced valves after surgery, and an effective monitoring of cardiac function provided by TEE can improve the outcome in patients undergoing cardiac surgery. Citation: Ling Peng, Wei Wei. Utility of transesophageal echocardiography in valvular heart surgery. J Anesth Perioper Med 2015; 2: 226-9. doi: 10.24015/JAPM.2015.0030This is an open-access article, published by Evidence Based Communications (EBC). This work is licensed under the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium or format for any lawful purpose. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Up-Regulating MEF2D Alleviates Hypoxia-Induced Injury in Cultured Rat Cortical Neurons

Background: Stroke is a severe disease and the associated molecular mechanisms for its pathogenesis have not been fully understood. Myocyte enhancer factor 2 (MEF2) is a family of transcription factors that promote the expression of more than 100 proteins responsible for development and surviving of neurons in central nervous system. Recently, it is reported in animal studies that MEF2D dysfunction plays an important role in neurodegenerative diseases. However, the role of MEF2D in stroke is unknown. The objective of the present study was to provide data for changes and role of MEF2 following hypoxic neuronal injury. Methods: The hypoxic injury was induced by oxygen-glucose deprivation (OGD) in primary cultured rat cortical neurons. The levels and activity of MEF2D mRNA and protein were measured by real-time reverse transcription polymerase chain reaction (RT-PCR) and western blot. Additionally, MEF2D overexpression by lentivirus was used to up-regulate the level of MEF2D. The effect of MEF2D up-regulation on neuron hypoxic tolerance was evaluated by assaying of cell viability and extracellular lactate dehydrogenase (LDH) release as well as cell apoptosis analysis.Results: Compared with control group, the level of MEF2D protein and the activity of MEF2D were decreased after OGD challenge. Up-regulating the level of MEF2D could increase the cell viability, decrease the LDH release and inhibit the activation of apoptotic protein caspase-3.Conclusion: MEF2D is involved in the pathophysiological process of hypoxic injury in rat primary cortical neurons. Up-regulation of MEF2D could alleviate the hypoxia-induced injury and increase neuronal tolerance against hypoxia. Citation: Li-Kai Shi, Min Cai, Zhi-Xin Wu, Si-Si Sun, Zong-Ping Fang, Ting Gu, et al. Up-regulating MEF2D alleviates hypoxia-induced injury in cultured rat cortical neurons. J Anesth Perioper Med 2015; 2: 175-82. doi: 10.24015/JAPM.2015.0024This is an open-access article, published by Evidence Based Communications (EBC). This work is licensed under the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium or format for any lawful purpose. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Transversus Abdominis Plane Block to Alleviate Postoperative Pain in Children: A Meta-Analysis of Randomized Controlled Trials

Background: Transversus abdominis plane (TAP) block has been applied as one of multimodal approaches to alleviate postoperative pain in children. The aim of this meta-analysis was to determine the effect of TAP block on postoperative pain management for children who underwent surgery. Methods: The randomized controlled trials (RCTs) which evaluated the analgesia effect of TAP block in children who underwent surgery were searched on the databases of Medline, Embase, the Cochrane Controlled Trials Register and Google Scholar. The RCTs which compared the analgesic effect of TAP block group with control group (placebo or no treatment) in children were included. Postoperative opioid consumption (48 hours) was considered as the primary outcomes. The secondary outcomes included the number of children needed postoperative opioid analgesia rescue, the time to first analgesic administration (hours) and pain score. The risk ratios (RR), weighted mean differences (WMDs), and their corresponding 95% confidence intervals (95% CIs) were calculated for both dichotomous and continuous outcomes.Results: Five RCT trials with 257 children met our criteria and were included in the analysis. Compared with the control group, TAP block reduced the 48 hours morphine consumption by 0.03 mg/kg (95% CI -0.05 to -0.00, P=0.03, 159 children in 3 RCTs). Besides, the non-significant reductions were shown in the number of children needed postoperative opioid analgesia rescue (217 children in 4 RCTs) and time to first analgesic administration (hours, 184 children in 3 RCTs). Conclusions: TAP block is one of the safe and effective multimodal-approaches to alleviate postoperative pain in children. Specially, when the TAP block was used, it can significantly reduce the opioid consumption, which may avoid the occurrence of dose-dependent side effects of opioid drugs. Citation: Xiang Li, Xiao-Yun Li, Ji-Bin Xing, Ping Xiang, Zi-Qing Hei. Transversus abdominis plane block to alleviate postoperative pain in children: a meta-analysis of randomized controlled trials. J Anesth Perioper Med 2015; 2: 197-204. doi: 10.24015/JAPM.2015.0027This is an open-access article, published by Evidence Based Communications (EBC). This work is licensed under the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium or format for any lawful purpose. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

The Genetics of Pain: Implications for Perioperative Pain Management

Aim of review: Postoperative pain is one of the most common symptoms in surgical patients. Although numerous measures, such as patient-controlled analgesia and multimodal analgesia, have been developed, postoperative pain treatment is not yet adequate. Human genome analysis allows us to investigate interindividual differences in pain thresholds and pain perception at the genetic level. This article aimed to review important and illustrative results from recent pain genetic studies in this field and to interpret their clinical implications for perioperative pain management.Method: Literatures were searched via PubMed with the key words of genetics of pain, perioperative pain, cytochrome P450 (CYP450), mu-opioid receptor (MOR)-1, catecholamine-O-methyltransferase (COMT), guanosine triphosphate (GTP) cyclohydrolase 1 (GCH1), interleukin (IL)-1B, SCN9A, CACNG2, transient receptor potential vanilloid-1 (TRPV1) and TRP ankyrin-1 (TRPA1). A few review articles in the relevant fields were also referenced.Recent findings: There is a growing body of compelling evidence indicating that interindividual differences in pain sensitivity and the predisposition to chronic pain are genetically determined. During the past decade, numerous pain-related genes and their functional polymorphisms have been identified, including CYP450, MOR-1, COMT, GCH1, etc. These functional gene polymorphisms are valuable to perioperative pain management.Summary: The identification of genetic markers relevant to perioperative pain management may help to predict pain susceptibility, severity, and treatment response in surgical patients. As the foundation for interindividual variability in the experience of postoperative pain, genetic variability will aid anesthesiologists to develop the personalized perioperative pain management strategy. Citation: Meng-Meng Bao, Fang Xie, Xue-Yang Li, Yun Yue, Yun Guan, Yun Wang. The genetics of pain: implications for perioperative pain management. J Anesth Perioper Med 2015; 2: 205-15. doi: 10.24015/JAPM.2015.0028This is an open-access article, published by Evidence Based Communications (EBC). This work is licensed under the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium or format for any lawful purpose. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Pre-Induction Dexamethasone Does Not Decrease Complications after Microvascular Decompression for Facial Spasm

Background: Postoperative pain, sore throat, hoarseness, early facial paralysis and pyrexia are common complications after microvascular decompression (MVD) for facial spasm. Dexamethasone (Dex) is used extensively in the perioperative setting as it is a high-potency, long-acting glucocorticoid with little mineralocorticoid effects. It may improve analgesia and decrease opioid consumption, significantly decrease the incidence and severity of sore throat and hoarseness after general anesthesia, and antagonize the inflammatory reaction in the postoperative period. We designed this study to determine the effects of Dex on these complications.Methods: A total of 1020 adult patients with hemifacial spasm who were scheduled to receive MVD, were randomly divided into three groups: Dex-0 (N=340), Dex-1 (N=340) and Dex-2 (N=340), respectively, and were administered normal sodium, Dex 0.1 mg/kg or 0.2 mg/kg before induction of anesthesia. Incision pain, sore throat and hoarseness, early facial paralysis, and pyrexia were evaluated. Postoperative incision pain was recorded during the first and second day after surgery; sore throat and hoarseness, early facial paralysis, and pyrexia were recorded from the day after surgery and until the end of the fifth day after surgery.Results: One thousand and fifteen patients completed this clinical trail. Within the 3 groups: Dex-0 group (N=337), Dex-1 group (N=339) and Dex-2 group (N=339), we found no significant differences concerning postoperative incision pain, sore throat, hoarse, early facial paralysis and the intensity of pyrexia (P>0.05).Conclusions: Administration of Dex (0.1 mg/kg or 0.2 mg/kg) before anesthesia induction did not limit adverse outcomes after MVD. Citation: Qi-Wu Fang, Xiao-Yan Qian, Jian-Xiong An, Hui Wen, Jian-Ping Wu, Doris K. Cope, et al. Pre-induction dexamethasone does not decrease complications after microvascular decompression for facial spasm. J Anesth Perioper Med 2015; 2: 192-6. doi: 10.24015/JAPM.2015.0026This is an open-access article, published by Evidence Based Communications (EBC). This work is licensed under the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium or format for any lawful purpose. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Effects of Mechanical Ventilation on Lung Grafts during Cold Ischemia Phase

Background: The preservation of donor lungs during cold ischemia phase plays an important role in improving the function of lung grafts after transplantation. Donor lungs were conventionally preserved with a method of static inflation during ischemia phase, but how mechanical ventilation would affect lungs during this stage was unknown. This study was undertaken to investigate the effects of mechanical ventilation on donor lungs during cold ischemia phase.Methods: Isolated lungs from 45 rats were randomized into control (CON), mechanical ventilation without positive end-expiratory pressure (PEEP) (MVNP) and mechanical ventilation with PEEP (MVP) groups. During the cold ischemia phase, lungs in the CON group were preserved with a conventional method of static inflation, while lungs in the MVNP and MVP groups were mechanically ventilated with tidal volume (VT) of 7 ml/kg without PEEP and VT of 7 ml/kg with 3 cm H2O PEEP, respectively. After 2 hours, bronchoalveolar lavage fluid (BALF) collected from lungs was subsequently analyzed for surfactant, inflammatory cytokines, and total protein; lung tissues were collected for analysis of morphology and the wet-to-dry (W/D) weight ratio; peak airway pressure was recorded before and after lung preservation to reflect the change of lung compliance.Results: Compared to CON group, the levels of surfactant protein B (SP-B), surfactant protein C (SP-C), total surfactant, and active large aggregates (LA) in MVP group raised significantly (P<0.05); meanwhile, W/D ratio, the lavage concentrations of interleukin (IL)-6, and tumor necrosis factor (TNF)-α in the MVNP group were higher than those in the CON group (P<0.05). In contrast with CON group, lung injury scores were higher in both MVNP and MVP groups (P<0.05); the level of peak airway pressure in the MVNP group was dramatically higher than that in the CON and MVP groups (P<0.05), while there were no differences between CON and MVP groups.Conclusions: Mechanical ventilation during cold ischemia phase with low VT and PEEP promoted the level of lung surfactant, but aggravated lung injuries with no effects observed on lung compliance. Citation: Yue Wang, Wen- Zhi Li. Effects of mechanical ventilation on lung grafts during cold ischemia phase. J Anesth Perioper Med 2015; 2: 146-52. doi: 10.24015/JAPM.2015.0020This is an open-access article, published by Evidence Based Communications (EBC). This work is licensed under the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium or format for any lawful purpose. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

NSC23766, A Specific Inhibitor of Rac1 GTPase, Attenuated Delayed Neuronal Cell Death and Cognitive Deficit in Rats with Cardiac Arrest

Background: Recent studies have implicated that inhibition of Rac1 GTPase protects the neuronal cells from cerebral ischemic injury, although its effects in a cardiac arrest (CA) global cerebral ischemia model have not been examined. The purpose of the current study was to examine the regulatory and functional role of the Rac1 in reactive oxygen species (ROS) generation and neuronal cell death/cognitive dysfunction following global cerebral ischemia in the rats.Methods: A rat model of CA was established by the delivery of alternating current between the esophagus and chest wall to induce ventricular fibrillation. Rats were randomly assigned to the following groups: 1) sham group, 2) CA group, 3) CA + NSC23766 group (NSC), and 4) CA + saline group. NSC23766 (50 μg, intracerebroventricular injection) or isotonic saline was administered 15 minutes before CA. Neurological function of rats after reperfusion was scored using the neurological deficit score evaluation method. Survival rates, neuronal counts, Rac1 activation, mitochondrial ROS formation and expression of thioredoxin2 (Trx2) and peroxiredoxin3 (Prx3) in the hippocampal CA1 region were assessed after reperfusion. Morris water maze task was used to quantify spatial learning and memory deficits after reperfusion.Results: NSC23766, the specific inhibitor of Rac1 GTPase, significantly attenuated neuronal damage and reduced the spatial learning and memory deficits associated with global cerebral ischemia induced by CA (P<0.05). Furthermore, NSC23766 exerted its neuroprotective function by decreasing the ROS generation (P<0.05). However, there was no significant difference of Trx2 and Prx3 protein expression in hippocampal CA1 region between the CA group and NSC group after 1 day reperfusion (P<0.05). Conclusions: Our findings suggested that NSC23766 not only ameliorated post-ischemic neuronal cell death, but also improved learning and memory deficits in a cerebral ischemia animal model through down-regulating ROS generation. Citation: Juan Liao, Chang Xu, Chang Liu, Na Wang, Guo-Qing Huang, Chang-Sheng Huang, et al. NSC23766, a specific inhibitor of Rac1 GTPase, attenuated delayed neuronal cell death and cognitive deficit in rats with cardiac arrest. J Anesth Perioper Med 2015; 2: 136-45. doi: 10.24015/JAPM.2015.0019This is an open-access article, published by Evidence Based Communications (EBC). This work is licensed under the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium or format for any lawful purpose. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Sevoflurane, Laryngeal Mask Airway and Single-Dose Dexmedetomidine: A Better Choice for Patients Undergoing Endovascular Coil Embolization

Background: Patients diagnosed with intracranial aneurysms who undergo endovascular coil embolization (ECE), require sufficient dose of anesthesia to prevent rupture of the aneurysms. However, surgeons often prefer fast-channel anesthesia techniques in order to evaluate the effects of the treatment. We designed a double-blind, randomized placebo-controlled study to determine the effects of dexmedetomidine (DEX) on the recovery characteristics of patients who were scheduled to undergo ECE. Methods: After intravenous anesthesia induction with propofol, fentanyl and cisatracurium, and laryngeal mask airway insertion, patients were randomly assigned to receive saline (Group C, N=33), 0.5 μg/kg DEX (Group DEX1, N=34), or 1 μg/kg DEX (Group DEX2, N=34). Maintenance of anesthesia was performed using 2 minimum alveolar concentration (MAC) of end-tidal sevoflurane. The length of time for the eyes to open and characteristics of emergence in patients were recorded after the anesthesia was discontinued. Results: The incidence of intraoperative bradycardia in Group DEX2 (26.4%) was significantly higher than that in the other groups (15.1% in Group C and 11.8% in Group DEX1). Four patients (12.1%) in Group C exhibited emergence agitation, but it was not observed in any of the patients in the other groups. The length of time for the eyes to open in Group DEX2 was nearly 10 minutes longer than that in the other two groups. Conclusions: We concluded that a single-dose of 0.5 μg/kg DEX administered after induction of anesthesia reduced post-sevoflurane agitation in patients undergoing ECE with no adverse effects. Citation: Wen-Fei Tan, Yan-Hua Jiang, Hong Ma, Jun-Ke Wang. Sevoflurane, laryngeal mask airway and single-dose dexmedetomidine: a better choice for patients undergoing endovascular coil embolization. J Anesth Perioper Med 2015; 2: 153-7. doi: 10.24015/JAPM.2015.0021This is an open-access article, published by Evidence Based Communications (EBC). This work is licensed under the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium or format for any lawful purpose. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Safety and Effectiveness of Reduced Red Blood Cells Consumption in Spine Surgery under the Guidance of West China Perioperative Transfusion Score (WCPTS): A Prospective, Randomized, Controlled Trial

Background: Transfusion trigger and target for surgical patients with hemoglobin (Hb) level between 7-10 per deciliter is not available worldwide, and the decision of whether red blood cells (RBCs) should be administered in these patients is made according to the experience of clinicians without evidences. Based on the physiology of the balance between oxygen supply and consumption, we suggested West China Perioperative Transfusion Score (WCPTS) to be safely applied to the patients undergoing spine surgery with effective reduction of RBCs transfusion.Methods: We enrolled patients who were aged 15 to 70 years undergoing elective spine surgery with the expected blood loss more than 800 ml or 20% of the patient's whole blood volume. We randomly assigned patients to the WCPTS group (transfusion threshold under guidance of WCPTS) or the liberal-strategy group (transfusion threshold of 10 per deciliter). The primary outcomes were the proportion of patients who received RBCs transfusion and the units of transfused RBCs.Results: The proportion of patients who received RBCs transfusion in the WCPTS group was significantly lower than that in the liberal-strategy group at all observed time periods (intraoperative: 24.0% vs. 88.2%, P 0.05), and there were no significant between-group differences in length of stay in hospital, length of stay after operation, stitches removal time, time to normal life, and time to work in the two groups (P>0.05).Conclusions: An objective evaluation of the status of oxygen supply and consumption could be achieved by application of WCPTS for patients with Hb level between 7-10 g/dl, and RBCs transfusion trigger and target could be determined on the basis of the evaluation, thus requirement of RBCs transfusion could be reduced by more than 70% under the guidance of WCPTS safely and effectively. Citation: Ren Liao, Hao-Rui Sun, Jin Liu, Shi-Mei Huai, Hong Zheng. Safety and effectiveness of reduced red blood cells consumption in spine surgery under the guidance of West China Perioperative Transfusion Score (WCPTS): a prospective, randomized, controlled trial. J Anesth Perioper Med 2015; 2: 117-25. doi: 10.24015/JAPM.2015.0017 This is an open-access article, published by Evidence Based Communications (EBC). This work is licensed under the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium or format for any lawful purpose. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Neuroprotective and Neurotoxic Properties of General Anesthetics: A Double-Edged Sword

Aim of review: Summarize current and past studies on the neuroprotective and neurotoxic properties of general anesthetics.Method: We have reviewed general anesthetic-induced dual effects of neuroprotection and neurotoxicity in cell culture, animal, and human studies.Recent findings: We have analyzed the contributing factors to the dual effects of neuroprotection and neurotoxicity by general anesthetics. Particularly, the concentration of intracellular calcium may moderate such dual effects of general anesthetics. A modest increase of intracellular calcium by general anesthetics provides neuroprotection, while an excessive or abnormal increase of intracellular calcium may result in neurotoxicity. Future studies are needed to identify the demarcation point upon which the use of general anesthetics becomes neurotoxic. By highlighting this issue, the article fills a gap in the general anesthetic literature. Summary: The variables governing the neuroprotective and neurotoxic effects of general anesthetics appear to be patient age, concentration of general anesthetic used, and length of anesthetic exposure. Preclinical studies suggested that preconditioning with inhalational anesthetics, especially isoflurane at low concentrations, provides neuroprotection. However, inhalational anesthetics can also cause neurotoxicity when used at high concentrations for prolonged periods. Elderly subjects with preexisting neurodegenerative conditions and subjects in their prenatal or postnatal periods seem sensitive to the neurotoxic effects of general anesthesia. Citation: Hua-Feng Wei, Alexander T. King, Saadet Inan. Neuroprotective and neurotoxic properties of general anesthetics: a double-edged sword. J Anesth Perioper Med 2015; 2: 158-66. doi: 10.24015/JAPM.2015.0022This is an open-access article, published by Evidence Based Communications (EBC). This work is licensed under the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium or format for any lawful purpose. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Percutaneous Minimally Invasive Treatment for the Trigeminal Neuralgia: A Review

Aim of review: The objective of this review is to evaluate the effect of percutaneous minimally invasive treatment for the trigeminal neuralgia (TN).Method: We systematically searched for clinical studies on the TN. We searched the MEDLINE (PubMed) and EMBASE database, using the free text terms: minimally invasive treatment, TN and combination of these. Date of last electronic search was 30 December 2012.Recent findings: From the available evidence, we can concluded that：1) Percutaneous glycerol gangliolysis is very effective and applicable to a wide variety of patients with TN. The presence of cerebrospinal fluid (CSF) outflow during puncture predicts better immediate and long-term outcomes; 2) It may be quite obvious that the high-speed real-time CT fluoroscopic method enables better imaging compared to X-ray fluoroscopy; 3) Computed tomography (CT) images are by far superior, when combined with neuronavigation, which allows trajectory visualization in three dimensions and multiple planes at the surgeon's choosing, and use of real-time annulations. Three dimensional (3D)-CT and electrophysiology Gasser's ganglion locations can raise the success rate of puncture, enhance the safety and reduce the incidence of complication, showing high academic value and its promising future; 4) Balloon Compression causes only a mild sensory loss with immediate pain relief in practically all patients; 5) Ultrasound-guided technique for the blockade of trigeminal nerve peripheral branches is very rational.Summary: For both treatment methods, the fused CT and magnetic resonance imaging (MRI) scans are used for improved treatment planning in the treatment for the TN. While the MRI scans provides better details on the anatomical situation, CT scans are required for dissymmetric assessment. In the future, other imaging methods like spectroscopy and evoked-potential imaging will become available to better shape the target volume and spare critical normal tissue structures. Citation: Xiang-Fei Guo, Jun Ma. Percutaneous minimally invasive treatment for the trigeminal neuralgia: a review. J Anesth Perioper Med 2015; 2: 167-74. doi: 10.24015/JAPM.2015.0023This is an open-access article, published by Evidence Based Communications (EBC). This work is licensed under the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium or format for any lawful purpose. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Effects of Sevoflurane and Propofol on Intestinal Ischemic Reperfusion Injury in Patients Undergoing Elective Open Infrarenal Abdominal Aortic Aneurysm Repair: A Randomized Controlled Trial

Background: We previously demonstrated that propofol had a protective effect on the intestine at risk after an ischemic injury in a rat model. The current study tested the hypothesis that such beneficial effects, so far mainly seen in the laboratory, are reproducible in humans.Methods: Seventy patients undergoing elective open infrarenal abdominal aortic aneurysm repair were randomized to receive general anesthesia with either propofol or sevoflurane. General anesthesia was induced with 3 µg/kg fentanyl, 0.2 mg/kg cisatracurium, and target-controlled infusion of propofol, set at a plasma target concentration of 4-6 µg/ml, or sevoflurane initially started at 8%. Anesthesia was maintained with target-controlled infusion of propofol (2-4 µg/ml) or sevoflurane (0.8-1.0 minimum alveolar concentration). Except for this, anesthetic and surgical management was the same in both groups. Serum intestinal fatty acid binding protein was taken as the primary outcome for evaluating intestinal injury. The secondary outcomes included other intestinal injury variables (serum endotoxin levels, serum diamine oxidase activity and the score of intestinal injury severity) as well as markers reflecting oxidative stress and systemic inflammatory response.Results: The levels of biomarkers reflecting intestinal injury were higher than baseline in both groups (all P<0.05). However, in sevoflurane-anesthetized patients, these variables increased significantly more than those in patients anesthetized with propofol (all P<0.05), whereas the scores of the intestinal injury severity didn't differ between two groups (P=0.53).Conclusions: Patients receiving propofol for abdominal aortic aneurysm repair surgery had less intestinal injury than patients receiving sevoflurane, which may be related to its better anti-oxidative property. Citation: Cai Li, Wu Yan, Jian- Tong Shen, Shi-Hong Wen, Ke-Xuan Liu. Effects of sevoflurane and propofol on intestinal ischemic reperfusion injury in patients undergoing elective open infrarenal abdominal aortic aneurysm repair: a randomized controlled trial. J Anesth Perioper Med 2015; 2: 126-35. Published on April 30, 2015. doi: 10.24015/JAPM.2015.0018This is an open-access article, published by Evidence Based Communications (EBC). This work is licensed under the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium or format for any lawful purpose. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Isoflurane Suppresses the Excitability and Synaptic Transmission of Spinal Nociceptive Pathway in Rats

Background: Isoflurane (IFL), one of the most widely used volatile anesthetics, has an anti-nociceptive effect at the spinal cord level. However, the reported spinal mechanisms of IFL analgesic action remain controversial. The aim of this study was to examine the effect of IFL on the excitability of spinal substantia gelatinosa (SG, lamina II) neurons and the synaptic transmission from primary nociceptive fibers to SG neurons.Methods: Parasagittal spinal slices with a dorsal root attached were cut from the Sprague-Dawley rats (4-6 weeks old). Whole-cell patch-clamp recordings were made from SG neurons at room temperature. Dorsal root stimulation was used to evoke excitatory postsynaptic currents (eEPSCs). Depolarizing current injection was used to display the firing pattern of action potentials. IFL was given as volume percent (3%) by passing the gas mixture (flow rate, 0.5 L/minute) into equilibrated artificial cerebral spinal fluid (ACSF) for at least 15 minutes at room temperature.Results: IFL significantly suppressed the peak amplitude of monosynaptic eEPSCs mediated by primary Aδ and C fibers. Regardless of neuron types, IFL significantly decreased the frequency of action potentials in all SG neurons tested.Conclusions: IFL may play analgesic role through inhibiting or weakening the excitability and synaptic transmission of spinal nociceptive pathway. Citation: Jie Liu, Gen-Lin Ji, Jian-Min Li, Tun Liu, Qun Wang, Ya-Nan Pu, et al. Isoflurane suppresses the excitability and synaptic transmission of spinal nociceptive pathway in rats. J Anesth Perioper Med 2015; 2: 61-5. doi: 10.24015/JAPM.2015.0010This is an open-access article, published by Evidence Based Communications (EBC). This work is licensed under the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium or format for any lawful purpose. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

S1P-S1PRs Alliance in Neuropathic Pain Processing

Aim of review: Neuropathic pain (NPP), a common clinical condition, is characterized by allodynia and hyperalgesia. In the setting of NPP, components in the peripheral and central transmission pathway of pain exhibit tremendous plasticity, facilitating pain signal conduction and giving rise to hypersensitivity. Clarifying the signal path of nociceptive processing and discovering the key molecules involved in NPP may allow improvement of its treatment.Method: This article reviewed the sphingosine-1-phosphate (S1P) and sphingosine-1-phosphate receptors (S1PRs) alliance that initiates and maintains peripheral and central sensitization in NPP, underlying the fundamental contribution and multiple mechanisms of this alliance in synaptic plasticity.Recent findings: In the peripheral nervous system, S1P-S1PRs alliance contributes to the inflammatory chemical milieu formation and ion channel function, which increase the ectopic action potentials of sensory neurons. In addition, S1P-S1PRs alliance affects thermal hyperalgesia through enhancing inward tetrodotoxin-resistant INa+ and decreasing total outward IK+ on the nociceptors. In the central nervous system, S1P-S1PRs alliance facilitates the neuroinflammatory response and glutamate accumulation at the first pain synapse, which leads to persistent central hypersensitization. Furthermore, S1P-S1PRs alliance could disequilibrate the extracellular glutamate via reducing the activities of glutamine synthetase (GS) and glutamate transporters (GTs), which are the key players in glutamate metabolism.Summary: Targeting S1P-S1PRs alliance may be an Achilles' heel of the Trojan horse model of NPP. Citation: Jin-Chao Hou, Xiang-Ming Fang. S1P-S1PRs alliance in neuropathic pain processing. J Anesth Perioper Med 2015; 2: 87-95. doi: 10.24015/JAPM.2015.0013This is an open-access article, published by Evidence Based Communications (EBC). This work is licensed under the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium or format for any lawful purpose. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Assessing Prophylactic Cephamycins Used in Colorectal Surgery: A Meta-Analysis

Background: Cephamycins prophylactic used in colorectal surgery have been widely evaluated, but the uncertainty remains about the comparative effects of different antibiotics. The meta-analysis aimed to assess the efficacy of cephamycins compared with other agents used as prophylaxis in colorectal surgery.Methods: PubMed, EMBASE, and Cochrane Library were searched for relevant studies. A meta-analysis of randomized controlled trials (RCTs) meeting the criteria was performed using Review Manager.Results: Thirty-nine trials involving 4,755 participants were included in this meta-analysis. The cephamycins were not as effective as other antibiotics for the prevention of postoperative surgical site infection (SSI) (Risk Ratio [RR] 1.18; 95% confidence interval [CI] 1.04, 1.34; P=0.008) and had no advantages in reduction of systemic infection and distal infection. For each antibiotic belonging to cephamycins, there was no statistical difference when cefoxitin and cefotetan were compared with penicillins and cephalosporins on prevention of SSI, while cefmetazole had advantages over cephalosporins on prevention of SSI (RR 0.46; 95% CI 0.22, 0.96; P=0.04).Conclusions: The prophylactic use of cefoxitin and cefotetan in colorectal operations has no significant advantages over other antibiotics. However, cefmetazole may be effective in the prevention of postoperative infections and its efficacy should be researched further and considered by perioperative medical staff. Therefore, it is of great importance to optimize the prophylactic use of antibiotics in colorectal operations. Citation: Yu Ding, Feng-Ying Xu, Miao Zhou, Yu- Xin Li, Hua He, Xue- Peng Zhang, et al. Assessing prophylacticcephamycins used in colorectal surgery: a meta- analysis. J Anesth Perioper Med 2015; 2: 75-86. doi: 10.24015/JAPM.2015.0012This is an open-access article, published by Evidence Based Communications (EBC). This work is licensed under the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium or format for any lawful purpose. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Protective Effect of Propofol on Electroconvulsive Shock Induced Learning and Memory Function Impairment Involves Up-Regulation of NMDA Receptor NR2A/2B Subunit in a Rat Model of Depression

Backgroud: The mechanism underlying the protective effect of propofol on electroconvulsive therapy (ECT) induced learning and memory function impairment remains largely unknown. The present study aimed to explore the effect of propofol on the expression of N-methyl-D-aspartic acid (NMDA) receptor subunit NR2A/2B and α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptor subunit glutamate receptor 1 (GluR1) in the hippocampus of rat depression model undergoing electroconvulsive shock (ECS, analog of ECT in animals) in order to uncover the mechanism underlying the damaging effect of ECS on the learning and memory function, and the mechanism underlying the protective effect of propofol on the learning and memory function in ECS treatment.Methods: This study was designed as a longitudinal study. Establishment of depression model was conducted with the application of chronic unpredictable mild stress (CUMS) in Sprague-Dawley rats. All 50 rats were randomly assigned into 5 groups (N=10) : one control group ( group C, 10 healthy rats) and four groups exposed to CUMS treatments for 28 days to construct the rat model of depression (group D, P, E, PE). Rats in group C were treated with intraperitoneal injection of 8 ml/kg normal saline and sham ECS (without the administration of current). Rats in group D received intraperitoneal injection of 8 ml/kg normal saline and then sham ECS. Rats in group P received intraperitoneal injection of propofol 80 mg/kg and then sham ECS, while rats in group E were treated with intraperitoneal injection of normal saline 8 ml/kg and then ECS. Rats in group PE were treated with intraperitoneal injection of propofol 80 mg/kg and then ECS. The treatments were conducted once a day for 7 consecutive days. The sucrose preference test was performed to assess the depression behavior. Learning and memory function of rats was evaluated with Morris water maze. Western-blot assay was applied to determine the expression levels of NR2A/2B subunit and GluR1 subunit in the hippocampus.Results: Sucrose preference percentage of the rats in group E and group PE was increased compared with rats in group D. Compared with group D, rats in group E showed increased escape latency, decreased space exploration time, as well as increased expression of GluR1, and decreased NR2A/2B expression. Shorter escape latency, longer space exploration time, and higher level of NR2A/2B expression were showed in rats in group PE than in group E.Conclusions: ECS treatment up-regulated the expression of GluR1 receptor while down-regulated the expression NR2A/2B receptors in rat hippocampus. Propofol mitigating learning and memory function impairment in depression model rats undergoing ECS may via alleviating the inhibitory effect induced by ECS on the NMDA receptor NR2A/2B subunit expression. Citation: Xue-Chao Hao, Xian-Lin Zhu, Ping Li, Jing Chen, Feng Lv, Su Min. Protective effect of propofol on electroconvulsive shock induced learning and memory function impairment involves up-regulation of NMDA receptor NR2A/2B subunit in a rat model of depression. J Anesth Perioper Med 2015; 2: 66-74. doi: 10.24015/JAPM.2015.0011This is an open-access article, published by Evidence Based Communications (EBC). This work is licensed under the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium or format for any lawful purpose. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Involvement of CCL1/CCR8 in Spinal Cord Dorsal Horn in Remifentanil-Induced Hyperalgesia in Rats

Background: Numerous researches manifested that remifentanil infusion might be responsible for opioid-induced hyperalgesia (OIH), but most studies exploring OIH were hardly designed to clarify underlying mechanisms. Chemokine (C-C motif) ligand 1 (CCL1) was found to be implicated in neuropathic pain, and our previous study has also shown that proinflammatory cytokines have been associated with the induction and maintenance of OIH. However, whether CCL1 could contribute to hyperalgesia induced by remifentanil in rats remains unclear.Methods: To explore effect of CCL1 on OIH, a neutralizing antibody against CCL1 (anti-CCL1) was administrated intrathecally after remifentanil infusion in rats. Western blotting and immunohistochemistry (IHC) were applied to analyze time course of CCL1 and CCR8 (specific CCL1 receptor) expression in dorsal horn after remifentanil administration. Expression of inflammatory mediators such as tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6 was evaluated by real-time quantitative polymerase chain reaction (RT-qPCR). Paw withdrawal threshold (PWT) and paw withdrawal latency (PWL) were measured and recorded for 48 post-infusion hours to evaluate mechanical and thermal hyperalgesia.Results: We discovered that CCL1 and CCR8 expressions in dorsal horn were increased and maintained at a high level from 2 hours to 48 hours, the last examination time, after remifentanil infusion. We found that intrathecal delivery of anti-CCL1 could ameliorate remifentanil related thermal and mechanical hyperalgesia without affecting baseline nociceptive threshold. It was also shown that enhancement of inflammatory mediators (TNF-α, IL-1β, and IL-6) expression in dorsal horn after remifentanil infusion was reversed by anti-CCL1 administration.Conclusions: Our current results indicated that CCL1 and CCR8 might be implicated in the development of remifentanil-induced hyperalgesia via regulation of cytokines (TNF-α, IL-1β, and IL-6) in dorsal horn in rats. Citation: Lin- Lin Zhang, Rui- Chen Shu, Nan Li, Zhi-Fen Wang, Chun-Yan Wang, Hai- Yun Wang, et al. Involvement of CCL1/CCR8 in spinal cord dorsal horn in remifentanil- induced hyperalgesia in rats. J Anesth Perioper Med 2015; 2: 53-60. doi: 10.24015/JAPM.2015.0009This is an open-access article, published by Evidence Based Communications (EBC). This work is licensed under the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium or format for any lawful purpose. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.