A Comparative Study Evaluating Effects of Intravenous Sedation by Dexmedetomidine and Propofol on Patient Hemodynamics and Postoperative Outcomes in Cardiac Surgery

Effect of dexmedetomidine on postoperative delirium in patients undergoing type A aortic dissection surgery: a prospective cohort study

Background

Postoperative delirium (POD) is a common neurocognitive complication after type A aortic dissection (TAAD), which seriously affects the recovery of patients, and the current intervention timing and treatment methods are still uncertain. This prospective observational cohort study aimed to discuss the effect of dexmedetomidine on POD in patients undergoing TAAD surgery.

Methods

Between February 2022 and March 2023, 167 eligible patients aged 18 to 85 years who underwent TAAD surgery participated in this study. The patients were assigned to either the dexmedetomidine or the control group, which did not receive dexmedetomidine treatment. The primary outcome of interest was the incidence of delirium within five days following surgery. Secondary outcomes included intubation duration, length of stay in the intensive care unit (ICU), total postoperative hospital stay, incidence of non-delirium complications, and all-cause mortality within seven days. To account for differences in baseline characteristics between the groups, propensity score matching (PSM) was utilized.

Results

Before PSM, the dexmedetomidine group was made up of 120 patients, whereas the control group comprised 47. The occurrence rate of POD increased from 35.0% in the dexmedetomidine group to 42.6% in the control group, but there was no significant difference [odds ratio (OR) 0.73; 95% confidence interval (CI): 0.37-1.45; P=0.36]. After 1:1 PSM, there were 42 patients in each of the dexmedetomidine and control groups. The occurrence of POD was 28.6% and 45.2% in the dexmedetomidine and control groups, respectively, with no statistically significant difference observed (OR 0.48; 95% CI: 0.20-1.20; P=0.12). The dexmedetomidine group showed a shorter ICU hospitalization time and postoperative hospital stay than the control group, but the differences were not statistically significant. Furthermore, the two groups had no statistical differences in other secondary outcomes.

Conclusions

Intraoperative dexmedetomidine did not decrease the occurrence rate of POD in TAAD patients. Additionally, no significant differences were observed between the dexmedetomidine and control groups regarding the occurrence of non-delirium complications, intubation time, ICU hospitalization time, and postoperative hospital stay.

Recommendations for fast-track extubation in adult cardiac surgery patients: a consensus statement

INTRODUCTION

Enhanced recovery after cardiac surgery in selected low-risk patients, has the potential to improve outcomes and reduce the burden of healthcare costs. Anesthesia-related challenges play a major role in the successful implementation of Enhanced Recovery After Surgery (ERAS) protocols, with particular emphasis placed on fast-track extubation. Acknowledging the importance of this practice, the Italian Association of Cardiac Anesthesiologists and Intensive Care (ITACTAIC) has advocated for an initiative to establish a consensus offering practical recommendations for fast-track extubation after adult cardiac surgery.

EVIDENCE ACQUISITION

After conducting a systematic review, all randomised control trials (RCTs) published between 2013 and 2023 were meticulously selected and analysed during a consensus meeting that involved statement voting.

EVIDENCE SYNTHESIS

Out of the 2268 publications identified using the search string, 60 RCTs were selected and classified into six groups, each evaluating specific interventions associated with extubation within 6 hours post-surgery. The authors examined 20 RCTs pertaining to loco-regional anesthesia, 19 analysing elements of general anesthesia, 12 focused on surgery-related aspects and techniques, three examining ventilation, two exploring anesthesia depth monitoring, and four addressing miscellaneous aspects. The expert panel approved 16 statements with 15 achieving high agreement and one obtaining moderate agreement. Finally a total of eight interventions were considered associated with fast-track extubation: parasternal block, erector spinae plane block, alpha agonist in the operating room (OR), opioids in the OR, dexmedetomidine in the intensive care unit (ICU), minimal invasive surgical access, anesthesia depth monitoring, adaptative support ventilation.

CONCLUSIONS

In the first consensus document ever published by a scientific society addressing practical recommendations for fast-track extubation post-cardiac surgery, the authors identified sixteen interventions commonly associated with fast-track extubation in selected adult cardiac surgery patients.

The effect of perioperative dexmedetomidine on postoperative delirium in adult patients undergoing cardiac surgery with cardiopulmonary bypass: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Dexmedetomidine is considered to have neuroprotective effects and may reduce postoperative delirium in both cardiac and major non-cardiac surgeries. Compared with non-cardiac surgery, the delirium incidence is extremely high after cardiac surgery, which could be caused by neuroinflammation induced by surgical stress and CPB. Thus, it is essential to explore the potential benefits of dexmedetomidine on the incidence of delirium in cardiac surgery under CPB.

METHODS

Randomized controlled trials studying the effect of perioperative dexmedetomidine on the delirium incidence in adult patients undergoing cardiac surgery with CPB were considered to be eligible. Data collection was conducted by two reviewers independently. The pre-specified outcome of interest is delirium incidence. RoB 2 was used to perform risk of bias assessment by two reviewers independently. The random effects model and Mantel-Haenszel statistical method were selected to pool effect sizes for each study.

RESULTS

PubMed, Embase, Cochrane Library, and Web of Science were systematically searched from inception to June 28, 2023. Sixteen studies including 3381 participants were included in our systematic review and meta-analysis. Perioperative dexmedetomidine reduced the incidence of postoperative delirium in patients undergoing cardiac surgery with CPB compared with the other sedatives, placebo, or normal saline (RR 0.57; 95% CI 0.41-0.79; P = 0.0009; I2 = 61%).

CONCLUSIONS

Perioperative administration of dexmedetomidine could reduce the postoperative delirium occurrence in adult patients undergoing cardiac surgery with CPB. However, there is relatively significant heterogeneity among the studies. And the included studies comprise many early-stage small sample trials, which may lead to an overestimation of the beneficial effects. It is necessary to design the large-scale RCTs to further confirm the potential benefits of dexmedetomidine in cardiac surgery with CPB.

REGISTRATION NUMBER

CRD42023452410.

Comparison Between Dexmedetomidine and Propofol for Sedation on Outcomes After Cardiac Surgery in Patients Requiring Mechanical Ventilation: A Meta-Analysis of Randomized-Control Trials

The aim of this study was to compare outcomes between dexmedetomidine and propofol for sedation after cardiac surgery in patients requiring mechanical ventilation. This meta-analysis was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Online databases, including EMBASE, PubMed, and the Cochrane Library, were comprehensively searched to identify relevant randomized controlled trials (RCTs) comparing the safety and efficacy of dexmedetomidine and propofol in patients undergoing cardiac surgery and requiring mechanical ventilation. The examined outcomes included the mean length of intensive care unit (ICU) stay in hours, duration of mechanical ventilation in hours, length of hospital stay in days, and number of patients diagnosed with delirium. A total of 14 studies were included in the present meta-analysis while 1360 patients undergoing cardiac surgery were involved in these studies. Pooled results showed that the duration of mechanical ventilation was lower in the dexmedetomidine group compared to the propofol group (mean difference (MD): 0.75, 95% confidence interval (CI): 0.06-1.44, p-value: 0.03). We also found a significantly low length of stay in ICU in the dexmedetomidine group compared to the propofol (MD: 0.89, 95% CI: 0.04-1.74, p-value: 0.04). The length of hospital stay was also significantly lower in patients receiving dexmedetomidine as compared to the propofol group (MD: 0.51, 95% CI: 0.32-0.70, p-value<0.001). Risk of delirium was significantly higher in patients receiving propofol compared to patients receiving dexmedetomidine (RR: 2.02, 95% CI: 1.48-2.74, p-value<0.001). In conclusion, our meta-analysis provides evidence of the beneficial impacts of dexmedetomidine on clinical outcomes in patients undergoing cardiac surgery. Dexmedetomidine was associated with a significant reduction in the duration of mechanical ventilation, length of stay in the intensive care unit (ICU) and hospital, and the risk of delirium.

Postoperative Application of Dexmedetomidine is the Optimal Strategy to Reduce the Incidence of Postoperative Delirium After Cardiac Surgery: A Network Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Previous pairwise meta-analyses demonstrated the efficacy and safety of dexmedetomidine in preventing postoperative delirium (POD) after cardiac surgery; however, the optimal time of applying dexmedetomidine remains unclear.

OBJECTIVE

This network meta-analysis aimed to determine the optimal time of using dexmedetomidine to reduce the incidence of POD following cardiac surgery.

METHODS

We first retrieved eligible randomized controlled trials (RCTs) from previous meta-analyses, and then an updated search was performed to identify additional RCTs in PubMed, Embase, and the Cochrane library from January 1, 2021 to October 31, 2021. Two authors screened literature, collected data, and evaluated bias risk of eligible studies. Finally, we performed Bayesian network analysis using R version 3.6.1 with the "gemtc" and "rjags" package.

RESULTS

Eighteen studies with 2636 patients were included, and all studies were identified from previous meta-analyses. Results showed that postoperative dexmedetomidine reduced the risk of POD compared with normal saline (NS) (odds ratio [OR], 0.13; 95% credible interval [CrI], 0.03-0.35) and propofol (PRO) (OR, 0.19; 95%CrI, 0.04-0.66). Postoperative dexmedetomidine was associated with a lower incidence of POD compared with perioperative dexmedetomidine (OR, 0.21; 95% CrI, 0.04-0.82). Moreover, postoperative dexmedetomidine had the highest probability of ranking best (90.98%), followed by intraoperative dexmedetomidine (46.83%), PRO (36.94%), perioperative dexmedetomidine (30.85%), and NS (60.02%).

CONCLUSION AND RELEVANCE

Dexmedetomidine reduces the incidence of POD compared with PRO and NS in patients undergoing cardiac surgery, and postoperative application of dexmedetomidine is the optimal time.

Cardiac surgery, ICU sedation, and delirium: is dexmedetomidine the silver bullet?

PURPOSE OF REVIEW

Delirium is a marker of acute brain insufficiency and a harbinger of poor outcomes and increased healthcare costs. Despite success preventing delirium by nonpharmacologic measures, the incidence in the postcardiac surgical ICU population remains high. Dexmedetomidine, a selective alpha-2 agonist, is a plausible preventive agent with sedative, anxiolytic, analgesic, sympatholytic and anti-inflammatory properties, and is the subject of very active study in cardiac surgery populations.

RECENT FINDINGS

Recent trials, including DEXACET (2019), DECADE (2020), LOWDEXDEL (2021), and DIRECT (2022) individually, failed to show a benefit for dexmedetomidine and highlighted associated risks. Meta-analyses have offered conflicting results, highlighting the complexity of delirium, and likely interaction of multiple etiological pathways; those that concluded benefit often were driven by trials at high risk of bias. Meta-analyses excluding biased trials currently suggest no benefit for dexmedetomidine over control in unselected cardiac surgical populations.

SUMMARY

Although using dexmedetomidine to prevent delirium in unselected cardiac surgical patients is not supported by current evidence, there remains hope that it may offer benefits in highly selected populations, and further trials are ongoing.

Comparison between dexmedetomidine and propofol on outcomes after coronary artery bypass graft surgery: a retrospective study

Background

Dexmedetomidine (DEX) has a pharmacological profile that should allow rapid recovery and prevent undesirable outcomes such as pulmonary complications.

Methods

This large retrospective study compared the beneficial effects of perioperative infusion of DEX with propofol on the postoperative outcome after coronary artery bypass graft surgery. We reviewed patients’ medical notes at Luoyang Central Hospital from 1st January 2012 to 31st December 2019. All continuous variables, if normally distributed, were presented as mean ± SD; Otherwise, the non-normally distributed data and categorical data were presented as median (25-75 IQR) or number (percentage). The Mann-Whitney U test and Chi-square test were used to evaluate the difference of variables between the DEX and propofol groups. Multivariate logistic regression analysis was performed on the main related and differential factors in the perioperative period.

Results

A total of 1388 patients were included in the study; of those, 557 patients received propofol infusion, and 831 patients received dexmedetomidine. DEX significantly reduced postoperative pulmonary complications compared with propofol, 7.82% vs 13.29%; P < 0.01, respectively. When compared with propofol, DEX significantly shortened the duration of mechanical lung ventilation, 18 (13,25) hours vs 21 (16,37) hours; P < 0.001, the length of stay in the intensive care unit, 51 (42,90) vs 59 (46,94.5) hours; P = 0.001 and hospital stay, 20 (17,24) vs 22 (17,28) days; P < 0.001, respectively. The incidences of postoperative wound dehiscence and infection were significantly reduced with DEX compared with propofol groups, 2.53% vs 6.64%; P < 0.001, respectively. Interestingly, patients receiving DEX had significantly shorter surgical time compared to propofol; 275 (240,310) vs 280 (250,320) minutes respectively (P = 0.005) and less estimated blood loss (P = 0.001).

Conclusion

Perioperative infusion of dexmedetomidine improved the desirable outcomes in patients who had coronary artery bypass graft surgery compared with propofol.

Is Perioperative Dexmedetomidine Associated With a Reduced Risk of Perioperative Neurocognitive Disorders Following Cardiac Surgery? A Systematic Review and Meta-Analysis With Trial Sequential Analysis of Randomized Controlled Trials

Background: To assess the effect of dexmedetomidine on the reducing risk of perioperative neurocognitive disorders (PNDs) following cardiac surgery.

Methods: A systematic review and meta-analysis with trial sequential analysis (TSA) of randomized controlled trials were performed. PubMed, Embase, Cochrane Library, and CNKI databases (to August 16, 2020) were searched for relevant articles to analyze the incidence of PND for intraoperative or postoperative dexmedetomidine administration after cardiac surgery. PND included postoperative cognitive dysfunction (POCD) and postoperative delirium (POD).

Results: A total of 24 studies with 3,610 patients were included. Compared with the control group, the incidence of POD in the dexmedetomidine group was significantly lower (odds ratio [OR]: 0.59, 95% CI: 0.43–0.82, P = 0.001), with firm evidence from TSA. Subgroup analyses confirmed that dexmedetomidine reduced the incidence of POD with firm evidence following coronary artery bypass grafting surgery (OR: 0.45, 95% CI: 0.26–0.79, P = 0.005), and intervention during the postoperative period (OR: 0.48, 95% CI: 0.34–0.67, P < 0.001). Furthermore, the incidence of POD in the dexmedetomidine group was also decreased in mixed cardiac surgery (OR: 0.68, 95% CI: 0.47–0.98, P = 0.039). Irrespective of whether “Confusion Assessment Method/Confusion Assessment Method for intensive care unit” or “other tools” were used as diagnostic tools, the results showed a decreased risk of POD in the dexmedetomidine group. There was no significant difference in the incidence of POCD (OR: 0.47, 95% CI: 0.22–1.03, P = 0.060) between the two groups, but this result lacked firm evidence from TSA.

Conclusion: The administration of dexmedetomidine during the perioperative period reduced the incidence of POD in patients after cardiac surgery, but there was no significant benefit in the incidence of POCD. The effect of dexmedetomidine on the incidence of POD or POCD following different types of surgery and the optimal dose and timing of dexmedetomidine warrant further investigation.

Trial registration: PROSPERO registration number: CRD42020203980. Registered on September 13, 2020.

Comparative effectiveness of pharmacological interventions to prevent postoperative delirium: a network meta-analysis

Many pharmacologic agents were investigated for the effect to prevent delirium. We aimed to comprehensively compare the effect of the pharmacological interventions to prevent postoperative delirium. A Bayesian network meta-analysis of randomized trials was performed using random effects model. PubMed, the Cochrane Central Register of Controlled Trials, and Embase were searched on 20 January 2021. Randomized trials comparing the effect of a drug to prevent postoperative delirium with another drug or placebo in adult patients undergoing any kind of surgery were included. Primary outcome was the postoperative incidence of delirium. Eighty-six trials with 26,992 participants were included. Dexmedetomidine, haloperidol, and atypical antipsychotics significantly decreased the incidence of delirium than placebo [dexmedetomidine: odds ratio 0.51, 95% credible interval (CrI) 0.40-0.66, moderate quality of evidence (QOE); haloperidol: odds ratio 0.59, 95% CrI 0.37-0.95, moderate QOE; atypical antipsychotics: odds ratio 0.27, 95% CrI 0.14-0.51, moderate QOE]. Dexmedetomidine and atypical antipsychotics had the highest-ranking probabilities to be the best. However, significant heterogeneity regarding diagnostic time window as well as small study effects precludes firm conclusion.

The effect of peri-operative dexmedetomidine on the incidence of postoperative delirium in cardiac and non-cardiac surgical patients: a randomised, double-blind placebo-controlled trial

Delirium occurs commonly following major non-cardiac and cardiac surgery and is associated with: postoperative mortality; postoperative neurocognitive dysfunction; increased length of hospital stay; and major postoperative complications and morbidity. The aim of this study was to investigate the effect of peri-operative administration of dexmedetomidine on the incidence of postoperative delirium in non-cardiac and cardiac surgical patients. In this randomised, double-blind placebo-controlled trial we included 63 patients aged ≥ 60 years undergoing major open abdominal surgery or coronary artery bypass graft surgery with cardiopulmonary bypass. The primary outcome was the incidence of postoperative delirium, as screened for with the Confusion Assessment Method. Delirium assessment was performed twice daily until postoperative day 5, at the time of discharge from hospital or until postoperative day 14. We found that dexmedetomidine was associated with a reduced incidence of postoperative delirium within the first 5 postoperative days, 43.8% vs. 17.9%, p = 0.038. Severity of delirium, screened with the Intensive Care Delirium Screening Checklist, was comparable in both groups, with a mean maximum score of 1.54 vs. 1.68, p = 0.767. No patients in the dexmedetomidine group died while five (15.6%) patients in the placebo group died, p = 0.029. For patients aged ≥ 60 years undergoing major cardiac or non-cardiac surgery, we conclude that the peri-operative administration of dexmedetomidine is associated with a lower incidence of postoperative delirium.

Protective effects of dexmedetomidine on the ischemic myocardium in patients undergoing rheumatic heart valve replacement surgery

The aim of the present study was to compare the effects of two methods of dexmedetomidine (Dex) administration on myocardial injury, inflammation and stress in ischemic myocardium during rheumatic heart valve replacement. In total, 90 patients were included in the present study and were divided into the following three groups: i) Dex group (1.0 µg/kg Dex pre-administered 10 min prior to anesthesia, then 0.5 µg/kg/h Dex for maintenance); ii) Dex pre-conditioning group (Pre-Dex; 1.0 µg/kg Dex administered 10 min prior to anesthesia, then saline for maintenance); and iii) control group (saline 10 min prior to anesthesia and saline during maintenance), with 30 patients in each group. Heart rate (HR) and mean artery pressure (MAP) were recorded at eight time-points: i) T1, pre-medication; ii) T2, 10 min post-medication; iii) T3, immediately post-intubation; iv) T4, upon skin incision; v) T5, upon sawing the sternum; vi) T6, immediately post-cardiopulmonary bypass; vii) T7, immediately post-operation; and viii) T8, 24 h post-operation. The serum cardiac troponin I (cTnI), interleukin (IL)-8, IL-10 and malondialdehyde (MDA) levels were also detected at T1, T6, T7 and T8. Blood glucose levels were detected at T1, T5, T6 and T7. In comparison with the control group, patients in the Dex group exhibited a significant increase in cardiac function, as indicated by an increase in HR, MAP and IL-10 levels, and a significant decrease in cTnI, IL-8, MDA and glucose levels. Both Dex perfusion and Dex preconditioning were able to reduce myocardial injury, inflammation, oxidative stress and stress response in rheumatic heart valve replacement surgery. However, Dex perfusion during the whole surgery was more effective than Dex preconditioning treatment. The study was registered with the Chinese Clinical Trial Registry (ChiCTR; no. ChiCTR-INR-17011955).

Pharmacological strategies to prevent postoperative delirium: a systematic review and network meta-analysis

Background

Postoperative delirium (POD) is a condition of cerebral dysfunction and a common complication after surgery. This study aimed to compare and determine the relative efficacy of pharmacological interventions for preventing POD using a network meta-analysis.

Methods

We performed a systematic and comprehensive search to identify and analyze all randomized controlled trials until June 29, 2020, comparing two or more pharmacological interventions, including placebo, to prevent or reduce POD. The primary outcome was the incidence of POD. We performed a network meta-analysis and used the surface under the cumulative ranking curve (SUCRA) values and rankograms to present the hierarchy of the pharmacological interventions evaluated.

Results

According to the SUCRA value, the incidence of POD decreased in the following order: the combination of propofol and acetaminophen (86.1%), combination of ketamine and dexmedetomidine (86.0%), combination of diazepam, flunitrazepam, and pethidine (84.8%), and olanzapine (75.6%) after all types of anesthesia; combination of propofol and acetaminophen (85.9%), combination of ketamine and dexmedetomidine (83.2%), gabapentin (82.2%), and combination of diazepam, flunitrazepam, and pethidine (79.7%) after general anesthesia; and ketamine (87.1%), combination of propofol and acetaminophen (86.0%), and combination of dexmedetomidine and acetaminophen (66.3%) after cardiac surgery. However, only the dexmedetomidine group showed a lower incidence of POD than the control group after all types of anesthesia and after general anesthesia.

Conclusions

Dexmedetomidine reduced POD compared with the control group. The combination of propofol and acetaminophen and the combination of ketamine and dexmedetomidine seemed to be effective in preventing POD. However, further studies are needed to determine the optimal pharmacological intervention to prevent POD.

Critical Review and Meta-Analysis of Postoperative Sedation after Adult Cardiac Surgery: Dexmedetomidine Versus Propofol

OBJECTIVE

To evaluate reports from the published literature of all randomized clinical trials (RCT) comparing postoperative sedation with dexmedetomidine versus propofol in adult patients, after open cardiac surgery.

DESIGN

A computerized search on Medline, EMBASE, Web of Science, and Agency for Healthcare Research and Quality databases was completed through June 2020. Meta-analysis of all published RCT comparing dexmedetomidine versus propofol utilization in the postoperative phase, using the standard Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist.

SETTING

Assemblage and critical discussion of 11 RCTs comparing postoperative sedation from standard published reports from 2003 to 2019.

PARTICIPANTS

The study comprised 1,184 patients and analyzed critical discussion of time-based parameters (time to extubation, intensive care unit length of stay, and hospital length of stay) and nontime-dependent factors (delirium, bradycardia, and hypotension).

MEASUREMENTS AND MAIN RESULTS

Time to extubation was significantly reduced in the dexmedetomidine group (standardized mean difference [SMD] = -0.70, 95% confidence interval [CI] -0.98 to -0.42, p < 0.001); however, no difference in mechanical ventilation time was observed (SMD = -0.72, 95% CI -1.60 to 0.15, N.S.). Dexmedetomidine significantly reduced the intensive care unit length of stay (SMD = 0.23, 95% CI -1.06 to -0.16, p = 0.008), but this did not translate into a reduced hospital length of stay (SMD = -1.13, 95% CI -2.43 to 0.16, N.S). For nontime-dependent factors, incidence of delirium was unaffected between groups (odds ratio [OR]: 0.68, 95% CI 0.43-1.06, N.S), and higher rates of bradycardia (OR: 3.39, 95% CI: 1.20-9.55, p = 0.020) and hypotension (OR: 1.68, 95% CI 1.09-2.58, p = 0.017) were reported with propofol.

CONCLUSIONS

Despite the ICU time advantages afforded by dexmedetomidine over propofol, the former did not seem to contribute to an overall reduction in hospital length of stay or improvement in postoperative outcomes of heart valve surgery and CABG patients.

Effect of intraoperative dexmedetomidine infusion on delirium in adult patients following cardiac valve surgery: a protocol of a randomized, double-blinded, and placebo-controlled study

Background

Delirium is an acute status of brain dysfunction that commonly occurs in patients who have undergone cardiac surgery, and increases morbidity and mortality. It is associated with risk factors, such as older age, use of narcotics, cardiopulmonary bypass, and hypothermia. Dexmedetomidine infusion might exert a neuroprotective effect. However, the effect of perioperative administration of dexmedetomidine on the incidence of postoperative delirium (POD) in patients undergoing cardiac or non-cardiac surgery is yet controversial. The present study aimed to reveal the effect of intraoperative dexmedetomidine administration on the incidence of delirium in adult patients following cardiac surgery.

Methods

This single-center, randomized, double-blinded, and placebo-controlled trial consisted of 652 patients randomly divided into two groups: dexmedetomidine and placebo. 0.6 μg/kg dexmedetomidine will be infused 10 min after central vein catheterization, followed by a continuous infusion at a speed of 0.4 μg/kg/h until the end of surgery in the dexmedetomidine group, while normal saline will be administered at the same rate in the placebo group. The primary outcome is the incidence of POD during the first 7 days post-surgery. The secondary outcomes include duration of mechanical ventilation after surgery, duration of stay in the intensive care unit and the hospital after surgery, incidence of hypotension during or after dexmedetomidine infusion, acute kidney injury and sudden arrhythmia during the hospital stay postoperatively, and all-cause mortality in 30 and 90 days after surgery, respectively.

Discussion

This study was approved by the Ethics Committee of the Chinese Academy of Medical Sciences Fuwai Hospital on 6 March 2019 (2019-1180). The results will be disseminated at academic conferences and submitted to peer-reviewed publications. Either positive or negative results will provide guidance for clinical practice.

Trial registration

The Chinese Clinical Trial Registry (http://www.chictr.org.cn) ChiCTR1900022583. Registered on 17 April 2019.

Brain protective effect and hemodynamics of dexmedetomidine hydrochloride in patients with intracranial aneurysm

The purpose of the study was to investigate the effect of dexmedetomidine hydrochloride (Dex) on the recovery of cognitive function, hemodynamics, and postoperative analgesia in patients undergoing intracranial aneurysm craniotomy. Methods: general anesthesia was performed on patients undergoing intracranial aneurysm craniotomy in neurosurgery. Patients were randomly divided into three groups: Dex 1 group (Dex dose: 1 μg/kg), Dex 2 group (Dex dose: 0.5 μg/kg), and blank control group (normal saline). The changes of heart rate, arterial pressure, intraoperative brain function index, and postoperative pain score were recorded and compared. Results: in Dex 1 group and Dex 2 group, the heart rate of T1 and T2 phase was significantly lower than that of T3-T7 phases (P < 0.05); compared with the control group, the heart rate of Dex 1 group and Dex 2 group was significantly lower (P < 0.05). The average arterial pressure of the control group and Dex groups was significantly different (P < 0.05). Compared with the control group, there were significant differences between Dex 1 group and Dex 2 group: S100 β protein in T7-T10, NSE (neuron specific enolase) in T9 and T10, pain score in T8, T9 and T10 after operation. Conclusion: the application of Dex in the resection of intracranial aneurysms can protect the brain of patients, minimize the influence of operation on hemodynamics, and relieve postoperative pain, which is worthy of clinical application.

The effect of perioperative anesthetics for prevention of postoperative delirium on general anesthesia: A network meta-analysis

STUDY OBJECTIVE

Postoperative delirium (POD) is a common neurological system disorder in surgical patients. Anesthesia providers have a wide choice of sedative agents involving different mechanisms in clinical practice, and the incidence of POD varies regarding which sedative agent administered. This network meta-analysis aimed to comprehensively analyze the safety and efficacy of each choice for patients.

DESIGN

A network meta-analysis.

SETTING

Vanderbilt University Medical Center.

MEASUREMENTS

We searched PubMed, EMBASE, Ovid Medline and Cochrane Central Register of Controlled Trials (CENTRAL) through the end of September 2018 with the registration number CRD42018110585. The randomized controlled trials were identified and extracted by two reviewers independently. Commonly used sedative agents such as placebo, sevoflurane, desflurane, isoflurane, dexmedetomidine, propofol, midazolam, and ketamine were assessed in this network meta-analysis and the primary outcome was the incidence of POD. The data were synthesized by network meta-analysis. Pair-wise meta-analyses were conducted using the random-effects model. Each intervention was ranked according to its corresponding surface under the cumulative ranking curve (SUCRA) values. The GRADE framework was undertaken to evaluate the risk of bias.

MAIN RESULTS

We identified 39 RCTs and 5991 patients in this meta-analysis. Dexmedetomidine was found to be the most effective option in reducing POD, compared to midazolam, propofol, desflurane, and sevoflurane. The results revealed that dexmedetomidine was associated with a lower incidence of POD, whereas midazolam was associated with a significantly higher number of patients with delirium. Midazolam and propofol were also associated with a higher incidence of perioperative hypotension and bradycardia.

CONCLUSION

Our study provided meta-analytic evidence and suggested dexmedetomidine could be considered as the most effective sedative agent to reduce POD. However, clinical practitioners still need to weigh the pros and cons before choosing a sedative agent for individual patient.

Intrathecal injection of dexmedetomidine ameliorates chronic neuropathic pain via the modulation of MPK3/ERK1/2 in a mouse model of chronic neuropathic pain

Objective: Despite the application of dexmedetomidine (DEX) as a perioperative adjuvant in local analgesia, the exact analgesic mechanism underpinning chronic neuropathic pain (CNP) awaits our elucidation. Methods: We investigated the molecular mechanisms of the anti-nociceptive effect of DEX on neuropathic pain in a mouse model induced by chronic constriction injury (CCI). Results: DEX administration significantly increased the paw withdrawal latency (PWL) values 0.5 to 2 h post-injection in CCI-induced CNP mice at day 5 to 21 versus dimethyl sulfoxide (DMSO)-treated mice, confirming its analgesic effect. The c-Fos expression was significantly elevated in CCI mice versus the sham-operated group, whereas the elevation was mitigated by DEX injection. Subsequently, the involvement of MKP1 and MKP3 in the pathogenesis of chronic neuropathic pain was evaluated. Western blotting analyses revealed significant decrease in both MKP1 and MKP3 in the spinal cord in CCI group versus the sham group. DEX markedly elevated the MKP3 expression and modestly reduced the MKP1 expression, with insignificant difference in the latter. Co-injection of BCI (an MKP3 inhibitor) and DEX evidently reduced the PWL values in CCI mice. Furthermore, DEX significantly downregulated the phosphorylation of extracellular-signal-regulated kinase (ERK) 1/2, down-stream effector of MKP3 in CCI mice, whereas the downregulation was reversed by BCI. Conclusion: We confirmed that DEX exerts the analgesic effect on chronic neuropathic pain via the regulation of MKP3/ERK1/2 signaling pathway, which may contribute to clarification of the molecular mechanism and novel therapy for chronic neuropathic pain.

Prevention of postoperative delirium in elderly patients planned for elective surgery: systematic review and meta-analysis

Introduction: Vulnerable or “frail” patients are susceptible to the development of delirium when exposed to triggers such as surgical procedures. Once delirium occurs, interventions have little effect on severity or duration, emphasizing the importance of primary prevention. This review provides an overview of interventions to prevent postoperative delirium in elderly patients undergoing elective surgery.

Methods: A literature search was conducted in March 2018. Randomized controlled trials (RCTs) and before-and-after studies on interventions with potential effects on postoperative delirium in elderly surgical patients were included. Acute admission, planned ICU admission, and cardiac patients were excluded. Full texts were reviewed, and quality was assessed by two independent reviewers. Primary outcome was the incidence of delirium. Secondary outcomes were severity and duration of delirium. Pooled risk ratios (RRs) were calculated for incidences of delirium where similar intervention techniques were used.

Results: Thirty-one RCTs and four before-and-after studies were included for analysis. In 19 studies, intervention decreased the incidences of postoperative delirium. Severity was reduced in three out of nine studies which reported severity of delirium. Duration was reduced in three out of six studies. Pooled analysis showed a significant reduction in delirium incidence for dexmedetomidine treatment, and bispectral index (BIS)-guided anaesthesia. Based on sensitivity analyses, by leaving out studies with a high risk of bias, multicomponent interventions and antipsychotics can also significantly reduce the incidence of delirium.

Conclusion: Multicomponent interventions, the use of antipsychotics, BIS-guidance, and dexmedetomidine treatment can successfully reduce the incidence of postoperative delirium in elderly patients undergoing elective, non-cardiac surgery. However, present studies are heterogeneous, and high-quality studies are scarce. Future studies should add these preventive methods to already existing multimodal and multidisciplinary interventions to tackle as many precipitating factors as possible, starting in the pre-admission period.

Pharmacological Prevention of Postoperative Delirium: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background

The high prevalence of delirium among postoperative patients has increased morbidity and mortality. The kind of drug that can effectively reduce the incidence of delirium has become the focus of discussion in recent years. However, a consensus in this respect has yet to be reached.

Methods

Randomized controlled trials (RCTs) were retrieved from the PubMed, Cochrane Library, ClinicalTrials.gov, and Embase databases from their inception through October 12, 2018. We included RCTs of pharmacological prevention for postoperative delirium in adults (at least 18 years), and the Cochrane risk of bias tool was used to evaluate the methodological quality of trials. The primary outcomes were the risk ratios (RRs) of incidence of postoperative delirium, and the secondary outcomes were the RRs of mortality and adverse events in the intervention and control groups.

Results

Thirty-eight trials, which comprised 20302 patients and 18 different drugs, were included in the analysis. Of the 38 studies, 17 were rated as low risk with respect to methodological quality. Dexmedetomidine administration (RR 0.58, 95%CI 0.44-0.76, P<0.01) was associated with a significantly lower incidence of postoperative delirium than the control conditions. However, the findings from the studies with a low risk of bias did not show a significant difference in this beneficial effect (RR 0.64, 95%CI 0.39-1.04, P=0.07). The antipsychotic drugs olanzapine (RR 0.44, 95%CI 0.30- 0.65, P<0.01) and risperidone (RR 0.42, 95%CI 0.19-0.92, P=0.03) had promising effects, but there was a lack of sufficient evidence to obtain a definitive conclusion. The beneficial effect of other drugs, including haloperidol, methylprednisolone, dexamethasone, gabapentin, ketamine, cyproheptadine, donepezil, hypertonic saline, melatonin, nimodipine, ondansetron, pregabalin, rivastigmine, TJ-54, and tryptophan, was not proven on the basis of present evidence.

Conclusion

Among the pharmacological prophylactic measures for postoperative delirium, dexmedetomidine, olanzapine, and risperidone showed higher efficacy than other drugs. However, more high-quality evidence is needed to confirm these results.

Dexmedetomidine in prevention and treatment of postoperative and intensive care unit delirium: a systematic review and meta-analysis

BACKGROUND

To determine the preventive and therapeutic effect of dexmedetomidine on intensive care unit (ICU) delirium.

METHODS

The literature search using PubMed and the Cochrane Central Register of Controlled Trials was performed (August 1, 2018) to detect all randomized controlled trials (RCTs) of adult ICU patients receiving dexmedetomidine. Articles were included if they assessed the influence of dexmedetomidine compared to a sedative agent on incidence of ICU delirium or treatment of this syndrome. Accordingly, relevant articles were allocated to the following two groups: (1) articles that assessed the delirium incidence (incidence comparison) or articles that assessed the treatment of delirium (treatment comparison). Incidence of delirium and delirium resolution were the primary outcomes. We combined treatment effects comparing dexmedetomidine versus (1) placebo, (2) standard sedatives, and (3) opioids in random-effects meta-analyses. Risk of bias for each included RCT was assessed following Cochrane standards.

RESULTS

The literature search resulted in 28 articles (25 articles/4975 patients for the incidence comparison and three articles/166 patients for the treatment comparison). In the incidence comparison, heterogeneity was present in different subgroups. Administration of dexmedetomidine was associated with significantly lower overall incidence of delirium when compared to placebo (RR 0.52; 95% CI 0.39-0.70; I² = 37%), standard sedatives (RR 0.63; 95% CI 0.46-0.86; I² = 69%), as well as to opioids (RR 0.61; 95% CI 0.44-0.83; I² = 0%). Use of dexmedetomidine significantly increased the risks of bradycardia and hypotension. Limited data were available on circulatory insufficiency and mortality. In the treatment comparison, the comparison drugs in the three RCTs were placebo, midazolam, and haloperidol. The resolution of delirium was measured differently in each study. Two out of the three studies indicated clear favorable effects for dexmedetomidine (i.e., compared to placebo and midazolam). The study comparing dexmedetomidine with haloperidol was a pilot study (n = 20) with high variability in the results.

CONCLUSION

Findings suggest that dexmedetomidine reduces incidence and duration of ICU delirium. Furthermore, our systematic searches show that there is limited evidence if a delirium shall be treated with dexmedetomidine.