GluR2 can Drive Neuroinflammation and Cognitive Impairments Following Peripherally Repeated Lipopolysaccharide Exposures.

Neuroinflammation is being increasingly recognized as a vital factor in the development of various neurological and neuropsychiatric diseases. Lipopolysaccharides (LPS), an outer membrane component of gram-negative bacteria, can trigger innate immune responses, resulting in neuroinflammation and subsequent cognitive deficits. The expression of glutamate receptors (GluRs) on glial cells can induce glial activation. Therefore, we hypothesized that repeated LPS exposure can increase GluR levels, promoting microglial activation and ultimately affecting synaptic plasticity and cognitive function. In this study, C57/BL6 mice were repeatedly exposed to LPS to construct a neuroinflammation animal model. The levels of GluRs, inflammatory cytokines, ionized calcium-binding adaptor molecule 1, postsynaptic density protein 95, synaptophysin 38, NMDA receptor 2 A, and NMDA receptor 2B (GluN2B) were measured in the hippocampi. Furthermore, dendritic spine density in the CA1 hippocampal region was determined. Repeated LPS exposure induced cognitive impairments and microglial activation and increased GluR1 and GluR2 levels. This was accompanied by a significant decrease in GluN2B expression and dendritic spine density in the hippocampi. However, CFM-2, an α-amino-3- hydroxy-5-methyl-4-isoxazolepropionate receptor antagonist, reversed these anomalies. Furthermore, minocycline, a microglial inhibitor, reversed these anomalies and downregulated GluR2 but not GluR1 expression. In summary, we demonstrated that GluR2 plays an essential role in microglia-induced neuroinflammation, resulting in synaptic plasticity and cognitive impairment induced by repeated exposure to LPS.

Risk Factors for Acute Postsurgical Pain: A Narrative Review.

Acute postsurgical pain (APSP) has received growing attention as a surgical outcome. When poorly controlled, APSP can affect short- and long-term outcomes in patients. Despite the steady increase in awareness about postoperative pain and standardization of pain prevention and treatment strategies, moderate-to-severe APSP is frequently reported in clinical practice. This is possibly because pain varies widely among individuals and is influenced by distinct factors, such as demographic, perioperative, psychological, and genetic factors. This review investigates the risk factors for APSP, including gender, age, obesity, smoking history, preoperative pain history, pain sensitivity, preoperative anxiety, depression, pain catastrophizing, expected postoperative pain, surgical fear, and genetic polymorphisms. By identifying patients having an increased risk of moderate-to-severe APSP at an early stage, clinicians can more effectively manage individualized analgesic treatment protocols with a combination of pharmacological and non-pharmacological interventions. This would alleviate the transition from APSP to chronic pain and reduce the severity of APSP-induced chronic physical disability and social psychological distress.

Neuroinflammation-induced parvalbumin interneuron and oscillation deficits might contribute to neurobehavioral abnormities in a two-hit model of depression.

Depression is a common neuropsychiatric disorder that causes profound disability worldwide, yet the underlying mechanism remains unclear. Thus, the present study aimed to evaluate the effects of a two-hit model of depression on glial activation, parvalbumin (PV) interneuron, oscillation activity, and behavior alternations, and whether chronic fluoxetine treatment can reverse these abnormalities. Male mice were submitted to lipopolysaccharide (LPS) injection, followed by a modified chronic unpredictable stress (CUS) protocol. In our study, we showed that mice exposed to LPS and CUS exhibited reduced body weight, anhedonic-like behavior as well as cognitive and anxiety symptoms. These behavioral alternations were related to enhanced neuroinflammation, as reflected by significantly increased IL-1ß and IL-6 levels and microglia activation in the prefrontal cortex (PFC). In addition, mice exposed to LPS and CUS displayed significantly decreased PV expression and disturbance of theta and gamma oscillations in the PFC. However, chronic fluoxetine treatment reversed most of these abnormalities. In conclusion, our study suggests that neuroinflammation-induced PV interneuron and oscillation deficits might contribute to neurobehavioral abnormalities in a two-hit model of depression.

Perioperative Administration of Pregabalin and Esketamine to Prevent Chronic Pain After Breast Cancer Surgery: A Randomized Controlled Trial.

Background: Perioperative multimodal analgesia can prevent chronic pain after breast cancer surgery. This study aimed to investigate the efficacy of combined perioperative oral pregabalin and postoperative esketamine in preventing chronic pain after breast cancer surgery. Methods: Ninety patients undergoing elective breast cancer surgery were randomized into the combined pregabalin and esketamine group (EP group) and the general anesthesia alone group (Control group). The EP group received 150 mg of oral pregabalin 1 h before surgery and twice daily for seven days postoperatively, and a patient-controlled analgesia pump after surgery that delivered 100 µg sufentanil + 1.25 mg/kg esketamine + 4 mg tropisetron in 100 mL saline solution intravenously. The Control group received placebo capsules before and after the surgery and routine postoperative analgesia (100 µg sufentanil + 4 mg tropisetron in 100 mL saline solution). The primary outcome was the incidence of chronic pain three and six months after surgery. Secondary outcomes included acute postoperative pain, postoperative opioid consumption, and incidence of adverse events. Results: The incidence of chronic pain in the EP group was significantly lower than in the Control group three (14.3% vs 46.3%, P = 0.005) and six (7.1% vs 31.7%, P = 0.009) months postoperatively. The rest numerical rating scale (NRS) pain scores 1-3 days postoperatively and coughing NRS pain scores 1-7 days postoperatively in the EP group were significantly lower than in the Control group (all P ˂ 0.05). The cumulative sufentanil consumption in the EP group during postoperative 0-12, 12-24, and 24-48, 0-24, and 0-48 hours were significantly lower than in the Control group (all P ˂ 0.05). Conclusion: Combined perioperative oral pregabalin and postoperative esketamine effectively prevented chronic pain after breast cancer surgery, improved acute postoperative pain, and reduced postoperative opioid consumption.

Effects of perioperative use of esketamine on postpartum depression risk in patients undergoing cesarean section: A randomized controlled trial.

BACKGROUND: Postpartum depression (PPD) is a prevalent public health issue. Although ketamine has prophylactic effects on PPD in women undergoing cesarean section, the effects of esketamine on PPD remain unclear. This trial aimed to evaluate the efficacy of perioperative esketamine infusion on PPD risk by assessing Edinburgh Postnatal Depression Scale (EPDS) scores and blood biomarkers. METHODS: A total of 150 participants undergoing elective cesarean section were randomly allocated to receive either esketamine or normal saline. Since 27 participants were excluded due to consent withdrawal or loss to follow-up, 123 patients were included. The primary outcome was the prevalence of PPD risk. Secondary outcomes included the prevalence of postpartum anxiety (PPA) risk, levels of biomarkers, postoperative pain intensity, and cumulative sufentanil consumption. RESULTS: The prevalence of PPD and PPA risk at 3 days, 42 days, 3 months, and 6 months postpartum did not differ between the two groups. Furthermore, EPDS scores, pain intensity at rest, and during coughing on postoperative days (POD) 1 and 2 did not differ between the two groups. Sufentanil consumption during 0-12 h, 12-24 h, 0-24 h, and 0-48 h postoperatively were significantly lower in the esketamine group compared to the control group. Blood biomarkers did not differ between the two groups on POD 3. LIMITATIONS: The sample size was small. PPD risk was simply screened, not diagnosed. CONCLUSIONS: Perioperative administration of esketamine did not decrease the incidence of PPD risk in women after elective cesarean section. However, esketamine reduced opioid consumption.

Ultrasound-Guided Quadratus Lumborum Block Enhances the Quality of Recovery after Gastrointestinal Surgery: A Randomized Controlled Trial.

Background: Quadratus lumborum block (QLB) has been used to reduce postoperative acute pain and opioid consumption. However, the efficacy of QLB on the quality of recovery (QoR) after gastrointestinal surgery has not been established. The aim of this study was to evaluate the ability of QLB to enhance the postoperative QoR in patients undergoing open gastrointestinal surgery. Methods: Eighty-four patients undergoing open gastrointestinal surgery were randomized to receive ultrasound-guided QLB with either 20 ml of 0.375% ropivacaine or saline. The primary outcome was the QoR-15 score at 24 h after surgery. The secondary outcomes were the postoperative pain intensity, opioid consumption, the incidence of nausea, vomiting, and chronic pain. Results: The global QoR-15 score at 24 h postoperatively was significantly higher in the QLB group than in the control group (mean difference: 16.9; 95% CI: 11.9-21.9). Additionally, the QoR-15 scores for five dimensions were significantly higher in the QLB group than in the control group. The cumulative oxycodone consumption was significantly lower in the QLB group during 0-6, 6-24, 0-24, 24-48, and 0-48 h postoperatively than in the control group. At rest or during coughing, the pain verbal rating scale scores were significantly lower at 1, 3, 6, 12, and 24 h after surgery in the QLB group than in the control group. The incidence of postoperative nausea was significantly different between the groups, but postoperative vomiting was not. Conclusion: Single-injection posteromedial QLB with ropivacaine enhanced the QoR at 48 h after surgery and improved analgesia during the early postoperative period in patients undergoing gastrointestinal surgery.

Predictors and predictive effects of acute pain trajectories after gastrointestinal surgery.

Few studies have investigated factors associated with acute postsurgical pain (APSP) trajectories, and whether the APSP trajectory can predict chronic postsurgical pain (CPSP) remains unclear. We aimed to identify the predictors of APSP trajectories in patients undergoing gastrointestinal surgery. Moreover, we hypothesised that APSP trajectories were independently associated with CPSP. We conducted a prospective cohort study of 282 patients undergoing gastrointestinal surgery to describe APSP trajectories. Psychological questionnaires were administered 1 day before surgery. Meanwhile, demographic characteristics and perioperative data were collected. Average pain intensity during the first 7 days after surgery was assessed by a numeric rating scale (NRS). Persistent pain intensity was evaluated at 3 and 6 months postoperatively by phone call interview. CPSP was defined as pain at the incision site or surrounding areas of surgery with a pain NRS score ≥ 1 at rest. The intercept and slope were calculated by linear regression using the least squares method. The predictors for the APSP trajectory and CPSP were determined using multiple linear regression and multivariate logistic regression, respectively. Body mass index, morphine milligram equivalent (MME) consumption, preoperative chronic pain and anxiety were predictors of the APSP trajectory intercept. Moreover, MME consumption and preoperative anxiety could independently predict the APSP trajectory slope. The incidence of CPSP at 3 and 6 months was 30.58% and 16.42% respectively. APSP trajectory and age were predictors of CPSP 3 months postoperatively, while female sex and preoperative anxiety were predictive factors of CPSP 6 months postoperatively. Preoperative anxiety and postoperative analgesic consumption can predict APSP trajectory. In addition, pain trajectory was associated with CPSP. Clinicians need to stay alert for these predictors and pay close attention to pain resolution.

Predictors of Acute Postsurgical Pain following Gastrointestinal Surgery: A Prospective Cohort Study.

Background: Several predictors have been shown to be independently associated with chronic postsurgical pain for gastrointestinal surgery, but few studies have investigated the factors associated with acute postsurgical pain (APSP). The aim of this study was to identify the predictors of APSP intensity and severity through investigating demographic, psychological, and clinical variables. Methods: We performed a prospective cohort study of 282 patients undergoing gastrointestinal surgery to analyze the predictors of APSP. Psychological questionnaires were assessed 1 day before surgery. Meanwhile, demographic characteristics and perioperative data were collected. The primary outcomes are APSP intensity assessed by numeric rating scale (NRS) and APSP severity defined as a clinically meaningful pain when NRS ≥4. The predictors for APSP intensity and severity were determined using multiple linear regression and multivariate logistic regression, respectively. Results: 112 patients (39.7%) reported a clinically meaningful pain during the first 24 hours postoperatively. Oral morphine milligram equivalent (MME) consumption (ß 0.05, 95% CI 0.03-0.07, p < 0.001), preoperative anxiety (ß 0.12, 95% CI 0.08-0.15, p < 0.001), and expected postsurgical pain intensity (ß 0.12, 95% CI 0.06-0.18, p < 0.001) were positively associated with APSP intensity. Furthermore, MME consumption (OR 1.15, 95% CI 1.10-1.21, p < 0.001), preoperative anxiety (OR 1.33, 95% CI 1.21-1.46, p < 0.001), and expected postsurgical pain intensity (OR 1.36, 95% CI 1.17-1.57, p < 0.001) were independently associated with APSP severity. Conclusion: These results suggested that the predictors for APSP intensity following gastrointestinal surgery included analgesic consumption, preoperative anxiety, and expected postsurgical pain, which were also the risk factors for APSP severity.

Quadratus Lumborum Block Spares Postoperative Opioid Usage but Does Not appear to Prevent the Development of Chronic Pain After Gastrointestinal Surgery.

BACKGROUND: Regional anesthesia has been used to reduce acute postsurgical pain and to  prevent chronic pain. The best technique, however, remains controversial. OBJECTIVES: The aim of this study was to assess the short- and long-term postoperative analgesic efficacy of ultrasound-guided quadratus lumborum block (QLB) in open gastrointestinal surgery. STUDY DESIGN: A randomized, double-blinded, controlled trial. SETTING: Operating room; postoperative recovery room and ward. METHODS: One hundred eighteen patients underwent elective gastrointestinal surgery randomly assigned into 2 groups (QLB group or control group). Before anesthetic induction, QLB was performed bilaterally under ultrasound guidance using 20 mL of 0.375% ropivacaine or saline solution at each abdominal wall. The primary outcome was cumulative oxycodone consumption within 24 h after surgery. The secondary outcomes were acute pain intensity, incidence of chronic pain, and incidence of postoperative nausea or vomiting (PONV), dizziness, and pruritus. RESULTS: The cumulative oxycodone consumption was significantly lower in the QLB group during the first 6, 6-24, 24, and 48 h postoperatively when compared to the control group. At rest or during coughing, the numeric rating scale scores were significantly lower at 1, 3, 6, and 12 h postoperatively in the QLB group compared to the control group. There were no significant differences between the 2 groups regarding the incidence of chronic postoperative pain at 3 or 6 months after surgery. Significant differences were found in the incidence of PONV between the two groups, but other complications, such as dizziness and pruritus, did not differ significantly. LIMITATIONS: We did not confirm the QLB effectiveness with sensory level testing after local anesthetic injection. Cumulative oxycodone consumption could have been affected by the patients' use of oxycodone for nonsurgical pain. CONCLUSIONS: Ultrasound-guided QLB provided superior short-term analgesia and reduced oxycodone consumption and the incidence of PONV after gastrointestinal surgery. However, the incidence of chronic pain was not significantly affected by this anesthetic technique.