Anesthesia and surgery-induced elevation of CSF sTREM2 is associated with early cognitive dysfunction after thoracoabdominal aortic dissection surgery.

PURPOSE: Soluble triggering receptor expressed on myeloid cells 2 (sTREM2) concentration is increased in cerebrospinal fluid (CSF) in early symptomatic phase of Alzheimer's disease (AD). This study investigated whether CSF sTREM2 has a relationship with early cognitive dysfunction following surgery in cardiac surgery patients. METHODS: A total of 82 patients undergoing thoracoabdominal aortic replacement were recruited in this study. Neuropsychological testing battery was conducted before and after surgery. Postoperative cognitive dysfunction (POCD) was defined as a Z-score > 1.96 on at least 2 different tests or Telephone Interviews for Cognitive Status-Modified (TICS-M) score < 27. The CSF and serum sTREM2, Aß42, T-tau and P-tau were collected and measured by ELISA on day before surgery and postoperative day 3. RESULTS: Patients were classified into POCD (n = 34) and non-POCD (n = 48) groups according to Z-score. Compared to non-POCD group, the levels of CSF sTREM2 (p < 0.001) and serum sTREM2 (p = 0.001) were significantly higher in POCD group on postoperative day 3. The levels of Aß42 (p = 0.005) and Aß42/T-tau ratio (p = 0.036) were significantly lower in POCD group on postoperative day 3. Multivariate logistic regression analysis revealed that higher value of postoperative CSF sTREM2 (odds ratio: 1.06, 95% confidence interval: 1.02-1.11, p = 0.009), age (OR: 1.15, 95%CI: 1.03-1.28, p = 0.014) and POD duration (OR: 2.47, 95%CI: 1.15-5.29, p = 0.02) were the risk factors of POCD. CONCLUSION: This study indicates that anesthesia and surgery-induced elevation of CSF sTREM2 is associated with an increased risk of early cognitive dysfunction following surgery.

TREM2 improves neurological dysfunction and attenuates neuroinflammation, TLR signaling and neuronal apoptosis in the acute phase of intracerebral hemorrhage.

Neuroinflammation contributes to secondary brain injury following intracerebral hemorrhage (ICH). Triggering receptor expressed on myeloid cells 2 (TREM2) confers strong neuroprotective effect by suppressing neuroinflammatory response in experimental ischemic stroke. This study aimed to clarify the neuroprotective role of TREM2 and potential underlying mechanism in a mouse model of ICH and in vitro. Adeno-associated virus (AAV) and green fluorescent protein-lentivirus (GFP-LV) strategies were employed to enhance TREM2 expression in the C57/BL6 mice and BV2 cells, respectively. The adult male C57/BL6 mice were subjected to ICH by administration of collagenase-IV in 1 month after the AAV particles injection. An in vitro ICH model was performed with oxygen hemoglobin in BV2 cells. Toll-like receptor 4 (TLR4) antagonist TAK242 was applied at 6 h following ICH. Neurological function, TREM2, pro-inflammatory cytokines, brain water content and Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining were evaluated at 24 h following ICH. TLR4, NF-κB and mitogen-activated protein kinases (MAPK) signaling pathways were also determined by Western blot analysis at the same time point. The levels of TREM2 were increased at 12 h, peaked at 24 h and recovered on 7d following ICH. TREM2 overexpression ameliorated ICH induced neurological dysfunction, inhibited neuroinflammation, and attenuated apoptosis and brain edema. Further mechanistic study revealed that TREM2 overexpression inhibited TLR4 activation and NF-κB and MAPK signaling pathways. ICH increased the percentage of TUNEL-positive cells, which was markedly decreased by TREM2 overexpression. A similar improvement was also observed by the administration of TAK242 following ICH. TREM2 improves neurological dysfunction and attenuates neuroinflammation and neuronal apoptosis in the acute phase of ICH, which is, at least in part, mediated by negatively regulating TLR4 signaling pathway. These findings highlight TREM2 as a potential target for early brain injury following ICH.

TREM2 ameliorates anesthesia and surgery-induced cognitive impairment by regulating mitophagy and NLRP3 inflammasome in aged C57/BL6 mice.

Postoperative cognitive dysfunction (POCD) is a major postoperative complication. Triggering receptor expressed on myeloid cells 2 (TREM2) exerts a neuroprotective function against neuro-inflammatory responses. The present study investigated the role of TREM2 in anesthesia and surgery-induced cognitive impairment and the potential related mechanism. Our results revealed that TREM2 was downregulated, coupled with activation of the NLRP3 inflammasome and subsequent IL-1ß expression on postoperative day 3. A corresponding decline in PSD-95 and BDNF was found at the same time point. The key regulator of mitophagy PINK1 and Parkin protein levels were significantly decreased following surgery and anesthesia. TREM2 overexpression partially reversed postoperative cognitive impairment and enhanced PSD-95 and BDNF expression. TREM2 overexpression also improved mitophagy function and inhibited activation of the NLRP3 inflammasome and associated production of IL-1ß. Our findings demonstrate that TREM2 rescues anesthesia and surgery-induced spatial learning and memory impairment and neuro-inflammation in aged C57/BL6 mice, which may be at least partially mediated through the activation of mitophagy and subsequent inhibition of the NLRP3 inflammasome.

A comparison of the analgesic efficacy of serratus anterior plane block vs. paravertebral nerve block for video-assisted thoracic surgery: a randomized controlled trial.

INTRODUCTION: Patients who undergo video-assisted thoracic surgery (VATS) frequently experience moderate to severe postoperative pain. Serratus anterior plane block (SAPB) is a relatively novel technique that can block the lateral cutaneous branches of the intercostal nerves as well as the long thoracic nerve. AIM: To evaluate the analgesic efficiency of deep serratus plane block (DSPB) and superficial serratus anterior plane block (SSPB) as well as paravertebral nerve block (PVB) in patients undergoing VATS. MATERIAL AND METHODS: A total of 74 patients aged 16-80 undergoing VATS were randomized to receive either DSPB or SSPB as well as PVB. Ultrasound (US) guided DSPB or SSPB as well as PVB was performed preoperatively on the patients according to their groups. All patients were provided with patient-controlled intravenous analgesia (PCIA) for postoperative analgesia. The primary outcomes were the levels of postoperative pain at rest and on coughing evaluated by the visual analog scale (VAS), and intraoperative and postoperative opioid consumption. The secondary outcomes included PCIA pressing times, side effects and satisfaction with analgesia, duration of nerve block, intraoperative hemodynamic changes and vasoactive drug dosage. RESULTS: No significant differences of VAS score were found. During the operation, PVB reduced consumption of opioids (27.23 ±5.10 mg) compared to DSPB (31.20 ±3.80 mg) and SSPB (32.61 ±5.28 mg). The effective pressing times of PCIA in the SSPB group (0.18 ±0.65) were significantly lower compared to the PVB group (1.09 ±1.50) at 12 h postoperatively. Accordingly, SSPB also reduced the dosage of PCIA (26.55 ±4.72 ml) compared to PVB (31.45 ±7.60 ml). Time of the PVB procedure was longer (11.14 ±1.66 min) than DSPB (5.68 ±1.10 min) and SSPB (4.77 ±1.04 min). CONCLUSIONS: DSPB and SSPB are easy to perform and can serve as a promising alternative technique to PVB that may offer comparable analgesic effectiveness for patients undergoing VATS.

TREM2 Ameliorates Lipopolysaccharide-Induced Oxidative Stress Response and Neuroinflammation by Promoting Sirtuin3 in BV2 Cells.

Triggering receptor expressed on myeloid cells 2 (TREM2) plays a crucial role in modulating microglial-mediated neuroinflammation. The NAD-dependent deacetylase protein Sirtuin 3 (SIRT3) regulates mitochondrial oxidative stress response and neuroinflammation. TREM2 deficiency impairs the denovo synthesis pathway of NAD+. Therefore, the aim of this study was to investigate the potential role of TREM2 and SIRT3 in LPS-induced oxidative stress and neuroinflammation in BV2 cells. Lentivirus vector-mediated TREM2 overexpression (TREM2-OE) and corresponding negative control vector (TREM2-NC) were synthesized. BV2 cells were treated with LPS and/or TREM2-OE. 3-TYP, a selective SIRT3 inhibitor, was applied to determine the role of SIRT3 in the anti-oxidant and anti-inflammatory effects of TREM2. TREM2, SIRT3, NLRP3 inflammasome, caspase-1, postsynaptic density-95 (PSD-95), and brain derived neurotrophic factor (BDNF) were measured by Western blot analysis. Superoxide dismutase (SOD) was tested by SOD Assay Kit. Reactive oxygen species (ROS) expression was examined by immunofluorescence. Interleukin 1ß (IL-1ß) was determined by ELISA. Contents of NAD+ and NADH were detected by WST-8 method. LPS (1ug/ml for 24 h) significantly decreased TREM2 expression at both RNA and protein levels (p < 0.01 and p < 0.05, respectively). Lower levels of SIRT3 protein and NAD+ were also detected following LPS stimulation (p < 0.05 and p < 0.05, respectively). LPS significantly enhanced ROS, NLRP3, caspase-1, and IL-1ß expression (p < 0.01, p < 0.05, p < 0.05, and p < 0.01, respectively). PSD-95 and BDNF expression were decreased triggered by LPS (p < 0.05 and p < 0.05, respectively). TREM2 overexpression enhanced NAD+ and SIRT3 protein expression following LPS challenge in BV2 cells (p < 0.01 and p < 0.05, respectively). TREM2 alleviated LPS-induced oxidative stress and neuroinflammation (p < 0.01 and p < 0.05, respectively). Similarly, TREM2 overexpression upregulated PSD-95 and BDNF expression (p < 0.05 and p < 0.05, respectively). The anti-oxidant and anti-inflammatory effects of TREM2 were partially abrogated by SIRT3 antagonist 3-TYP (p < 0.05 and p < 0.05, respectively). Similarly, selective SIRT3 inhibition also partially abrogated TREM2-induced BDNF protein upregulation (p < 0.05) but failed to influence PSD-95 protein expression following LPS stimulation. LPS induces oxidative stress and neuroinflammation in BV2 cells, which may be mediated in part by the downregulation of TREM2 and SIRT3. TREM2 overexpression ameliorates LPS-induced oxidative stress and neuroinflammation through enhancing SIRT3 function via NAD+.

A comparison of paravertebral block, erector spinae plane block and the combination of erector spinae plane block and paravertebral block for post-operative analgesia after video-assisted thoracoscopic surgery: A randomised controlled trial.

BACKGROUND: This study was to determine the analgesic effect of ultrasound-guided erector spinae plane block (ESPB) and paravertebral block (PVB) as well as the combination of PVB and ESPB (P + E) after video-assisted thoracoscopic surgery (VATS). PATIENTS AND METHODS: Patients were randomly assigned to receive ESPB, PVB or PVB combined with ESPB with 0.5% ropivacaine (20 ml). The primary outcomes were cumulative hydromorphone consumption and Visual Analogue Scale (VAS) scores at rest and while coughing at 0 h, 12 h, 24 h, 48 h and 72 h postoperatively. The secondary outcomes were effective PCA usage count and rescue analgesia requirement at the same time points. RESULTS: The median (interquartile range) hydromorphone consumption, including converted oxycodone, was significantly different at 48 h postoperatively among the three groups (ESPB, 10.24 [9.53-11.71] mg; PVB, 9.94 [9.19-10.75] mg; P + E, 9.44 [8.96-9.97] mg; P = 0.011). Hydromorphone consumption in P + E group was lower compared with that in ESPB group at 12 h, 24 h and 48 h (P < 0.001, P = 0.004 and P = 0.003, respectively). VAS scores at rest were significantly higher for ESPB group compared to P + E group at 0 h postoperatively (P = 0.009). VAS scores while coughing were significantly higher for ESPB group compared to P + E group at 0 h and 12 h postoperatively (P = 0.015 and P < 0.001) and to the PVB group at 12 h postoperatively (P = 0.002). The effective PCA usage count in P + E group was lower than in ESPB group in 0-12 h (P < 0.001). More patients needed rescue analgesia in ESPB group compared to those in P + E group in 0-12 h, 0-24 h and 0-48 h (P = 0.022, 0.035 and 0.035, respectively). CONCLUSIONS: Ultrasound-guided PVB combined with ESPB provided superior analgesia to ESPB for VATS. The combination of PVB and ESPB had a similar analgesic effect compared with PVB alone.

Gut Microbial Metabolite Short-Chain Fatt Acids Partially Reverse Surgery and Anesthesia-Induced Behavior Deficits in C57BL/6J Mice.

Accumulating evidence has demonstrated that damages of gut microbiota are strongly associated with central nervous system (CNS) diseases, such as perioperative neurocognitive disorders (PND). The present study investigated the role of gut microbial metabolite short-chain fatty acids (SCFAs) in surgery-induced cognitive deficits and neuroinflammation in the hippocampus. Adult male C57BL/6J mice received either SCFA mixture or saline orally for 4 weeks, and then partial hepatectomy was performed. The fecal supernatant of surgical mice was transplanted to normal mice for 3 weeks. The Morris water maze (MWM) and open-field tests were used to evaluate behavioral performance on postoperative or post-transplantation days 3 and 7. In the MWM test, pretreatment with exogenous SCFAs partially reversed surgery-induced impairments in crossing times and the time spent in the target quadrant on postoperative day 3 (p < 0.05, p < 0.05, respectively). In the open-field test, compared with the surgical mice, exogenous SCFA administration prior to surgery partially improved the locomotor activity (p < 0.05) and anxiety-like behavior (p < 0.05) on postoperative day 3. Surgical trauma and anesthesia enhanced ionized calcium-binding adapter molecule 1 (Iba-1) expression (p < 0.001), increased the levels of interleukin (IL)-1ß (p < 0.001) and IL-6 (p < 0.001), and inhibited SCFA production (p < 0.001) on postoperative day 3. The expression of the brain-derived neurotrophic factor (BDNF) was also decreased (p < 0.001). Overall, surgical trauma and anesthesia exacerbated cognitive impairment, enhanced neuroinflammatory responses, and inhibited SCFA production. Pretreatment with SCFAs attenuated these effects partially by reversing microglial overactivation, inhibiting neuroinflammatory responses, and enhancing BDNF expression.

Anesthesia Considerations and Infection Precautions for Trauma and Acute Care Cases During the COVID-19 Pandemic: Recommendations From a Task Force of the Chinese Society of Anesthesiology.

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread worldwide. During the ongoing COVID-19 epidemic, most hospitals have postponed elective surgeries. However, some emergency surgeries, especially for trauma patients, are inevitable. For patients with suspected or confirmed COVID-19, a standard protocol addressing preoperative preparation, intraoperative management, and postoperative surveillance should be implemented to avoid nosocomial infection and ensure the safety of patients and the health care workforce. With reference to the guidelines and recommendations issued by the National Health Commission and Chinese Society of Anesthesiology, this article provides recommendations for anesthesia management of trauma and emergency surgery cases during the COVID-19 pandemic.

Autophagy Dysfunction and mTOR Hyperactivation Is Involved in Surgery: Induced Behavioral Deficits in Aged C57BL/6J Mice.

Autophagy is crucial for cell survival, development, division, and homeostasis. The mammalian target of rapamycin (mTOR), which is the foremost negative controller of autophagy, plays a key role in many endogenous processes. The present study investigated whether rapamycin can ameliorate surgery-induced cognitive deficits by inhibiting mTOR and activating autophagy in the hippocampus. Both adult and aged C57BL/6J mice received an intraperitoneal injection of rapamycin (10 mg/kg/day) for 5 days per week for one and a half months. Mice were then subjected to partial hepatectomy under general anesthesia. Behavioral performance was assessed on postoperative days 3, 7, and 14. Hippocampal autophagy-related (Atg)-5, phosphorylated mTOR, and phosphorylated p70S6K were examined at each time point. Brain derived neurotrophic factor (BDNF), synaptophysin, and tau hyperphosphorylation (T396) in the hippocampus were also examined. Surgical trauma and anesthesia exacerbated spatial learning and memory impairment in aged mice on postoperative days 3 and 7. Following partial hepatectomy, the levels of phosphorylated mTOR, phosphorylated 70S6K, and phosphorylated tau were all increased in the hippocampus. A corresponding decline in BDNF and synaptophysin were observed. Rapamycin treatment restored autophagy function, attenuated phosphorylation of tau protein, and increased BDNF and synaptophysin expression in the hippocampus of surgical mice. Furthermore, surgery and anesthesia induced spatial learning and memory impairments were also reversed by rapamycin treatment. Autophagy impairments and mTOR hyperactivation were detected along with surgery-induced behavioral deficits. Inhibiting the mTOR signaling pathway with rapamycin successfully ameliorated surgery-related cognitive impairments by sustaining autophagic degradation, inhibiting tau hyperphosphorylation, and increasing synaptophysin and BDNF expression.

Downregulation of LncRNA TUG1 Inhibited TLR4 Signaling Pathway-Mediated Inflammatory Damage After Spinal Cord Ischemia Reperfusion in Rats via Suppressing TRIL Expression.

Toll-like receptor 4 (TLR4) and TLR4 interactor with leucine-rich repeats (TRIL) play a crucial role in the inflammatory response. This study investigated the role of long noncoding RNA taurine-upregulated gene 1 (lncRNA TUG1) in TRIL/TLR4 signaling in spinal cord ischemia reperfusion (IR) injury. IR injury was induced in experimental rats; knockdown of TUG1 and TRIL was induced by intrathecal injection of siRNAs and overexpression of TRIL was induced by pcDNA3.3-TRIL. The results showed that the mRNA levels of TUG1 were increased at 12 hours after IR; this was accompanied by increased expression of the TRIL- and TLR4-mediated NF-κB/IL-1ß signaling pathway. Activated microglia, detected with increased ionized calcium-binding adapter molecule 1 as a marker, exacerbated the hind-limb neurological impairment and blood-spinal cord barrier (BSCB) leakage after IR. TUG1 knockdown inhibited expression of TRIL and TLR4 signaling proinflammatory cytokines and microglial activation, and attenuated neurological deficit and BSCB leakage. TRIL knockdown inhibited the TLR4-mediated inflammatory response, while TRIL expression reversed the inhibited inflammatory effect caused by TUG1 knockdown. These data suggest that TUG1 knockdown inhibited inflammatory damage of the TLR4-mediated NF-κB/IL-1ß signaling pathway after IR via suppressing TRIL expression.

Exendin-4 improves behaviorial deficits via GLP-1/GLP-1R signaling following partial hepatectomy.

Recent studies indicate that glucagon-like peptide 1 (GLP-1) receptor (GLP-1R) agonists exhibit neurotrophic and neuroprotective effects. The aim of this study was to explore whether the GLP-1R agonist exendin-4 can alter surgery-induced behavioral deficits and exert neuroprotective effects via the activation of the hippocampal GLP-1/GLP-1R pathway. 120 male Sprague-Dawley rats (aged 18-20 months old) were randomly divided into four groups: control group, exendin-4 group, surgery group, and surgery + exendin-4 group. The animals received either exendin-4 (5 µg/kg/day) or saline intra-peritoneally for 14 days, and then were subjected to partial hepatectomy 24 h after the last injection. Behavioral changes were evaluated with Morris Water Maze and Open field testing on postoperative days 7 and 14. The levels of IL-1ß, NF-κB, Iba-1, Synaptophysin, GLP-1/GLP-1R, GSK-3ß, p-GSK-3ß (Ser9), p-Tau (Ser396), and p-Tau (Ser202/199) in the hippocampus were measured at the same time point. Surgical trauma induced an exacerbated spatial learning and memory impairment, increased the levels of depressive performance, and enhanced hippocampal NF-κB and IL-1ß expression in the aged rats on postoperative day 7. A corresponding decline in GLP-1R was also found following surgical challenge on postoperative day 7. Exendin-4 treatment partly reversed surgery-induced postoperative behavioral impairment, downregulated the levels of NF-κB and IL-1ß, ameliorated tau hyperphosphorylation and enhanced the activity of p-GSK-3ß (Ser9). Together, the downregulation of GLP-1R exacerbated surgery-induced behavior deficits. Exendin-4 treatment attenuated these effects by inhibiting neuroinflammation and tau hyperphosphorylation. These findings suggest that pretreatment with exendin-4 is a potential adjuvant for preventing surgery-induced behavioral deficits.

Surgical Trauma Exacerbates Cognitive Deficits and Neuroinflammation in Aged Rats: The Role of CX3CL1-CX3CR1 Signaling.

Age is the most prominent risk factor for the development of postoperative cognitive dysfunction. The present study investigated the role of CX3CL1-CX3CR1 signaling in age-related differences in surgery-induced cognitive deficits and neuroinflammation. Adult and aged male Sprague-Dawley rats were subjected to partial hepatectomy or partial hepatectomy with intracerebroventricular infusion of CX3CL1. On postoperative days 3, 7, and 14, the rats were subjected to an open field test and the Morris water maze test. Hippocampal interleukin-1ß, CX3CL1, CX3CR1, brain derived neurotrophic factor (BDNF), ionized calcium-binding adapter molecule 1 (Iba-1), and Arginase-1 (Arg1) levels were measured. Age exacerbated cognitive impairment and increased neuroinflammation following surgery. Surgery-induced decreases in CX3CL1 and CX3CR1 proteins were accompanied by increased microglial activation, as indicated by increased Iba-1 expression. Corresponding decline in Arg1 and BDNF levels were observed. Treatment with CX3CL1 decreased proinflammatory cytokines expression, increased BDNF and Arg1 levels in the brain, and enhanced behavioral recovery. The surgery-induced decreases in CX3CL1 and CX3CR1 expression exacerbated postoperative cognitive deficits and exaggerated neuroinflammatory responses in this rodent model. Treatment with CX3CL1 attenuated these effects, at least partly by inhibiting microglial activation, decreasing the associated production of proinflammatory cytokines, and enhancing BDNF expression.

Upregulation of TREM2 Ameliorates Neuroinflammatory Responses and Improves Cognitive Deficits Triggered by Surgical Trauma in Appswe/PS1dE9 Mice.

BACKGROUND/AIMS: TREM2 plays a crucial role in modulating microglial function through interaction with DAP12, the adapter for TREM2. Emerging evidence has demonstrated that TREM2 could suppress neuroinflammatory responses by repression of microglia-mediated cytokine production. This study investigated the potential role of TREM2 in surgery-induced cognitive deficits and neuroinflammatory responses in wild-type (WT) and APPswe/PS1dE9 mice. METHODS: Adult APPswe/PS1dE9 transgenic male mice (a classic transgenic model of Alzheimer's disease, 3 months old) and their age-matched WT mice received intracerebral lentiviral particles encoding the mouse TREM2 gene and then were subjected to partial hepatectomy at 1 month after the lentiviral particle injection. The behavioral changes were evaluated with an open-field test and Morris water maze test on postoperative days 3, 7, and 14. Hippocampal TREM2, DAP12, and interleukin (IL)-1ß were measured at each time point. Ionized calcium-binding adapter molecule 1 (Iba-1), microglial M2 phenotype marker Arg1, synaptophysin, tau hyperphosphorylation (T396), and glycogen synthase kinase-3ß (GSK-3ß) were also examined in the hippocampus. RESULTS: Surgical trauma induced an exacerbated cognitive impairment and enhanced hippocampal IL-1ß expression in the transgenic mice on postoperative days 3 and 7. A corresponding decline in the levels of TREM2 was also found on postoperative days 3, 7, and 14. Overexpression of TREM2 downregulated the levels of IL-1ß, ameliorated T396 expression, inhibited the activity of GSK-3ß, and improved sickness behavior. Increased Arg1 expression and a high level of synaptophysin were also observed in the transgenic mice following TREM2 overexpression. CONCLUSION: The downregulation of TREM2 exacerbated surgery-induced cognitive deficits and exaggerated neuroinflammatory responses in this rodent model. Overexpression of TREM2 potentially attenuated these effects by decreasing the associated production of proinflammatory cytokines, inhibiting tau hyperphosphorylation, and enhancing synaptophysin expression.

Chronic unpredictable stress exacerbates surgery-induced sickness behavior and neuroinflammatory responses via glucocorticoids secretion in adult rats.

METHODS: Sprague-Dawley adult male rats (12-14 weeks old) were exposed to 14-day CUS and then subjected to partial hepatectomy 24 h after the last stress session. The rats were pretreated with an antagonist of the glucocorticoids (GCs) receptor RU486 (30 mg/kg, i.p.) 1 h prior to stress exposure. The behavioral changes were evaluated with open field test and elevated plus-maze test. The hippocampal cytokines interleukin (IL)-1ß and IL-6 were measured on postoperative days 1, 3 and 7. Ionized calcium binding adaptor protein (Iba)-1, microglial M2 phenotype marker Arg1, brain derived neurotrophic factor (BDNF) and CD200 were also examined at each time point. RESULTS: CUS exacerbated surgery-induced sickness behavior. Exposure to CUS alone failed to alter the levels of pro-inflammatory cytokines in the brain. However, CUS exaggerated surgery-induced pro-inflammatory cytokines expression (e.g. IL-1ß and IL-6) and upregulated the levels of Iba-1 on postoperative days 1 and 3. An additional significant decreased BDNF, CD200 and a lower level of Arg1 were also observed in the stressed rats following surgical procedure. Pretreatment with RU486 blunted the potentiating effects of CUS on surgery-induced sickness behavior and neuroinflammatory responses. CONCLUSION: Chronic unpredictable stress enhanced surgery-induced sickness behavior and neuroinflammatory responses. Stress-induced GCs played a pivotal role in enhancing surgery-induced neuroinflammatory processes by modulation of microglia functions.

Perioperative Care of Elderly Surgical Outpatients.

The ambulatory setting offers potential advantages for elderly patients undergoing elective surgery due to the advancement in both surgical and anesthetic techniques resulting in quicker recovery times, fewer complications, higher patient satisfaction, and reduced costs of care. This review article aims to provide a practical guide to anesthetic management of elderly outpatients. Important considerations in the preoperative evaluation of elderly outpatients with co-existing diseases, as well as the advantages and disadvantages of different anesthetic techniques on a procedural-specific basis, and recommendations regarding the management of common postoperative complications (e.g., pain, postoperative nausea and vomiting [PONV], delirium and cognitive dysfunction, and gastrointestinal dysfunction) are discussed. The role of anesthesiologists as perioperative physicians is important for optimizing surgical outcomes for elderly patients undergoing ambulatory surgery. The implementation of high-quality, evidence-based perioperative care programs for the elderly on an ambulatory basis has assumed increased importance. Optimal management of perioperative pain using opioid-sparing multimodal analgesic techniques and preventing PONV using prophylactic antiemetics are key elements for achieving enhanced recovery after surgery.

An update on the management of postoperative nausea and vomiting.

Postoperative nausea and vomiting (PONV) and postdischarge nausea and vomiting (PDNV) remain common and distressing complications following surgery. PONV and PDNV can delay discharge and recovery and increase medical costs. The high incidence of PONV has persisted in part because of the tremendous growth in ambulatory surgery and the increased emphasis on earlier mobilization and discharge after both minor and major operations. Pharmacological management of PONV should be tailored to the patients' risk level using the PONV and PDNV scoring systems to minimize the potential for these adverse side effects in the postoperative period. A combination of prophylactic antiemetic drugs should be administered to patients with moderate-to-high risk of developing PONV in order to facilitate the recovery process. Optimal management of perioperative pain using opioid-sparing multimodal analgesic techniques and preventing PONV using prophylactic antiemetics are key elements for achieving an enhanced recovery after surgery. Strategies that include reductions of the baseline risk (e.g., adequate hydration, use of opioid-sparing analgesic techniques) as well as a multimodal antiemetic regimen will improve the likelihood of preventing both PONV and PDNV.

Age exacerbates surgery-induced cognitive impairment and neuroinflammation in Sprague-Dawley rats: the role of IL-4.

Age is the most prominent risk factor for the development of postoperative cognitive dysfunction. This study investigated the potential role of anti-inflammatory interleukin (IL)-4 in age-related differences of surgery-induced cognitive deficits and neuroinflammatory responses. Both adult and aged Sprague-Dawley male rats were subjected to partial hepatectomy or partial hepatectomy with a cisterna magna infusion of IL-4. On postoperative days 1, 3, and 7, the rats were subjected to a reversed Morris water maze test. Hippocampal IL-1ß, IL-6, IL-4, and IL-4 receptor (IL-4R) were measured at each time point. Brain derived neurotrophic factor (BDNF), synaptophysin, Ionized calcium-binding adapter molecule 1 (Iba-1), microglial M2 phenotype marker Arg1, and CD200 were also examined in the hippocampus. Age induced an exacerbated cognitive impairment and an amplified neuroinflammatory response triggered by surgical stress on postoperative days 1 and 3. A corresponding decline in the anti-inflammatory cytokine IL-4 and BDNF were also found in the aged rats at the same time point. Treatment with IL-4 downregulated the expression of proinflammatory cytokines (e.g., IL-1ß and IL-6), increased the levels of BDNF and synaptophysin in the brain and improved the behavioral performance. An increased Arg1 expression and a high level of CD200 were also observed after a cisterna magna infusion of IL-4. An age-related decrease in IL-4 expression exacerbated surgery-induced cognitive deficits and exaggerated the neuroinflammatory responses. Treatment with IL-4 potentially attenuated these effects by enhancing BDNF and synaptophysin expression, inhibiting microglia activation and decreasing the associated production of proinflammatory cytokines.

A novel visual facial anxiety scale for assessing preoperative anxiety.

BACKGROUND: There is currently no widely accepted instrument for measuring preoperative anxiety. The objective of this study was to develop a simple visual facial anxiety scale (VFAS) for assessing acute preoperative anxiety. METHODS: The initial VFAS was comprised of 11 similarly styled stick-figure reflecting different types of facial expressions (Fig 1). After obtaining IRB approval, a total of 265 participant-healthcare providers (e.g., anesthesiologists, anesthesiology residents, and perioperative nurses) were recruited to participate in this study. The participants were asked to: (1) rank the 11 faces from 0-10 (0 = no anxiety, while 10 = highest anxiety) and then to (2) match one of the 11 facial expression with a numeric verbal rating scale (NVRS) (0 = no anxiety and 10 = highest level of anxiety) and a specific categorical level of anxiety, namely no anxiety, mild, mild-moderate, moderate, moderate-high or highest anxiety. Based on these data, the Spearman correlation and frequencies of the 11 faces in relation to the 11-point numerical anxiety scale and 6 categorical anxiety levels were calculated. The highest frequency of a face assigned to a level of the numerical anxiety scale resulted in a finalized order of faces corresponding to the 11-point numeric rating scale. RESULTS: The highest frequency for each of the NVRS anxiety scores were as follow: A0, A1, A2, A3, A4, A5, A7, A6, A8, A9 and A10 (Fig 2). For the six categorical anxiety levels, a total of 260 (98.1%) participants chose the face A0 as representing 'no' anxiety, 250 (94.3%) participants chose the face A10 as representing 'highest' anxiety and 147 (55.5%) participants chose the face A8 as representing 'moderate-high' anxiety. Spearman analysis showed a significant correlation between the faces A3 and A5 assigned to the mild-moderate anxiety category (r = 0.58), but A5 was ultimately chosen due to its higher frequency compared to the frequency of A3 (30.6% vs 24.9%)(Fig 3). Similarly, the correlation of the faces A7 and A6 was significantly correlated with moderate anxiety (r = 0.87), but A7 remained because of its higher frequency (35.9% vs 22.6%). Using frequency and Spearman correlations, the final order of the faces assigned to the categories none, mild, mild-moderate, moderate, moderate-high and highest anxiety levels was A0, A1, A5, A7, A8 and A10, respectively (Fig 4). CONCLUSION: The proposed VFAS was a valid tool for assessing the severity of acute [state] anxiety, and could be easy to administer in routine clinical practice.