Organ-Protective Effects and the Underlying Mechanism of Dexmedetomidine

Clinical adverse events to dexmedetomidine: a real-world drug safety study based on the FAERS database

Objective

Adverse events associated with dexmedetomidine were analyzed using data from the FDA's FAERS database, spanning from 2004 to the third quarter of 2023. This analysis serves as a foundation for monitoring dexmedetomidine's safety in clinical applications.

Methods

Data on adverse events associated with dexmedetomidine were standardized and analyzed to identify clinical adverse events closely linked to its use. This analysis employed various signal quantification analysis algorithms, including Reporting Odds Ratio (ROR), Proportional Reporting Ratio (PRR), Bayesian Confidence Propagation Neural Network (BCPNN), and Multi-Item Gamma Poisson Shrinker (MGPS).

Results

In the FAERS database, dexmedetomidine was identified as the primary suspect in 1,910 adverse events. Our analysis encompassed 26 organ system levels, from which we selected 346 relevant Preferred Terms (PTs) for further examination. Notably, adverse drug reactions such as diabetes insipidus, abnormal transcranial electrical motor evoked potential monitoring, acute motor axonal neuropathy, and trigeminal cardiac reflex were identified. These reactions are not explicitly mentioned in the drug's specification, indicating the emergence of new signals for adverse drug reactions.

Conclusion

Data mining in the FAERS database has elucidated the characteristics of dexmedetomidine-related adverse drug reactions. This analysis enhances our understanding of dexmedetomidine's drug safety, aids in the clinical management of pharmacovigilance studies, and offers valuable insights for refining drug-use protocols.

Dexmedetomidine Alleviates Acute Stress-Induced Acute Kidney Injury by Attenuating Inflammation and Oxidative Stress via Inhibiting the P2X7R/NF-κB/NLRP3 Pathway in Rats

This study aimed to investigate the potential protective effects of Dexmedetomidine (DEX) against acute kidney injury (AKI) induced by acute stress (AS). Wistar rats were divided into five groups: Control, DEX, AS, AS + DEX, and AS + A438079. The results showed that AS led to AKI by increasing inflammatory biomarkers and oxidative stress-related indicators. The acute stress model in rats was successfully established. Renal function, histopathology, oxidative stress, and inflammation were assessed. Localization of P2X7 receptor (P2X7R) was determined by immunofluorescence. Additionally, the key inflammatory proteins of the P2X7R/NF-κB/NLRP3 signaling pathway were measured by Western blotting. DEX significantly improved kidney function, alleviated kidney injury, and reduced oxidative stress and inflammation. DEX inhibited the activation of the P2X7R, decreased the expression of NF-κB, NLRP3 inflammasome, and Caspase-1, and inhibited the expression of interleukin-1β (IL-1β) and tumor necrosis factor α (TNFα). Furthermore, DEX also alleviated AS-induced AKI by inhibiting the excessive production of reactive oxygen species (ROS) and reducing oxidative stress. In conclusion, DEX attenuates AS-induced AKI by mitigating inflammation and oxidative stress through the inhibition of the P2X7R/NF-κB/NLRP3 pathway in rats.

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.

Insight into Cardioprotective Effects and Mechanisms of Dexmedetomidine

PURPOSE

Cardiovascular disease remains the leading cause of death worldwide. Dexmedetomidine is a highly selective α2 adrenergic receptor agonist with sedative, analgesic, anxiolytic, and sympatholytic properties, and several studies have shown its possible protective effects in cardiac injury. The aim of this review is to further elucidate the underlying cardioprotective mechanisms of dexmedetomidine, thus suggesting its potential in the clinical management of cardiac injury.

RESULTS AND CONCLUSION

Our review summarizes the findings related to the involvement of dexmedetomidine in cardiac injury and discusses the results in the light of different mechanisms. We found that numerous mechanisms may contribute to the cardioprotective effects of dexmedetomidine, including the regulation of programmed cell death, autophagy and fibrosis, alleviation of inflammatory response, endothelial dysfunction and microcirculatory derangements, improvement of mitochondrial dysregulation, hemodynamics, and arrhythmias. Dexmedetomidine may play a promising and beneficial role in the treatment of cardiovascular disease.

Opioid-free anaesthesia with dexmedetomidine and lidocaine versus remifentanil-based anaesthesia in cardiac surgery: study protocol of a French randomised, multicentre and single-blinded OFACS trial

INTRODUCTION

Intraoperative opioids have been used for decades to reduce negative responses to nociception. However, opioids may have several, and sometimes serious, adverse effects. Cardiac surgery exposes patients to a high risk of postoperative complications, some of which are common to those caused by opioids: acute respiratory failure, postoperative cognitive dysfunction, postoperative ileus (POI) or death. An opioid-free anaesthesia (OFA) strategy, based on the use of dexmedetomidine and lidocaine, may limit these adverse effects, but no randomised trials on this issue have been published in cardiac surgery.We hypothesised that OFA versus opioid-based anaesthesia (OBA) may reduce the incidence of major opioid-related complications after cardiac surgery.

METHODS AND ANALYSIS

Multicentre, randomised, parallel and single-blinded clinical trial in four cardiac surgical centres in France, including 268 patients scheduled for coronary artery bypass grafting under cardiac bypass, with or without aortic valve replacement. Patients will be randomised to either a control OBA protocol using remifentanil or an OFA protocol using dexmedetomidine/lidocaine. The primary composite endpoint is the occurrence of at least one of the following: (1) postoperative cognitive disorder evaluated by the Confusion Assessment Method for the Intensive Care Unit test, (2) POI, (3) acute respiratory distress or (4) death within the first 48 postoperative hours. Secondary endpoints are postoperative pain, morphine consumption, nausea-vomiting, shock, acute kidney injury, atrioventricular block, pneumonia and length of hospital stay.

ETHICS AND DISSEMINATION

This trial has been approved by an independent ethics committee (Comité de Protection des Personnes Ouest III-Angers on 23 February 2021). Results will be submitted in international journals for peer reviewing.

TRIAL REGISTRATION NUMBER

NCT04940689, EudraCT 2020-002126-90.

Dexmedetomidine and acute kidney injury after non-cardiac surgery: A meta-analysis with trial sequential analysis

BACKGROUND

Acute kidney injury (AKI) is a common complication after surgery and is associated with detrimental outcomes. This systematic review and meta-analysis evaluated perioperative dexmedetomidine on AKI and renal function after non-cardiac surgery.

METHODS

PubMed, Embase, and Cochrane Library databases were searched until August 2023 for randomised trials comparing dexmedetomidine with normal saline on AKI and renal function in adults undergoing non-cardiac surgery. The primary outcome was the incidence of AKI (according to Kidney Disease Improving Global Outcomes or Acute Kidney Injury Network criteria). Meta-analysis was performed using a random-effect model. We conducted sensitivity analysis, trial sequential analysis (TSA), and Grading of Recommendations Assessment, Development and Evaluation level of evidence.

RESULTS

Twenty-three trials involving 2440 patients were included. Dexmedetomidine administration, as compared to normal saline, significantly reduced the incidence of AKI (7.4% vs. 13.2%; risk ratio = 0.57, 95% CI = 0.40-0.83, P =  0.003, I2 = 0%; a high level of evidence); TSA and sensitivity analyses suggested the robustness of this outcome. For the renal function and inflammation parameters, dexmedetomidine decreased serum creatinine, blood urea nitrogen, cystatin C, tumour necrosis factor-α, and interleukin-6, and increased urine output and estimated glomerular filtration rate. Additionally, dexmedetomidine reduced postoperative nausea and vomiting and length of hospital stay. Dexmedetomidine was associated with an increased rate of bradycardia, but not hypotension.

CONCLUSION

Dexmedetomidine administration reduced the incidence of AKI and improved renal function after non-cardiac surgery. Based on a high level of evidence, dexmedetomidine is recommended as a component of perioperative renoprotection.

REGISTRATION

International Prospective Register of Systematic Reviews; Registration number: CRD42022299252.

Dexmedetomidine's Effects on the Livers and Kidneys of Rats with Pancreatic Ischemia-Reperfusion Injury

Objective

Pancreatic surgeries inherently cause ischemia-reperfusion (IR) injury, affecting not only the pancreas but also distant organs. This study was conducted to explore the potential use of dexmedetomidine, a sedative with antiapoptotic, anti-inflammatory, and antioxidant properties, in mitigating the impacts of pancreatic IR on kidney and liver tissues.

Methods

A total of 24 rats were randomly divided into four groups: control (C), dexmedetomidine (D), ischemia reperfusion (IR), and dexmedetomidine ischemia reperfusion (D-IR). Pancreatic ischemia was induced in the IR and D-IR groups. Dexmedetomidine was administered intraperitoneally to the D and D-IR groups. Liver and kidney tissue samples were subjected to microscopic examinations after hematoxylin and eosin staining. The levels of thiobarbituric acid reactive substances (TBARS), aryllesterase (AES), catalase (CAT), and glutathione S-transferase (GST) enzyme activity were assessed in liver and kidney tissues. The serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN), and creatinine were measured.

Results

A comparison of the groups revealed that the IR group exhibited significantly elevated TBARS (p < 0.0001), AES (p = 0.004), and CAT enzyme activity (p < 0.0001) levels in the liver and kidney compared to groups C and D. Group D-IR demonstrated notably reduced histopathological damage (p < 0.05) and low TBARS (p < 0.0001), AES (p = 0.004), and CAT enzyme activity (p < 0.0001) in the liver and kidney as well as low AST and ALT activity levels (p < 0.0001) in the serum compared to the IR group.

Conclusion

The preemptive administration of dexmedetomidine before pancreatic IR provides significant protection to kidney and liver tissues, as evidenced by the histopathological and biochemical parameters in this study. The findings underscored the potential therapeutic role of dexmedetomidine in mitigating the multiorgan damage associated with pancreatic surgeries.

[Effects of Dexmedetomidine on the Recovery Quality of Donors Undergoing Pure Laparoscopic Donor Hepatectomy]

Objective

To investigate the effects of intraoperative intravenous administration of dexmedetomidine (DEX) on the recovery quality of donors undergoing pure laparoscopic donor hepatectomy.

Methods

A total of 56 liver donors who were going to undergo scheduled pure laparoscopic donor hepatectomy were enrolled and randomly assigned to two groups, a DEX group ( n=28) and a control group ( n=28). Donors in the DEX group received DEX infusion at a dose of 1 μg/kg over 15 minutes through a continuous pump, which was followed by DEX at 0.4 μg/(kg·h) until the disconnection of the portal branch. Donors in the control group were given an equal volume of 0.9% normal saline at the same infusion rate and over the same period of time as those of the dex infusion in the DEX group. The primary outcome was the incidence of emergence agitation (EA). The Aono's Four-point Scale (AFPS) score was used to assess EA. The secondary observation indicators included intraoperative anesthesia and surgery conditions, spontaneous respiration recovery time, recovery time, extubation time, scores for the Ramsay Sedation Scale, the incidence of chills, numeric rating scale (NRS) score for pain, and blood pressure and heart rate after extubation.

Results

The incidence of EA was 10.7% and 39.3% in the DEX group and the control group, respectively, and the incidence of EA was significantly lower in the DEX group than that in the control group ( P=0.014). The APFS scores after extubation in the DEX group were lower than those in the control group (1 [1, 1] vs. 2 [1, 3], P=0.005). Compared to the control group, the dosages of intraoperative propofol and remifentanil were significantly reduced in the DEX group ( P<0.05). During the recovery period, the number of donors requiring additional boluses of analgesia, the blood pressure, and the heart rate were all lower in the DEX group than those in the control group ( P<0.05). No significant differences between the two groups were observed in the spontaneous respiration recovery time, recovery time, extubation time, the incidence of chills, NRS score, scores for the Ramsay Sedation Scale, and the length-of-stay in postanesthesia care unit (PACU) ( P>0.05).

Conclusion

DEX can reduce the incidence of EA after pure laparoscopic donor hepatectomy and improve the quality of recovery without prolonging postoperative recovery time or extubation time.

Comparison of dexmedetomidine versus propofol sedation on microcirculation and organ injuries in critically ill surgical patients: A randomized controlled pilot study

BACKGROUND

Recent studies have shown that dexmedetomidine may improve microcirculation and prevent organ failure. However, most evidence was obtained from experimental animals and patients receiving cardiac surgery with cardiopulmonary bypass. This study aimed to investigate the effect of dexmedetomidine on microcirculation and organ injuries in critically ill general surgical patients.

METHODS

In this prospective randomized trial, patients admitted to the surgical intensive care unit after general surgery were enrolled and randomly allocated to the dexmedetomidine or propofol groups. Patients received continuous dexmedetomidine or propofol infusions to meet their requirement of sedation according to their grouping. At each time point, sublingual microcirculation images were obtained using the incident dark field video microscope.

RESULTS

Overall, 60 patients finished the trial and were analyzed. Microcirculation parameters did not differ significantly between two groups. Heart rate at 4 h after ICU admission and mean arterial pressures at 12 h and 24 h after ICU admission were lower in the dexmedetomidine group than in the propofol group. At 24 h, serum aspartate aminotransferase (41 (25-118) vs 86 (34-129) U/L, p = 0.035) and alanine aminotransferase (50 (26-160) vs 68 (35-172) U/L, p = 0.019) levels were significantly lower in the dexmedetomidine group than in the propofol group.

CONCLUSION

Microcirculation parameters did not differ significantly between the dexmedetomidine and propofol groups. At 24 h after ICU admission, serum liver enzyme levels were lower in patients receiving dexmedetomidine as compared to propofol.

Dexmedetomidine attenuates acute stress-impaired learning and memory in mice by maintaining the homeostasis of intestinal flora

Dexmedetomidine (Dex) has been used in surgery to improve patients' postoperative cognitive function. However, the role of Dex in stress-induced anxiety-like behaviors and cognitive impairment is still unclear. In this study, we tested the role of Dex in anxiety-like behavior and cognitive impairment induced by acute restrictive stress and analyzed the alterations of the intestinal flora to explore the possible mechanism. Behavioral and cognitive tests, including open field test, elevated plus-maze test, novel object recognition test, and Barnes maze test, were performed. Intestinal gut Microbe 16S rRNA sequencing was analyzed. We found that intraperitoneal injection of Dex significantly improved acute restrictive stress-induced anxiety-like behavior, recognition, and memory impairment. After habituation in the environment, mice (male, 8 weeks, 18-23 g) were randomly divided into a control group (control, N = 10), dexmedetomidine group (Dex, N = 10), AS with normal saline group (AS + NS, N = 10) and AS with dexmedetomidine group (AS + Dex, N = 10). By the analysis of intestinal flora, we found that acute stress caused intestinal flora disorder in mice. Dex intervention changed the composition of the intestinal flora of acute stress mice, stabilized the ecology of the intestinal flora, and significantly increased the levels of Blautia (A genus of anaerobic bacteria) and Coprobacillus. These findings suggest that Dex attenuates acute stress-impaired learning and memory in mice by maintaining the homeostasis of intestinal flora.

Does dexmedetomidine reduce the risk of acute kidney injury after cardiac surgery? A meta-analysis of randomized controlled trials

BACKGROUND

Acute Kidney Injury (AKI) is a common complication after cardiac surgery and has been associated with poor outcomes. Dexmedetomidine (DEX) has been shown to confer direct renoprotection based on some animal and clinical studies, but data from other trials came to the opposite conclusion following cardiac surgery. This meta-analysis was conducted to evaluate the effects of perioperative DEX administration on the occurrence of AKI and the outcomes after cardiac surgery.

METHODS

We searched databases including EMBASE, PubMed, and Cochrane CENTRAL for Randomized Controlled Trials (RCTs) focused on DEX for AKI in adult patients after cardiac surgery. The primary outcome was incidence of AKI. Secondary outcomes were Mechanical Ventilation (MV) duration, Intensive Care Unit (ICU) Length Of Stay (LOS), hospital LOS and mortality.

RESULTS

Fifteen trials enrolling 2907 study patients were collected in the meta-analyses. Compared with controls, DEX reduced the incidence of postoperative AKI (Odds Ratio [OR = 0.66]; 95% Confidence Interval [95% CI 0.48-0.91]; p = 0.01), and there was no significant difference between groups in postoperative mortality (OR = 0.63; 95% CI 0.32-1.26; p = 0.19), MV duration (Weighted Mean Difference [WMD = -0.44]; 95% CI -1.50-0.63; p = 0.42), ICU LOS (WMD = -1.19; 95% CI -2.89-0.51; p = 0.17), and hospital LOS (WMD = -0.31; 95% CI -0.76-0.15; p = 0.19).

CONCLUSIONS

Perioperative DEX reduced the incidence of postoperative AKI in adult patients undergoing cardiac surgery. No significant decrease existed in mortality, MV duration, ICU LOS and hospital LOS owing to DEX administration.

Dexmedetomidine and Perioperative Arrhythmias

The highly selective α2-adrenoceptor agonist dexmedetomidine is a commonly used sedative drug for patients undergoing anesthesia and intensive care treatment. Several studies have indicated that dexmedetomidine may have a potential role in preventing and treating perioperative tachyarrhythmias. However, the specific effect and mechanism of action of dexmedetomidine in this context remain unclear. Dexmedetomidine is known to regulate the electrophysiologic function of the myocardium by inhibiting the function of the sinus node and atrioventricular node, as well as affecting myocardial repolarization. This paper aims to provide a theoretical basis for the prevention and treatment of perioperative arrhythmias by summarizing the effects of dexmedetomidine on myocardial electrophysiologic function and its impact on different types of arrhythmias.

The effect of the concurrent use of Dexmedetomidine (DEX) during the perioperative period on the renal function of patients following craniocerebral interventional surgery

BACKGROUND

Craniocerebral interventional surgery is a common and essential treatment for cerebrovascular diseases. Despite continuous progress in interventional diagnosis and treatment technology, there is no effective method to alleviate contrast-induced kidney injuries. In this retrospective cohort study, we investigated the effect of the concurrent use of Dexmedetomidine (DEX) during the perioperative period on the renal function of patients following craniocerebral interventional surgery.

METHODS

We identified 228 cases of patients underwent craniocerebral interventional surgery from January 2018 to March 2022. Patients who used DEX during general anesthesia were in the DEX group (DEX group) or that did not use dexmedetomidine as the control group (CON group). The markers of kidney injury were recorded before and within 48 h after surgery.

RESULTS

Compared with CON group, the urea nitrogen (BUN) of the DEX group decreased significantly on the first day and the second day after surgery (p < 0.05). The serum cystatin-C and the blood urea nitrogen/creatinine ratio (BUN/Cr) was significantly lower than that in CON group on the second day (p < 0.05). The urine output in the DEX group increased significantly, and the mean arterial pressure (MAP) was higher than the CON group (p < 0.01). There was no difference in postoperative complications, ICU stay time and hospitalization time between the two groups.

CONCLUSION

The combined use of dexmedetomidine in general anesthesia for craniocerebral interventional surgery can reduce BUN levels within 48 h after surgery, significantly increase intraoperative urine volume, maintain intraoperative circulation stability.

Effect of Postoperative Prolonged sedation with Dexmedetomidine after successful reperfusion with Endovascular Thrombectomy on long-term prognosis in patients with acute ischemic stroke (PPDET): study protocol for a randomized controlled trial

BACKGROUND

Endovascular thrombectomy (EVT) is a standard treatment for acute ischemic stroke (AIS) with large vessel occlusion. Hypertension and increased blood pressure variability within the first 24 h after successful reperfusion are related to a higher risk of symptomatic intracerebral hemorrhage and higher mortality. AIS patients might suffer from ischemia-reperfusion injury following reperfusion, especially within 24 h. Dexmedetomidine (DEX), a sedative commonly used in EVT, can stabilize hemodynamics by inhibiting the sympathetic nervous system and alleviate ischemia-reperfusion injury through anti-inflammatory and antioxidative properties. Postoperative prolonged sedation for 24 h with DEX might be a potential pharmacological approach to improve long-term prognosis after EVT.

METHODS

This single-center, open-label, prospective, randomized controlled trial will include 368 patients. The ethics committee has approved the protocol. After successful reperfusion (modified thrombolysis in cerebral infarction scores 2b-3, indicating reperfusion of at least 50% of the affected vascular territory), participants are randomly assigned to the intervention or control group. In the intervention group, participants will receive 0.1~1.0 μg/kg/h DEX for 24 h. In the control group, participants will receive an equal dose of saline for 24 h. The primary outcome is the functional outcome at 90 days, measured with the categorical scale of the modified Rankin Scale, ranging from 0 (no symptoms) to 6 (death). The secondary outcome includes (1) the changes in stroke severity between admission and 24 h and 7 days after EVT, measured by the National Institute of Health Stroke Scale (ranging from 0 to 42, with higher scores indicating greater severity); (2) the changes in ischemic penumbra volume/infarct volume between admission and 7 days after EVT, measured by neuroimaging scan; (3) the length of ICU/hospital stay; and (4) adverse events and the all-cause mortality rate at 90 days.

DISCUSSION

This randomized clinical trial is expected to verify the hypothesis that postoperative prolonged sedation with DEX after successful reperfusion may promote the long-term prognosis of patients with AIS and may reduce the related socio-economic burden.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04916197. Prospectively registered on 7 June 2021.

Dexmedetomidine Sedation in Dogs: Impact on Electroencephalography, Behavior, Analgesia, and Antagonism with Atipamezole

This study aimed to assess the impact of dexmedetomidine constant rate infusion (CRI) on key parameters in dogs. Six dogs received a 60 µg/kg/h dexmedetomidine infusion over 10 min, followed by three 15 min decremental CRIs (3, 2, and 1 µg/kg/h). A subsequent reversal phase employed 600 µg/kg/h atipamezole over 5 min. Continuous electroencephalogram (EEG) assessment, and cardiorespiratory and analgesia monitoring (every 3 min) were conducted, including analgesia evaluation through responses to electric stimulation. Dexmedetomidine induced profound sedation, evidenced by lateral recumbency and immobility. Patient State Index (PSI) decreased from awake (90.4 ± 4.3) to Phase 1 (50.9 ± 30.7), maintaining sedation (29.0 ± 18.1 to 33.1 ± 19.1 in Phases 2-4). Bradycardia (37.8 ± 3.5 bpm, lowest at Phase 3) and hypertension (133.7 ± 17.0 mmHg, highest at Phase 1) were observed, with minimal analgesia. Atipamezole promptly reversed sedation, restoring cognitive function (tail wagging behavior), and normalizing cardiovascular parameters. During atipamezole CRI, the EEG exhibited a transition from delta waves to alpha and low beta waves. This transition was observed alongside gradual increases in PSI and electromyographic activities. Additionally, spindle activities disappeared during this process. This study's results suggest potential clinical utility for EEG-guided dexmedetomidine sedation with reversal using atipamezole, warranting further investigation.

Perioperative acute kidney injury: The renoprotective effect and mechanism of dexmedetomidine

Dexmedetomidine (DEX) is a highly selective and potent α2-adrenoceptor (α2-AR) agonist that is widely used as a clinical anesthetic to induce anxiolytic, sedative, and analgesic effects. In recent years, a growing body of evidence has demonstrated that DEX protects against acute kidney injury (AKI) caused by sepsis, drugs, surgery, and ischemia-reperfusion (I/R) in organs or tissues, indicating its potential role in the prevention and treatment of AKI. In this review, we summarized the evidence of the renoprotective effects of DEX on different models of AKI and explored the mechanism. We found that the renoprotective effects of DEX mainly involved antisympathetic effects, reducing inflammatory reactions and oxidative stress, reducing apoptosis, increasing autophagy, reducing ferroptosis, protecting renal tubular epithelial cells (RTECs), and inhibiting renal fibrosis. Thus, the use of DEX is a promising strategy for the management and treatment of perioperative AKI. The aim of this review is to further clarify the renoprotective mechanism of DEX to provide a theoretical basis for its use in basic research in various AKI models, clinical management, and the treatment of perioperative AKI.

Regional Anesthesia for Arthroscopic Knee Repair in a Patient With Hypertrophic Obstructive Cardiomyopathy (HOCM) Under Monitored Anesthesia Care With Dexmedetomidine Infusion

Patients with hypertrophic obstructive cardiomyopathy (HOCM) who are scheduled for elective, noncardiac surgery present a distinctive challenge for perioperative healthcare providers. The use of general anesthesia and neuraxial anesthesia carries the risk of unpredictable hemodynamic changes and potential complications. Regional anesthesia (RA) emerges as a prudent and effective option for HOCM patients. RA provides advantages such as minimizing hemodynamic fluctuations, avoiding intubation, reducing pharmacologic side effects, facilitating enhanced recovery after surgery, and contributing to greater patient satisfaction. We share the case of a 15-year-old individual diagnosed with HOCM and exercise intolerance, undergoing arthroscopic repair for right patellar instability. In this instance, the patient received preoperative peripheral nerve blocks for surgical anesthesia and underwent repair utilizing monitored anesthesia care (MAC) with a dexmedetomidine (DEX) infusion.

Efficacy and safety of dexmedetomidine for analgesia and sedation in neonates: a systematic review

Opioids and benzodiazepines have historically been employed for pain relief; however, they are associated with detrimental long-term neurodevelopmental consequences. Dexmedetomidine, a highly selective alpha-2-adrenoreceptor agonist, has piqued interest as a viable alternative for neonates, owing to its potential analgesic and neuroprotective attributes. We conducted a systematic review to assess the efficacy and safety of dexmedetomidine utilization in neonates. We conducted a comprehensive search of Ovid, MEDLINE, EMBASE, PubMed, Cochrane, and CINAHL, spanning from January 2010 to September 2022. Our review encompassed six studies involving 252 neonates. Overall, dexmedetomidine may be effective in achieving sedation and analgesia. Furthermore, it may reduce the need for adjunctive sedation or analgesia, shorten the time to extubation, decrease the duration of mechanical ventilation, and accelerate the attainment of full enteral feeds. Notably, no significant adverse effects associated with dexmedetomidine were reported. Nevertheless, additional well-designed studies to establish both the efficacy and safety of dexmedetomidine in neonatal care are needed.

Effect of dexmedetomidine on postoperative nausea and vomiting in female patients undergoing radical thoracoscopic lung cancer resection

Introduction: Postoperative nausea and vomiting (PONV) is a prevalent postsurgical complication. The objective of our study was to compare the effect of different doses of dexmedetomidine on PONV in female patients undergoing radical thoracoscopic lung cancer resection. Methods: A total of 164 female patients undergoing elective thoracoscopic radical lung cancer surgery were enrolled and assigned to one of four groups. Patients received 0.2 μg/kg/h, 0.4 μg/kg/h, 0.8 μg/kg/h dexmedetomidine and normal saline in the Dex1, Dex2, Dex3 and Control groups, respectively. The primary outcome was the incidence of PONV during 48 h postoperatively. The second outcomes included the incidence of PONV and postoperative vomiting (POV) at four time points postoperatively (T1: PACU retention period; T2: PACU discharge to postoperative 12 h; T3: postoperative 12 h-postoperative 24 h; T4: postoperative 24 h-postoperative 48 h), the area under the curve of PONV grade (PONVAUC), PONV grade, POV grade and other postoperative recovery indicators. Results: The incidence of PONV differed among the four groups. The Dex2 group (29.27%) was lower than that in the Dex1 group (61.90%) and Control group (72.50%). The incidence of PONV at T2 in the Dex1 group (11.90%) and Dex2 group (9.76%) was lower than that in the Control group (42.50%). The incidence of PONV at T3 in the Dex2 group (29.27%) was lower than that in the Dex1 group (61.90%) and Control group (62.50%). The PONVAUC was lower in the Dex2 group than in the Control group. The incidence of POV at T3 in the Dex2 and Dex3 groups was lower than that in the Control group. The consumption of remifentanil, norepinephrine, PACU dwell time, VAS scores, postoperative PCA press frequency, and the time for the first postoperative oral intake were different among the four groups. The regression model shows that the Dex2 group is a protective factor for PONV. Conclusion: Dexmedetomidine can reduce the incidence of PONV and accelerate postoperative recovery in female patients undergoing radical thoracoscopic lung cancer resection. Compared with the other two dosages, 0.4 μg/kg/h dexmedetomidine is preferable. Clinical Trial Registration: chictr.org.cn, identifier ChiCTR2300071831.

Sigma-1 receptor regulates the endoplasmic reticulum stress pathway in the protective mechanism of dexmedetomidine against hyperoxia-induced lung injury

Perioperative hyperoxia therapy is of great significance to save the lives of patients, but little is known about the possible mechanisms that induce hyperoxia-induced acute lung injury (HALI) and the measures for clinical prevention and treatment. In this experiment, the models were established with a feeding chamber with automatic regulation of oxygen concentration. The results showed that with the increase in inhaled oxygen concentration and the prolongation of exposure time, the severity of lung injury also increases significantly, reaching the diagnostic indication of HALI after 48 h of inhaling 95 % oxygen concentration. Subsequently, according to the dynamic changes of apoptosis in lung specimens, and the expression changes in Sig-1R-regulated ER stress pathway proteins (Sig-1R, GRP78, p-PERK, ATF6, IRE1, Caspase-12, ATF4, CHOP, Caspase-3 and p-JNK), it was confirmed that the Sig-1R-regulated ER stress signaling pathway was involved in the occurrence of HALI. To explore the preventive and therapeutic effects of routine clinical medication on HALI during the perioperative period, our research group selected dexmedetomidine (Dex) with lung protection. The experimental results revealed that Dex partially reversed the changes in the expression levels of Sig-1R-regulated ER stress pathway proteins. These results preliminarily confirmed that Dex may inhibit apoptosis induced by high oxygen concentration through the Sig-1R-regulated ER stress signaling pathway, thus playing a protective role in HALI.

Intrathecal dexamethasone-bupivacaine combination with bupivacaine alone in spinal anesthesia for cesarean delivery

Background

Postoperative pain management can be achieved by adjuvant medications during the analgesia procedure. The study investigated the effect of intrathecal dexamethasone-bupivacaine combination with bupivacaine alone in spinal anesthesia for cesarean delivery.

Methods

This randomized, double-blind clinical examination included 50 females who had previously experienced a cesarean section. The participants were assigned randomly into two categories: the intervention group, received intrathecal bupivacaine-dexamethasone, and the control group, received intrathecal bupivacaine-normal saline. Levels of pain were evaluated using a 10 cm visual analog scale (VAS) at intervals of 30 minutes, 1 hour, 2 hours after the operation. The span of the sensory block and postoperative analgesia were assessed.

Results

The inclusion of intrathecal dexamethasone with bupivacaine resulted in a significant enhancement in the duration of pain relief during the intervention, lasting for an average of 473.4 ± 39.95 minutes (p<0.001). The duration of sensory and motor block analgesia in the intervention group was more than the control group (128.32 ± 7.30 vs. 92.84 ± 7.84) and (155.6±12.34 vs. 126.16±11.89), respectively (p<0.001). Pain score on the VAS scale at 30, 60, and 120 minutes was significantly lower in the intervention group (p<0.001). There was no difference in side effects and onset time between the study groups.

Conclusion

The inclusion of intrathecal dexamethasone alongside bupivacaine has demonstrated enhancement in the duration of sensory block during spinal anesthesia. This improvement was observed without any alterations in the time it takes for the anesthesia to take effect and without any adverse effects during the postoperative period.

Incidence, associated factors, and outcomes of delirium in critically ill children in china: a prospective cohort study

BACKGROUND

Delirium occurs frequently in critically ill children and has been reported in many countries, but delirium is not well-characterized in China. The aim of this study was to represent the incidence of delirium in critically ill children in China, its associated factors, and the influence of delirium on in-hospital outcomes.

METHODS

This observational prospective cohort study was set up in a large academic medical center with a 57-bed PICU in southwestern China. Critically ill children who required PICU stays over 24 h and were admitted between November 2019 and February 2022 were included in this study. The Cornell Assessment of Pediatric Delirium was used twice daily for delirium evaluation by bedside nurses, and twenty-four clinical features were collected from medical and nursing records during hospitalization.

RESULTS

The incidence of delirium was 26.0% (n = 410/1576). Multivariate analysis revealed that seven independent risk factors including days of mechanical ventilation and physical restraints, admission diagnosis (neurologic disorder), sleep deprivation, use of benzodiazepines and dexmedetomidine, liver failure/liver dysfunction associated with delirium in critically ill children. One potentially protective factor was the watching television /listening to music/playing with toys. Children with delirium had longer lengths of stay in the PICU (median 11 vs. 10 days, p < 0.001) and hospital (median 18 vs. 15 days, p < 0.001) compared to those without delirium. Additionally, the in-hospital mortality rates were 4.63% and 0.77% in patients with and without delirium (p < 0.05).

CONCLUSIONS

Delirium is common in critically ill children in China and related to poor outcomes. Interventional studies are warranted to determine the best practices to reduce delirium exposure in at-risk children.

Ultrasound-guided dexmedetomidine combination with modified high fascia iliaca compartment block for arthroscopic knee surgery: what is the optimal dose of dexmedetomidine?

BACKGROUND

Total knee arthroplasty (TKA) is a common orthopedic procedure for end-stage knee osteoarthritis. Although effective in relieving pain and improving function, postoperative pain is still a common and distressing problem for many patients. This study aims to investigate efficacy of combined administration of dexmedetomidine and modified high fascia iliaca compartment block (H-FICB) in managing acute and chronic pain after TKA, as well as to identify the optimal dosage of dexmedetomidine.

METHODS

A double-blind, randomized controlled trial was conducted to evaluate the effects of dexmedetomidine in patients undergoing TKA. A total of 96 patients undergoing TKA were randomly assigned to one of three groups, were treated with different doses of dexmedetomidine All groups received H-FIB. Pain scores, opioid consumption, side effects, and quality of life were recorded 48 h postoperatively.

RESULTS

The intraoperative consumption of remifentanil and propofol in Group Db was significantly reduced compared with that in Group D0 and Da (P < 0.05). Compared with D0 and Da group, Db group had the lowest number of rescue analgesia, analgesia time and morphine accumulative dosage 48 h after operation (P < 0.05). The Db group had the lowest scores on the numerical rating scale at rest (P < 0.05) and during movement (P < 0.01), followed by the Da group and then the D0 group. Additionally, the incidence of nausea and vomiting was significantly reduced in the Db group (P < 0.05). Furthermore, the Db group had the lowest incidence of chronic pain (P < 0.05).

DISCUSSION

In comparison to the other two groups, the administration of combined dexmedetomidine and H-FIB resulted in a significant reduction in pain scores, opioid consumption, and side effects. The optimal dosage of dexmedetomidine was determined to be 1 μg/kg, which provided the most favorable pain relief with minimal adverse effects.

Dexmedetomidine at Home for Intractable Dystonia and Insomnia in Children With Special Needs: A Case Series

BACKGROUND

We know that syndromic conditions and severe chronic diseases can be associated with symptoms that may interfere with sleep, significantly impacting the life quality of children and caregivers. Drugs commonly used in treating insomnia, such as melatonin, benzodiazepines, niaprazine, and antihistamines, are often either ineffective or associated with adverse effects, requiring new therapeutic perspectives. Dexmedetomidine is a selective alpha-2 agonist with hypnotic and anxiolytic effects, which, by stimulating alpha-2 adrenergic receptors in the locus coeruleus, induces sleep comparable to stages 2-3 of the non-REM phase without substantially affecting the respiratory drive during sedation. Its use has already been extensively described in pediatric intensive care or procedural sedation literature. In 2018, the Italian Medicines Agency (Agenzia Italiana Del Farmaco AIFA) authorized the off-label use of dexmedetomidine outside of intensive care in Children undergoing palliative treatment to control distressing symptoms related to pathology and refractory sleep disorders, and the literature reported cases of children who received dexmedetomidine at home.

OBJECTIVE

Our study aims to describe the home use of dexmedetomidine in children with insomnia or intractable dystonic states.

MEASURES

We conducted a retrospective analysis through a questionnaire addressed to 12 Italian pediatric palliative care centers regarding the home use of dexmedetomidine in sleep disorders and intractable dystonic states.

INTERVENTION

We collected a case series of 9 children treated with dexmedetomidine at home, 8 via intranasal and 1 via intravenous route. All children received the first drug administration in the hospital or hospice during a dedicated admission, under close monitoring of vital signs parameters for 72 hours (3 days, range 2-7 days). After discharge, the potential side effects of the drug were explained to the patient's families, and, once informed consent was obtained, the home administration of dexmedetomidine continued, with follow-up by the palliative care team. At home, dexmedetomidine was administered for 3000 days (minimum 1 month, maximum 36 months). The first patient was treated for 1095 days, from 2019 to 2021 (discontinued due to underlying condition-related death).

OUTCOMES

All patients observed a persistent benefit from the treatment on symptoms, and none of them discontinued dexmedetomidine administration due to drug-related adverse effects or perceived lack of therapeutic efficacy.

CONCLUSIONS

Therefore, its use at home may represent a promising therapeutic approach for intractable sleep disorders or dystonic states in pediatric palliative care children. Further studies are needed to confirm our results.

Intranasal dexmedetomidine vs. oral midazolam for premedication in children: a systematic review and meta-analysis

Objective

To compare the effects of intranasal dexmedetomidine (Dex) and oral midazolam in the preoperative medication of children by using a method of meta-analysis.

Methods

Cochrane Library, Pubmed, Embase, and Web of Science were searched from inception to July 2023. Randomized controlled trials (RCTs) of intranasal Dex vs. oral midazolam in pediatric premedication were collected. Stata 15.0 statistical software was used to analyze the collected data. Relative risk (RR) and 95% confidence interval (CI) were used as effect sizes.

Results

A total of 11 studies with 824 children were included, containing 415 patients in the Dex group and 409 patients in the midazolam group. Compared with the oral midazolam group, the intranasal Dex group had a better preoperative sedation effect at parent-child separation (RR = 1.37, 95% CI: 1.14-1.64) and anesthesia induction (RR = 2.08, 95% CI: 1.03-4.22). In addition, there was no significant difference in the incidence of analgesia remedy (RR = 0.60, 95% CI: 0.36-1.00) the acceptance of anesthesia masks (RR = 0.97, 95% CI: 0.83-1.12), and incidence of adverse events between (RR = 0.25, 95% CI: 0.06-1.13, P = 0.072) between the intranasal Dex and oral midazolam groups.

Conclusion

Compared with oral midazolam, intranasal Dex has better sedative effects of parent-child separation and anesthesia induction in pediatric premedication, but there was no difference in the incidence of anesthesia remedy, anesthesia mask acceptance, and incidence of adverse events. Therefore, compared with oral midazolam, intranasal Dex is a better choice for premedication in children.

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.

Dexmedetomidine combined with propofol attenuates myocardial ischemia/reperfusion injury by activating the AMPK signaling pathway

Objective

Myocardial ischemia/reperfusion (MI/R) injury is a major cause of cardiac tissue damage, with high disability and death rates. Although both dexmedetomidine (Dex) and propofol (PPF) have been indicated to alleviate MI/R injury in rat models, the effects of the combined use of these two drugs remain unclear. This study aimed to investigate the combined effects of Dex and PPF against MI/R injury and related mechanisms.

Methods

A rat model of MI/R injury was established and used to explore the combined effects of Dex and PPF on MI/R injury. Hematoxylin-eosin (HE) and Masson staining were used for histopathological evaluation. 2,3,5-triphenyltetrazolium chloride (TTC), echocardiography, terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining were used to determine myocardial infarction size, cardiac function, and apoptosis, respectively. Enzyme-linked immunosorbent assay (ELISA) was performed to assess myocardial function and oxidative stress (OS). Autophagy was observed through transmission electron microscopy. Moreover, western blotting was conducted to detect autophagy markers and the AMPK pathway.

Results

The combination of Dex and PPF alleviated histopathological injury, reduced myocardial infarction, and rescued cardiac dysfunction in MI/R rats. Furthermore, Dex combined with PPF decreased the levels of MDA and ROS and increased the SOD level in MI/R rats. Besides, Dex combined with PPF inhibited myocardial apoptosis in MI/R rats. After combined treatment with Dex and PPF, the number of autophagosomes, expression levels of Beclin-1 and LC3II/LC3I were elevated, while the expression levels of p62 were reduced in MI/R rats. The combined use of Dex and PPF activated the AMPK pathway in MI/R rats. Compound C (an AMPK inhibitor) could abolish the combined effects of Dex and PPF on alleviating myocardial injury and enhancing autophagy in MI/R rats.

Conclusion

The combination of Dex and PPF attenuated MI/R injury in rats, which may be associated with the activation of the AMPK signaling pathway.

Effect of dexmedetomidine on perioperative haemodynamics and early cognitive function in elderly patients undergoing laparoscopic surgery

Introduction

Laparoscopic minimally invasive surgery has been widely used in the diagnosis and treatment of gynaecological diseases.

Aim

To investigate the effect of dexmedetomidine on perioperative haemodynamics and cognitive function in elderly gynaecological patients who underwent laparoscopic surgery.

Material and methods

Clinical baseline characteristics, haemodynamic parameters, renin activity, norepinephrine level, cognitive function, pain level, and sedation were compared between the 2 groups.

Results

At T4 (10 min after extubation) and T5 (1 h after extubation), significant differences were found in systolic blood pressure, diastolic blood pressure, and heart rate between the 2 groups (p < 0.05); renin activity and norepinephrine level were much lower in the dexmedetomidine group than in the control group at T3 (10 min before extubation) and T4 (p < 0.05). One day before surgery, there were no significant differences in Mini-mental state examination (MMSE), visual analogue scale (VAS), and Ramsay scores between the 2 groups (p > 0.05), but the MMSE score 1 day after surgery and the Ramsay score at 12 h after surgery in the dexmedetomidine group were much higher than that in the control group (p < 0.05). Notably, at 2, 4, 12, 24, and 48 h after surgery, the VAS score in the dexmedetomidine group was significantly lower than that in the control group (p < 0.05).

Conclusions

Dexmedetomidine has a better clinical effect in improving perioperative haemodynamics and early cognitive function in elderly gynaecological patients who received laparoscopic surgery.

MicroRNA-323-5p Involved in Dexmedetomidine Preconditioning Impart Neuroprotection

Background and Objectives: Cerebral ischemia is one of the major preoperative complications. Dexmedetomidine is a well-known sedative-hypnotic agent that has potential organ-protective effects. We examine the miRNAs associated with preconditioning effects of dexmedetomidine in cerebral ischemia. Materials and Methods: Transient infarcts were induced in mice via reperfusion after temporary occlusion of one side of the middle cerebral artery. A subset of these mice was exposed to dexmedetomidine prior to cerebral infarction and miRNA profiling of the whole brain was performed. We administered dexmedetomidine and miRNA-323-5p mimic/inhibitor to oxygen-glucose deprivation/reoxygenation astrocytes. Additionally, we administered miR-323-5p mimic and inhibitor to mice via intracerebroventricular injection 2 h prior to induction of middle cerebral artery occlusion. Results: The infarct volume was significantly lower in the dexmedetomidine-preconditioned mice. Analysis of brain samples revealed an increased expression of five miRNAs and decreased expression of three miRNAs in the dexmedetomidine-pretreated group. The viability of cells significantly increased and expression of miR-323-5p was attenuated in the dexmedetomidine-treated oxygen-glucose deprivation/reoxygenation groups. Transfection with anti-miR-323-5p contributed to increased astrocyte viability. When miRNA-323-5p was injected intraventricularly, infarct volume was significantly reduced when preconditioned with the miR-323-5p inhibitor compared with mimic and negative control. Conclusions: Dexmedetomidine has a protective effect against transient neuronal ischemia-reperfusion injury and eight specific miRNAs were profiled. Also, miRNA-323-5p downregulation has a cell protective effect under ischemic conditions both in vivo and in vitro. Our findings suggest the potential of the miR-323-5p inhibitor as a therapeutic agent against cerebral infarction.

As an inhibitor of norepinephrine release, dexmedetomidine provides no improvement on stroke-associated pneumonia in mice

Background: Dexmedetomidine (DEX) is commonly employed as a sedative agent to attenuate sympathetic tone and reduce norepinephrine (NE) levels. In the context of stroke-associated pneumonia (SAP), which is believed to arise from heightened sympathetic nervous system activity and elevated NE release, the precise influence of DEX remains uncertain. Methods: In this study, we generated an SAP model using middle cerebral artery occlusion (MCAO) and examined NE levels, immunological statuses in the brain and periphery, pneumonia symptoms, and extent of infarction. We aimed to determine the effects of DEX on SAP and explore the underlying. Despite its potential to reduce NE levels, DEX did not alleviate SAP symptoms or decrease the infarct area. Interestingly, DEX led to an increase in spleen size and spleen index. Furthermore, we observed a decrease in the CD3+ T cell population in both the blood and brain, but an increase in the spleen following DEX administration. The precise mechanism linking decreased CD3+ T cells and DEX's role in SAP requires further investigation. Conclusion: The clinical use of DEX in stroke patients should be approached with caution, considering its inability to alleviate SAP symptoms and reduce the infarct area. Further research is necessary to fully understand the relationship between decreased CD3+ T cells and DEX's influence on SAP.

Opioid-Free Versus Opioid-Based Anesthesia on Postoperative Pain After Thoracoscopic Surgery: The Use of Intravenous and Epidural Esketamine

BACKGROUND

The effectiveness and safety of opioid-free anesthesia (OFA) regimens in distinct types of surgeries remain controversial. In this study, we investigated whether OFA could reduce the occurrence of chronic postoperative pain in patients receiving video-assisted thoracoscopic surgery (VATS).

METHODS

We conducted a 2-center, randomized, controlled trial from September 2021 to January 2022. A total of 162 lung tumor patients scheduled to undergo VATS were randomly divided into an opioid-based anesthesia (OA) group and an OFA group. The OA group received general anesthesia combined with thoracic epidural block using morphine, while the OFA group received general anesthesia combined with thoracic epidural block using esketamine. Patient-controlled epidural analgesia (PCEA) was used after surgery (ropivacaine and morphine for the OA group versus ropivacaine and esketamine for the OFA group). The primary end point was chronic pain rates at 3 months after VATS, which were analyzed using a logistic regression model. The secondary end points were chronic pain rates at 6 months, acute pain rates at 24 hours and 48 hours postoperatively, postoperative side effects, and perioperative variables.

RESULTS

The final analysis included 159 patients. Acute postoperative pain at 24 hours occurred in 0 of the 79 (0%) patients in the OA group and 10 of the 80 (17.5%) patients in the OFA group (odds ratio, 52.14; 95% confidence interval [CI], 6.47-420.10; P < .001). Acute postoperative pain at 48 hours occurred in 3 of the 79 (3.8%) patients in the OA group and 2 of the 80 (2.5%) patients in the OFA group (odds ratio, 2.07; 95% CI, 0.99-4.32; P = .053). In this study, none of the patients had moderate or severe pain in either group at 3 and 6 months postsurgically. Mild chronic postoperative pain at 3 months occurred in 27 of the 79 (34.2%) patients in the OA group and 14 of the 80 (17.5%) patients in the OFA group (odds ratio, 3.52; 95% CI, 1.49-8.31; P = .004). At 6 months, mild chronic pain still occurred in 23 of the 79 (29.1%) patients in the OA group and 9 of the 80 (11.3%) patients in the OFA group (odds ratio, 5.55; 95% CI, 2.01-15.33; P = .001). In addition, the OFA group included fewer patients with side effects, including nausea, vomiting, and pruritus, within 48 hours after surgery.

CONCLUSIONS

Replacement of opioids by esketamine, intraoperatively as intravenous injection and epidural infusion and postoperatively as epidural infusion, reduces the incidence of mild chronic postoperative pain and side effects in patients after VATS.

Multiple-Factors-Induced Rheumatoid Arthritis Synoviocyte Activation Is Attenuated by the α2-Adrenergic Receptor Agonist Dexmedetomidine

Dexmedetomidine (Dex) has analgesic and sedative properties and anti-inflammatory functions. Although the effects of Dex on arthritis have been revealed, the physiological mechanism underlying the interaction between Dex and rheumatoid arthritis (RA)-mediated inflammatory cytokines has not been fully studied. Inflamed and migrated fibroblast-like synoviocytes (FLSs) are involved in RA severity. Thus, we aimed to determine the effects of Dex on RA-FLSs treated with inflammatory cytokines and a growth factor as multiple stimulating inputs. TNF-α, IL-6, and EGF as multiple stimulating inputs increased the cAMP concentration of RA-FLSs, while Dex treatment reduced cAMP concentration. Dex reduced electroneutral sodium-bicarbonate cotransporter 1 (NBCn1) expression, NBC activity, and subsequent RA-FLS migration. The mRNA expression levels of RA-related factors, such as inflammatory cytokines and osteoclastogenesis factors, were enhanced by multiple-input treatment. Notably, Dex effectively reduced these expression levels in RA-FLSs. These results indicate that multiple inflammatory or stimulating inputs enhance RA-FLS migration, and treatment with Dex relieves activated RA-FLSs, suggesting that Dex is a potential therapeutic drug for RA.

Pharmacological interventions for preventing opioid-induced hyperalgesia in adults after opioid-based anesthesia: a systematic review and network meta-analysis

Background: Opioid-induced hyperalgesia (OIH) is an adverse event of prolonged opioid use that increases pain intensity. The optimal drug to prevent these adverse effects is still unknown. We aimed to conduct a network meta-analysis to compare different pharmacological interventions for preventing the increase in postoperative pain intensity caused by OIH. Methods: Several databases were searched independently for randomized controlled trials (RCTs) comparing various pharmacological interventions to prevent OIH. The primary outcomes were postoperative pain intensity at rest after 24 h and the incidence of postoperative nausea and vomiting (PONV). Secondary outcomes included pain threshold at 24 h after surgery, total morphine consumption over 24 h, time to first postoperative analgesic requirement, and shivering incidence. Results: In total, 33 RCTs with 1711 patients were identified. In terms of postoperative pain intensity, amantadine, magnesium sulphate, pregabalin, dexmedetomidine, ibuprofen, flurbiprofen plus dexmedetomidine, parecoxib, parecoxib plus dexmedetomidine, and S (+)-ketamine plus methadone were all associated with milder pain intensity than placebo, with amantadine being the most effective (SUCRA values = 96.2). Regarding PONV incidence, intervention with dexmedetomidine or flurbiprofen plus dexmedetomidine resulted in a lower incidence than placebo, with dexmedetomidine showing the best result (SUCRA values = 90.3). Conclusion: Amantadine was identified as the best in controlling postoperative pain intensity and non-inferior to placebo in the incidence of PONV. Dexmedetomidine was the only intervention that outperformed placebo in all indicators. Clinical Trial Registration: https://www.crd.york.ac. uk/prospero/display_record.php?, CRD42021225361.

Anesthesia, the developing brain, and dexmedetomidine for neuroprotection

Anesthesia-induced neurotoxicity is a set of unfavorable adverse effects on central or peripheral nervous systems associated with administration of anesthesia. Several animal model studies from the early 2000's, from rodents to non-human primates, have shown that general anesthetics cause neuroapoptosis and impairment in neurodevelopment. It has been difficult to translate this evidence to clinical practice. However, some studies suggest lasting behavioral effects in humans due to early anesthesia exposure. Dexmedetomidine is a sedative and analgesic with agonist activities on the alpha-2 (ɑ₂) adrenoceptors as well as imidazoline type 2 (I2) receptors, allowing it to affect intracellular signaling and modulate cellular processes. In addition to being easily delivered, distributed, and eliminated from the body, dexmedetomidine stands out for its ability to offer neuroprotection against apoptosis, ischemia, and inflammation while preserving neuroplasticity, as demonstrated through many animal studies. This property puts dexmedetomidine in the unique position as an anesthetic that may circumvent the neurotoxicity potentially associated with anesthesia.

Multiple uses of dexmedetomidine in small animals: a mini review

Dexmedetomidine is an alpha-2 adrenergic agonist, which use had an exponential increase in human and veterinary medicine in the last 10 years. The aim of this mini review is to summarize the various uses of dexmedetomidine underlining its new applications and capabilities in the small animals' clinical activity. While this drug was born as sedative in veterinary medicine, some studies demonstrated to be effective as an analgesic both in single administration and in continuous infusion. Recent studies have also shown the role of dexmedetomidine as an adjuvant during locoregional anesthesia, increasing the duration of the sensitive block and consequently decreasing the demand for systemic analgesics. The various analgesic properties make dexmedetomidine an interesting drug for opioid-free analgesia. Some studies highlighted a potential neuroprotective, cardioprotective and vasculoprotective role of dexmedetomidine, thus conferring it a place in critical care medicine, such as trauma and septic patients. Dexmedetomidine has demonstrated to be a multitasking molecule and it is ready to face new challenges.

Cardioprotective Effects of Dexmedetomidine in an Oxidative-Stress In Vitro Model of Neonatal Rat Cardiomyocytes

Preterm birth is a risk factor for cardiometabolic disease. The preterm heart before terminal differentiation is in a phase that is crucial for the number and structure of cardiomyocytes in further development, with adverse effects of hypoxic and hyperoxic events. Pharmacological intervention could attenuate the negative effects of oxygen. Dexmedetomidine (DEX) is an α2-adrenoceptor agonist and has been mentioned in connection with cardio-protective benefits. In this study, H9c2 myocytes and primary fetal rat cardiomyocytes (NRCM) were cultured for 24 h under hypoxic condition (5% O₂), corresponding to fetal physioxia (pO₂ 32-45 mmHg), ambient oxygen (21% O₂, pO₂ ~150 mmHg), or hyperoxic conditions (80% O₂, pO₂ ~300 mmHg). Subsequently, the effects of DEX preconditioning (0.1 µM, 1 µM, 10 µM) were analyzed. Modulated oxygen tension reduced both proliferating cardiomyocytes and transcripts (CycD2). High-oxygen tension induced hypertrophy in H9c2 cells. Cell-death-associated transcripts for caspase-dependent apoptosis (Casp3/8) increased, whereas caspase-independent transcripts (AIF) increased in H9c2 cells and decreased in NRCMs. Autophagy-related mediators (Atg5/12) were induced in H9c2 under both oxygen conditions, whereas they were downregulated in NRCMs. DEX preconditioning protected H9c2 and NRCMs from oxidative stress through inhibition of transcription of the oxidative stress marker GCLC, and inhibited the transcription of both the redox-sensitive transcription factors Nrf2 under hyperoxia and Hif1α under hypoxia. In addition, DEX normalized the gene expression of Hippo-pathway mediators (YAP1, Tead1, Lats2, Cul7) that exhibited abnormalities due to differential oxygen tensions compared with normoxia, suggesting that DEX modulates the activation of the Hippo pathway. This, in the context of the protective impact of redox-sensitive factors, may provide a possible rationale for the cardio-protective effects of DEX in oxygen-modulated requirements on survival-promoting transcripts of immortalized and fetal cardiomyocytes.

Use of Dexmedetomidine During an Emergent Exploratory Laparotomy in a High-Risk Cardiac Patient With an Intra-aortic Balloon Pump

An intra-aortic balloon pump (IABP) may be placed preoperatively for high-risk patients with reduced ejection fraction or multivessel coronary disease undergoing non-cardiac surgery. Dexmedetomidine (DEX) has both anesthetic and cardioprotective effects, and little evidence is present on its effect on minimum alveolar concentration (MAC) and bispectral index (BIS). We present the case of a high-risk cardiac patient who was admitted and required fluid optimization prior to coronary artery bypass grafting (CABG). An IABP was placed after failure to tolerate intermittent hemodialysis (iHD). Bowel ischemia complicated this patient's course, necessitating an urgent exploratory laparotomy with the IABP in place. DEX and 0.3-MAC sevoflurane were successfully used without perioperative cardiac complications. Continuous BIS monitoring was performed to maintain an adequate level of anesthesia. DEX should be considered as an alternative anesthetic adjuvant in high-risk and medically complex patients.

Influencing factors of dexmedetomidine on postoperative myocardial protection in patients with Video-Assisted Thoracoscopic Surgery lobectomy: A retrospective cohort study

Objective

To investigate factors affecting the cardioprotective proprieties of dexmedetomidine in patients after pulmonary lobectomy.

Methods

The data of 504 patients who received dexmedetomidine combined with general anesthesia and video-assisted thoracoscopic surgery (VATS) lobectomy in Shanghai Lung Hospital from April 2018 to April 2019 were analyzed retrospectively. Patients were divided into normal troponin group (LTG) and high troponin group (HTG) according to whether the postoperative troponin level was greater than 13. Ratio of systolic blood pressure greater than 180, heart rate greater than 110, the dose of dopamine and other drugs, the ratio of neutrophils to lymphocytes, postoperative visual analog scale (VAS) pain score and hospital stay were compared between the two groups.

Results

Preoperative systolic blood pressure, intraoperative maximum systolic blood pressure, intraoperative maximum heart rate, intraoperative minimum heart rate and N-terminal pro hormone brain natriuretic peptide (NT-proBNP) correlated with troponin values. The proportion of patients with systolic blood pressure greater than 180 in the HTG was higher than that in the LTG (p=0.0068), and the proportion of patients with heart rate greater than 110 was significantly higher in the HTG compared to the LTG (p=0.044). The ratio of neutrophils/lymphocytes in the LTG was lower than that in the HTG (P<0.001). At 24 and 48 hours after operation, the VAS score in the LTG was lower than that in the HTG. Patients with high troponin had longer hospital stay.

Conclusions

Intraoperative systolic blood pressure, maximum heart rate, and postoperative neutrophil/lymphocyte ratio are important factors that affect the myocardial protection properties of dexmedetomidine and may affect the postoperative analgesia effect and the length of hospital stay.

Analgesics can affect the sensitivity of temozolomide to glioma chemotherapy through gap junction

This study investigated the effect of frequently used analgesics in cancer pain management (flurbiprofen (FLU), tramadol (TRA), and morphine (MOR)) and a novel α2-adrenergic agonist (dexmedetomidine, DEX) on temozolomide (TMZ) sensitivity in glioma cells. Cell counting kit-8 and colony-formation assays were performed to analyze the viability of U87 and SHG-44 cell lines. A high and low cell density of colony method, pharmacological methods, and connexin43 mimetic peptide GAP27 were used to manipulate the function of gap junctions; "Parachute" dye coupling and western blot were employed to determine junctional channel transfer ability and connexin expression. The results showed that DEX (in the concentration range of 0.1 to 5.0 ng/ml) and TRA (in the concentration range of 1.0 to 10.0 µg/ml) reduced the TMZ cytotoxicity in a concentration-dependent manner but was only observed with high cell density (having formed gap junction). The cell viability percentage was 71.3 to 86.8% when DEX was applied at 5.0 ng/ml, while tramadol showed 69.6 to 83.7% viability at 5.0 μg/ml in U87 cells. Similarly, 5.0 ng/ml of DEX resulted in 62.6 to 80.5%, and 5.0 μg/ml TRA showed 63.5 to 77.3% viability in SHG-44 cells. Further investigating the impact of analgesics on gap junctions, only DEX and TRA were found to decrease channel dye transfer through connexin phosphorylation and ERK pathway, while no such effect was observed for FLU and MOR. Analgesics that can affect junctional communication may compromise the effectiveness of TMZ when used simultaneously.

Dexmedetomidine only regimen for long-term sedation is associated with reduced vasopressor requirements in septic shock patients: A retrospective cohort study from MIMIC-IV database

Background

Previous studies have shown that dexmedetomidine (DEX) may be associated with reduced vasopressor requirements in septic shock patients, however, long-term DEX-only sedation in reducing vasopressor requirements is still controversial.

Methods

A retrospective study was conducted among patients with septic shock on mechanical ventilation using the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. The primary outcome was the ratio of norepinephrine equivalent dose to mean arterial pressure (NEq/MAP) in the first 72 h after DEX or other sedatives for sedation. The secondary outcomes were key organ function parameters, 28-day mortality, and 90-day mortality. Univariate, propensity score matching (PSM), and generalized linear mixed model (GLMM) analyses were performed.

Results

DEX was associated with decreased NEq/MAP in the first 72 h (difference = 0.05, 95% CI = -0.02-0.08, p = 0.002) after adjusting for confounders in the GLMM analysis. The DEX group was also associated with a lower heart rate, cardiac output (CO), lactate level, aspartate transaminase (AST) level, and higher PaO2/FiO2 ratio (p < 0.0125). Moreover, DEX only sedation was associated with reduced 90-day mortality (OR = 0.60, 95% CI = 0.37-0.94, p = 0.030).

Conclusion

DEX may be associated with decreased vasopressor requirements, improved AST and PaO2/FiO2 levels, and reduced 90-day mortality in patients with septic shock, which warrants further study.

Dexmedetomidine Protects against Airway Inflammation and Airway Remodeling in a Murine Model of Chronic Asthma through TLR4/NF-κB Signaling Pathway

Asthma is a common respiratory disease characterized by chronic airway inflammation. Dexmedetomidine (DEX), a highly selective α2 adrenergic receptor agonist, has been shown to participate in regulating inflammatory states and thus exert organ protective actions. However, the potential of DEX in asthma is still unknown. This study is aimed at investigating the role of DEX in a mouse model of house dust mite- (HDM-) induced asthma and exploring its underlying mechanism. Here, we found that DEX treatment significantly ameliorated airway hyperresponsiveness, airway inflammation, and airway remodeling in the asthmatic mice, which were similar to the efficacy of the reference anti-inflammatory drug dexamethasone. In addition, DEX reversed the increased expression of toll-like receptor 4 (TLR4) and its downstream signaling adaptor molecule nuclear factor-κB (NF-κB) in the lung tissue of asthmatic mice. Furthermore, these protective effects of DEX were abolished by yohimbine, an α2 adrenergic receptor antagonist. These results indicate that DEX is capable of ameliorating airway inflammation and remodeling in asthmatic mice, and this protective effect is associated with the inhibition of the TLR4/NF-κB signaling pathway.

A comprehensive overview of clinical research on dexmedetomidine in the past 2 decades: A bibliometric analysis

Introduction: Dexmedetomidine is a potent, highly selective α-2 adrenoceptor agonist with sedative, analgesic, anxiolytic, and opioid-sparing properties. A large number of dexmedetomidine-related publications have sprung out in the last 2 decades. However, no bibliometric analysis for clinical research on dexmedetomidine has been published to analyze hot spots, trends, and frontiers in this field. Methods: The clinical articles and reviews related to dexmedetomidine, published from 2002 to 2021 in the Web of Science Core Collection, were retrieved on 19 May 2022, using relevant search terms. VOSviewer and CiteSpace were used to conduct this bibliometric study. Results: The results showed that a total of 2,299 publications were retrieved from 656 academic journals with 48,549 co-cited references by 2,335 institutions from 65 countries/regions. The United States had the most publications among all the countries (n = 870, 37.8%) and the Harvard University contributed the most among all institutions (n = 57, 2.48%). The most productive academic journal on dexmedetomidine was Pediatric Anesthesia and the first co-cited journal was Anesthesiology. Mika Scheinin is the most productive author and Pratik P Pandharipande is the most co-cited author. Co-cited reference analysis and keyword analysis illustrated hot spots in the dexmedetomidine field including pharmacokinetics and pharmacodynamics, intensive care unit sedation and outcome, pain management and nerve block, and premedication and use in children. The effect of dexmedetomidine sedation on the outcomes of critically ill patients, the analgesic effect of dexmedetomidine, and its organ protective property are the frontiers in future research. Conclusion: This bibliometric analysis provided us with concise information about the development trend and provided an important reference for researchers to guide future research.

Impact of pharmacological interventions on intrapulmonary shunt during one-lung ventilation in adult thoracic surgery: a systematic review and component network meta-analysis

BACKGROUND

Intrapulmonary shunt is a major determinant of oxygenation in thoracic surgery under one-lung ventilation. We reviewed the effects of available treatments on shunt, Pao₂/FiO₂ and haemodynamics through systematic review and network meta-analysis.

METHODS

Online databases were searched for RCTs comparing pharmacological interventions and intrapulmonary shunt in thoracic surgery under one-lung ventilation up to March 30, 2022. Random-effects (component) network meta-analysis compared 24 treatments and 19 treatment components. The Confidence in Network Meta-Analysis (CINeMA) framework assessed evidence certainty. The primary outcome was intrapulmonary shunt fraction during one-lung ventilation.

RESULTS

A total of 55 RCTs were eligible for systematic review (2788 participants). The addition of N₂O (mean difference [MD]=-15%; 95% confidence interval [CI], -25 to -5; P=0.003) or almitrine (MD=-13%; 95% CI, -20 to -6; P<0.001) to propofol anaesthesia were efficient at decreasing shunt. Combined epidural anaesthesia (MD=3%; 95% CI, 1-5; P=0.005), sevoflurane (MD=5%; 95% CI, 2-8; P<0.001), isoflurane (MD=6%; 95% CI, 4-9; P<0.001), and desflurane (MD=9%; 95% CI, 4-14; P=0.001) increased shunt vs propofol. Almitrine (MD=147 mm Hg; 95% CI, 58-236; P=0.001), dopexamine (MD=88 mm Hg; 95% CI, 4-171; P=0.039), and iloprost (MD=81 mm Hg; 95% CI, 4-158; P=0.038) improved Pao₂/FiO₂. Certainty of evidence ranged from very low to moderate.

CONCLUSIONS

Adding N₂O or almitrine to propofol anaesthesia reduced intrapulmonary shunt during one-lung ventilation. Halogenated anaesthetics increased shunt in comparison with propofol. The effects of N₂O, iloprost, and dexmedetomidine should be investigated in future research. N₂O results constitute a research hypothesis currently not backed by any direct evidence. The clinical availability of almitrine is limited.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO CRD42022310313.

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.

Protective Effects of Dexmedetomidine Infusion on Genotoxic Potential of Isoflurane in Patients Undergoing Emergency Surgery

BACKGROUND

Isoflurane (ISO) has been extensively uses in general anesthesia and reported to cause deoxyribonucleic acid (DNA) damage in prolonged surgical procedures. Dexmedetomidine (DEX) is an adrenergic agonist and having antioxidant activity that may reduce the genotoxic potential (DNA damage) and oxidative stress induced by ISO in patients undergoing major neurosurgical procedures. Methods and Findings. Twenty-four patients of ASA (American Society of Anesthesiologists) classes I and II were randomly divided into two groups (n = 12). Group A patients received ISO, while group B patients received DEX infusion for maintenance of anesthesia. Venous blood samples were collected at different time intervals and used to evaluate the oxidative stress marker malondialdehyde (MDA) and endogenous antioxidants superoxide dismutases (SOD) and catalases (CAT). A single-cell gel electrophoresis (SCGE)-comet assay was used to investigate the genotoxic potential of ISO.

CONCLUSION

Increased level of antioxidants and decreased value of MDA and genetic damage index were seen in group B (P < 0.001) in a time-dependent manner. Genetic damage was highest at point T ₂ (0.77 vs. 1.37), and continued to decrease till T ₃ (0.42 vs. 1.19), with respect to negative controls or baseline values following DEX infusion. Significantly, higher level of MDA was recorded in serum of group A (P < 0.001) as compared to group B (1.60 ± 0.33 vs. 0.03 ± 0.001). Enzymatic activities of CAT and SOD were significantly higher in group B than group A (10.11 ± 2.18 vs. 5.71 ± 0.33), (1.04 ± 0.05 vs. 0.95 ± 0.01), respectively. It may play a contributing role in daily anesthesia practice and improve the toxic effects on patients as well as anesthesia personnel. Trial Registration. Ethical Committee of Post Graduate Medical Institute (PGMI), Lahore General Hospital approved the use of humans in this study vide human subject application number ANS-6466 dated February 04, 2019. Furthermore, as the clinical trials required registration from an appropriate registry approved by World Health Organization (WHO), this trail also retrospectively registered at Thai Clinical Trials Registry (an approved WHO registry for clinical trials registration) under reference ID TCTR20211230001 on December 30, 2021.

Dexmedetomidine Sedation Combined With Remifentanil in MitraClip Procedures is Feasible and Improves Hemodynamics

OBJECTIVES

The objective of the study was to compare the overall feasibility, respiratory and hemodynamic stability, as well as process times of a dexmedetomidine-based sedative regimen compared with general anesthesia among patients undergoing MitraClip procedures.

DESIGN

A retrospective cohort study.

SETTING

A single tertiary care university center.

PARTICIPANTS

The study included 79 patients.

INTERVENTIONS

Dexmedetomidine sedation versus general anesthesia.

MEASUREMENTS AND MAIN RESULTS

Seventy-nine MitraClip procedures in dexmedetomidine/remifentanil conscious sedation (DCS, n = 26) or general anesthesia (GA, n = 53), performed between 2018 and 2020 at Charité - Universitätsmedizin Berlin, were analyzed retrospectively. Patients' median age was 81 years in both groups without differences in preinterventional EuroScore I (DCS 6 [5; 8], GA 7 [6; 8]) or systolic function (left ventricular ejection fraction: DCS 50% [32; 60] v. GA 50% [36; 60]; tricuspid annular plane systolic excursion: DCS 19 mm [16; 22] v GA 19 mm [15; 22]). During MitraClip procedures, respiratory parameters revealed no differences between groups, whereas patients under DCS showed higher mean arterial pressures (DCS 64 mmHg [59; 74] v GA 58 mmHg [53; 66]) and needed less norepinephrine (DCS 0.0µg/kg/min [0.0; 0.2] v GA 0.08 µg/kg/min [0.05; 0.15]). Emergence from both anesthesia regimens to readiness for intensive care unit transfer was faster in DCS (8 min [4; 18] v GA 16 min [11; 23]); however, total process time was comparable between groups (DCS 128 min [104; 155] v GA 142 min [117; 190]). Two patients required a switch from DCS to GA due to oral bleeding or prolonged procedure time. Both were excluded from the analysis. There was no switch to open surgery and no differences in postoperative complications between DCS and GA.

CONCLUSION

Dexmedetomidine/remifentanil sedation appears to be feasible and a safe option for MitraClip procedures, and provides better hemodynamic stability with faster emergence times compared with general anesthesia.

Dexmedetomidine attenuates subarachnoid hemorrhage-induced acute lung injury through regulating autophagy and TLR/NFκB signaling pathway

BACKGROUND

Acute lung injury (ALI) is the most serious complication of subarachnoid hemorrhage (SAH). We investigated role of autophagy and inflammatory signaling pathways in lung damage and therapeutic effects of dexmedetomidine (DEX).

METHODS

Fifty male Wistar rats were randomly divided into five groups: sham, SAH, SAH+ DEX5, SAH+DEX25, and SAH+DEX50. SAH was induced using endovascular perforation technique. All rats received mechanical ventilation for 60 minutes. At 2 and 24 h of SAH induction, SAH+DEX groups were treated with 5, 25, and 50 µg/kg of DEX, respectively. Histological ALI score and pulmonary edema were assessed after 48 h. Lung expression of LC3B, ATG3, p62, TLR4, TLR9, and NFκB was assessed using western blotting and quantitative PCR. Blood levels of IL-6, IL-1β, IFN-γ, and TNFα were also assessed.

RESULTS

SAH induced ALI and pulmonary edema, which were attenuated in SAH+DEX5 (P < 0.001 for both) and SAH+DEX25 groups (P = 0.001 and P < 0.001 for ALI and edema, respectively). Lung expressions of LC3B and ATG3 were upregulated in SAH group, which was attenuated in SAH+DEX5 and SAH+DEX25 groups. Lung expressions of TLR4, TLR9, and NFκB were increased in SAH group, which was attenuated in SAH+DEX5 group. Blood IL-6 level was increased in SAH group and attenuated in SAH+DEX5 and SAH+DEX25 groups. Blood IFN-γ level was lower in SAH group than in sham group, and it was increased in SAH+DEX25 group.

CONCLUSIONS

Low-dose DEX treatment after SAH may protect against ALI by disrupting pathological brain-lung crosstalk and alleviating autophagy flux and TLR-dependent inflammatory pathways.

Effects of Dexmedetomidine on Basic Cardiac Electrophysiology in Adults; a Descriptive Review and a Prospective Case Study

Dexmedetomidine (DEX) is a commonly used sedative agent with no or minimal effects on breathing. DEX may also be beneficial in myocardial protection. Since the mechanisms of cardiac effects are not well known, we carried out a descriptive review and examined the effects of DEX on myocardial electrical conduction in a prospective and controlled manner. For the review, clinical studies exploring DEX in myocardial protection published between 2020-2022 were explored. A case study included 11 consecutive patients at a median (range) age of 48 (38-59), scheduled for elective radiofrequency ablation of paroxysmal atrial fibrillation. A bolus dose of DEX 1 µg/kg given in 15 min was followed by a continuous infusion of 0.2-0.7 µg/kg/h. Direct intracardiac electrophysiologic measurements, hemodynamics and oxygenation were measured before and after the DEX bolus. Experimental studies show that DEX protects the heart both via stabilizing cardiac electrophysiology and reducing apoptosis and autophagy after cell injury. The clinical evidence shows that DEX provides cardiac protection during different surgeries. In a clinical study, DEX increased the corrected sinus node recovery time, prolongated the atrioventricular (AV) nodal refractory period and cycle length producing AV nodal Wenckebach retrograde conduction block. DEX has a putative role in organ protection against hypoxic, oxidative and reperfusion injury. DEX slows down the firing of the sinus node and prolongs AV refractoriness.

[New aspects of perioperative organ protection]

BACKGROUND

Acutely occurring organ damage significantly contributes to morbidity and mortality in the perioperative context.

OBJECTIVE

This article highlights new clinical perspectives on how perioperative organ damage can be prevented and ameliorated by influencing the high mobility group box 1 protein (HMGB1) signaling.

MATERIAL AND METHODS

A MEDLINE search was performed in the fields of clinical and basic research. The presentation of basic mechanisms of perioperative organ damage and the discussion of the importance of HMGB1 in prevention and treatment by pharmaceutical and nonpharmaceutical interventions are the focus of the review.

RESULTS

The HMGB1 is a central element in the pathogenesis of septic and aseptic inflammation-induced organ damage. Remote ischemic preconditioning (RIPC) and dexmedetomidine are highly effective approaches to mitigate or prevent organ damage.

CONCLUSION

The RIPC and dexmedetomidine offer protective properties in ischemia-reperfusion injury as well as in inflammation-related organ damage, which are mediated by HMGB1, among others. This effectively protects the kidneys, heart, lungs, liver and brain. The application of these concepts should be considered in routine clinical practice.