Influence Of Dexmedetomidine Research Articles

Intravenous infusion of dexmedetomidine during the surgery to prevent postoperative delirium and postoperative cognitive dysfunction undergoing non-cardiac surgery: a meta-analysis of randomized controlled trials.

Dexmedetomidine plays a pivotal role in mitigating postoperative delirium and cognitive dysfunction while enhancing the overall quality of life among surgical patients. Nevertheless, the influence of dexmedetomidine on such complications in various anaesthesia techniques remains inadequately explored. As such, in the present study, a meta-analysis was conducted to comprehensively evaluate its effects on postoperative delirium and cognitive dysfunction. A number of databases were searched for randomised controlled trials comparing intravenous dexmedetomidine to other interventions in preventing postoperative delirium and cognitive dysfunction in non-cardiac and non-neurosurgical patients. These databases included PubMed, Embase, and Cochrane Library. Statistical analysis and graphing were performed using Review Manager, STATA, the second version of the Cochrane risk-of-bias tool for randomised controlled trials, and GRADE profiler. This meta-analysis comprised a total of 24 randomised controlled trials, including 20 trials assessing postoperative delirium and 6 trials assessing postoperative cognitive dysfunction. Across these 24 studies, a statistically significant positive association was observed between intravenous administration of dexmedetomidine and a reduced incidence of postoperative delirium (RR: 0.55; 95% CI 0.47 to 0.64,p < 0.00001, I2 = 2%) and postoperative cognitive dysfunction (RR: 0.60; 95% CI 0.38 to 0.96,p = 0.03, I2 = 60%). Subgroup analysis did not reveal a significant difference in the incidence of postoperative delirium between the general anaesthesia and non-general anaesthesia groups, but a significant difference was observed in the incidence of postoperative cognitive dysfunction. Nonetheless, when the data were pooled, it was evident that the utilisation of dexmedetomidine was associated with an increased incidence of hypotension (RR: 1.42; 95% CI 1.08 to 1.86,p = 0.01, I2 = 0%) and bradycardia (RR: 1.66; 95% CI 1.23 to 2.26,p = 0.001, I2 = 0%) compared with other interventions. However, there was no significantly higher occurrence of hypertension in the DEX groups (RR = 1.35, 95% CI 0.81-2.24, p = 0.25,I2 = 0%). Compared with other interventions, intravenous dexmedetomidine infusion during non-cardiac and non-neurosurgical procedures may significantly reduce the risk of postoperative delirium and cognitive dysfunction. The results of subgroup analysis reveal a consistent preventive effect on postoperative delirium in both general and non-general anaesthesia groups. Meanwhile, continuous infusion during general anaesthesia was more effective in reducing the risk of cognitive dysfunction. Despite such findings, hypotension and bradycardia were more frequent in patients who received dexmedetomidine during surgery.

Influences of dexmedetomidine on stress responses and postoperative cognitive and coagulation functions in patients undergoing radical gastrectomy under general anesthesia.

Radical gastrectomy (RG) is commonly used in the treatment of patients with gastric cancer (GC), but this procedure may lead to stress responses, postoperative cognitive dysfunction, and blood coagulation abnormalities in patients. To investigate the influences of dexmedetomidine (DEX) on stress responses and postoperative cognitive and coagulation functions in patients undergoing RG under general anesthesia (GA). One hundred and two patients undergoing RG for GC under GA from February 2020 to February 2022 were retrospectively reviewed. Of these, 50 patients had received conventional anesthesia intervention [control group (CG)] and 52 patients had received DEX in addition to routine anesthesia intervention [observation group (OG)]. Inflammatory factor (IFs; tumor necrosis factor-α, TNF-α; interleukin-6, IL-6), stress responses (cortisol, Cor; adrenocorticotropic hormone, ACTH), cognitive function (CF; Mini-Mental State Examination, MMSE), neurological function (neuron-specific enolase, NSE; S100 calcium-binding protein B, S100B), and coagulation function (prothrombin time, PT; thromboxane B2, TXB2; fibrinogen, FIB) were compared between the two groups before surgery (T0), as well as at 6 h (T1) and 24 h (T2) after surgery. Compared with T0, TNF-α, IL-6, Cor, ACTH, NSE, S100B, PT, TXB2, and FIB showed a significant increase in both groups at T1 and T2, but with even lower levels in OG vs CG. Both groups showed a significant reduction in the MMSE score at T1 and T2 compared with T0, but the MMSE score was notably higher in OG compared with CG. In addition to a potent inhibitory effect on postoperative IFs and stress responses in GC patients undergoing RG under GA, DEX may also alleviate the coagulation dysfunction and improve the postoperative CF of these patients.

Retracted: Influence of Dexmedetomidine on Myocardial Injury in Patients with Simultaneous Pancreas-Kidney Transplantation.

[This retracts the article DOI: 10.1155/2022/7196449.].

Retracted: Influence of Dexmedetomidine on Diaphragm Function and Postoperative Outcomes in ICU Patients with Mechanical Ventilation.

[This retracts the article DOI: 10.1155/2021/1990838.].

Influence of Dexmedetomidine on Myocardial Injury in Patients with Simultaneous Pancreas-Kidney Transplantation.

Diabetes is one of the most common chronic diseases in the world. End-stage renal disease (ESRD) caused by diabetes is the most serious long-term complication. The main cause of death in patients with simultaneous pancreas-kidney transplantation (SPKT) is cardiovascular disease. Although dexmedetomidine (Dex) has unique advantages in heart protection against ischaemic/reperfusion injury, few clinical studies have been conducted on its cardioprotective effect in SPKT. This study aimed to explore the influence of Dex on myocardial injury in patients undergoing SPKT and to analyze its possible mechanism. A randomized controlled trial (RCT) was performed from July 1, 2018 to December 1, 2020. Eighty patients, regardless of gender, scheduled for SPKT were randomly allocated into a Dex group (D group) receiving Dex at a rate of 1 µg/kg for 10 minutes before anaesthesia induction and then continuous infusion at 0.5 µg/kg/hour until the end of surgery and control group (C group) receiving equivalent capacity of saline. Serum cardiac troponin I (cTnI), creatine kinase isoenzyme (CK-MB), tumour necrosis factor-α (TNF-α), and interleukin-6 (IL-6) were recorded at 5 minutes after anaesthesia induction (baseline,T0), 5 minutes before renal arteriovenous opening (T1), 30 minutes after renal arteriovenous opening (T2), 30 minutes after pancreatic related arteriovenous opening (T3), immediately after surgery (T4), 4 hours after surgery (T5), and 24 hours after surgery (T6). Adverse cardiovascular events were recorded during the perioperative period. Changes in ECG S-T segments and T waves were monitored at T0-T6. Myocardial infarction and percutaneous coronary intervention were recorded with an average follow-up of one year. Compared with T0, TNF-α and IL-6 concentrations significantly increased at T1-T6 in the C and D groups (P < 0.05). IL-6 concentration increased significantly after renal artery opening and reached the peak after the opening of pancreatic blood vessels. Compared with the C group, TNF-α, and IL-6 concentrations were significantly reduced in group D at T2-T6 (P < 0.05). Compared with T0, cTnI and CK-MB concentrations were significantly increased at T3-T6 in the C and D groups (P < 0.05). cTnI and CK-MB concentrations increased significantly after the opening of renal artery, and reached the peak after the opening of pancreatic blood vessels. Compared with the C group, cTnI and CK-MB concentrations were significantly reduced in the D group at T3-T6 (P < 0.05). There was no significant difference in patient characteristics amongst groups, including the proportion of intraoperative vasoactive drug use and adverse cardiovascular events during the follow-up period. Heart rate, mean blood pressure, central venous pressure, and cardiac output were not remarkably different between the two groups at any time point. Perioperative reperfusion could aggravate myocardial injury in SPKT. Dex may be considered a way to reduce myocardial injury caused by inflammatory action by decreasing the release of inflammatory factors. Trial Registration Number: Chinese Clinical Trial Registry ID: ChiCTR2200060084.

Influence of dexmedetomidine on postoperative cognitive dysfunction in the elderly: A meta-analysis of randomized controlled trials.

IntroductionDexmedetomidine (Dex) is suggested to be neuroprotective. However, influence of Dex on postoperative cognitive dysfunction (POCD) in the elderly remains unknown.MethodsWe performed a meta‐analysis of randomized controlled trials (RCTs) to evaluate the effect of Dex on POCD. Relevant studies were obtained by search of PubMed, Embase, and Cochrane's Library databases. A random‐effect model was used to pool the results.ResultsFourteen RCTs including 1626 adults of 60 years or older who received surgery with general anesthesia were included. Because methodologically diverse scales were used for POCD, eight RCTs with POCD diagnosed with Mini‐Mental State Examination (MMSE) were included in the meta‐analysis, while the remaining six RCTs with POCD diagnosed with other scales were qualitative synthesized. Pooled results of RCTs with MMSE showed that Dex significantly reduced the incidence of POCD (risk ratio: 0.47, 95% confidence interval: 0.37–0.60, p < 0.001) with no significant heterogeneity (I 2 = 0%) or publication bias (p for Egger's regression test = 0.579). For the remaining six RCTs with POCD diagnosed with other scales, three of them showed that Dex was associated with a significantly lower incidence of POCD, while the other three RCTs did not show a significant difference.ConclusionsDex is associated with a reduced risk of POCD in elderly patients receiving surgeries with general anesthesia, and the results were mainly obtained in studies with POCD diagnosed with MMSE. Based on these findings, Dex may be considered as a preventative measure for POCD in elderly patients.

Application Effect of Dexmedetomidine and Dezocine in Patients Undergoing Lung Cancer Surgery under General Anesthesia and Analysis of Their Roles in Recovery Time and Cognitive Function.

Objective To explore the application influence of dexmedetomidine (DEX) and dezocine in patients undergoing lung cancer surgery under general anesthesia and analysis of their roles in recovery time and cognitive function. Methods A total of 120 patients who accepted thoracoscopic pulmonary wedge resection in our hospital from November 2021 to April 2022 were selected and randomly divided into group A (n =60) and group B (n =60). DEX combined with dezocine-assisted anesthesia was performed to group A, and the equal dose of normal saline was administered to group B, so as to compare their inflammatory influence level, brain function, arterial blood gas index, and cognitive function. Results Compared with group B, group A obtained significantly lower intraoperative and postoperative inflammatory factor levels (P < 0.001), better postoperative brain function and arterial blood gas index (P < 0.001), and lower Loewenstein Occupational Therapy Cognitive Assessment (LOTCA) scores after surgery (P < 0.001). Combining DEX with dezocine-assisted general anesthesia can improve the inflammatory factors level of patients undergoing lung cancer surgery and maintain their brain function and oxygen saturation, so that they have better postoperative cognitive function. Therefore, such anesthesia modality should be promoted in practice.

Curve Fitting Algorithm-Based Contrast-Enhanced Ultrasound Image for Evaluating the Effect of Dexmedetomidine on Neurological Function in Patients Undergoing Brain Tumor Surgery

Objective. The study aimed to explore the influence of dexmedetomidine (Dex) guided by ultrasonic contrast on postoperative cognitive function, serum nerve injury factors, inflammatory response, and blood glucose in patients undergoing intracerebral tumor resection through curve fitting algorithm. Methods. 80 patients who underwent tumor resection were selected and randomly rolled into control (Ctrl) group and Dex group, with 40 in each. Then, patients in the Dex group received 0.4 μg/kg⋅h Dex, and patients in Ctrl received the same amount of normal saline. Both groups were diagnosed with benign or malignant tumors by contrast-enhanced ultrasound (CEUS) based on time-intensity curve (TIC) before surgery. Cognitive Capacity Screening Examination (CCSE) and Montreal Cognitive Assessment (MoCA) were used to assess the cognitive function 1 day before and 3 days after the operation, and the ELISA method was used to detect levels of nerve damage-related factors and inflammation factor. Finally, the fasting blood glucose (FBG) levels were detected at the same time. Results. In contrast with benign lesions, the AUC, MTT, and PI of malignant lesions were obviously reduced ( P &lt; 0.05 ), while TP was obviously increased ( P &lt; 0.05 ). The postoperative CCSE and MoCA scores of the Dex group were obviously higher than Ctrl ( P &lt; 0.05 ). In contrast with the Ctrl, the CCSE and MoCA scores in the Dex group increased obviously after 3 days ( P &lt; 0.05 ). In addition, the incidence of postoperative cognitive dysfunction (POCD) in the Dex group was obviously reduced ( P &lt; 0.05 ). Besides, levels of S100β, NSE, and GFAP were obviously reduced in the Dex group 1 day after surgery ( P &lt; 0.05 ), while levels of IL-6 and TNF-α were obviously reduced ( P &lt; 0.05 ), and returned to the level of Ctrl 3 days after surgery. There was no obvious difference in FBG at each time point between the two. Conclusion. CEUS based on curve fitting algorithm is effective on nursing treatment of intracranial tumors. Dex can obviously improve POCD and reduce levels of serum nerve injury factors and inflammatory factors.

Safe electrophysiologic profile of dexmedetomidine in different experimental arrhythmia models

Previous studies suggest an impact of dexmedetomidine on cardiac electrophysiology. However, experimental data is sparse. Therefore, purpose of this study was to investigate the influence of dexmedetomidine on different experimental models of proarrhythmia. 50 rabbit hearts were explanted and retrogradely perfused. The first group (n = 12) was treated with dexmedetomidine in ascending concentrations (3, 5 and 10 µM). Dexmedetomidine did not substantially alter action potential duration (APD) but reduced spatial dispersion of repolarization (SDR) and rendered the action potentials rectangular, resulting in no proarrhythmia. In further 12 hearts, erythromycin (300 µM) was administered to simulate long-QT-syndrome-2 (LQT2). Additional treatment with dexmedetomidine reduced SDR, thereby suppressing torsade de pointes. In the third group (n = 14), 0.5 µM veratridine was added to reduce the repolarization reserve. Further administration of dexmedetomidine did not influence APD, SDR or the occurrence of arrhythmias. In the last group (n = 12), a combination of acetylcholine (1 µM) and isoproterenol (1 µM) was used to facilitate atrial fibrillation. Additional treatment with dexmedetomidine prolonged the atrial APD but did not reduce AF episodes. In this study, dexmedetomidine did not significantly alter cardiac repolarization duration and was not proarrhythmic in different models of ventricular and atrial arrhythmias. Of note, dexmedetomidine might be antiarrhythmic in acquired LQT2 by reducing SDR.

Influence of Dexmedetomidine on Diaphragm Function and Postoperative Outcomes in ICU Patients with Mechanical Ventilation.

Objective To probe into the influence of dexmedetomidine (DEX) on diaphragm function and postoperative outcomes of mechanically ventilated patients in the intensive care unit (ICU). Methods 84 patients with mechanical ventilation (MV) in the ICU of our hospital were selected as the research participants, including 38 patients in the control group (CG) sedated with midazolam (MZ) and 46 patients in the research group (RG) with DEX sedation. Ramsay sedation score, visual analogue scale (VAS), and restlessness score (RS) were used to evaluate their state before sedation (T0), as well as 2 h (T1), 6 h (T2), and 24 h (T3) after sedation, and the alterations of mean arterial pressure (MAP) and heart rate (HR) were recorded. Serum cortisol (Cor), adrenocorticotropic hormone (ACTH), superoxide dismutase (SOD), malondialdehyde (MDA), interleukin- (IL-) 1β, IL-6, and tumor necrosis factor-α (TNF-α) were measured before and 24 h after sedation. The end-inspiratory diaphragm thickness (DTei) and end-expiratory diaphragm thickness (DTee) were measured within 2 h after the initiation of MV and 5 min after the spontaneous breathing test (SBT), and the diaphragm thickening fraction (DTF) was calculated. Finally, the ventilator weaning, MV time, and the incidence of adverse reactions (ADs) of the two groups were counted. Results T0 and T3 witnessed no distinct difference in Ramsay, VAS, and RS scores between the two arms (P > 0.05), but at T1 and T2, RG had better sedation state and lower VAS and RS scores than CG (P < 0.05), with more stable vital signs (P < 0.05). After sedation, the contents of oxidative stress and inflammatory factors in RG were lower, while DTee, DTei, and DTF were higher, versus CG (P < 0.05). Moreover, RG presented higher success rate of first ventilator weaning, less MV time, and lower incidence of ADs than CG (P < 0.05). Conclusions DEX is effective in mechanically ventilated patients in the ICU, which can protect patients against diaphragm function damage, improve the success rate of ventilator weaning, and benefit the postoperative outcome, with excellent and rapid sedation effect and less stress damage to patients.

Dexmedetomidine reduces inflammation in mice with acute pancreatitis by inhibiting NLRP3 inflammasome and sympathetic nerve activity

Purpose: To study the anti-inflammatory influence of dexmedetomidine (DEX) in mice with acute pancreatitis (AP), and to determine the underlying mechanism.Methods: A total of 75 healthy ICR male mice were randomly divided into control, mild acute pancreatitis (MAP), MAP+DEX, severe acute pancreatitis (SAP), and SAP+DEX groups, with 15 mice/group. Blood levels of inflammatory factors (TNF-α and IL-1β) and norepinephrine were assayed ineach group. Western blotting was used to assay the protein expressions of NLRP3 and norepinephrine transporter (NET) in the pancreatic tissue of each group.Results: The levels of inflammatory factors in the MAP+DEX group were markedly lower than those in the MAP group after 10 h of MAP induction (p &lt; 0.01). Mice in MAP+DEX group had significantly lower expression of NLRP3 in pancreatic tissue, and significantly higher NET protein level, relative to the MAP mice. Following 10 h of SAP, concentrations of the inflammatory factors and the pancreatic expression of NLRP3 were lower in SAP+DEX-treated mice than in SAP mice, while NET protein was significantly higher in SAP mice (p &lt; 0.01).Conclusion: DEX reduces the expressions of inflammation-related factors TNF-α and IL-1β, and inhibits inflammatory response in mice with AP via downregulation of NET protein expression via inhibition of NLRP3 and early sympathetic events.&#x0D; Keywords: Dexmedetomidine, NLRP3 inflammasome, Sympathetic nerve, Acute pancreatitis, Inflammatory response

Circulating extracellular vesicles from patients with valvular heart disease induce neutrophil chemotaxis via FOXO3a and the inhibiting role of dexmedetomidine.

We previously demonstrated that circulating extracellular vesicles (EVs) from patients with valvular heart disease (VHD; vEVs) contain inflammatory components and inhibit endothelium-dependent vasodilation. Neutrophil chemotaxis plays a key role in renal dysfunction, and dexmedetomidine (DEX) can reduce renal dysfunction in cardiac surgery. However, the roles of vEVs in neutrophil chemotaxis and effects of DEX on vEVs are unknown. Here, we investigated the impact of vEVs on neutrophil chemotaxis in kidneys and the influence of DEX on vEVs. Circulating EVs were isolated from healthy subjects and patients with VHD. The effects of EVs on chemokine generation, forkhead box protein O3a (FOXO3a) pathway activation and neutrophil chemotaxis on cultured human umbilical vein endothelial cells (HUVECs) and kidneys in mice and the influence of DEX on EVs were detected. vEVs increased FOXO3a expression, decreased phosphorylation of Akt and FOXO3a, promoted FOXO3a nuclear translocation, and activated the FOXO3a signaling pathway in vitro. DEX pretreatment reduced vEV-induced CXCL4 and CCL5 expression and neutrophil chemotaxis in cultured HUVECs via the FOXO3a signaling pathway. vEVs were also found to suppress Akt phosphorylation and activate FOXO3a signaling to increase plasma levels of CXCL4 and CCL5 and neutrophil accumulation in kidney. The overall mechanism was inhibited in vivo with DEX pretreatment. Our data demonstrated that vEVs induced CXCL4-CCL5 to stimulate neutrophil infiltration in kidney, which can be inhibited by DEX via the FOXO3a signaling. Our findings reveal a unique mechanism involving vEVs in inducing neutrophils chemotaxis and may provide a novel basis for using DEX in reducing renal dysfunction in valvular heart surgery.

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

BackgroundSurgery and diseases modify inflammatory responses and the immune system. Anesthetic agents also have effects on the human immune system but the responses they induce may be altered or masked by the surgical procedures or underlying illnesses. The aim of this study was to assess how single-drug dexmedetomidine and propofol anesthesia without any surgical intervention alter acute immunological biomarkers in healthy subjects.MethodsThirty-five healthy, young male subjects were anesthetized using increasing concentrations of dexmedetomidine (n = 18) or propofol (n = 17) until loss of responsiveness (LOR) was detected. The treatment allocation was randomized. Multi-parametric immunoassays for the detection of 48 cytokines, chemokines and growth factors were used. Concentrations were determined at baseline and at the highest drug concentration for each subject.ResultsThe changes in the concentration of eotaxin (decrease after dexmedetomidine) and platelet-derived growth factor (PDGF, increase after propofol) were statistically significantly different between the groups. Significant changes were detected within both groups; the concentrations of monocyte chemotactic protein 1, chemokine ligand 27 and macrophage migration inhibitory factor were lower in both groups after the drug administration. Dexmedetomidine decreased the concentration of eotaxin, interleukin-18, interleukin-2Rα, stem cell factor, stem cell growth factor and vascular endothelial growth factor, and propofol decreased significantly the levels of hepatocyte growth factor, IFN-γ-induced protein 10 and monokine induced by IFN-γ, and increased the levels of interleukin-17, interleukin-5, interleukin-7 and PDGF.ConclusionsDexmedetomidine seemed to have an immunosuppressive effect on the immune system whereas propofol seemed to induce mixed pro- and anti-inflammatory effects on the immune system. The choice of anesthetic agent could be relevant when treating patients with compromised immunological defense mechanisms.Trial registrationBefore subject enrollment, the study was registered in the European Clinical Trials database (EudraCT number 2013–001496-21, The Neural Mechanisms of Anesthesia and Human Consciousness) and in ClinicalTrials.gov (Principal Investigator: Harry Scheinin, number NCT01889004, The Neural Mechanisms of Anesthesia and Human Consciousness, Part 2, on the 23rd of June 2013).

Influence of dexmedetomidine and lidocaine on perioperative opioid consumption in laparoscopic intestine resection: a randomized controlled clinical trial

ObjectiveThe consumption of opioid analgesics could be reduced by the use of analgesics with different mechanisms of action. We investigated whether additional treatment with dexmedetomidine or lidocaine could reduce opioid consumption.MethodsWe randomized 59 study participants into three groups and examined: (i) fentanyl consumption, (ii) consumption of piritramide, and (iii) cognitive function and neuropathic pain. The control group received continuous propofol infusion and fentanyl boluses. Continuous intravenous infusion of dexmedetomidine (0.5 µg/kg/h) was administered to the dexmedetomidine group and lidocaine (1.5 mg/kg/h) was administered to the lidocaine group.ResultsNo reduction in fentanyl consumption was observed among the groups. However, we noted a significantly lower consumption of piritramide on the first and second postoperative day in the lidocaine group. Total consumption of piritramide was significantly lower in the lidocaine group compared with the control group.ConclusionsLidocaine and dexmedetomidine reduced intraoperative propofol consumption, while lidocaine reduced postoperative piritramide consumption.Clinical trial registration: NCT02616523

Abstract P-478: DEXMEDETOMIDINE AND IATROGENIC WITHDRAWAL SYNDROME IN CRITICALLY ILL CHILDREN

Aims & Objectives: Many children whom require invasive mechanical ventilation need sedation in order to tolerate the associated discomfort. Classically opioids and benzodiazepines are used, however, these drugs may lead to Iatrogenic Withdrawal Syndrome (IWS), when stopped. Up to a third of all children admitted to the Pediatric Intensive Care Unit are at risk for IWS. When a proper level of sedation cannot be reached, dexmedetomidine is added to the drug therapy. We performed a review of the literature to study whether additional dexmedetomidine influences the risk of IWS in critically ill children. Methods Search of PubMed, Cochrane and CINAHL. No limits were applied. The articles were selected on title, abstract and full text according predefined inclusions and exclusion criteria. We assessed study quality and extracted data using tools of the Cochrane Collaboration. Results Twelve studies were included in our review. A systematic review found no eligible studies in critically ill children. Other relevant articles we found had a high risk of bias and did not show a clear effect on the risk of IWS. Another review showed a potential beneficial effect of dexmedetomidine in the treatment of IWS, but included studies were very small. One study showed a significant correlation between the increase of IWS in critically ill children and (a)total cumulative dosage dexmedetomidine (p=0.039) and (b)total duration of dexmedetomidine (p=0.037). Conclusions There is a lack of high quality evidence on the influence of dexmedetomidine on the risk of IWS in critically ill children.

The influence of dexmedetomidine on the emergence agitation of pediatric patients after the operations of sense organs under general anesthesia using sevoflurane

We investigated the influence of dexmedetomidine on the emergence agitation of pediatric patients after ophthalmologic operation under general anesthesia using sevoflurane. We selected 90 patients that were administered pediatric ophthalmologic operation for the study. The patients were randomly divided into 3 groups according to the administration way of drugs, i.e. the normal saline group (group S, N.=30), the midazolam group (group M, N.=30) and the dexmedetomidine group (group D, N.=30). For all patients, anesthesia induction was performed using sevoflurane before anesthesia, and the anesthesia was maintained in the operation with a combination of sevoflurane and remifentanil; laryngeal mask airway (LMA) was used for assisted ventilation. Ten minutes before the end of operation, 15 mL of 0.9% normal saline, 0.05 mg/kg of midazolam and 0.5 μg/kg of dexmedetomidine were administered to group S, group M and group D, respectively. After the operation, we observed the awakening time, time of the LMA removal as well as the recovery time in the Post Anesthesia Care Unit (PACU) of patients in all three groups. We evaluated the postoperative condition of sedation and agitation of the patients using Ramsay Sedation Scale, 5-point scale and Pediatric Anesthesia Emergence Deliriums Scale (PAED) and performed statistical analysis. In the comparisons of awakening time, time of the LMA removal as well as the recovery time, we found that group M was the longest sequentially followed by group D and group S with statistically significant differences (P<0.05). While the comparison of the scores of Ramsay Sedation Scale revealed that group D scored highest followed by group M and group S with statistically significant differences (P<0.05), both of the comparisons of the scores of 5-point scale and PAED Scale showed that group D scored the lowest, followed by group M and group S in sequence with statistically significant differences (P<0.05). Dexmedetomidine can significantly lower the incidence of emergence agitation of pediatric patients after the ophthalmologic operation under sevoflurane anesthesia.

Influence of dexmedetomidine on cardiac complications in non-cardiac surgery: a meta-analysis of randomized trials.

Background The cardiac protection of dexmedetomidine (Dex) in peri-operative period of patients with non-cardiac surgery is still controversial. Aim of the Review We aimed to evaluate the influence of Dex on cardiac complications in peri-operative period of non-cardiac surgery by using a meta-analysis. Methods PubMed, Embase, the Cochrane library and Springer databases were searched for relevant studies. Patients in the eligible studies were divided into Dex group and placebo group. Relative risk (RR) and the 95% confidence interval (CI) were calculated to evaluate the outcomes including all-cause mortality, myocardial infarction, myocardial ischaemia, hypotension and bradycardia. Subgroup analysis was performed based on the dosage of Dex. Publication bias was assessed by Egger's test. Results Twenty double-blind randomized controlled trials containing 1157 patients were included in this meta-analysis. The pooled results showed no significant difference between Dex group and placebo group in peri-operative myocardial infarction, myocardial ischaemia and all-cause mortality. However, Dex group showed higher risk of hypotension (RR=1.46, 95% CI 1.07, 2.01) and bradycardia (RR=1.98, 95% CI 1.33, 2.95) than that of placebo group. In addition, significant publication bias was found among studies involving hypotension and bradycardia. In subgroup analysis, the risk of bradycardia was significantly higher in 1.0μg/kg Dex group than that in placebo group. Besides, a higher risk of hypotension in 0.5μg/kg Dex group than that in placebo group was found. Conclusions Dex supplement might not reduce the risk of cardiac complications but increases the risk of hypotension and bradycardia in peri-operative period of patients who underwent non-cardiac surgeries.

The influence of dexmedetomidine on opioid consumption in radical prostatectomy

Objective. Multimodal analgesia and anal-gesics with different modes of action can reduce perioperative opioid demand and their undesirable side effects. In our study we presumed that patients anesthetised with additional perioperative dexmedetomidine infusion, during radi-cal prostatectomy, would need less opioids during and after surgery compared to the control group.Materials and methods. 40 patients, 18-80 years of age, ASA class 1-3 (American So-ciety of Anesthesiologists), scheduled for radical prostatectomy, were included in the study. Patients were randomly divided into two groups (20 pts in each group). In both groups, fentanyl in repeated boluses was used as an analgesic; in the studied group, an additional infusion of dexme-detomidine (0.3 µg/kg/h) was started with intravenous line insertion and continued until the beginning of wound closure. An-algesic consumption during the operation, in the post-anaesthesia care unit, in the In-tensive Care Unit on the day of the opera-tion and on the first postoperative day was recorded.Results. The patients with perioperative dexmedetomidine infusion were slightly younger (p=0.007), also the duration of their surgery was shorter (p =0.05). Differ-ences in opioid consumption between the groups were not found. Also, pain assess-ment, by visual analogue scale (VAS) after 12, 18, 24, 30, 36 and 42 hours, was not sta-tistically different between groups. Conclusion. In our study, perioperative dexmadetomidine did not reduce peri- and postoperative opioid consumption. Also, undesirable dexmedetomidine side effects, such as bradycardia and hypoten-sion, were not observed.

Perioperative dexmedetomidine for acute pain after abdominal surgery in adults.

Acute postoperative pain is still an issue in patients undergoing abdominal surgery. Postoperative pain and side effects of analgesic treatment, in particular those of opioids, need to be minimized. Opioid-sparing analgesics, possibly including dexmedetomidine, seem a promising avenue by which to improve postoperative outcomes. Our primary aim was to determine the analgesic efficacy and opioid-sparing effect of perioperative dexmedetomidine for acute pain after abdominal surgery in adults.Secondary aims were to establish effects of dexmedetomidine on postoperative nausea and vomiting (PONV), gastrointestinal function and mobilization, together with the side effect profile of dexmedetomidine. We searched the following databases: Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, Institute for Scientific Information (ISI), Web of Science and Cumulative Index to Nursing and Allied Health Literature (CINAHL), and reference lists of articles to May 2014. We searched the Science Citation Index, ClinicalTrials.gov and Current Controlled Trials, and we contacted pharmaceutical companies to identify unpublished and ongoing studies. We applied no language restrictions. We reran the search in May 2015 and found nine studies of interest. We will deal with the studies of interest when we update the review. We included randomized, controlled trials of perioperative dexmedetomidine versus placebo or other drug during abdominal surgery in adults. Trials included one of the following outcomes: amount of 'rescue' opioid, postoperative pain, time to 'rescue' analgesia, participants requiring 'rescue' analgesia, postoperative sedation, PONV, time to first passage of flatus and stool or time to first out-of-bed mobilization. Two review authors independently screened the titles and abstracts for eligibility. We retrieved full trial reports if necessary, and we extracted relevant data from the included studies using a data collection form and assessed risk of bias. We resolved disagreements by discussion with the third review author. We sought additional information of relevance for risk of bias assessment or extraction of data by contacting study authors or, if necessary, co-authors from present or former studies. Our systematic review included seven studies with a total of 492 participants. We included 422 participants in our analysis. Thirteen studies are awaiting classification. For the comparison dexmedetomidine versus placebo (six studies, 402 participants), most studies found a reduction in 'rescue' opioid consumption in the first 24 hours after surgery, together with in general no clinically important differences in postoperative pain (visual analogue scale (VAS) 0 to 100 mm, where 0 = no pain and 100 = worst imaginable pain) in the first 24 hours after surgery - except for one study (80 participants) with a reduction in VAS pain at two hours after surgery in favour of dexmedetomidine, with a mean difference of -30.00 mm (95% confidence interval (CI) -38.25 to -21.75). As the result of substantial heterogeneity, pooling of data in statistical meta-analyses was not appropriate. The quality of evidence was very low for our primary outcomes because of imprecision of results and risk of bias. Regarding our secondary aims, evidence was too scant in general to allow robust conclusions, or the estimates too imprecise or of poor methodological quality. Regarding adverse effects, low quality data (one study, 80 participants) suggest that the proportion of participants with hypotension requiring intervention was slightly higher in the high-dose dexmedetomidine group with a risk ratio of 2.50 (95% CI 0.94 to 6.66), but lower doses of dexmedetomidine led to no differences compared with control. Evidence for the comparison dexmedetomidine versus fentanyl was insufficient to permit robust conclusions (one study, 20 participants). Dexmedetomidine, when administered perioperatively for acute pain after abdominal surgery in adults, seemed to have some opioid-sparing effect together with in general no important differences in postoperative pain when compared with placebo. However the quality of the evidence was very low as the result of imprecision, methodological limitations and substantial heterogeneity among the seven included studies. The clinical importance for patients is uncertain, in as much as the influence of dexmedetomidine on patient-important outcomes such as gastrointestinal function, mobilization and adverse effects could not be satisfactorily determined. All included studies were relatively small, and publication bias could not be ruled out. Applicability of evidence was limited to middle-aged participants who were relatively free of co-morbidity and were undergoing elective abdominal surgery. A potential bias was a considerable quantity of unobtainable data from studies with mixed surgery. To detect and investigate patient-important outcomes, larger studies with longer periods of follow-up are needed.

The Influence of Dexmedetomidine on Ultrasound-induced Pulmonary Capillary Hemorrhage in Rats

The use of xylazine, a veterinary sedative, with ketamine for rat anesthesia has been shown to enhance the pulmonary capillary hemorrhage (PCH) effect of diagnostic ultrasound. This study was undertaken to assess whether the sedative/analgesic dexmedetomidine, commonly used in the intensive care unit, can also enhance ultrasound-induced PCH. Female Sprague Dawley rats were anesthetized with various combinations of ketamine plus xylazine or dexmedetomidine. The dosage of dexmedetomidine was reduced for some groups to doses relevant to human clinical usage. The right thorax of all rats was shaved and depilated for ultrasound transmission and the rats were scanned with diagnostic ultrasound using a 7.6-MHz linear array in a 38°C de-gassed water bath. There was no significant difference in PCH results for the recommended anesthetic dosages of ketamine plus xylazine and ketamine plus 500 μg/kg dexmedetomidine. The varied doses of dexmedetomidine enhanced the PCH, even for the lowest dose of 4 μg/kg, equivalent to a low human dose of 0.64 μg/kg. There was no significant difference in PCH for 500 μg/kg dexmedetomidine with or without ketamine. Further research is needed to identify and characterize other factors that may modify the patient risk from ultrasound-induced PCH.