The influence of dexmedetomidine and propofol on circulating cytokine levels in healthy subjects

Anesthesia Medication's Impacts on Inflammatory and Neuroendocrine Immune Response in Patients Undergoing Digestive Endoscopy

The aim of this study was to explore the impact of anesthetic drugs currently used to perform lower digestive endoscopy on serum concentrations of inflammation markers and catecholamines. We selected 120 patients and divided them into three lots of 40 patients each: L1, in which no anesthetics were used; L2, in which propofol was used; and L3, in which propofol combined with fentanyl was used. All patients had serum concentrations of adrenaline/epinephrine (EPI), noradrenaline/norepinephrine (NE), tumor necrosis factor alpha (TNF-α), interleukin-4 (IL-4), IL-6, IL-8, and IL-10, taken at three time points: at the beginning of the endoscopic procedure (T0), 15 min after (T1), and 2 h after the end of the endoscopic procedure (T2). The results of the research showed changes in the levels of catecholamines and interleukins (ILs) at T0, with an increased response in L1 above the mean recorded in L2 and L3 (p < 0.001). At T1, increased values were recorded in all lots; values were significantly higher in L1. At T2, the values recorded in L3 were significantly lower than the values in L2 (student T, p < 0.001) and L1, in which the level of these markers continued to increase, reaching double values compared to T0 (student T, p < 0.001). In L2 at T1, the dose of propofol correlated much better with NE, EPI, and well-known cytokines. Our results show that propofol combined with fentanyl can significantly inhibit the activation of systemic immune and neuroendocrine response during painless lower digestive endoscopy.

Effects of dexmedetomidine on early cognitive function in elderly patients after abdominal surgery: a meta-analysis

INTRODUCTION

This meta-analysis aims to investigate the effect of dexmedetomidine (Dex) on postoperative cognitive dysfunction (POCD) in elderly patients undergoing abdominal surgery under general anesthesia.

EVIDENCE ACQUISITION

Six online databases were searched for studies on the effects of Dex on POCD in elderly patients (≥60 years) who underwent abdominal surgery under general anesthesia. The experimental group was treated with Dex and the control group with normal saline. The retrieval period was from the database's inception to March 2023. Stata 15.0 statistical software was utilized to analyze the data.

EVIDENCE SYNTHESIS

In total, 14 studies were entered into this meta-analysis, including 675 patients. On the first, third, and seventh days after surgery, the Mini-Mental State Examination (MMSE) scores in the experimental group were significantly higher than those in the controls (first day: weighted mean difference [WMD] = 2.52, 95% CI: 1.13~3.90, P<0.001; third day: WMD=2.58, 95% CI: 0.76~4.40, P=0.005; seventh day: WMD=1.43, 95% CI: 0.57~2.29, P=0.001). On the first day after surgery, there was a lot less cognitive dysfunction in the Dex group than in the controls (odds ratio [OR] = 0.25, 95% CI: 0.15~0.42, P<0.001).

CONCLUSIONS

Dex administered intraoperatively can enhance early cognitive function in elderly patients undergoing abdominal surgery.

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.

Prolonged and intense neuroinflammation after severe traumatic brain injury assessed by cerebral microdialysis with 300 kDa membranes

BACKGROUND

A neuroinflammatory response that may lead to edema and secondary brain damage is elicited in severe traumatic brain injury (TBI). Previous studies using microdialysis (MD) membranes with 100 k Dalton (kDa) cut-off found a transient intracerebral release of cytokines and chemokines without significant correlations to clinical course, intracranial pressure (ICP) or metabolites. In this study, a (300 kDa) MD probe was used to measure the levels of cytokines and chemokines in relation to ICP and metabolites.

METHODS

Seven patients with severe TBI received 2 MD catheters. In four patients sufficient dialysate could be retrieved for analysis from both catheters. MD samples were analyzed bedside, then frozen and analyzed for chemokines and cytokines using a multiplex assay (Mesoscale Discovery).

RESULTS

MD sampling was performed from 9 to 350 h. In total, 17 chemokines and cytokines were detected. Of these, IL-6, IL-8, IP-10, MCP-1 and MIP-1β were consistently elevated, and investigated further in relation to metabolites, and ICP. Levels of chemokines and cytokines were higher than previously reported from TBI patients, and partially higher than those reported in patients with cytokine release syndrome. There were no significant differences between the two catheters regarding cytokine/chemokine concentrations, except for IL-6 which was higher in the peri-contusional area. No correlation with metabolites and ICP was observed. No significant increase or decline of chemokine or cytokine secretion was observed during the study period.

CONCLUSION

Our data suggest that cytokine and chemokine levels reflect a perpetual, potent and pan-cerebebral inflammatory response that persists beyond 15 days following TBI.

Effect of sevoflurane versus propofol on neutrophil-to-lymphocyte ratio in healthy individuals: a sub-study of a randomised crossover trial

Background

Sevoflurane and propofol are commonly used drugs in general anaesthesia. However, their effects on perioperative immune function are incompletely understood. We hypothesised that sevoflurane and propofol differentially affect immune function in healthy individuals. Therefore, we investigated the effect of sevoflurane and propofol on neutrophil-to-lymphocyte ratio before, during, and after general anaesthesia.

Methods

In this randomised crossover study, 19 healthy individuals underwent 2 h of general anaesthesia with either propofol or sevoflurane. After 4 weeks, anaesthesia was repeated using the other drug. Blood samples were obtained before, during, 1 h after, and 1 day after anaesthesia. The primary outcome was whole-blood neutrophil-to-lymphocyte ratio, and secondary outcomes were specific white blood cell differential counts. A linear mixed-effects model was used to estimate effect sizes.

Results

The neutrophil-to-lymphocyte ratio was higher in the propofol compared with the sevoflurane group during anaesthesia, 2.8 (confidence interval [CI]: 2.3-3.3) vs 1.6 (CI: 1.1-2.1), and 1 day after anaesthesia, 2.6 (CI: 2.1-3.1) vs 1.9 (CI: 1.4-2.4). In all patients, we observed transient lymphopaenia during propofol anaesthesia, 1.1 × 109 cells × L-1 (CI: 0.9-1.4), compared with sevoflurane anaesthesia, 1.9 × 109 cells × L-1 (CI: 1.7-2.1). In addition, neutrophil counts were higher 1 day after propofol anaesthesia, 4.4 × 109 cells × L-1 (CI: 4.0-4.9), compared with sevoflurane anaesthesia, 3.5 × 109 cells × L-1 (CI: 3.1-4.0). We observed no differences in the remaining white blood cell subgroups.

Conclusions

In healthy individuals undergoing general anaesthesia without surgery, the neutrophil-to-lymphocyte ratio was affected by the type of hypnotic used. Transient lymphopaenia was observed in all participants during propofol anaesthesia.

Effects of Dexmedetomidine on Immune Cells: A Narrative Review

As we all know, dexmedetomidine (DEX), as a highly selective α₂ adrenergic receptor agonist, exerts sedative, anti-anxiety and hypnotic effects by inhibiting the discharge of norepinephrine neurons in locus coeruleus and GABA-related hypnotic pathways. However, the role of DEX in anti-inflammatory and immune regulation has gradually attracted the attention of researchers in recent years. The α₂ adrenergic receptor is one of the members of the adrenergic receptor family, which is widely present in a variety of immune cells and mediates the biological behavior of the inflammatory immune system. At present, there have been more and more studies on the effects of DEX on immune cells and inflammatory responses, but few studies have systematically explored the anti-inflammatory and immunomodulatory effects of DEX. Here, we comprehensively review the published human and animal studies related to DEX, summarize the effects of DEX on immune cells and its role in related diseases, and propose potential research direction.

Baseline Values and Kinetics of IL-6, Procalcitonin, and TNF-α in Landrace-Large White Swine Anesthetized with Propofol-Based Total Intravenous Anesthesia

The baseline levels of various inflammatory mediators and their changes during anesthesia in swine are not known. The aim of this animal study was to measure the baseline values and kinetics of interleukin-6, procalcitonin, and tumor necrosis factor-alpha in healthy Landrace-Large White swine anesthetized with propofol-based total intravenous anesthesia. We included 8 healthy male pigs with an average weight of 19 ± 2 kg (aged 10-15 weeks) that were subjected to propofol-based total intravenous anesthesia for 8 hours. Complete blood count, serum chemistry, and serum levels of interleukin-6, procalcitonin, and tumor necrosis factor-alpha were analyzed, and serum levels were quantified hourly. Blood was also collected for bacterial culturing. Baseline values of interleukin-6 and procalcitonin were 18 pg/ml and 21 ng/ml, respectively, while tumor necrosis factor-alpha was not detectable during collection of baseline samples. A statistically significant difference was observed in interleukin-6 levels between time points (p < 0.0001). Procalcitonin increased with time, but there were no significant differences between time points (p = 0.152). Tumor necrosis factor-alpha increased until the 3rd hour of propofol-based total intravenous anesthesia, while after the 4th hour, it gradually decreased, reaching its baseline undetectable values by the 7th hour (p < 0.001). Our results can serve as the basis for further translational research.

Immunomodulators in anesthesia

PURPOSE OF REVIEW

Anesthetics are known to have immunomodulatory effects. These can be detrimental, inducing immunosuppression and facilitating the development of opportunistic infections, especially when used at high doses, for prolonged periods, or in patients with preexisting immune deficiency; or beneficial, modulating the inflammatory response, particularly in critical illness and systemic hyperinflammatory states.

RECENT FINDINGS

Anesthetics can have microbicidal properties, and both anti- and pro-inflammatory effects. They can act directly on immune cells as well as modulate immunity through indirect pathways, acting on the neuroimmune stress response, and have recently been described to interact with the gut microbiota.

SUMMARY

Anesthesiologists should take into consideration the immunomodulatory properties of anesthetic agents in addition to their hemodynamic, neuroprotective, and other impacts. In future, patient stratification according to the perioperative assessment of serum biomarkers associated with postoperative complications may be used to guide anesthetic agent selection based on their immunomodulatory properties.

Effects of propofol and dexmedetomidine with and without remifentanil on serum cytokine concentrations in healthy volunteers: a post hoc analysis

BACKGROUND

Anaesthetic agents are likely to alter circulating cytokine concentrations. Because preceding studies have not been able to exclude the contribution of surgical trauma, perioperative stress, or both to circulating cytokine concentrations, the effects of anaesthesia remain unclear. The aim of this study was to quantify serum cytokines in healthy volunteers administered i.v. anaesthetic agents in the absence of surgical trauma and perioperative stress.

METHODS

Serum samples obtained during previous standardised studies from healthy volunteers were compared before and 6-8 h after induction of anaesthesia with propofol (n=31), propofol/remifentanil (n=30), dexmedetomidine (n=17) or dexmedetomidine/remifentanil (n=15). Anaesthetic regimens were standardised and volunteers did not undergo any surgical intervention. Serum concentrations of interleukin (IL)2, IL4, IL6, IL10, IL17, IL18, IL21, IL22, IL23, C-X-C motif ligand 8, interferon gamma, E-selectin, L-selectin, major histocompatibility complex class I chain-polypeptide-related sequence (MIC)A, MICB, Granzyme A, and Granzyme B were quantified using a multiplexed antibody-based assay (Luminex).

RESULTS

Samples were obtained from volunteers of either sex aged 18-70 yr. After anaesthesia with propofol alone, concentrations of IL4 (P=0.012), IL6 (P=0.027), IL21 (P=0.035), IL22 (P=0.002), C-X-C motif ligand 8 (P=0.004), MICB (P=0.046), and Granzyme A (P=0.045) increased. After anaesthesia with propofol and remifentanil, IL17 (P=0.013), interferon gamma (P=0.003), and MICA (P=0.001) decreased, but IL6 (P=0.006) and L-selectin (P=0.001) increased. After dexmedetomidine alone, IL18 (P=0.002), L-selectin (P=0.017), E-selectin (P=0.002), and Granzyme B (P=0.023) decreased. After dexmedetomidine with remifentanil no changes were observed.

CONCLUSIONS

In healthy volunteers not undergoing surgery, different i.v. anaesthesia regimens were associated with differential effects on circulating cytokines.