Anti-inflammatory Effects of Perioperative Dexmedetomidine Administered as an Adjunct to General Anesthesia: A Meta-analysis

Impact of Dexmedetomidine on Analgesia and Inflammatory Response in Knee Surgery: A Study of IPACK and ACB Techniques

BACKGROUND The interspace between the popliteal artery and posterior capsule of the knee block (IPACK) combined with adductor canal block (ACB) has short-term analgesic effect after arthroscopic knee surgery(AKS), and prolonging the duration of analgesia is very important for patients to recover quickly after surgery. The purpose of this study was to investigate whether perineural dexmedetomidine (DEX) or intravenous can prolong the analgesic time of IPACK and ACB, and ultimately promote the postoperative rehabilitation of patients undergoing AKS. MATERIAL AND METHODS In this randomized controlled trial, 102 eligible AKS patients were allocated to 3 groups: perineural DEX with ropivacaine for Group E (n=34), intravenous DEX for Group I (n=34), and standard IPACK-ACB (ropivacaine alone) for Group C (n=34). The outcomes included resting and active Visual Analog Scale (VAS) scores at 6 h, 12 h, 24 h, 48 h, 54 h, and 60 h postoperatively, inflammatory marker levels on the first postoperative day, and maximum walking distance at 24 and 48 hours after surgery. RESULTS There were no significant demographic differences between the 3 groups. Resting and active VAS scores in Group E were significantly lower than those in Group C within 48 hours postoperatively (P<0.05), VAS at 48 h resting state (P<0.001, mean difference,-1.15; 95% CI, -1.65 to -0.65), VAS at 48 h active state (P<0.001, mean difference,-0.91; 95% CI, -1.32 to -0.50). On the first postoperative day, IL-1β levels in Groups E and I were significantly lower than in Group C (P<0.05). Group E had a significantly longer maximum walking distance at 24 and 48 hours after surgery compared to Groups I and C (P<0.001). CONCLUSIONS Perineural DEX prolongs IPACK-ACB analgesia to 48 hours, improves functional recovery, and attenuates IL-1β release, outperforming intravenous administration. These findings support the integration of route-specific DEX into enhanced recovery protocols for AKS.

The immune-inflammatory responses on the hypothalamic-pituitary-adrenal axis and the neurovascular unit in perioperative neurocognitive disorder

Perioperative neurocognitive disorders (PNDs) refer to a wide spectrum of cognitive impairment persisting days to even after a year postoperative with significant morbidity and mortality. However, despite much efforts involving perioperative managements, PNDs are still prevalent with no standard preventative and therapeutic strategy. To overcome PNDs, a better understanding of pathophysiology of PNDs is crucial and a large number of studies have proven that immune-inflammatory responses from surgical stress are involved in the abnormal activation of the hypothalamic-pituitary-adrenal (HPA) axis and destabilization of neurovascular unit (NVU) that lead to PNDs. The HPA axis is one of the key components to maintaining physiological homeostasis in response to stress. Under normal conditions, the HPA axis is involved in multiple roles from memory consolidation to regulating the circadian rhythm by activating adrenal cortex to secret cortisol. However, when overwhelmed with inflammatory response from surgical stress, HPA axis may be abnormally activated to release excessive glucocorticoids to cause PNDs. In addition, NVU, the functional unit of the brain essential for maintaining blood brain barrier and cerebral blood flow, is another possible factor that may lead to PNDs as compromised NVU from inflammatory response can result in disrupted blood brain barrier and impaired brain homeostasis. Therefore, the interaction of immune-inflammatory response with the HPA axis and the NVU seems to play a significant role and therapeutic and/or preventive strategies focused on these interactions may be promising direction for future managements of PNDs.

Postoperative recovery of colorectal patients enhanced with dexmedetomidine (PReCEDex): a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Intraoperative administration of dexmedetomidine has shown promise in improving postoperative gastrointestinal function. In the context of colorectal surgery, the results remain inconsistent. This review aims to provide a synthesis of studies assessing the effect of dexmedetomidine on postoperative gastrointestinal function in colorectal surgery patients.

METHODS

CENTRAL, Emcare, Embase, and MEDLINE were searched up to September 2023. Randomized controlled trials involving adult patients (≥ 18 years) undergoing elective colorectal surgery, comparing dexmedetomidine administration to a control group, and reporting on postoperative gastrointestinal function were included. Non-comparative and emergent procedures were excluded. Primary outcome was time to first flatus or bowel movement, and secondary outcomes included length of stay and time to solid oral intake. Risk of bias was assessed using the Cochrane risk of bias tool for randomized studies.

RESULTS

After screening 1194 citations, eight studies were included. Studies comprised of 570 patients in the dexmedetomidine group (mean age: 65.8 years, 43% female, mean BMI: 22.7 kg/m2) and 556 patients in control group (mean age 70.6 years, 40% female, mean BMI 22.5 kg/m2). Dexmedetomidine administration resulted in a shorter time to flatus (MD -4.55 h, 95% CI: 20.14-8.95, p < 0.005, very low certainty of evidence), a shorter time to first bowel movement (MD -11.9 h, 95% CI: 18.74-5.05, p < 0.005, very low certainty of evidence), a shorter time to solid oral intake (MD -4.34 h, 95% CI: 17.43-11.24, p < 0.005, moderate certainty of evidence), and a shorter length of stay (MD -.06 days, 95% CI: 1.99-0.12, p < 0.05, very low certainty of evidence).

CONCLUSION

In adult patients undergoing elective colorectal surgery, intraoperative use of dexmedetomidine results in clinically meaningful improvements in postoperative gastrointestinal function and consequently, shorter length of stay. Therefore, dexmedetomidine may serve as a valuable adjunct in enhancing postoperative recovery of patients following elective colorectal surgery, thereby reducing healthcare utilization, and improving patient outcomes.

Combining O2 High Flow Nasal or Non-Invasive Ventilation with Cooperative Sedation to Avoid Intubation in Early Diffuse Severe Respiratory Distress Syndrome, Especially in Immunocompromised or COVID Patients?

This overview addresses the pathophysiology of the acute respiratory distress syndrome (ARDS; conventional vs. COVID), the use of oxygen high flow (HFN) vs. noninvasive ventilation (NIV; conventional vs. helmet) and a multi-modal approach to avoid endotracheal intubation ("intubation"): low normal temperature, cooperative sedation, normalized systemic and microcirculation, anti-inflammation, reduced lung water, upright position, lowered intra-abdominal pressure. Increased ventilatory muscle activity ("respiratory drive") is observed in early ARDS, at variance with ventilatory fatigue observed in decompensated chronic obstructive pulmonary disease (COPD). This increased drive leads to impending then overt ventilatory failure. Therefore, muscle relaxation presents little rationale and should be replaced by lowering the excessive respiratory drive, increased work of breathing, continued or increased labored breathing, self-induced lung injury (SILI), i.e. preserving spontaneous breathing. As CMV is a lifesaver in the setting of failure but does not heal the lung, side-effects of intubation, controlled mechanical ventilation (CMV), paralysis and deep sedation are to be avoided. Additionally, critical care resources shortage requires practice changes. Therefore, NIV should be routine when addressing immune-compromised patients. The SARS-CoV2 pandemics extended this approach to most patients, which are immune-compromised: elderly, obese, diabetic, etc. The early COVID is a pulmonary vascular endothelial inflammatory disease requiring lower positive-end-expiratory pressure than the typical pulmonary alveolar epithelial inflammatory diffuse ARDS. This leads one to reassess a) the technique of NIV b) the sedation regimen facilitating continuous and extended NIV to avoid intubation. Autonomic, circulatory, respiratory, ventilatory physiology is hierarchized under HFN/NIV and cooperative sedation (dexmedetomidine, clonidine). A prospective randomized pilot trial, then a larger trial are required to ascertain our working hypotheses.

Absorption pharmacokinetics and feasibility of intranasal dexmedetomidine in patients under general anaesthesia

BACKGROUND

The use of intranasal dexmedetomidine is hampered by a limited understanding of its absorption pharmacokinetics.

METHODS

We examined the pharmacokinetics and feasibility of intranasal dexmedetomidine administered in the supine position to adult patients undergoing general anaesthesia. Twenty-eight patients between 35 and 80 years of age, ASA 1-3 and weight between 50 and 100 kg, who underwent elective unilateral total hip or knee arthroplasty under general anaesthesia were recruited. All patients received 100 μg of intranasal dexmedetomidine after anaesthesia induction. Six venous blood samples (at 0, 5, 15, 45, 60, 240 min timepoints from dexmedetomidine administration) were collected from each patient and dexmedetomidine plasma concentrations were measured. Concentration-time profiles after nasal administration were pooled with earlier data from a population analysis of intravenous dexmedetomidine (n = 202) in order to estimate absorption parameters using nonlinear mixed effects. Peak concentration (CMAX) and time (TMAX) were estimated using simulation (n = 1000) with parameter estimates and their associated variability.

RESULTS

There were 28 adult patients with a mean (SD) age of 66 (8) years and weight of 83 (10) kg. The mean weight-adjusted dose of dexmedetomidine was 1.22 (0.15) μg kg-1. CMAX 0.273 μg L-1 was achieved at 98 min after intranasal administration (TMAX). The relative bioavailability of dexmedetomidine was 80% (95% CI 75-91%). The absorption half-time (TABS = 120 min; 95% CI 90-147 min) was slower than that in previous pharmacokinetic studies on adult patients. Perioperative haemodynamics of all patients remained stable.

CONCLUSIONS

Administration of intranasal dexmedetomidine in the supine position during general anaesthesia is feasible with good bioavailability. This administration method has slower absorption when compared to awake patients in upright position, with consequent concentrations attained after TMAX for several hours.

Effects of dexmedetomidine and ketorolac applied for patient‑controlled analgesia on the balance of Th1/Th2 and level of VEGF in patients undergoing laparoscopic surgery for cervical cancer: A randomized controlled trial

The aim of the present study was to explore the effects of dexmedetomidine (DEX) combined with ketorolac on postoperative patient-controlled analgesia (PCA), the balance of Th1/Th2 and the level of vascular endothelial growth factor (VEGF) in patients with cervical cancer following laparoscopic radical surgery. A total of 70 women with cervical cancer undergoing laparoscopic radical hysterectomy were enrolled in the study to randomly receive postoperative dexmedetomidine combined with ketorolac analgesia (DK group) and postoperative sufentanil analgesia (SUF group). The primary outcomes were the serum levels of interleukin-4 (IL-4), interferon-γ (IFN-γ) and VEGF, and the IFN-γ/IL-4 ratio 30 min before induction (T0), and 24 and 48 h after surgery. Secondary outcomes included numerical rating scale scores at 0 h (T0), 4 h (T1), 12 h (T2), 24 h (T3) and 48 h (T4) postoperatively, cumulative times of rescue analgesia, as well as the incidence of postoperative side effects within 48 h from surgery. Patients in the DK group reported similar analgesic effects as patients in the SUF group at T2, T3 and T4, and the incidence of postoperative nausea and vomiting was significantly lower in the DK group. In the DK group, the serum concentration of IFN-γ and IFN-γ/IL-4 ratio at 24 and 48 h after surgery were higher compared with those in the SUF group. Conversely, the serum concentrations of IL-4 at 24 h after surgery and VEGF at 24 and 48 h after surgery were significantly lower. The results indicated that the combination of DEX and ketorolac for PCA significantly improved postoperative pain and decreased the serum level of VEGF, which are associated with tumor angiogenesis. In addition, it maintained the homeostasis of postoperative immune dysfunction of patients with cervical cancer by shifting the balance between type 1 T helper cells and type 2 T helper cell (Th1/Th2 balance) to Th1 (registration no. ChiCTR1900027979; December 7, 2019).

The significant mechanism and treatments of cell death in heatstroke

With global warming, extreme environmental heat is becoming a social issue of concern, which can cause adverse health results including heatstroke (HS). Severe heat stress is characterized by cell death of direct heat damage, excessive inflammatory responses, and coagulation disorders that can lead to multiple organ dysfunction (MODS) and even death. However, the significant pathophysiological mechanism and treatment of HS are still not fully clear. Various modes of cell death, including apoptosis, pyroptosis, ferroptosis, necroptosis and PANoptosis are involved in MODS induced by heatstroke. In this review, we summarized molecular mechanism, key transcriptional regulation as for HSF1, NRF2, NF-κB and PARP-1, and potential therapies of cell death resulting in CNS, liver, intestine, reproductive system and kidney injury induced by heat stress. Understanding the mechanism of cell death provides new targets to protect multi-organ function in HS.

A Comprehensive Review on the Role of Melatonin's Anesthetic Applications in Pediatric Care

Anesthesia is critical to pediatric care, ensuring the safety and comfort of children undergoing medical procedures. With a growing interest in alternative anesthetic agents, melatonin has emerged as a promising candidate due to its sedative, analgesic, anti-inflammatory, and neuroprotective properties. This comprehensive review explores the potential applications of melatonin in pediatric anesthesia. We delve into the pharmacological characteristics of melatonin, its anesthetic properties, and its clinical applications in pediatric care, including preoperative sedation, adjunct to general anesthesia, postoperative pain management, and prevention of emergence delirium. Additionally, we discuss the safety profile of melatonin, potential adverse effects, and comparative analysis with traditional anesthetics. Finally, we highlight future research directions to provide insights into melatonin's role in pediatric anesthesia and its implications for clinical practice.

Anti-inflammatory potential of remimazolam: A laboratory and clinical investigation

BACKGROUND

Anesthetic agents, particularly intravenous anesthetics, may affect immune function and tumorigenic factors. We herein investigated whether the anti-inflammatory effects of anesthetic agents are attributed to their antioxidant properties. The antioxidant and anti-inflammatory effects of remimazolam, a new anesthetic, remain unclear. We hypothesized that remimazolam exerts anti-inflammatory effects due to its antioxidant properties, which may affect the postoperative inflammatory response. This retrospective clinical study examined this hypothesis using laboratory and clinical approaches.

METHODS

The antioxidant effects of remimazolam and dexmedetomidine were assessed by electron spin resonance (ESR) spectroscopy, and postoperative inflammatory responses were compared in 143 patients who underwent transcatheter aortic valve replacement at Kindai University Hospital between April 2021 and December 2022. The primary endpoint was the presence or absence of the antioxidant effects of the anesthetics themselves using ESR.

RESULTS

Remimazolam at clinical concentrations exerted antioxidant effects, whereas dexmedetomidine did not. Increases in C-reactive protein (CRP) levels on POD3 from preoperative values were significantly smaller in the remimazolam group than in the dexmedetomidine group (1.33 ± 1.29 vs. 2.17 ± 1.84, p = .014).

CONCLUSIONS

Remimazolam exerted stronger anti-inflammatory effects than dexmedetomidine, and these effects were enhanced by its antioxidant properties, which may have affected postoperative CRP production.

The role of dexmedetomidine administered via intravenous infusion as adjunctive therapy to mitigate postoperative delirium and postoperative cognitive dysfunction in elderly patients undergoing regional anesthesia: a meta-analysis of randomized controlled trials

STUDY OBJECTIVE

This meta-analysis aimed to assess whether continuous intravenous administration of DEX during surgery can be part of the measures to prevent the onset of postoperative delirium and postoperative cognitive dysfunction in elderly individuals following regional anesthesia.

METHODS

We searched the databases of PubMed, Embase, the Cochrane Library and China National Knowledge Infrastructure (by June 1, 2023) for all available randomized controlled trials assessing whether intravenous application of dexmedetomidine can help with postoperative delirium and postoperative cognitive dysfunction in the elderly with regional anesthesia. Subsequently, we carried out statistical analysis and graphing using Review Manager software (RevMan version 5.4.1) and STATA software (Version 12.0).

MAIN RESULTS

Within the scope of this meta-analysis, a total of 18 randomized controlled trials were included. Among them, 10 trials aimed to assess the incidence of postoperative delirium as the primary outcome, while the primary focus of the other 8 trials was on the incidence of postoperative cognitive dysfunction. The collective evidence from these 10 studies consistently supports a positive relationship between the intravenous administration of dexmedetomidine and a decreased risk of postoperative delirium (RR: 0.48; 95%CI: 0.37 to 0.63, p < 0.00001, I2 = 0%). The 8 literature articles and experiments evaluating postoperative cognitive dysfunction showed that continuous intravenous infusion of dexmedetomidine during the entire surgical procedure exhibited a positive preventive effect on cognitive dysfunction among the elderly population with no obvious heterogeneity (RR: 0.35; 95%CI: 0.25 to 0.49,p < 0.00001, I2 = 0%).

CONCLUSION

Administering dexmedetomidine intravenously during surgery can potentially play a significant role in preventing postoperative delirium and postoperative cognitive dysfunction in patients older than 60 years with regional anesthesia according to this meta-analysis.

A pre-anesthetic bolus of ketamine versus dexmedetomidine for prevention of postoperative delirium in elderly patients undergoing emergency surgery: a randomized, double-blinded, placebo-controlled study

BACKGROUND

We aimed to evaluate whether a single dose of ketamine or dexmedetomidine before induction of general anesthesia could reduce the incidence of postoperative delirium (primary outcome) or cognitive dysfunction (secondary outcome) in elderly patients undergoing emergency surgery.

PATIENTS AND METHODS

This randomized, double-blinded, placebo-controlled trial included 60 elderly patients who were scheduled for emergency surgery. The patients were randomly assigned into one of three groups (n = 20): group I received 0.9% normal saline, group II received 1 µg/kg dexmedetomidine, and group III received 1 mg/kg ketamine right before anesthesia induction. Patients were observed for three days after surgery and tested for postoperative delirium and cognitive dysfunction using the delirium observation screening scale and the mini-mental state examination score, respectively.

RESULTS

The dexmedetomidine group had the lowest incidence of delirium (p = 0.001) and cognitive dysfunction (p = 0.006) compared to the ketamine and placebo groups. The multivariate logistic regression model revealed that dexmedetomidine reduced the incidence of postoperative delirium by 32% compared to placebo (reference) (OR = 0.684, 95% CI: 0.240-0.971, p = 0.025), whereas ketamine increased the risk by threefold (OR = 3.012, 95% CI: 1.185-9.681, p = 0.013). Furthermore, dexmedetomidine reduced the incidence of postoperative cognitive dysfunction by 62% (OR = 0.375, 95% CI: 0.091-0.543, p = 0.012), whereas ketamine increased the risk by 4.5 times (OR = 4.501, 95% CI: 1.161-8.817, p = 0.006).

CONCLUSION

A single pre-anesthetic bolus of dexmedetomidine is a practical choice for preventing postoperative delirium in elderly patients undergoing emergency surgery.

TRIAL REGISTRATION

This study was approved by the Ethics Committee of Aswan University Hospital (approval number: aswu/548/7/2021; registration date: 06/07/2021) and registered on ClinicalTrials.gov (NCT05341154) (22/04/2022).

Dexmedetomidine alleviates propofol-induced neural injury in developing rats

Propofol, a commonly used intravenous anesthetic, has been associated with neurodegeneration in the developing brain upon repeated exposure. Dexmedetomidine is an α2 adrenoceptor agonist that was previously reported to possess neuroprotective properties. Here, we confirmed the impacts of dexmedetomidine on propofol-induced neuroapoptosis and subsequent spatial learning and memory deficits in neonatal rats. We found that dexmedetomidine effectively mitigated propofol-induced spatial learning and memory impairments and improved aversive memory in developing rats. Dexmedetomidine reduced propofol-induced cell apoptosis in the hippocampus and modulated the mRNA expression of Bcl-2 and Bax. Additionally, dexmedetomidine attenuated the propofol-induced increase of inflammatory factors IL-6 and TNF-α. The reduced phosphorylation levels of Akt and CREB levels by propofol were re-activated by dexmedetomidine. In conclusion, our findings demonstrated that dexmedetomidine effectively mitigated propofol-induced cognitive and memory impairments in developing rats by modulating apoptosis and reducing inflammation via activating the Akt/CREB/BDNF signaling pathway. These findings suggest potential strategies to protect the developing brain from the adverse effects of anesthetics and improve patient care in pediatric anesthesia practice.

Improved understanding of the respiratory drive pathophysiology could lead to earlier spontaneous breathing in severe acute respiratory distress syndrome

Optimisation of the respiratory drive, as early as possible in the setting of severe acute respiratory distress syndrome (ARDS) and not its suppression, could be a new paradigm in the management of severe forms of ARDS. Severe ARDS is characterised by tachypnoea and hyperpnoea, a consequence of a high respiratory drive. Some patients require endotracheal intubation, controlled mechanical ventilation (CMV) and paralysis to prevent overt ventilatory failure and self-inflicted lung injury. Nevertheless, intubation, CMV and paralysis do not address per se the high respiratory drive, they only suppress it. Optimisation of the respiratory drive could be obtained by a multimodal approach that targets attenuation of fever, agitation, systemic and peripheral acidosis, inflammation, extravascular lung water and changes in carbon dioxide levels. The paradigm we present, based on pathophysiological considerations, is that as soon as these factors have been controlled, spontaneous breathing could resume because hypoxaemia is the least important input to the respiratory drive. Hypoxaemia could be handled by combining positive end-expiratory pressure (PEEP) to prevent early expiratory closure and low pressure support to minimise the work of breathing (WOB). 'Cooperative' sedation with alpha-2 agonists, supplemented with neuroleptics if required, is the pharmacological adjunct, administered immediately after intubation as the first-line sedation regimen during the multimodal approach. Given relative contraindications (hypovolaemia, auriculoventricular block, sick sinus syndrome), alpha-2 agonists can help attenuate or moderate fever, increased oxygen consumption VO2, agitation, high cardiac output, inflammation and acidosis. They may also help to preserve microcirculation, cognition and respiratory rhythm generation, thus promoting spontaneous breathing. Returning the physiology of respiratory, ventilatory, circulatory and autonomic systems to normal will support the paradigm of optimised respiratory drive favouring early spontaneous ventilation, at variance with deep sedation, extended paralysis, CMV and use of the prone position as therapeutic strategies in severe ARDS.

GLOSSARY

Glossary and Abbreviations_SDC.

Effect of Dexmedetomidine on Postoperative Plasma Neurofilament Light Chain in Elderly Patients Undergoing Thoracoscopic Surgery: A Prospective, Randomized Controlled Trial

Purpose

Dexmedetomidine exerts a neuroprotective effect, however, the mechanism underlying this effect remains unclear. This study aimed to explore whether dexmedetomidine can reduce the increase in neurofilament light chain (NfL) protein concentration to play a neuroprotective role during thoracoscopic surgery.

Patients and Methods

Patients aged ≥60 years undergoing general anesthesia for thoracoscopic surgery were randomly assigned to receive dexmedetomidine (group D) or not receive dexmedetomidine (group C). Patients in group D received a loading dose of dexmedetomidine 0.5 µg/kg before anesthesia induction and a continuous infusion at 0.5 μg·kg-1·h-1 until the end of the surgery. Dexmedetomidine was not administered in group C. The primary outcome was the NfL concentration on postoperative day 1. The concentrations of procalcitonin (PCT), serum amyloid A (SAA), and high-sensitivity C-reactive protein (hs-CRP) were detected preoperatively and on postoperative day 1. In addition, the numerical rating scale (NRS) and quality of recovery-40 (QoR-40) scores were evaluated.

Results

A total of 38 patients in group D and 37 in group C were included in the analysis. No differences were observed between the groups in terms of the plasma concentration of NfL preoperatively and on postoperative day 1 (11.17 [8.86, 13.93] vs 13.15 [10.76, 15.56] pg/mL, P > 0.05; 16.70 [12.23, 21.15] vs 19.48 [15.25, 22.85] pg/mL, P > 0.05, respectively). However, the postoperative plasma NfL concentration was significantly higher than the preoperative value in both groups (both P < 0.001). The groups exhibited no differences in PCT, SAA, hs-CRP, NRS, and QoR-40 (all P > 0.05).

Conclusion

Intraoperative administration of dexmedetomidine at a conventional dose does not appear to significantly reduce the increase in postoperative plasma NfL concentration in elderly patients undergoing thoracoscopic surgery. This finding suggests that the neuroprotective effect of dexmedetomidine at a conventional dose was not obvious during general anesthesia.

Systemic inflammation, neuroinflammation and perioperative neurocognitive disorders

Perioperative neurocognitive disorder (PND) is a common disorder following anesthesia and surgery, especially in the elderly. The complex cellular and molecular processes are involved in PND, but the underlying pathogenesis of which remains inconclusive due to conflicting data. A growing body of evidence has been shown that perioperative systemic inflammation plays important roles in the development of PND. We reviewed the relevant literature retrieved by a search in the PubMed database (on July 20, 2023). The search terms used were "delirium", "post operative cognitive dysfunction", "perioperative neurocognitive disorder", "inflammation" and "systemic", alone and in combination. All articles identified were English-language, full-text papers. The ones cited in the review are those that make a substantial contribution to the knowledge about systemic inflammation and PNDs. The aim of this review is to bring together the latest evidence for the understanding of how perioperative systemic inflammation mediates neuroinflammation and brain injury, how the inflammation is regulated and how we can translate these findings into prevention and/or treatment for PND.

Dexmedetomidine in the Treatment of Depression: An Up-to-date Narrative Review

Depressive disorders (DD) are common, and their prevalence is expected to rise over the next decade. Depressive disorders are linked to significant morbidity and mortality. The clinical conundrum of depressive disorders lies in the heterogeneity of their phenomenology and etiology. Further, the currently available antidepressants have several limitations, including a delayed onset of action, limited efficacy, and an unfavorable side effect profile. In this review, Dexmedetomidine (DEX), a highly selective and potent α2-adrenergic receptor (α2-AR) agonist, is proposed as a potentially novel antidepressant with multiple mechanisms of action targeting various depression pathophysiological processes. These mechanisms include modulation of the noradrenergic system, regulation of neuroinflammation and oxidative stress, influence on the Brain-Derived Neurotrophic Factor (BDNF) levels, and modulation of neurotransmitter systems, such as glutamate. The review begins with an introduction before moving on to a discussion of DEX's pharmacological features. The pathophysiological and phenomenological targets of DD are also explored, along with the review of the existing preclinical and clinical evidence for DEX's putative anti-depressant effects. Finally, the review ends by presenting the pertinent conclusions and future directions.

Dexmedetomidine improves the outcomes for pediatric severe sepsis with mechanical ventilation

BACKGROUND

The sedative dexmedetomidine has been shown to reduce mortality in adult patients with severe sepsis, but it is not known whether children benefit. This study explored the effects of dexmedetomidine on the outcomes of children with severe sepsis with mechanical ventilation.

METHODS

In this retrospective cohort study, children with severe sepsis requiring mechanical ventilation from 2016 to 2020 were categorized as dexmedetomidine and non-dexmedetomidine group. The propensity score matching was performed to match cases in both groups. The primary outcome was 28-day mortality, and the secondary outcomes were acute kidney injury, ventilator-free days, lengths of PICU and hospital stays. The Kaplan-Meier method and was the log-rank test used to estimate the 28-day mortality rate and assess between-group differences.

RESULTS

In total, 250 patients were eligible patients: 138 in the dexmedetomidine group and 112 in the non-dexmedetomidine group. After 1:1 propensity score matching, 61 children in each group. dexmedetomidine group showed more lower 28-day mortality (9.84% vs. 26.23%, P = 0.008). During the 7-day observation period after PICU admission, the dexmedetomidine group showed significantly lower neurological and renal sub-scores at day 7 and serum creatinine level at day 3 and day 7. There were no statistical differences in the incidence of acute kidney injury, ventilator-free days, lengths of PICU and hospital stays between the two groups.

CONCLUSIONS

dexmedetomidine treatment in children with severe sepsis is associated with better outcomes and should therefore be considered for the sedation strategy.

Differential effects of dexmedetomidine on Gram-positive and Gram-negative bacterial killing and phagocytosis

Dexmedetomidine is a commonly used sedative in perioperative and intensive care settings with purported immunomodulatory properties. Since its effects on immune functions against infections have not been extensively studied, we tested the effects of dexmedetomidine on Gram-positive [Staphylococcus aureus and Enterococcus faecalis] and Gram-negative bacteria [Escherichia coli], and on effector functions of human monocytes THP-1 cells against them. We evaluated phagocytosis, reactive oxygen species (ROS) formation, and CD11b activation, and performed RNA sequencing analyses. Our study revealed that dexmedetomidine improved Gram-positive but mitigated Gram-negative bacterial phagocytosis and killing in THP-1 cells. The attenuation of Toll-like receptor 4 (TLR4) signaling by dexmedetomidine was previously reported. Thus, we tested TLR4 inhibitor TAK242. Similar to dexmedetomidine, TAK242 reduced E. coli phagocytosis but enhanced CD11b activation. The reduced TLR4 response potentially increases CD11b activation and ROS generation and subsequently enhances Gram-positive bacterial killing. Conversely, dexmedetomidine may inhibit the TLR4-signaling pathway and mitigate the alternative phagocytosis pathway induced by TLR4 activation through LPS-mediated Gram-negative bacteria, resulting in worsened bacterial loads. We also examined another α2 adrenergic agonist, xylazine. Because xylazine did not affect bacterial clearance, we proposed that dexmedetomidine may have an off-target effect on bacterial killing process, potentially involving crosstalk between CD11b and TLR4. Despite its potential to attenuate inflammation, we provide a novel insight into potential risks of dexmedetomidine use during Gram-negative infections, highlighting the differential effect of dexmedetomidine on Gram-positive and Gram-negative bacteria.

Dexmedetomidine, an α2 agonist, increases the morphine analgesic effect and decreases morphine tolerance development by suppressing oxidative stress and TNF/IL-1 signalling pathway in rats

BACKGROUND

The aim of the present study is to examine the possible effect de dexmedetomidine on the development of morphine tolerance in rats including nociception, morphine analgesia, apoptosis, oxidative stress, and tumour necrosis factor (TNF)/ interleukin-1 (IL-1) pathways.

MATERIALS AND METHODS

In this study, 36 Wistar Albino (225-245 g) rats were used. Animals were divided into 6 groups: saline (S), 20 mcg/kg dexmedetomidine (D), 5 mg/kg morphine (M), M + D, morphine tolerance (MT), and MT + D. The analgesic effect was measured with hot plate and tail-flick analgesia tests. After the analgesia tests, the dorsal root ganglia (DRG) tissues were excised. Oxidative stress parameters [total antioxidant status (TAS), total oxidant status (TOS)], TNF, IL-1 and apoptosis enzymes (Caspase-3, Caspase-9), were measured in DRG tissues.

RESULTS

Dexmedetomidine showed an antinociceptive effect when given alone (p < 0.05 to p < 0.001). In addition, dexmedetomidine increased the analgesic effect of morphine (p < 0.001), and also decreased the tolerance to morphine at a significant level (p < 0.01 to p < 0.001). Moreover, it decreased oxidative stress (p < 0.001) and TNF/IL-1 levels when given as an additional drug of single-dose morphine and morphine tolerance group (p < 0.001). Furthermore, dexmedetomidine decreased Caspase-3 and Caspase-9 levels after tolerance development (p < 0.001).

CONCLUSION

Dexmedetomidine has antinociceptive properties, and it increases the analgesic effect of morphine and also prevents tolerance development. These effects probably occur by the modulation of oxidative stress, inflammation and apoptosis.

Dexmedetomidine ameliorates liver injury and maintains liver function in patients with hepatocellular carcinoma after hepatectomy: a retrospective cohort study with propensity score matching

Background

Although dexmedetomidine (DEX) is widely used during the perioperative period in patients with hepatocellular carcinoma (HCC), its clinical effects on liver function and postoperative inflammation are unclear. This study aimed to explore effects of DEX on postoperative liver function and inflammation in patients with HCC after hepatectomy.

Methods

A retrospective cohort study with propensity score matching was performed. A total of 494 patients who underwent hepatectomy from June 2019 to July 2020 and fulfilled the eligibility criteria were included in this study. Baseline data, liver function indexes and inflammation-related biomarkers were collected and compared between the two groups. Survival analysis was conducted to investigate the effects of DEX on the overall survival (OS) of patients. Propensity score matching (PSM) was used to minimize bias between the two groups.

Results

The study cohort comprised 189 patients in the DEX-free group and 305 patients in the DEX group. Patients in the DEX group had lower levels of alanine transaminase (ALT, P = 0.018) and lactate dehydrogenase (LDH, P = 0.046) and higher level of serum albumin (ALB, P < 0.001) than patients in the DEX-free group before discharge. A total of 107 pairs of patients were successfully matched by PSM. Results consistently suggested that ALT and LDH levels were significantly lower (P = 0.044 and P = 0.046, respectively) and ALB levels were significantly higher (P = 0.002) in the DEX group than in the DEX-free group in the early postoperative period. No significant differences of inflammation-related biomarkers were observed between two groups after PSM. Neither the Kaplan-Meier survival analysis nor the multiple Cox regression survival analysis identified DEX as a contributing factor that would affect the OS of patients after PSM.

Conclusion

DEX exerts protective effects on liver function while has little effects on inflammation-related biomarkers in the early postoperative period in patients undergoing hepatectomy due to HCC.

Effects of Dexmedetomidine on Immunomodulation and Pain Control in Videolaparoscopic Cholecystectomies: A Randomized, Two-Arm, Double-Blinded, Placebo-Controlled Trial

AIM

Digital and robotic technology applications in laparoscopic surgery have revolutionized routine cholecystectomy. Insufflation of the peritoneal space is vital for its safety but comes at the cost of ischemia-reperfusion-induced intraabdominal organ compromise before the return of physiologic functions. Dexmedetomidine in general anesthesia promotes controlling the response to trauma by altering the neuroinflammatory reflex. This strategy may improve clinical outcomes in the postoperative period by reducing postoperative narcotic use and lowering the risk of subsequent addiction. In this study, the authors aimed to evaluate dexmedetomidine's therapeutic and immunomodulatory potential on perioperative organ function.

METHODS

Fifty-two patients were randomized 1:1: group A-sevoflurane and dexmedetomidine (dexmedetomidine infusion [1 µg/kg loading, 0.2-0.5 µg/kg/h maintenance dose]), and group B-sevoflurane with saline 0.9% infusion as a placebo control. Three blood samples were collected: preoperatively (T0 h), 4-6 h after surgery (T4-6 h), and 24 h postoperatively (T24 h). The primary outcome was the level analysis of inflammatory and endocrine mediators. Secondary outcome measures were the time to return to normal preoperative hemodynamic parameters, spontaneous ventilation, and postoperative narcotic requirements to control surgical pain.

RESULTS

A reduction of Interleukin 6 was found at 4-6 h after surgery in group A with a mean of 54.76 (27.15-82.37; CI 95%) vs. 97.43 (53.63-141.22); p = 0.0425) in group B patients. Systolic and diastolic blood pressure and heart rate were lower in group A patients, who also had a statistically significantly lower opioid consumption in the first postoperative hour when compared to group B patients (p < 0.0001). We noticed a similar return to spontaneous ventilation pattern in both groups.

CONCLUSIONS

Dexmedetomidine decreased interleukin-6 4-6 h after surgery, likely by providing a sympatholytic effect. It provides good perioperative analgesia without respiratory depression. Implementing dexmedetomidine during laparoscopic cholecystectomy has a good safety profile and may lower healthcare expenditure due to faster postoperative recovery.

In a secondary analysis from a randomised, double-blind placebo-controlled trial Dexmedetomidine blocks cholinergic dysregulation in delirium pathogenesis in patients with major surgery

Dexmedetomidine is an alpha-2 adrenoreceptor agonist with anti-inflammatory and anti-delirogenic properties. Pathogenesis of postoperative delirium (POD) includes cholinergic dysfunction and deregulated inflammatory response to surgical trauma. Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are discussed as biomarkers for both POD and severity in acute inflammation. To show whether there is a link between blood cholinesterase activities and dexmedetomidine, we performed a secondary analysis of a randomised, double-blind, placebo-controlled trial that recently showed a lower incidence of POD in the dexmedetomidine group. Abdominal or cardiac surgical patients aged ≥ 60 years were randomised to receive dexmedetomidine or placebo intra- and postoperatively in addition to standard general anaesthesia. We analysed the course of perioperative cholinesterase activities of 56 patients, measured preoperatively and twice postoperatively. Dexmedetomidine resulted in no change in AChE activity and caused a rapid recovery of BChE activity after an initial decrease, while placebo showed a significant decrease in both cholinesterase activities. There were no significant between-group differences at any point in time. From these data it can be assumed that dexmedetomidine could alleviate POD via altering the cholinergic anti-inflammatory pathway (CAIP). We advocate for further investigations to show the direct connection between dexmedetomidine and cholinesterase activity.

Anesthesia and pain management of pediatric cytoreductive surgery with hyperthermic intraperitoneal chemotherapy

BACKGROUND

Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy has shown to improve survival in patients with extensive or refractory abdominal tumors of many different histologies. Postoperative pain control can be challenging as the surgical procedure is performed through a midline laparotomy incision from xiphoid to symphysis pubis, and patients are usually nothing by mouth for the first 8-10 postoperative days.

AIMS

We present the anesthetic management and postoperative pain control strategies for cytoreductive surgery with hyperthermic intraperitoneal chemotherapy using a multimodal, opioid-sparing, and total intravenous anesthetic technique with a tunneled thoracic epidural.

METHODS

A single institution retrospective review of anesthetic management, intraoperative fluid and blood administration, and postoperative pain control for pediatric patients undergoing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy between July 2018 and December 2020 was conducted. We employed a novel anesthetic and analgesia protocol consisting of premedication with gabapentin followed by intraoperative infusions of propofol, dexmedetomidine, ketamine, and cisatracurium. A tunneled thoracic epidural catheter was placed for management of pain.

RESULTS

We reviewed and analyzed the first 25 patient records. The most common diagnosis was desmoplastic small round cell tumor (n = 12). Median age of patients was 14 years (range 21 months-22 years). All patients were extubated in the operating room and no patients required reintubation. There were no incidences of acute kidney injury. Epidural infusions were used for a median of 8 days (range 2-14 days). Median postoperative intravenous opioid use (morphine equivalent) through postoperative day 10 was 0.02 mg/kg/day (range 0-0.86 mg/kg/day) administered for a median of 2 days (range 0-17 days). Nine patients (36%) did not require any intravenous opioids in the postoperative period.

CONCLUSIONS

Utilizing a multimodal, opioid-sparing, total intravenous anesthetic technique in conjunction with a tunneled thoracic epidural catheter, we were able to avoid the need for postoperative mechanical ventilation and minimize both intraoperative and postoperative opioid requirements.

Outcomes of dexmedetomidine as adjuvant drug in patients undergoing videolaparoscopic cholecystectomy: A randomized and prospective clinical trial

OBJECTIVE

The repercussions of ischemia-reperfusion and inflammatory response to surgical injury may compromise the return of physiologic processes in video-laparoscopic surgeries. Dexmedetomidine, as an adjuvant drug in general anesthesia, alters the neuroinflammatory reaction, provides better clinical outcomes in the perioperative period, and may reduce the excessive use of chronic medication in patients with a history of addiction. This study evaluated the immunomodulatory potential of dexmedetomidine on perioperative organ function in video-laparoscopic cholecystectomy patients.

METHODS

There were two groups: Sevoflurane and Dexmedetomidine A (26 patients) vs. Sevoflurane and Saline 0.9% B (26 patients). Three blood samples were collected three times: 1) before surgery, 2) 4-6h after surgery, and 3) 24h postoperatively. Inflammatory and endocrine mediators were protocolized for analysis. Finally, hemodynamic outcomes, quality upon awakening, pain, postoperative nausea and vomiting, and opioid use were compared between groups.

RESULTS

We have demonstrated a reduction of Interleukin 6 six hours after surgery in group A: 34.10 (IQR 13.88-56.15) vs. 65.79 (IQR 23.13-104.97; p = 0.0425) in group B. Systolic blood pressure, diastolic blood pressure, and mean arterial pressure was attenuated in group A in their measurement intervals (p < 0.0001). There was a lower incidence of pain and opioid consumption in the first postoperative hour favoring this group (p < 0.0001). We noticed better quality upon awakening after the intervention when comparing the values of peripheral oxygen saturation and respiratory rate.

CONCLUSIONS

Dexmedetomidine provided anti-inflammatory benefits and contributed to postoperative analgesia without the depressive side effects on the respiratory and cardiovascular systems commonly observed with opioids.

TRIAL REGISTRATION

Immunomodulatory Effect of Dexmedetomidine as an Adjuvant Drug in Laparoscopic Cholecystectomies, NCT05489900, Registered 5 August 2022-Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT05489900?term=NCT05489900&draw=2&rank=1.

Standard opioid-containing versus opioid-sparing anesthesia on early postoperative recovery after video-assisted thoracic surgery: A propensity-weighted analysis

PURPOSE

Opioids have several adverse effects. At present, there are no large clinical studies on the effects of opioid-sparing anesthesia on early postoperative recovery after thoracoscopic surgery. This study was to investigate the effects of opioid-sparing anesthesia on early postoperative recovery after thoracoscopic surgery.

METHODS

Adult patients who underwent video-assisted thoracic surgery from 1 January 2019 to 28 February 2021 were enrolled by reviewing the electronic medical records. Participants were divided into opioid-sparing anesthesia (OSA group) and opioid-containing anesthesia (STD group) based on intraoperative opioid usage. The propensity-score analysis was to compare the early postoperative recovery of two groups. The outcome measurements included the incidence of postoperative nausea and vomiting (PONV) during an entire hospital stay, need for rescue antiemetic medication, postoperative-pain episodes within 48 h after surgery, need for rescue analgesia 48 h postoperatively, duration of postoperative hospital stay, length of PACU stay, postoperative fever, postoperative shivering, postoperative atrial fibrillation, postoperative pulmonary infection, postoperative hypoalbuminemia, postoperative hypoxemia, intraoperative blood loss, and intraoperative urine output.

RESULTS

A total of 1,975 patients were identified. No significant difference was observed in patient characteristics between the OSA and STD groups after adjusting for propensity score-based inverse probability treatment weighting. The incidence of postoperative nausea and vomiting was significantly lower in the OSA group than in the STD group (14.7% vs. 18.9%, p = 0.041). The rescue antiemetic use rate was lower in the OSA group than in the STD group (7.5% vs.12.2%; p = 0.002). PACU duration was longer in the OSA group than in the STD group (70.8 ± 29.0 min vs. 67.3 ± 22.7 min; p = 0.016). The incidence of postoperative fever was higher in the STD group than that in the OSA group (11.0% vs.7.7%; p = 0.032). There were no differences between the groups in terms of other outcomes.

CONCLUSIONS

Our results suggest that opioid-sparing anesthesia has a lower incidence of postoperative complications than opioid-based anesthetic techniques.

A comparison of opioid-containing anesthesia versus opioid-free anesthesia using the Cortínez-Sepúlveda model on differential cytokine responses in obese patients undergoing gastric bypass surgery: a randomized controlled trial

Background

Opioid anesthetic agents can modulate the impaired immune response in obese patients through mechanisms that involve the expression and release of cytokines. For this reason, anesthetic care for obese patients remains controversial. Therefore, the aim of the study was to compare the effect of opioid-containing anesthesia (OCA) vs opioid-free anesthesia (OFA) using the Cortínez-Sepúlveda model on IL-6, IL-1β and TNF-α serum levels before and after surgery in obese patients undergoing bypass surgery.

Methods

This randomized cross-sectional study conducted among 40 unrelated obese adults was performed in the Civil Hospital of Guadalajara “Dr. Juan I. Menchaca”. Before undergoing laparoscopic Roux-en-Y gastric bypass, patients were randomly assigned to two anesthesia groups: OCA (n = 20) or OFA (n = 20). Fentanyl was the opioid used in the OCA group. The Cortínez-Sepúlveda pharmacokinetic model was used to characterize the disposition of intravenous propofol for the target-controlled infusion technique in obese patients. Body mass was determined to the nearest 0.05 kg using a balance scale (Seca 703; Seca, Hamburg, Germany). Blood samples were taken before and immediately after surgery and cytokine concentrations were determined by ELISA. Pain was assessed using a numerical pain rating scale. Adverse effects were collected within the first 24 h after surgery.

Results

A total of 6 men and 34 women were included (37.9 ± 10.6 years). Pre-surgery IL-6 and TNF-α serum levels were not detected in study subjects. However, IL-1β levels significantly decreased after surgery (49.58 pg/mL (18.50–112.20)-before surgery vs 13 pg/mL (5.43–22)-after surgery, p = 0.019). IL-6 concentrations were significantly higher in subjects who received OCA (with fentanyl) compared to subjects with OFA (224.5 pg/mL (186.3–262.8) vs 99.5 pg/mL (60.8–138.2), respectively, p < 0.001; adjusted by age, gender, and BMI). In addition, the use of opioids confers an increased risk for higher IL-6 levels in obese patients (OR = 2.95, 95% CI: 1.2–7.2, p = 0.010). A linear regression model showed that the operative time (in hours) of bypass surgery and anesthetic technique were positively correlated with IL-6 levels.

Conclusion

Anesthesia with opioids correlated positively with IL-6 serum levels in obese patients undergoing bypass surgery. This finding could have clinical relevance when an appropriate anesthetic management plan is selected for bariatric surgical patients.

Trial registration

The study was retrospectively registered at ClinicalTrials.gov Identification Number: NCT04854252, date 22/04/2021.

Impact of intravenous dexmedetomidine on gastrointestinal function recovery after laparoscopic hysteromyomectomy: a randomized clinical trial

Postoperative intestinal ileus is common after laparoscopic surgery, the incidence of those after hysterectomy was 9.2%. Anesthesia is one of the independent risk factors of postoperative ileus. Dexmedetomidine has been widely used in perioperative anesthesia and previous reports suggested that intraoperative dexmedetomidine may be associated with the improvement of gastrointestinal function recovery after abdominal surgery. We hypothesized that dexmedetomidine could improve gastrointestinal function recovery after laparoscopic hysteromyomectomy. Participants in elective laparoscopic hysteromyomectomy were enrolled with a single dose of 0.5 μg kg⁻¹ dexmedetomidine or the same volume of placebo intravenously administered for 15 min, followed by continuous pumping of 0.2 μg kg⁻¹ h⁻¹ of corresponding drugs until 30 min before the end of surgery. The primary outcome was the time to first flatus. Secondary outcomes were the time to first oral feeding and the first defecation, the occurrence of flatulence, pain score and postoperative nausea and vomiting until 48 h after the surgery. Eventually, 106 participants (54 in dexmedetomidine group and 52 in placebo group) were included for final analysis. The time to first flatus (SD, 25.83 [4.18] vs 27.67 [3.77], P = 0.019), oral feeding time (SD, 27.29 [4.40] vs 28.92 [3.82], P = 0.044), the time to first defecation (SD, 59.82 [10.49] vs 63.89 [7.71], P = 0.025), abdominal distension (n%, 12 (22.2) vs 21 (40.4), P = 0.044), PONV at 24 h (n%, 10 (18.5) vs 19 (36.5), P = 0.037), NRS 6 h (3.15(0.68) vs 3.46 (0.87), P = 0.043) and NRS 12 h (3.43 (0.88) vs 3.85 (0.85), P = 0.014) of dexmedetomidine group were significantly shorter than those of the placebo group. Intraoperative dexmedetomidine reduced the time to first flatus, first oral feeding, and first defecation. These results suggested that this treatment may be a feasible strategy for improving postoperative gastrointestinal function recovery in patients undergoing laparoscopic hysteromyomectomy.

The Effect of Low-Dose Dexmedetomidine on Pain and Inflammation in Patients Undergoing Laparoscopic Hysterectomy

Dexmedetomidine has sedative, sympatholytic, analgesic, and anti-inflammatory effects. We investigated the effects of intraoperative dexmedetomidine infusion without a loading dose in the prevention of pain and inflammation after laparoscopic hysterectomy. In this study, 100 patients undergoing laparoscopic hysterectomy under desflurane anesthesia were randomized to receive either 0.9% saline or dexmedetomidine (0.4 μg/kg/h) after induction to trocar removal. The primary endpoints were postoperative pain and inflammatory response presented by the level of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), IL-10, and C-reactive protein (CRP). The secondary endpoints were hemodynamics during the anesthesia and surgery and postoperative nausea and vomiting. Postoperative pain was decreased in the dexmedetomidine group for every time point, and post-anesthesia care unit (PACU) rescue fentanyl doses were decreased in the dexmedetomidine group. The inflammatory response representing TNF-α, IL-6, IL-10, and CRP were similar across the two groups. Postoperative nausea and vomiting from PACU discharge to 24 h post-surgery were reduced in the dexmedetomidine group. During anesthesia and surgery, the patient's heart rate was maintained lower in the dexmedetomidine-receiving group. Dexmedetomidine of 0.4 μg/kg/h given as an intraoperative infusion significantly reduced postoperative pain but did not reduce the inflammatory responses in patients undergoing laparoscopic hysterectomy.

Extra Loading Dose of Dexmedetomidine Enhances Intestinal Function Recovery After Colorectal Resection: A Retrospective Cohort Study

Importance: Postoperative gastrointestinal dysfunction (POGD) may be caused by postoperative vagus nerve tension inhibition and systemic inflammation. Dexmedetomidine (Dex) increases vagus nerve tone and affords an anti-inflammatory property, which may play a role in pathogenesis. Objective: To investigate whether a higher dose of Dex enhances gastrointestinal function recovery. Design: In this retrospective study, patients receiving colorectal surgery at the First Affiliated Hospital of Xi'an Jiaotong University from 2017 to 2019 were included. We evaluated the postoperative flatus time between recipients who received loading plus maintenance dose of DEX (LMD group, 237 recipients) and those who recieved maintenance dose of DEX (MD group, 302 recipients). Data were analyzed by logical regression and stratified and interaction analyses. The simulated pharmacokinetics of two DEX regimens was compared using the Tivatrainer software. Thirty paired blood samples from patients whose propensity scores matched with POGD-related factors at 24 h postoperatively were randomly selected, and their tumor necrosis factor-α (TNF-α), cyclooxygenase-2 (COX-2), d-lactate (DLA), acetylcholine (Ach), interleukin (IL)-10, lipopolysaccharide (LPS), IL-6, and inducible nitric oxide synthase (iNOS) levels were measured. Setting: Operating rooms and general surgery wards. Participants: Among the 644 patients undergoing colorectal surgery, 12 who had a colostomy, 26 without Dex infusion, 20 whose Dex administration mode cannot be classified, and 47 with a history of intestinal surgery were excluded. A total of 539 patients were included. Result: Compared with the MD group, the LMD group had a shorter recovery time to flatus; lower incidences of nausea, vomiting, abdominal distension, and abdominal pain (p < 0.05); and a slightly decreased heart rate. The LMD group was the independent factor of POGD (OR = 0.59, 95% CI = 0.41-0.87, p = 0.007) without being reversed in stratified and interaction analyses and had higher Dex plasma concentration from skin incision to 8 h postoperatively. The LMD group had a 39% and 43% increase in Ach and IL-10 levels, respectively, and a 33%-77% decrease in TNF-α, IL-6, COX-2, iNOS, LPS, and DLA levels (p < 0.05). Conclusion: Adding an extra loading dose of Dex can increase parasympathetic tone and decrease inflammation; hence, it can enhance postoperative gastrointestinal function recovery following colorectal surgery.

The Role of miRNAs in Dexmedetomidine's Neuroprotective Effects against Brain Disorders

There are limited neuroprotective strategies for various central nervous system conditions in which fast and sustained management is essential. Neuroprotection-based therapeutics have become an intensively researched topic in the neuroscience field, with multiple novel promising agents, from natural products to mesenchymal stem cells, homing peptides, and nanoparticles-mediated agents, all aiming to significantly provide neuroprotection in experimental and clinical studies. Dexmedetomidine (DEX), an α2 agonist commonly used as an anesthetic adjuvant for sedation and as an opioid-sparing medication, stands out in this context due to its well-established neuroprotective effects. Emerging evidence from preclinical and clinical studies suggested that DEX could be used to protect against cerebral ischemia, traumatic brain injury (TBI), spinal cord injury, neurodegenerative diseases, and postoperative cognitive disorders. MicroRNAs (miRNAs) regulate gene expression at a post-transcriptional level, inhibiting the translation of mRNA into functional proteins. In vivo and in vitro studies deciphered brain-related miRNAs and dysregulated miRNA profiles after several brain disorders, including TBI, ischemic stroke, Alzheimer's disease, and multiple sclerosis, providing emerging new perspectives in neuroprotective therapy by modulating these miRNAs. Experimental studies revealed that some of the neuroprotective effects of DEX are mediated by various miRNAs, counteracting multiple mechanisms in several disease models, such as lipopolysaccharides induced neuroinflammation, β-amyloid induced dysfunction, brain ischemic-reperfusion injury, and anesthesia-induced neurotoxicity models. This review aims to outline the neuroprotective mechanisms of DEX in brain disorders by modulating miRNAs. We address the neuroprotective effects of DEX by targeting miRNAs in modulating ischemic brain injury, ameliorating the neurotoxicity of anesthetics, reducing postoperative cognitive dysfunction, and improving the effects of neurodegenerative diseases.

The Effects of Dexmedetomidine on Perioperative Neurocognitive Outcomes After Noncardiac Surgery: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Objective

The purpose of this review is to examine the effect of dexmedetomidine on delayed neurocognitive recovery (dNCR; cognitive dysfunction ≥1 week postoperative) after major noncardiac surgery.

Background

Dexmedetomidine (DEX) effectively reduces delirium in the intensive care unit and reportedly attenuates cognitive decline following major noncardiac surgery. Ascertaining the true effect on postoperative cognition is difficult because studies are limited by suboptimal selection of cognitive assessment tools, timing of testing, and criteria for defining significant cognitive decline.

Methods

Prospective randomized trials comparing perioperative DEX to placebo for major noncardiac surgery assessing cognitive function ≥1 week postoperative were included. Pediatric, nonhuman, and non-English trials, and those where executive function was not assessed were excluded. Data were abstracted by 3 reviewers independently and in parallel according to PRISMA guidelines. The a priori binary primary outcome is dNCR defined as cognitive function declining by the minimal clinically important difference or accepted alternate measure (eg, Reliable Change Index ≥1.96). Bias was assessed with the Cochrane Collaboration tool. Data were pooled using a random effects model.

Results

Among 287 citations identified, 26 (9%) met criteria for full-text retrieval. Eleven randomized trials (1233 participants) were included for qualitative analysis, and 7 trials (616 participants) were included for meta-analysis of dNCR. Dexmedetomidine did not reduce the incidence of dNCR significantly (OR 0.57, 95% CI 0.30-1.10, P = 0.09) compared with placebo. There was no difference in the incidence of delirium (OR 0.94, 95% CI 0.55-1.63, P = 0.83) and a higher incidence of hemodynamic instability (OR 2.11, 95% CI 1.22-3.65, P = 0.008).

Conclusions

Dexmedetomidine does not reduce dNCR 1 week after major noncardiac surgery. This meta-analysis does not yet support the use of perioperative DEX to improve short term cognitive outcomes at this time; trials underway may yet change this conclusion while larger trials are needed to refine the point estimate of effect and examine long-term cognitive outcomes.

Effects of dexmedetomidine on surgery for type A acute aortic dissection outcome

No study has evaluated the effect of dexmedetomidine in patients who received surgery for type A aortic dissection. This is the first study to evaluate the effect of dexmedetomidine in aortic dissection patients. This study was executed using data from the Chang Gung Research Database in Taiwan. The CGRD contains the multi‐institutional standardized electronic medical records from seven Chang Gung Memorial hospitals, the largest medical system in Taiwan. We retrospectively evaluate patients who received surgery for acute type A aortic dissection between January 2014 and December 2018. Overall, 511 patients were included, of whom 104 has received dexmedetomidine infusion in the postoperative period. One-to-two propensity score-matching yielded 86 cases in the dexmedetomidine group and 158 cases in the non-dexmedetomidine group. The in-hospital mortality and composite outcome including all-cause mortality, acute kidney injury, delirium, postoperative atrial fibrillation, and respiratory failure, were considered primary outcomes. The in-hospital mortality and composite outcome were similar between groups. The risk of Acute Kidney Injury Network stage 3 acute kidney injury was significantly lower in the dexmedetomidine group than in the non-dexmedetomidine group (8.1% vs 19.0%; OR, 0.38; 95% CI, 0.17–0.86; p = 0.020. The risk of newly-onset dialysis was also significantly lower in the dexmedetomidine group than in the non-dexmedetomidine group (4.7% vs 13.3%; OR, 0.32; 95% CI, 0.11–0.90; p = 0.031). Post-operative dexmedetomidine infusion significantly reduced the rate of severe acute kidney injury and newly-onset dialysis in patients who received surgery for acute type A aortic dissection.

An Update on Postoperative Cognitive Dysfunction Following Cardiac Surgery

Postoperative cognitive dysfunction is extremely prevalent following cardiac surgery. The increasing patient age and comorbidity profile increases their susceptibility to cognitive impairment. The underlying pathophysiological mechanisms leading to cognitive impairment are not clearly elucidated. Using the contemporary literature (2015-present), this narrative review has three aims. Firstly, to provide an overview of postoperative cognitive impairment. Secondly, to analyse the predominant pathophysiological mechanisms leading to cognitive dysfunction following cardiac surgery such as inflammation, cerebral hypoperfusion, cerebral microemboli, glycaemic control and anaesthesia induced neurotoxicity. Lastly, to assess the current therapeutic strategies of interest to address these pathophysiological mechanisms, including the administration of dexamethasone, the prevention of prolonged cerebral desaturations and the monitoring of cerebral perfusion using near-infrared spectroscopy, surgical management strategies to reduce the neurological effects of microemboli, intraoperative glycaemic control strategies, the effect of volatile vs. intravenous anaesthesia, and the efficacy of dexmedetomidine.

Comparison of the Effect of Propofol and Dexmedetomidine on Hemodynamic Parameters and Stress Response Hormones During Laparoscopic Cholecystectomy Surgery

Background

General anesthesia induces endocrine, immunologic, and metabolic responses. Anesthetic drugs affect the endocrine system by changing the level of stress hormones and hemodynamic variables of the patient.

Objectives

The purpose of this study was to compare the effects of propofol and dexmedetomidine on hemodynamic parameters and stress-induced hormones in laparoscopic cholecystectomy (LC) surgery.

Methods

Seventy patients of elective LC were included in this study. The patients were randomly assigned into two equal groups of propofol (75 µg/kg/min) and dexmedetomidine (0.5 µg/kg/hour) as anesthesia maintenance. Hemodynamic parameters (heart rate and mean atrial pressure), blood sugar, and serum epinephrine level were monitored and recorded from pre-anesthesia period to 10 min after entry to post-anesthesia care unit (PACU) according to a planned method.

Results

Heart rate and mean atrial pressure changes were significantly lower in dexmedetomidine group in all stages compared to propofol group (P < 0.001). Also, the rises in blood glucose and serum epinephrine levels in the dexmedetomidine group were significantly higher than in the propofol group (P < 0.001).

Conclusions

Anesthesia maintenance by dexmedetomidine showed a significant difference in hemodynamic parameters in comparison with propofol. While dexmedetomidine had better effects on controlling hemodynamic parameters, propofol showed better effects on decreasing stress hormones, and it can be suggested for LC surgery.

The Anti-inflammatory Effect of Dexmedetomidine Administration on Patients Undergoing Intestinal Surgery: A Randomized Study

BACKGROUND AND OBJECTIVE

Dexmedetomidine is a highly selective α2-adrenergic receptor agonist with sedative, analgesic, anti-sympathetic and stress-reducing effects. It has been widely used as an adjunct for general anesthesia of multiple surgeries. However, the relationship between the utilization of dexmedetomidine in intestinal surgery and the postoperative inflammatory response of patients remains unclear.

METHODS

A randomized, controlled, single-blinded clinical trial was performed. Eighty-six patients assigned for intestinal surgery were recruited and were randomly divided into two groups (dexmedetomidine group, n = 40; control group, n = 40) [six participants were excluded due to multiple reasons, such as allergy and drug use history]. The clinical characteristics and physiological outcomes of participants who received different treatments (dexmedetomidine and 0.9% sodium chloride) were collected and analyzed. Blood samples of the two groups were collected before administration (T0), 10 min after pumping dexmedetomidine/saline solution (T1), immediately after the operation started (T2), 30 min after the operation started (T3), and immediately after the operation ended (T4). Enzyme-linked immunosorbent assay (ELISA) was performed to evaluate the proinflammatory factors.

RESULTS

Intravenous injection of dexmedetomidine before intestinal surgery decreased a variety of circulating proinflammatory factors. Dexmedetomidine alleviated the stress response and promoted the recovery of cognitive ability among patients undergoing intestinal surgery.

CONCLUSION

Dexmedetomidine administration in patients undergoing intestinal surgery inhibited the surgery-induced inflammatory reactions.

Assessing the Antioxidant Activity of Dexmedetomidine by Measuring the Plasma Antioxidant Enzyme Activity of Catalase, Glutathione Peroxidase, and Superoxide Dismutase During Lumbar Spine Laminectomy

Background: Current knowledge on antioxidant properties of anesthetics is inconclusive. Nevertheless, experiments on different anesthesia-related drugs and techniques are growing. Objectives: The aim of this prospective blinded randomized study was to assess the effect of dexmedetomidine (Dex) infusion during anesthesia on oxidative stress resulting from lumbar laminectomy. Methods: The antioxidant activity of Dex compared to placebo (normal saline) was evaluated by measuring the antioxidant enzyme activity of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPX). A total of 56 patients who underwent laminectomy surgery were allocated into two groups of intervention and control. Dex group received 0.6 µg.kg-1 dexmedetomidine infusion before induction of anesthesia over 15 minutes, followed by 0.4 µg.kg-1.hr-1 maintenance. Control group received the same volume and sequence of normal saline. Anesthesia protocol was similar in both groups. The antioxidant activity of the previously mentioned enzymes was measured at the beginning of the anesthesia (T1) and after surgery (T2). Propofol consumption, hemodynamic indices, shivering, bleeding volume, and pain numeric rating scale (NRS) were recorded. Results: Although the serum levels of CAT and GPX increased during the procedure, these changes were not significant (P-values 0.579 and 0.762, respectively). Also, the mean SOD level did not change over time in any of the groups, and it was not meaningfully different between the groups at any of the predetermined times (P-value 0.665). Conclusions: As expected, Dex decreased propofol consumption, mean heart rate, mean arterial pressure, and pain intensity allover the perioperative period. It seems that adding Dex to anesthesia regimen during laminectomy had no dominant antioxidant effects.

How should dexmedetomidine and clonidine be prescribed in the critical care setting?

Cardiac, ventilatory and kidney management in the critical care setting has been optimized over the past decades. Cognition and sedation represent one of the last remaning challenges. As conventional sedation is suboptimal and as the sedation evoked by alpha-2 adrenergic agonists ("cooperative" sedation with dexmedetomidine, clonidine or guanfacine) represents a valuable alternative, this manuscript covers three practical topics for which evidence-based medicine is lacking: a) Switching from conventional to cooperative sedation ("switching"): the short answer is the abrupt withdrawal of conventional sedation, immediate implementation of alpha-2 agonist infusion and the use of "rescue sedation" (midazolam bolus[es]) or "breakthrough sedation" (haloperidol bolus[es]) to stabilize cooperative sedation. b) Switching from conventional to cooperative sedation in unstable patients (e.g., refractory delirium tremens, septic shock, acute respiratory distress syndrome, etc.): to avoid hypotension and bradycardia evoked by sympathetic deactivation, the short answer is to maintain the stroke volume through volume loading, vasopressors and inotropes. c) To avoid these switches and associated difficulties, alpha-2 agonists may be considered first-line sedatives. The short answer is to administer alpha-2 agonists slowly from admission or endotracheal intubation up to stabilized cooperative sedation. The "take home" message is as follows: a) alpha-2 agonists are jointly sympathetic deactivators and sedative agents; b) sympathetic deactivation implies maintaining the stroke volume and iterative assessment of volemia. Evidence-based medicine should document our propositions.

Is the Sympathetic System Detrimental in the Setting of Septic Shock, with Antihypertensive Agents as a Counterintuitive Approach? A Clinical Proposition

Mortality in the setting of septic shock varies between 20% and 100%. Refractory septic shock leads to early circulatory failure and carries the worst prognosis. The pathophysiology is poorly understood despite studies of the microcirculatory defects and the immuno-paralysis. The acute circulatory distress is treated with volume expansion, administration of vasopressors (usually noradrenaline: NA), and inotropes. Ventilation and anti-infectious strategy shall not be discussed here. When circulation is considered, the literature is segregated between interventions directed to the systemic circulation vs. interventions directed to the micro-circulation. Our thesis is that, after stabilization of the acute cardioventilatory distress, the prolonged sympathetic hyperactivity is detrimental in the setting of septic shock. Our hypothesis is that the sympathetic hyperactivity observed in septic shock being normalized towards baseline activity will improve the microcirculation by recoupling the capillaries and the systemic circulation. Therefore, counterintuitively, antihypertensive agents such as beta-blockers or alpha-2 adrenergic agonists (clonidine, dexmedetomidine) are useful. They would reduce the noradrenaline requirements. Adjuncts (vitamins, steroids, NO donors/inhibitors, etc.) proposed to normalize the sepsis-evoked vasodilation are not reviewed. This itemized approach (systemic vs. microcirculation) requires physiological and epidemiological studies to look for reduced mortality.

Effects of Glucocorticoids on Postoperative Delirium in Adult Patients Undergoing Cardiac Surgery: A Systematic Review and Meta-analysis

PURPOSE

Delirium is a common neurologic complication after cardiac surgery and is associated with a poor prognosis. Several studies have explored the effects of glucocorticoids on postoperative delirium (POD). However, conclusion have been inconsistent. The purpose of this systematic review and meta-analysis is to evaluate the effects of glucocorticoids on POD in adult patients undergoing cardiac surgery.

METHODS

A systematic literature search was conducted using PubMed/MEDLINE, Embase, Cochrane Library/Central, and Web of Science from inception to January 28, 2021. Randomized controlled trials evaluating the effects of perioperative glucocorticoids administration on the incidence of POD in adults (≥18 years of age) undergoing cardiac surgery were included. The primary outcome of incidence of POD was assessed using the risk ratio (RR) with a fixed-effects model. Secondary analyses included the severity or duration of delirium, mortality at 30 days, length of hospital and intensive care unit (ICU) stay, duration of mechanical ventilatory support, the incidence of myocardial injury, new atrial fibrillation, renal and respiratory failure, postoperative infection and stroke, and the level of glucose and inflammatory factors.

FINDINGS

A total 4 trials (n = 8448 patients) were included. Glucocorticoids did not significantly reduce the incidence of POD (RR = 0.99; 95% CI, 0.86-1.14) but increased the risk of myocardial injury (RR = 1.22; 95% CI, 1.08-1.38), decreased the duration of mechanical ventilatory support (mean difference, -0.83; 95% CI, -1.32 to -0.34), and led to a tendency toward short length of ICU stay (mean difference, -0.22; 95% CI, -0.47 to -0.03). No significant differences were observed in other secondary outcomes.

IMPLICATIONS

The perioperative administration of glucocorticoids did not reduce the incidence of POD in adult patients undergoing cardiac surgery but might be associated with shorter duration of mechanical ventilatory support and a tendency toward a shorter length of ICU stay. Furthermore, we found that glucocorticoids may increase the rate of myocardial injury but have no effects on other clinical outcomes. International Prospective Register of Systematic Reviews identifier: CRD42021233458.

The effect of perioperative dexmedetomidine on postoperative bowel function recovery in adult patients receiving general anaesthesia: a systematic review and meta-analysis of randomised controlled trials

INTRODUCTION

Dexmedetomidine has opioid sparing actions but its effect on bowel recovery is controversial. Primary aim of this review was to evaluate the effect of perioperative dexmedetomidine on postoperative bowel recovery. Secondary aim was to evaluate the effect of dexmedetomidine on hospital discharge.

EVIDENCE ACQUISITION

Randomised controlled trials in English language reporting any or all of the following parameters of bowel recovery; time to first bowel sounds, first flatus, first faeces, or time to oral diet were included.

EVIDENCE SYNTHESIS

Twelve hundred and thirty-five patients from 13 studies were analysed. There were insufficient studies evaluating bowel sounds. Perioperative dexmedetomidine usage significantly reduced the time to first flatus [MD -5.61 hours (95% CI -8.61 to -2.60); P = 0.0003; I2 = 95%], first faeces [MD -12.70 hours (95% CI -19.11 to -6.29); P = 0.0001; I2 = 76%] and the composite outcome of bowel recovery (flatus, faeces, oral diet) [MD -7.44 hours (95% CI -10.31 to -4.57); P < 0.00001; I2 = 96%]. No difference was seen in the time to oral diet [MD -6.29 hours (95% CI -13.48 to 0.91); P = 0.09; I2 = 88%] or hospital discharge [MD -0.47 days (95% CI -1.27 to 0.33); P = 0.25; I2 = 86%].

CONCLUSIONS

Perioperative dexmedetomidine usage significantly shortens the time to first flatus, faeces and composite bowel recovery but does not result in a shorter time to oral diet or earlier hospital discharge in adult patients receiving general anaesthesia. Strength of evidence is however very low for the effect of dexmedetomidine on bowel recovery.

Dexmedetomidine in combination with ketamine for pediatric procedural sedation or premedication: A meta-analysis

OBJECTIVE

To evaluate effectiveness of combinational use of dexmedetomidine and ketamine (DEX-KET) for pediatric procedural sedation or premedication.

METHODS

Relevant studies were identified after a literature search in electronic databases and study selection was based on precise eligibility criteria. Meta-analyses of mean differences were performed to examine differences in sedation onset and recovery times between DEX-KET and comparators. Changes from baseline in heart rate (HR), respiratory rate, oxygen saturation, and mean arterial pressure (MAP), were pooled. Meta-analyses of proportions were performed to estimate incidence of adverse events.

RESULTS

15 studies (1087 patients) were included. Onset of sedation was significantly shorter in DEX-KET than in DEX group. HR declined in DEX-KET group from start (-3.5 beats per minute (BPM) [95% CI: -5.1, -1.9]) through midpoint (-7.2 BPM [95% CI: -12.1, -2.3]) and at end of sedation (-8.7 BPM [95% CI: -13.1, -4.4]). Decrease in HR after DEX administration at start was -11.6 BPM [95% CI: -16.0, -7.1] and remained consistent afterward. There was no change in MAP during DEX-KET sedation. However, after DEX administration, MAP decreased by -6.9 [95% CI: -10.4, -3.3] at start, -7.8 [95% CI: -11.4, -4.2] at middle, and by -6.6 [95% CI: -14.4, 1.1] at end of sedation. Incidence of hypotension was 3% [95% CI: 0, 9] in DEX-KET, 7% [95% CI: 2, 14] in DEX, and 0% [95% CI: 0, 2] in KET groups. Incidence of bradycardia was 2% [95% CI: 0, 6] with DEX-KET and 12% [95% CI: 5, 20] with DEX. Incidence of oxygen desaturation was 3% [95% CI: 0, 8] in DEX-KET, 2% [95% CI: 0, 6] in DEX, 12% [95% CI: 5, 20] in KET, and 13% [95% CI: 6, 21] in PROP-KET groups. MIDA-KET sedation had 13% [95% CI: 4, 25] incidence of tachycardia.

CONCLUSIONS

DEX-KET for pediatric sedation results in better sedation outcomes than DEX or KET by shortening onset of sedation and recovery while maintaining hemodynamic and respiratory stability with low incidence of adverse events. DEX sedation was associated with higher incidence of bradycardia. Higher incidence of oxygen desaturation was observed with KET and PROP-KET whereas MIDA-KET was associated with higher incidence of tachycardia.

Dexmedetomidine attenuates one-lung ventilation associated lung injury by suppressing inflammatory responses: A systematic review and meta-analysis

One-lung ventilation (OLV), a common ventilation technique, is associated with perioperative lung injury, tightly connected with inflammatory responses. Dexmedetomidine has shown positive anti-inflammatory effects in lung tissues in pre-clinical models. This study investigated the efficacy of dexmedetomidine for suppressing inflammatory responses in patients requiring OLV. We searched PubMed, MEDLINE, Embase, Scopus, Ovid, and Cochrane Library for randomized controlled trials focusing on dexmedetomidine's anti-inflammatory effects on patients requiring OLV without any limitation on the year of publication or languages. 20 clinical trials were assessed with 870 patients in the dexmedetomidine group and 844 in the control group. Our meta-analysis investigated the anti-inflammatory property of dexmedetomidine perioperatively [T1 (30-min OLV), T2 (90-min OLV), T3 (end of surgery) and T4 (postoperative day 1)], demonstrating that dexmedetomidine's intraoperative administration resulted in a significant reduction in serum concentration of interleukin-6, tumor necrosis factor-α and other inflammatory cytokines perioperatively. By calculating specific I2 index, significant heterogeneity was observed on all occasions, with I2 index ranging from 95% to 99%. For IL-6 changes, sensitivity analysis showed that the exclusion of a single study led to a significant decrease of heterogeneity (96%-0%; p < 0.00001). Besides, pulmonary oxygenation was ameliorated in the dexmedetomidine group comparing with the control group. In conclusion, perioperative administration of dexmedetomidine can attenuate OLV induced inflammation, ameliorate pulmonary oxygenation, and may be conducive to a decreased occurrence of postoperative complications and better prognosis. However, the results should be prudently interpreted due to the evidence of heterogeneity and the limited number of studies.

Myocardial protective and anti-inflammatory effects of dexmedetomidine in patients undergoing cardiovascular surgery with cardiopulmonary bypass: a systematic review and meta-analysis

Cardiopulmonary bypass (CPB) technology provides potential for cardiac surgery, but it is followed by myocardial injury and inflammation related to ischemia–reperfusion. This meta-analysis aimed to systematically evaluate the cardioprotective effect of dexmedetomidine on cardiac surgery under CPB and its effect on accompanied inflammation. PubMed, Cochrane Library, EMBASE and Web of Science databases were comprehensively searched for all randomized controlled trials (RCTs) published before April 1st, 2021 that explored the application of dexmedetomidine in cardiac surgery. Compared with the control group (group C), the concentrations of CK-MB in the perioperative period and cTn-I at 12 h and 24 h after operation in dexmedetomidine group (group D) were significantly decreased (P < 0.05). In addition, in group D, the levels of interleukin-6 at 24 h after operation, tumor necrosis factor-a at the 12 h and 24 h after operation were significantly decreased (P < 0.05). At the same time, the length of Intensive Care Unit stay in group D was significantly shorter than group C (P < 0.05). However, there was no significant difference in interleukin-10 level, C reactive protein level, the time on ventilator and length of hospital stay between the two groups (P > 0.05). The application of dexmedetomidine in cardiac surgery with CPB can reduce CK-MB and cTn-I concentration and interleukin-6, tumor necrosis factor-α levels to a certain extent and shorten the length of Intensive Care Unit stay, but it has no significant effect on IL-10 level, C reactive protein level, the time on ventilator and length of hospital stay.

Breast Cancer and Anaesthesia: Genetic Influence

Breast cancer is the leading cause of mortality in women. It is a heterogeneous disease with a high degree of inter-subject variability even in patients with the same type of tumor, with individualized medicine having acquired significant relevance in this field. The clinical and morphological heterogeneity of the different types of breast tumors has led to a diversity of staging and classification systems. Thus, these tumors show wide variability in genetic expression and prognostic biomarkers. Surgical treatment is essential in the management of these patients. However, the perioperative period has been found to significantly influence survival and cancer recurrence. There is growing interest in the pro-tumoral effect of different anaesthetic and analgesic agents used intraoperatively and their relationship with metastatic progression. There is cumulative evidence of the influence of anaesthetic techniques on the physiopathological mechanisms of survival and growth of the residual neoplastic cells released during surgery. Prospective randomized clinical trials are needed to obtain quality evidence on the relationship between cancer and anaesthesia. This document summarizes the evidence currently available about the effects of the anaesthetic agents and techniques used in primary cancer surgery and long-term oncologic outcomes, and the biomolecular mechanisms involved in their interaction.

Administration of Low-Dose Dexmedetomidine Did Not Affect Acute Inflammatory Response after Cytoreductive Surgery Combined with Hyperthermic Intraperitoneal Chemotherapy: A Double-Blind Randomized Controlled Trial

During cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC), attenuation of inflammatory responses that increase susceptibility to postoperative complications, morbidity, and mortality is important. We aimed to evaluate whether intraoperative dexmedetomidine infusion impacted inflammatory response in patients undergoing CRS with HIPEC. Fifty-six patients scheduled for CRS with HIPEC were randomly assigned to the control (n = 28) and dexmedetomidine (n = 28) groups. The primary endpoint was the effect of dexmedetomidine on the interleukin-6 (IL-6) level measured at pre-operation (Pre-OP), before HIPEC initiation (Pre-HIPEC), immediately after HIPEC; after the end of the operation; and on postoperative day (POD) 1. In both groups, the IL-6 levels from Pre-HIPEC until POD 1 and the C-reactive protein (CRP) levels on PODs 1, 2, and 3 were significantly higher than the Pre-OP values (all Bonferroni corrected, p < 0.001). However, total differences in IL-6 and CRP levels, based on the mean area under the curve, were not detected between the two groups. The continuous intraoperative infusion of dexmedetomidine (0.4 μg/kg/h) in patients undergoing CRS with HIPEC did not significantly lower the inflammatory indices. Further dose investigative studies are needed to find the dexmedetomidine dose that provides anti-inflammatory and sympatholytic effects during HIPEC.

Modulation of microglial phenotypes by dexmedetomidine through TREM2 reduces neuroinflammation in heatstroke

No FDA approved pharmacological therapy is available to reduce neuroinflammation following heatstroke. Previous studies have indicated that dexmedetomidine (DEX) could protect against inflammation and brain injury in various inflammation-associated diseases. However, no one has tested whether DEX has neuro-protective effects in heatstroke. In this study, we focused on microglial phenotypic modulation to investigate the mechanisms underlying the anti-inflammatory effects of DEX in vivo and in vitro. We found that DEX treatment reduced the expression of CD68, iNOS, TNF-α, and IL-1β, and increased the expression of CD206, Arg1, IL-10 and TGF-β in microglia, ameliorating heatstroke induced neuroinflammation and brain injury in mice. TREM2, whose neuro-protective function has been validated by genetic studies in Alzheimer's disease and Nasu-Hakola disease, was significantly promoted by DEX in the microglia. TREM2 esiRNA reversed the DEX-induced activation of PI3K/Akt signalling. Overall these findings indicated that DEX may serve, as a potential therapeutic approach to ameliorate heatstroke induced neuroinflammation and brain injury via TREM2 by activating PI3K/Akt signalling.