Dexmedetomidine sedation reduces atrial fibrillation after cardiac surgery compared to propofol: a randomized controlled trial

The effectiveness of dexmedetomidine for preventing acute kidney injury after surgery: a systematic review and meta-analysis

Background

Postoperative acute kidney injury (AKI) is a serious and distressing complication connected to various adverse outcomes following the surgical operation. Controversy remains regarding the dexmedetomidine's preventive impact on postoperative AKI. Therefore, this investigation aims to explore the efficiency and safety of dexmedetomidine in preventing AKI after surgical operation.

Methods

We systematically searched electronic databases such as PubMed, Embase, Web of Science, and the Cochrane Library to detect eligible randomized controlled studies that used dexmedetomidine for the prevention of AKI following operation up to April 30, 2023. The main outcome evaluated was AKI incidence. The evidence quality was assessed employing the Grading of Recommendations Assessment, Development, and Evaluation.

Results

The meta-analysis included 25 trials, including 3,997 individuals. Of these, 2,028 were in the dexmedetomidine group, and 1,969 were in the control group. The result showed that patients administered dexmedetomidine significantly decreased the AKI incidence following surgical operation in contrast to the control group (risk ratio, 0.60; 95% confidence intervals, 0.45-0.78; p < 0.05; I 2 = 46%). In addition, dexmedetomidine decreased the period of hospitalization in both the intensive care unit (ICU) and the hospital while also reducing postoperative delirium (POD) occurrence. However, dexmedetomidine elevated the incidence of bradycardia but did not have a significant impact on other indicators.

Conclusion

Our meta-analysis indicates that the dexmedetomidine treatment reduces the postoperative AKI and POD risk while also shortening the time of hospitalization in the ICU and hospital. However, it is connected to an increased bradycardia risk.

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.

Pulmonary, circulatory and renal considerations in the early postoperative management of the lung transplant recipient

Lung transplantation volumes and survival rates continue to increase worldwide. Primary graft dysfunction (PGD) and acute kidney injury (AKI) are common early postoperative complications that significantly affect short-term mortality and long-term outcomes. These conditions share overlapping risk factors and are driven, in part, by circulatory derangements. The prevalence of severe PGD is up to 20% and is the leading cause of early death. Patients with pulmonary hypertension are at a higher risk. Prevention and management are based on principles learned from acute lung injury of other causes. Targeting the lowest effective cardiac filling pressure will reduce alveolar edema formation in the setting of increased pulmonary capillary permeability. AKI is reported in up to one-half of lung transplant recipients and is strongly associated with one-year mortality as well as long-term chronic kidney disease. Optimization of renal perfusion is critical to reduce the incidence and severity of AKI. In this review, we highlight key early post-transplant pulmonary, circulatory, and renal perturbations and our center's management approach.

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.

Propofol and survival: an updated meta-analysis of randomized clinical trials

BACKGROUND

Propofol is one of the most widely used hypnotic agents in the world. Nonetheless, propofol might have detrimental effects on clinically relevant outcomes, possibly due to inhibition of other interventions' organ protective properties. We performed a systematic review and meta-analysis of randomized controlled trials to evaluate if propofol reduced survival compared to any other hypnotic agent in any clinical setting.

METHODS

We searched eligible studies in PubMed, Google Scholar, and the Cochrane Register of Clinical Trials. The following inclusion criteria were used: random treatment allocation and comparison between propofol and any comparator in any clinical setting. The primary outcome was mortality at the longest follow-up available. We conducted a fixed-effects meta-analysis for the risk ratio (RR). Using this RR and 95% confidence interval, we estimated the probability of any harm (RR > 1) through Bayesian statistics. We registered this systematic review and meta-analysis in PROSPERO International Prospective Register of Systematic Reviews (CRD42022323143).

RESULTS

We identified 252 randomized trials comprising 30,757 patients. Mortality was higher in the propofol group than in the comparator group (760/14,754 [5.2%] vs. 682/16,003 [4.3%]; RR = 1.10; 95% confidence interval, 1.01-1.20; p = 0.03; I² = 0%; number needed to harm = 235), corresponding to a 98.4% probability of any increase in mortality. A statistically significant mortality increase in the propofol group was confirmed in subgroups of cardiac surgery, adult patients, volatile agent as comparator, large studies, and studies with low mortality in the comparator arm.

CONCLUSIONS

Propofol may reduce survival in perioperative and critically ill patients. This needs careful assessment of the risk versus benefit of propofol compared to other agents while planning for large, pragmatic multicentric randomized controlled trials to provide a definitive answer.

Association of Dexmedetomidine With New-Onset Atrial Fibrillation in Patients With Critical Illness

Importance

Dexmedetomidine is a widely used sedative in the intensive care unit (ICU) and has unique properties that may be associated with reduced occurrence of new-onset atrial fibrillation (NOAF).

Objective

To investigate whether the use of dexmedetomidine is associated with the incidence of NOAF in patients with critical illness.

Design, Setting, and Participants

This propensity score-matched cohort study was conducted using the Medical Information Mart for Intensive Care-IV database, which includes records of patients admitted to the ICU at Beth Israel Deaconess Medical Center in Boston dating 2008 through 2019. Included patients were those aged 18 years or older and hospitalized in the ICU. Data were analyzed from March through May 2022.

Exposure

Patients were divided into 2 groups according to dexmedetomidine exposure: those who received dexmedetomidine within 48 hours after ICU admission (dexmedetomidine group) and those who never received dexmedetomidine (no dexmedetomidine group).

Main Outcomes and Measures

The primary outcome was the occurrence of NOAF within 7 days of ICU admission, as defined by the nurse-recorded rhythm status. Secondary outcomes were ICU length of stay, hospital length of stay, and in-hospital mortality.

Results

This study included 22 237 patients before matching (mean [SD] age, 65.9 [16.7] years; 12 350 male patients [55.5%]). After 1:3 propensity score matching, the cohort included 8015 patients (mean [SD] age, 61.0 [17.1] years; 5240 males [65.4%]), among whom 2106 and 5909 patients were in the dexmedetomidine and no dexmedetomidine groups, respectively. Use of dexmedetomidine was associated with a decreased risk of NOAF (371 patients [17.6%] vs 1323 patients [22.4%]; hazard ratio, 0.80; 95% CI, 0.71-0.90). Although patients in the dexmedetomidine group had longer median (IQR) length of stays in the ICU (4.0 [2.7-6.9] days vs 3.5 [2.5-5.9] days; P < .001) and hospital (10.0 [6.6-16.3] days vs 8.8 [5.9-14.0] days; P < .001), dexmedetomidine was associated with decreased risk of in-hospital mortality (132 deaths [6.3%] vs 758 deaths [12.8%]; hazard ratio, 0.43; 95% CI, 0.36-0.52).

Conclusions and Relevance

This study found that dexmedetomidine was associated with decreased risk of NOAF in patients with critical illness, suggesting that it may be necessary and warranted to evaluate this association in future clinical trials.

Dexmedetomidine for adult cardiac surgery: a systematic review, meta-analysis and trial sequential analysis

The effects of dexmedetomidine in adults undergoing cardiac surgery are inconsistent. We conducted a systematic review and meta-analysis to analyse the effects of peri-operative dexmedetomidine in adults undergoing cardiac surgery. We searched MEDLINE via Pubmed, EMBASE, Scopus and Cochrane for relevant randomised controlled trials between 1 January 1990 and 1 March 2022. We used the Joanna Briggs Institute methodology checklist to assess study quality and the GRADE approach to certainty of evidence. We assessed the sensitivity of results to false data. We used random-effects meta-analyses to analyse the primary outcomes: durations of intensive care and tracheal intubation. We included 48 trials of 6273 participants. Dexmedetomidine reduced the mean (95%CI) duration of intensive care by 5.0 (2.2-7.7) h, p = 0.001, and tracheal intubation by 1.6 (0.6-2.7) h, p = 0.003. The relative risk (95%CI) for postoperative delirium was 0.58 (0.43-0.78), p = 0.001; 0.76 (0.61-0.95) for atrial fibrillation, p = 0.015; and 0.49 (0.25-0.97) for short-term mortality, p = 0.041. Bradycardia and hypotension were not significantly affected. Trial sequential analysis was consistent with the primary meta-analysis. Adjustments for possible false data reduced the mean (95%CI) reduction in duration of intensive care and tracheal intubation by dexmedetomidine to 3.6 (1.8-5.4) h and 0.8 (0.2-1.4) h, respectively. Binary adjustment for methodological quality at a Joanna Briggs Institute score threshold of 10 did not alter the results significantly. In summary, peri-operative dexmedetomidine reduced the durations of intensive care and tracheal intubation and the incidence of short-term mortality after adult cardiac surgery. The reductions in intensive care stay and tracheal intubation may or may not be considered clinically useful, particularly after adjustment for possible false data.

Postoperative delirium, neuroinflammation, and influencing factors of postoperative delirium: A review

Postoperative delirium (POD) is an acute cognitive dysfunction that is mainly characterized by memory impairment and disturbances in consciousness. POD can prolong the hospital stay and increase the 1-month mortality rate of patients. The overall incidence of POD is approximately 23%, and its prevalence can go up to 50% in high-risk surgeries. Neuroinflammation is an important pathogenic mechanism of POD that mediates microglial activation and leads to synaptic remodeling. Neuroinflammation, as an indispensable pathogenesis of POD, can occur due to a variety of factors, including aseptic inflammation caused by surgery, effects of anesthetic drugs, disruption of the blood-brain barrier, and epigenetics. Understanding these factors and avoiding the occurrence of risk factors may help prevent POD in time. This review provides a brief overview of POD and neuroinflammation and summarizes various factors affecting POD development mediated by neuroinflammation, which may serve as future targets for the prevention and treatment of POD.

New-Onset Post-Operative Atrial Fibrillation in Patients Undergoing Coronary Artery Bypass Grafting Surgery - A Retrospective Case-Control Study

INTRODUCTION

New-onset postoperative atrial fibrillation (POAF) is a common complication following coronary artery bypass grafting (CABG) surgery.

OBJECTIVE

To explore predictive factors and potential mechanisms of new-onset POAF in isolated off-pump CABG patients.

METHODS

Retrospective observational case-control study of 233 patients undergoing isolated off-pump CABG surgery between August 2018 and July 2020 at the Department of Thoracic and Cardiovascular Surgery, the Affiliated Drum Tower Hospital of Nanjing University Medical School. Associations between predictor variables and new-onset POAF were identified. The main outcome was new-onset POAF after CABG surgery.

RESULTS

A total of 75 (32.19%) patients developed new-onset POAF after CABG surgery. The new-onset POAF patients had advanced age, higher baseline systolic blood pressure, more preoperative use of diuretic drug, more transfusion of blood products, atrial dilation and postoperative positive inotropic drug treatment. Nineteen variates entered the multivariable logistic regression model with a Hosmer-Lemeshow test score of 7.565 (P=0.477). Postoperative left atrial enlargement, postoperative drainage in the first 24 hours and total length of hospital stay were statistically significant, while postoperative right atrial enlargement (OR and 95% CI, 7.797 [0.200, 304.294], P=0.272) and left atrial enlargement (3.524 [1.141, 10.886], P=0.029) assessed by echocardiography had the largest OR value.

CONCLUSION

Atrial enlargement is strongly associated with new-onset POAF in patients with isolated off-pump CABG, thus it highlights the advantage of echocardiography as a useful tool for predicting new-onset POAF. Careful monitoring and timely intervention should be considered for these patients.

Healthcare resource utilization and costs for patients with postoperative atrial fibrillation in the United States

BACKGROUND

Postoperative atrial fibrillation (POAF) is one of the most common complications following cardiac surgery. POAF is associated with increased hospitalization costs, but its long-term economic burden is not well defined.

OBJECTIVE

To assess 30-day and 1-year incremental healthcare resource utilization (HRU) and costs associated with POAF in the United States (US).

METHODS

This retrospective cohort study used claims data from the IBM Watson MarketScan database. A cohort of US adults aged 55--90 years who underwent open-heart surgery between 1 January 2017 and 31 December 2018 was used to compare patients who experienced POAF versus patients who did not (controls). The outcomes of interest were incremental HRU and costs, which were assessed during the index hospitalization and 30-day and 1-year postdischarge time periods. Inverse probability weighting was used to adjust for differences in baseline characteristics.

RESULTS

A total of 8,020 patients met the study inclusion criteria with 5,765 patients in the control cohort (mean age, 63.4 years) and 2,255 patients in the POAF cohort (mean age, 65.8 years). After adjustment, patients with POAF had an index hospitalization that was 1.9 days longer (99% CI, 1.3-2.4 days; p < 0.001) and cost $13,919 more (99% CI, $2,828-$25,011; p < 0.001) than for patients without POAF. POAF patients also had significantly higher HRU at 30 days and 1-year postdischarge with incremental costs of $4,649 (99% CI, $1,479-$7,819; p < 0.001) and $10,671 (99% CI, $2,407-$18,935; p < 0.001), respectively.

CONCLUSION

POAF following open-heart surgery poses a significant economic burden up to 1 year postdischarge.

Awake Cranioplasty in a Patient with Rheumatic Heart Disease: A Novel Approach

Cranioplasty is a surgical procedure that restores the normal anatomy following craniectomy. Restoring the skull bone ensures protection and normalizes the physiology as well as the cerebrospinal fluid dynamics. This surgical procedure usually requires administration of general anesthesia for retrieving the bone placed in the abdominal region and thereafter placing it in the cranium. We report the anesthetic management of a high-risk case who had severe mitral stenosis and was scheduled for cranioplasty. The anesthetic management of a patient with rheumatic heart disease, with severe mitral stenosis, posted for cranioplasty, is extremely challenging. The presence of cardiac pathology necessitates the need to balance patient's hemodynamics in accordance with the cardiac grid and tests the limits of the anesthesiologist's preparedness. We describe our experience of conduct of this case in regional anesthesia using scalp block on the defect site with an oblique transverse abdominis plane block for abdominal bone retrieval.

Dexmedetomidine Increases MMP-12 and MBP Concentrations after Coronary Artery Bypass Graft Surgery with Extracorporeal Circulation Anaesthesia without Impacting Cognitive Function: A Randomised Control Trial

Postoperative neurological deficits remain a concern for patients undergoing cardiac surgeries. Even minor injuries can lead to neurocognitive decline (i.e., postoperative cognitive dysfunction). Dexmedetomidine may be beneficial given its reported neuroprotective effect. We aimed to investigate the effects of dexmedetomidine on brain injury during cardiac surgery anaesthesia. This prospective observational study analysed data for 46 patients who underwent coronary artery bypass graft surgery with extracorporeal circulation between August 2018 and March 2019. The patients were divided into two groups: control (CON) with typical anaesthesia and dexmedetomidine (DEX) with dexmedetomidine infusion. Concentrations of the biomarkers matrix metalloproteinase-12 (MMP-12) and myelin basic protein (MBP) were measured preoperatively and at 24 and 72 h postoperatively. Cognitive evaluations were performed preoperatively, at discharge, and 3 months after discharge using Addenbrooke's Cognitive Examination version III (ACE-III). The primary endpoint was the ACE-III score at discharge. Increased MMP-12 and MBP concentrations were observed in the DEX group 24 and 72 h postoperatively. No significant differences in ACE-III scores were observed between the groups at discharge; however, the values were increased when compared with initial values after 3 months (p = 0.000). The current results indicate that the administration of dexmedetomidine as an adjuvant to anaesthesia can increase MMP-12 and MBP levels without effects on neurocognitive outcomes at discharge and 3 months postoperatively.

Effect of dexmedetomidine for prevention of acute kidney injury after cardiac surgery: an updated systematic review and meta-analysis

BACKGROUND

Acute kidney injury (AKI) is a serious complication related to cardiac surgery. Several studies have been conducted to investigate the effect of dexmedetomidine administration on AKI prevention.

OBJECTIVE

To assess if dexmedetomidine is associated with a protective effect of renal function after cardiac surgery. And the aim of conducting this meta-analysis is to summarize the literature and determine the clinical utility of dexmedetomidine administration in patients undergoing cardiac surgery.

METHODS

PubMed, Cochrane Library, and EMBASE databases were comprehensively searched for all randomized controlled trials (RCTs) published before 1 December, 2021 that investigated the effect of dexmedetomidine on AKI prevention.

RESULTS

Our analysis included 16 studies involving 2148 patients. Compared with the control group, dexmedetomidine administration significantly reduced AKI incidence (OR, 0.47; 95% CI, 0.36-0.61; p <  0.00001; I2 = 26%) and the length of stay in the intensive care unit (ICU) but did not alter mortality rate, length of stay in the hospital, and mechanical ventilation time. Furthermore, the incidence of delirium among patients treated with dexmedetomidine was significantly decreased.

CONCLUSION

Dexmedetomidine administration has a positive effect on preventing AKI and postoperative delirium after cardiac surgery and significantly reduces the length of stay in the ICU.

Outcomes of dexmedetomidine versus propofol sedation in critically ill adults requiring mechanical ventilation: a systematic review and meta-analysis of randomised controlled trials

BACKGROUND

Guidelines have recommended the use of dexmedetomidine or propofol for sedation after cardiac surgery, and propofol monotherapy for other patients. Further outcome data are required for these drugs.

METHODS

This systematic review and meta-analysis was prospectively registered on PROSPERO. The primary outcome was ICU length of stay. Secondary outcomes included duration of mechanical ventilation, ICU delirium, all-cause mortality, and haemodynamic effects. Intensive care patients were analysed separately as cardiac surgical, medical/noncardiac surgical, those with sepsis, and patients in neurocritical care. Subgroup analyses based on age and dosage were conducted.

RESULTS

Forty-one trials (N=3948) were included. Dexmedetomidine did not significantly affect ICU length of stay across any ICU patient subtype when compared with propofol, but it reduced the duration of mechanical ventilation (mean difference -0.67 h; 95% confidence interval: -1.31 to -0.03 h; P=0.041; low certainty) and the risk of ICU delirium (risk ratio 0.49; 95% confidence interval: 0.29-0.87; P=0.019; high certainty) across cardiac surgical patients. Dexmedetomidine was also associated with a greater risk of bradycardia across a variety of ICU patients. Subgroup analyses revealed that age might affect the incidence of haemodynamic side-effects and mortality among cardiac surgical and medical/other surgical patients.

CONCLUSION

Dexmedetomidine did not significantly impact ICU length of stay compared with propofol, but it significantly reduced the duration of mechanical ventilation and the risk of delirium in cardiac surgical patients. It also significantly increased the risk of bradycardia across ICU patient subsets.

Dexmedetomidine vs other sedatives in critically ill mechanically ventilated adults: a systematic review and meta-analysis of randomized trials

Conventional gabaminergic sedatives such as benzodiazepines and propofol are commonly used in mechanically ventilated patients in the intensive care unit (ICU). Dexmedetomidine is an alternative sedative that may achieve lighter sedation, reduce delirium, and provide analgesia. Our objective was to perform a comprehensive systematic review summarizing the large body of evidence, determining if dexmedetomidine reduces delirium compared to conventional sedatives. We searched MEDLINE, EMBASE, CENTRAL, ClinicalTrials.gov and the WHO ICTRP from inception to October 2021. Independent pairs of reviewers identified randomized clinical trials comparing dexmedetomidine to other sedatives for mechanically ventilated adults in the ICU. We conducted meta-analyses using random-effects models. The results were reported as relative risks (RRs) for binary outcomes and mean differences (MDs) for continuous outcomes, with corresponding 95% confidence intervals (CIs). In total, 77 randomized trials (n = 11,997) were included. Compared to other sedatives, dexmedetomidine reduced the risk of delirium (RR 0.67, 95% CI 0.55 to 0.81; moderate certainty), the duration of mechanical ventilation (MD - 1.8 h, 95% CI  - 2.89 to  - 0.71; low certainty), and ICU length of stay (MD  - 0.32 days, 95% CI  - 0.42 to  - 0.22; low certainty). Dexmedetomidine use increased the risk of bradycardia (RR 2.39, 95% CI 1.82 to 3.13; moderate certainty) and hypotension (RR 1.32, 95% CI 1.07 to 1.63; low certainty). In mechanically ventilated adults, the use of dexmedetomidine compared to other sedatives, resulted in a lower risk of delirium, and a modest reduction in duration of mechanical ventilation and ICU stay, but increased the risks of bradycardia and hypotension.

Effect of Dexmedetomidine on Tachyarrhythmias After Cardiac Surgery: A Systematic Review and Meta-Analysis

ABSTRACT

Tachyarrhythmias after cardiac surgery is a common occurrence in clinical practice, which can be life threatening. We searched 6 databases, including Embase, PubMed, Cochrane, CNKI, Wanfang, and Sinomed, to evaluate the effect of dexmedetomidine on tachyarrhythmias after adult cardiac surgery. The primary end point was the number of patients with atrial fibrillation (AF) after cardiac surgery. The secondary end points included the number of patients with supraventricular tachycardia or with ventricular tachycardia or with ventricular fibrillation or with myocardial infarction or deceased patients, the duration of mechanical ventilation, the intensive care unit stay, hospital stay, and the number of patients with bradycardia and those with hypotension. Among the 1388 retrieved studies, 18 studies (n = 3171 participants) met our inclusion criteria. Dexmedetomidine reduced the incidence of AF by 17% [relative risk (RR) = 0.83; 95% confidence interval (CI), 0.73-0.93; P = 0.002]. Through subgroup analysis, we found that when the maintenance dose of dexmedetomidine was >0.7 µg·kg-1·h-1, the effect of preventing AF was obvious (RR = 0.58; 95%CI 0.43-0.78; P = 0.0003). Dexmedetomidine also reduced the incidence of supraventricular tachycardia by approximately 70% (RR = 0.29; 95% CI, 0.11-0.77; P = 0.01) and the incidence of ventricular tachycardia by approximately 80% (RR = 0.23; 95% CI, 0.08-0.63; P = 0.004) but had no effect on ventricular fibrillation (RR = 1.02; 95% CI, 0.14-7.31; P = 0.99). The major side effect of dexmedetomidine was bradycardia. Dexmedetomidine can reduce the incidence of AF (especially high dosages), supraventricular tachycardia, and ventricular tachycardia after cardiac surgery in adults, but it does not affect the occurrence of ventricular fibrillation.

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

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

Influence of Dexmedetomidine on Post-operative Atrial Fibrillation After Cardiac Surgery: A Meta-Analysis of Randomized Controlled Trials

Background: Previous clinical studies and meta-analysis evaluating the influence of dexmedetomidine on postoperative atrial fibrillation showed inconsistent results. We performed an updated meta-analysis to evaluate the influence of dexmedetomidine on incidence of postoperative atrial fibrillation after cardiac surgery.

Methods: Randomized controlled trials that evaluated the potential influence of dexmedetomidine on the incidence of atrial fibrillation after cardiac surgery were obtained by search of PubMed, Embase, and Cochrane's Library databases from inception to April 12, 2021. A random-effects model incorporating the potential publication bias was used to pool the results. Influences of patient or study characteristics on the efficacy of dexmedetomidine on atrial fibrillation after cardiac surgery were evaluated by meta-regression and subgroup analyses.

Results: Fifteen studies with 2,733 patients were included. Pooled results showed that dexmedetomidine significantly reduced the incidence of atrial fibrillation compared to control (OR: 0.72, 95% CI: 0.55–0.94, p = 0.02) with mild heterogeneity (I² = 26%). Subgroup analysis showed that dexmedetomidine significantly reduced the incidence of atrial fibrillation in studies from Asian countries (OR: 0.41, 95% CI: 0.26–0.66, p < 0.001), but not in those from non-Asian countries (OR: 0.89, 95% CI: 0.71–1.10, p = 0.27; p for subgroup difference = 0.004). Meta-regression analysis showed that the mean age and proportion of male patients may modify the influence of dexmedetomidine on POAF (coefficient = 0.028 and 0.021, respectively, both p < 0.05). Subgroup analysis further showed that Dex was associated with reduced risk of atrial fibrillation after cardiac surgery in studies with younger patients (mean age ≤ 61 years, OR = 0.44, 95% CI: 0.28–0.69, p = 0.004) and smaller proportion of males (≤74%, OR = 0.55, 95% CI: 0.36–0.83, p = 0.005), but not in studies with older patients or larger proportion of males (p for subgroup difference = 0.02 and 0.04).

Conclusions: Current evidence supports that perioperative administration of dexmedetomidine may reduce the risk of incidental atrial fibrillation after cardiac surgery, particularly in Asians.

Challenging Airway Management in Patients With Zenker's Diverticulum

The acquired hypopharyngeal diverticulum (Zenker's) is characterized by a posterior wall outpouching of the pharyngeal mucosa and submucosa through the vulnerable points of the pharyngoesophageal junction. We describe the case of a 67-year-old male who was recently diagnosed with Zenker's diverticulum and had complaints of dysphagia and halitosis. An endoscopic treatment (diverticulotomy) was performed without difficulties. The anesthetic management included rapid sequence induction, avoiding succinylcholine, and intraoperative infusion of dexmedetomidine. The neuromuscular blockade was reversed using sugammadex, decreasing the risk of failed extubation and possible airway re-intervention. The patient was discharged home the following day without complications.

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.

Role of dexmedetomidine in the treatment of delirium in critically ill patients: a systematic review and meta-analysis

INTRODUCTION

Although dexmedetomidine has been found to prevent delirium in critically ill patients, it is uncertain whether it can treat acute delirium. This study aimed to evaluate the efficacy and safety of dexmedetomidine in treating delirium, by analyzing and reviewing data from previous studies.

EVIDENCE ACQUISITION

Clinical trial data on the use of dexmedetomidine in adult critically ill patients with delirium were retrieved from four databases (PubMed, Embase, Web of Science, and the Cochrane Library) and clinicaltrials.gov, from inception to May, 2020.

EVIDENCE SYNTHESIS

Ten randomized controlled trials (RCTs) and five non-RCTs met the selection criteria and data were obtained from 1017 patients. In one study, dexmedetomidine reduced the duration of delirium to a greater extent than did the placebo. In six studies, it was associated with a lower point-prevalence of delirium after treatment (OR, 0.39; 95% CI, 0.20, 0.76; P=0.006) and a shorter time to resolution of delirium (hours; MD, -23.25; 95% CI, -45.28, -1.21; P=0.04) compared with those of other drugs. In four RCTs, it was superior to haloperidol in reducing the time to resolution of delirium (hours; MD, -30.17; P=0.01). However, in seven studies, it showed a higher risk of bradycardia (OR, 3.48; 95% CI, 1.47, 8.23; P=0.004) than that of comparators.

CONCLUSIONS

Dexmedetomidine promotes the resolution of delirium but also increases the incidence of bradycardia during treatment. Furthermore, it may be superior to haloperidol in treating delirium, although more studies are needed to confirm this.

Effect of dexmedetomidine on delirium during sedation in adult patients in intensive care units: A systematic review and meta-analysis

STUDY OBJECTIVE

To compare the effect of sedation protocols with and without dexmedetomidine on delirium risk and duration in adult patients in intensive care units (ICUs).

DESIGN

A meta-analysis of randomized controlled trials.

REVIEW METHODS

We searched the Cochrane Central Register of Controlled Trials, PubMed, EMBASE, and ISI Web of Science from inception to September 3, 2020. We included studies comparing the effect of dexmedetomidine-based sedation on delirium risk with non-dexmedetomidine-based sedation in adult patients in ICUs. We pooled the data using a random-effects model using Review Manager 5.2, and assessed publication bias using Stata 11.0. The quality of evidence was rated using the Grading of Recommendations, Assessment, Development and Evaluation system.

MAIN RESULTS

We included 36 studies involving 9623 participants. The use of dexmedetomidine was associated with reduced risk of delirium (risk ratio [RR], 0.63; 95% confidence interval [CI], 0.54-0.75; very low-quality evidence), but higher incidences of hypotension and bradycardia during hospital stay. Dexmedetomidine was also associated with shorter durations of ICU stay, hospital stay and mechanical ventilation. Dexmedetomidine did not affect ICU mortality (RR, 1.01; 95% CI, 0.89-1.14; low-quality evidence), hospital mortality (RR, 1.01; 95% CI, 0.91-1.12; very low-quality evidence), or 30-day mortality (RR, 0.77; 95% CI, 0.58-1.01; moderate-quality evidence), or duration of delirium (mean difference, -0.74 days; 95% CI, -1.83 to 0.36 days; very low-quality evidence). We identified publication bias for risk and duration of delirium, length of ICU stay, and hospital stay.

CONCLUSIONS

Low- or very low-quality evidence suggests that dexmedetomidine was associated with a clinically-small reduction of delirium risk, ICU/hospital stay and mechanical ventilation duration, but were not associated with improved mortality or shorter delirium duration in ICU patients. These findings were inconclusive because of publication bias, heterogeneity, and limited sample size. Significant adverse effects of dexmedetomidine include hypotension and bradycardia. PROSPERO registration number: CRD42018095358.

Mechanisms, Prevention, and Treatment of Atrial Fibrillation After Cardiac Surgery: A Narrative Review

New onset of postoperative atrial fibrillation (AF) generally is recognized as a frequent and debilitating complication after cardiac surgery, contributing to a considerable health- care cost. Extensive research has been conducted to study the underlying mechanisms and risk factors of AF in the perioperative period. Many options have been suggested to lower the incidence, and the concurrent cost in health resources. This review attempts to synthesize the large body of existing literature on AF, as well as expand and illustrate the available knowledge on its management strategies. The latter incorporates recent developments in the anesthesthetic approach as well as in the pharmacologic arsenal. In addition, the current review provides a tool for understanding the pathophysiology of AF and for reducing the occurrence after cardiac surgery. By using it, clinicians can manage patients with AF in the perioperative period of cardiac surgery and minimize the relatively high economic cost that accompanies it.

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.

Effectiveness and harms of pharmacological interventions for the treatment of delirium in adults in intensive care units after cardiac surgery: a systematic review

OBJECTIVE

The objective of this review was to synthesize the best available evidence on the effectiveness and harms of pharmacological interventions for the treatment of delirium in adult patients in the intensive care unit (ICU) after cardiac surgery.

INTRODUCTION

Patients who undergo cardiac surgery are at high risk of delirium (incidence: 50-90%). Delirium has deleterious effects, increasing the risk of death and adversely affecting recovery. Clinical interventional trials have been conducted to prevent and treat postoperative delirium pharmacologically including antipsychotics and sedatives. These trials have provided some evidence about efficacy and influenced clinical decision making. However, much reporting is incomplete and provides biased assessments of efficacy; benefits are emphasized while harms are inadequately reported.

INCLUSION CRITERIA

Participants were ≥ 16 years, any sex or ethnicity, who were treated postoperatively in a cardiothoracic ICU following cardiac surgery and were identified as having delirium. Any pharmacological intervention for the treatment of delirium was included, regardless of drug classification, dosage, intensity or frequency of administration. Outcomes of interest of this review were: mortality, duration and severity of delirium, use of physical restraints, quality of life, family members' satisfaction with delirium management, duration/severity of the aggressive episode, associated falls, severity of accidental self-harm, pharmacological harms, harms related to over-sedation, ICU length of stay, hospital length of stay (post ICU), total hospital length of stay, need for additional intervention medication and need for rescue medication. Randomized controlled trials were considered first and in their absence, non-randomized controlled trials and quasi-experimental would have been considered, followed by analytical observational studies.

METHODS

A search was conducted in PubMed, Embase, CINAHL, Web of Science, Cochrane Central Register of Controlled Trials, Scopus, Epistemonikos, Australian New Zealand Clinical Trials Registry, ClinicalTrials.gov, Clinical Trials in New Zealand, and ProQuest Dissertations and Theses to locate both published and unpublished studies. There was no date limit for the search. A hand search for primary studies published between January 1, 2012 and November 17, 2018 in relevant journals was also conducted. Only studies published in English were considered for inclusion. Two reviewers independently assessed the methodological quality using standardized critical appraisal instruments from JBI and McMaster University. Quantitative data were extracted using the standardized JBI data extraction tool. A meta-analysis was not performed, as there was too much clinical and methodological heterogeneity in the included studies. Results have been presented in a narrative form. Standard GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) evidence assessment of outcomes has been reported.

RESULTS

Three RCTs investigating morphine versus haloperidol (n = 53), ondansetron versus haloperidol (n = 72), and dexmedetomidine versus midazolam (n = 80) were included. Due to heterogeneity and incomplete reporting, a meta-analysis was not feasible. Overall, the methodological quality of these studies was found to be low. Additionally, this review found reporting of harms to be inadequate and superficial for all three studies and did not meet the required standards for harms reporting, as defined by the CONSORT statement extension for harms.

CONCLUSIONS

It was not possible to draw any valid conclusions regarding the effectiveness of morphine vs haloperidol, ondansetron vs haloperidol or dexmedetomidine vs midazolam in treating delirium after cardiac surgery. This is due to the low number of studies, the poor methodological quality in conducting and reporting and the heterogeneity between the studies.

Dexmedetomidine Is an Equal Cost Alternative to Propofol in Transcatheter Aortic Valve Replacement, With Equivalent In-Hospital and 30-Day Outcomes

OBJECTIVE

Transcatheter aortic valve replacement (TAVR) with monitored anesthesia care (MAC) is well-tolerated and is growing in popularity. Differences in outcomes based on anesthetic agent choice with MAC has received less attention. The authors sought to determine whether differences in outcomes and cost exist based on whether patients receive dexmedetomidine or propofol when undergoing TAVR with MAC.

DESIGN

Retrospective cohort study.

SETTING

The Penn State Milton S. Hershey Medical Center, Hershey, Pennsylvania.

PARTICIPANTS

The study comprised 161 patients who underwent TAVR with MAC between May 2014 and March 2019.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A propofol-only (n = 58) group and dexmedetomidine-only (n = 103) group were identified. No differences in in-hospital mortality or complication rate were identified when evaluating for stroke, transfusion, new arrhythmia, cardiac arrest, or bleeding and vascular complications (p > 0.05, all). Thirty-day outcomes were also equivalent, with no differences in mortality, stroke, vascular complication, new arrhythmia, or myocardial infarction (p > 0.05, all). The average amount of epinephrine, norepinephrine, or phenylephrine used intraoperatively was not significantly different. Overall median hospitalization costs were equivalent ($57,554.31 with dexmedetomidine v $58,538.08 with propofol, p = 0.97).

CONCLUSIONS

There were no significant differences in in-hospital outcomes, 30-day outcomes, or total cost of the patient's hospitalization, based on the use of dexmedetomidine versus propofol in patients undergoing TAVR.

Comparison of sedation between dexmedetomidine and propofol during transesophageal echocardiography: A randomized controlled trial

Background:

This study aimed to compare sedation characteristics of dexmedetomidine (Dex) and propofol during transesophageal echocardiography (TEE) in cardiac patients.

Methods:

This clinical trial was conducted on 65 cardiac patients, who underwent TEE in a referral heart hospital. The patients were randomly divided into two groups: Dex (n = 34) and propofol (n = 31). The depth of sedation in the patients was assessed at 5-min intervals until the end of the TEE examination. The patient, physicians’ satisfaction was recorded. Furthermore, blood pressure, heart and respiratory rates, peripheral oxygen saturation, and the bispectral index (BIS) of the patients were measured. The occurrence of apnea, hypotension or bradycardia was documented.

Results:

Demographic variables were similar in both groups. Time from the beginning of sedation to the start of TEE was significantly longer in the Dex group (P = 0.01). Duration of the TEE examination was not different between the two groups. Interestingly, the recovery time was shorter in the Dex group than in the propofol group. There were no significant differences regarding patient and physician satisfaction with sedation quality. Hemodynamic profile was mainly similar in both groups. There was a significantly lower BIS level in the Dex group. There was no significant difference in the incidence of apnea or hypotension between the groups.

Conclusions:

Time from the beginning of sedation with Dex was longer than that with propofol. However, Dex was able to provide satisfactory sedation levels, hemodynamic stability, short recovery time, and acceptable patient and practitioner satisfaction during TEE in our cardiac patients.

Dexmedetomidine for reduction of atrial fibrillation and delirium after cardiac surgery (DECADE): a randomised placebo-controlled trial

BACKGROUND

Atrial fibrillation and delirium are common consequences of cardiac surgery. Dexmedetomidine has unique properties as sedative agent and might reduce the risk of each complication. This study coprimarily aimed to establish whether dexmedetomidine reduces the incidence of new-onset atrial fibrillation and the incidence of delirium.

METHODS

A randomised, placebo-controlled trial was done at six academic hospitals in the USA. Patients who had had cardiac surgery with cardiopulmonary bypass were enrolled. Patients were randomly assigned 1:1, stratified by site, to dexmedetomidine or normal saline placebo. Randomisation was computer generated with random permuted block size 2 and 4, and allocation was concealed by a web-based system. Patients, caregivers, and evaluators were all masked to treatment. The study drug was prepared by the pharmacy or an otherwise uninvolved research associate so that investigators and clinicians were fully masked to allocation. Participants were given either dexmedetomidine infusion or saline placebo started before the surgical incision at a rate of 0·1 μg/kg per h then increased to 0·2 μg/kg per h at the end of bypass, and postoperatively increased to 0·4 μg/kg per h, which was maintained until 24 h. The coprimary outcomes were atrial fibrillation and delirium occurring between intensive care unit admission and the earlier of postoperative day 5 or hospital discharge. All analyses were intention-to-treat. The trial is registered with ClinicalTrials.gov, NCT02004613 and is closed.

FINDINGS

798 patients of 3357 screened were enrolled from April 17, 2013, to Dec 6, 2018. The trial was stopped per protocol after the last designated interim analysis. Among 798 patients randomly assigned, 794 were analysed, with 400 assigned to dexmedetomidine and 398 assigned to placebo. The incidence of atrial fibrillation was 121 (30%) in 397 patients given dexmedetomidine and 134 (34%) in 395 patients given placebo, a difference that was not significant: relative risk 0·90 (97·8% CI 0·72, 1·15; p=0·34). The incidence of delirium was non-significantly increased from 12% in patients given placebo to 17% in those given dexmedetomidine: 1·48 (97·8% CI 0·99-2·23). Safety outcomes were clinically important bradycardia (requiring treatment) and hypotension, myocardial infarction, stroke, surgical site infection, pulmonary embolism, deep venous thrombosis, and death. 21 (5%) of 394 patients given dexmedetomidine and 8 (2%) of 396 patients given placebo, had a serious adverse event as determined by clinicians. 1 (<1%) of 391 patients given dexmedetomidine and 1 (<1%) of 387 patients given placebo died.

INTERPRETATION

Dexmedetomidine infusion, initiated at anaesthetic induction and continued for 24 h, did not decrease postoperative atrial arrhythmias or delirium in patients recovering from cardiac surgery. Dexmedetomidine should not be infused to reduce atrial fibrillation or delirium in patients having cardiac surgery.

FUNDING

Hospira Pharmaceuticals.

Dexmedetomidine Reduces Atrial Fibrillation After Adult Cardiac Surgery: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Dexmedetomidine has been shown to have antiarrhythmic effects by exhibiting sympatholytic properties and activating the vagus nerve in preclinical studies. Results from clinical trials of dexmedetomidine on atrial fibrillation (AF) following adult cardiac surgery are controversial.

MATERIALS AND METHODS

We searched EMBASE, PubMed and Cochrane CENTRAL databases for randomized controlled trials (RCTs) comparing the antiarrhythmic effect of dexmedetomidine versus placebo or other anesthetic drugs in adult patients undergoing cardiac surgery. The primary outcome was the incidence of AF. The secondary outcomes were ventricular arrhythmias [ventricular fibrillation (VF), ventricular tachycardia (VT)], mechanical ventilation (MV) duration, intensive care unit (ICU) length of stay, and hospital length of stay, and all-cause mortality.

RESULTS

Thirteen trials with a total of 1684 study patients were selected. Compared with controls, dexmedetomidine significantly reduced the incidence of postoperative AF [odds ratio (OR) 0.75; 95% confidence interval (CI) 0.58-0.97; P = 0.03] and VT (OR 0.23; 95% CI 0.11-0.48; P < 0.0001). No significant difference for the incidence of VF existed (OR 0.80; 95% CI 0.21-3.03; P = 0.74). There was no significant difference between groups in MV duration [weighted mean difference (WMD) - 0.10; 95% CI - 0.42 to 0.21; P = 0.52], postoperative ICU stay (WMD - 0.49; 95% CI - 2.64 to 1.66; P = 0.65), hospital stay (WMD - 0.01; 95% CI - 0.16 to 0.13; P = 0.88) and mortality (OR 0.59; 95% CI 0.15-2.37; P = 0.46).

CONCLUSIONS

Perioperative administration of dexmedetomidine in adult patients undergoing cardiac surgery reduced the incidence of postoperative AF and VT. But there was no significant difference in incidence of VF, MV duration, ICU stay, hospital stay and mortality.

Dexmedetomidine in Adult Patients in Cardiac Surgery Critical Care: An Evidence-Based Review

Although several options are available for postoperative sedation in the intensive care unit, the selective α2-adrenoceptor agonist dexmedetomidine may offer advantages for patients after cardiac surgery. The author conducted a review of the literature on the use of dexmedetomidine in the cardiac surgery population to determine possible advantages and disadvantages in this patient population. Although the use of dexmedetomidine has not been conclusively shown to change overall morbidity and mortality and may be associated with higher drug cost, its other demonstrated effects offer advantages for postoperative cardiac surgery patients that other forms of sedation cannot match.

Dexmedetomidine pretreatment inhibits cerebral ischemia/reperfusion‑induced neuroinflammation via activation of AMPK

Focal ischemia/reperfusion (I/R) injury induced cerebral inflammation, aggravates brain damage. The aim of the present study was to investigate the protective mechanisms of dexmedetomidine (DEX) on I/R brain injury in rats. Sprague‑Dawley rats were divided to seven experimental groups (18 rats/group): Sham surgery; middle cerebral artery occlusion (MCAO) surgery (90 min); DEX10 [10 µg/kg intraperitoneal (i.p.) injection 30 min prior to MCAO]; DEX50 (50 µg/kg i.p. 30 min prior to MCAO); DEX100 (100 µg/kg i.p. 30 min prior to MCAO); DEX50+Yohimbine [YOH; 5 mg/kg 10 min prior to DEX (50 µg/kg i.p.) administration and MCAO] and YOH (5 mg/kg 40 min prior to MCAO). At 24 h post‑MCAO surgery, neurological deficit was examined by staining damaged brain tissues with 2,3,5‑triphenyltetrazolium chloride. Neuronal apoptosis in the cerebral cortex was histologically assessed by terminal deoxynucleotidyl‑transferase‑mediated dUTP nick end labeling staining, and the expression levels of phosphorylated (p)‑AMP‑activated protein kinase (AMPK; Thr172) was detected by western blotting. In addition, the expression levels of tumor necrosis factor (TNF)‑α and interleukin (IL)‑1β were assessed by ELISA. At days 1, 2 and 5 following I/R, motor functions were assessed by an observer blinded to the study. The brain infarct size, neurological deficit scores, number of apoptotic neurons, expression levels of pro‑inflammatory cytokines TNF‑α and IL‑1β were increased following MCAO, whereas the motor function scores were reduced. Pretreatment with DEX prior to MCAO can reverse the effects induced by I/R. Compared with rats in the Sham group, the expression levels of p‑AMPK were mildly increased in the MCAO group and highly increased in the three DEX‑treatment groups. Pretreatment with YOH reversed the above effects of DEX and produced a similar level of cerebral I/R injury. The results demonstrated that precondition with DEX exhibited anti‑inflammatory effects on brain ischemic injury mediated by AMPK signal pathway.

Can dexmedetomidine reduce atrial fibrillation after cardiac surgery? A systematic review and meta-analysis

Purpose

Cardiac surgery patients always present with atrial fibrillation (AF) after admission to the intensive care unit, leading to high mortality and lengthy hospitalization. Dexmedetomidine (DEX) is a popular medication used for sedation in the intensive care unit; however, whether it can reduce AF needs to be analyzed.

Materials and methods

Three primary databases, Medline, Embase (Ovid SP) and the Cochrane Central Register of Controlled Trials (CENTRAL), were searched. All English language and randomized control designed clinical publications comparing DEX to control medicines for sedation after elective cardiac surgery were included. Two independent colleagues conducted the data extraction and quality assessments. The subgroup analysis was performed according to the medicine used, age, AF history, and whether previous beta-blocker premedication and cardiopulmonary bypass (CPB) were applied. The overall incidence of AF was analyzed.

Results

A total of 1,295 patients in nine studies met the selection criteria among 2,587 studies screened from the database. After quantitative synthesis, our results revealed that the DEX group was not associated with a decreased incidence of AF compared with the placebo (risk ratio [RR] 0.76, 95% CI 0.37, 1.55, P=0.44) and morphine groups (RR 0.86, 95% CI 0.56, 1.31, P=0.48). Subgroup analysis also indicated that the DEX vs propofol comparison exhibited no difference: 1) for patients of age >60 years (P=0.69) or ≤60 years (P=0.69); 2) under CPB surgery (P=0.45) or without CPB surgery (P=0.88); 3) with beta-blocker premedication (P=0.32) or without beta-blocker premedication (P=0.90); and 4) with AF history (RR 1.07, 95% CI 0.85, 1.36, P=0.57) or without AF history (P=0.30).

Conclusion

This meta-analysis revealed that DEX could not reduce the incidence of AF compared to control medicines following cardiac surgery. DEX may have an increased influence on AF occurrence if patients had a history of AF. However, cautious interpretation should be made due to high clinical heterogeneity.

Alpha-2 adrenergic agonists for the prevention of cardiac complications among adults undergoing surgery

BACKGROUND

The surgical stress response plays an important role on the pathogenesis of perioperative cardiac complications. Alpha-2 adrenergic agonists attenuate this response and may help prevent postoperative cardiac complications.

OBJECTIVES

To determine the efficacy and safety of α-2 adrenergic agonists for reducing mortality and cardiac complications in adults undergoing cardiac surgery and non-cardiac surgery.

SEARCH METHODS

We searched CENTRAL (2017, Issue 4), MEDLINE (1950 to April Week 4, 2017), Embase (1980 to May 2017), the Science Citation Index, clinical trial registries, and reference lists of included articles.

SELECTION CRITERIA

We included randomized controlled trials that compared α-2 adrenergic agonists (i.e. clonidine, dexmedetomidine or mivazerol) against placebo or non-α-2 adrenergic agonists. Included trials had to evaluate the efficacy and safety of α-2 adrenergic agonists for preventing perioperative mortality or cardiac complications (or both), or measure one or more relevant outcomes (i.e. death, myocardial infarction, heart failure, acute stroke, supraventricular tachyarrhythmia and myocardial ischaemia).

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality, extracted data and independently performed computer entry of abstracted data. We contacted study authors for additional information. Adverse event data were gathered from the trials. We evaluated included studies using the Cochrane 'Risk of bias' tool, and the quality of the evidence underlying pooled treatment effects using GRADE methodology. Given the clinical heterogeneity between cardiac and non-cardiac surgery, we analysed these subgroups separately. We expressed treatment effects as pooled risk ratios (RR) with 95% confidence intervals (CI).

MAIN RESULTS

We included 47 trials with 17,039 participants. Of these studies, 24 trials only included participants undergoing cardiac surgery, 23 only included participants undergoing non-cardiac surgery and eight only included participants undergoing vascular surgery. The α-2 adrenergic agonist studied was clonidine in 21 trials, dexmedetomidine in 24 trials and mivazerol in two trials.In non-cardiac surgery, there was high quality evidence that α-2 adrenergic agonists led to a similar risk of all-cause mortality compared with control groups (1.3% with α-2 adrenergic agonists versus 1.7% with control; RR 0.80, 95% CI 0.61 to 1.04; participants = 14,081; studies = 16). Additionally, the risk of cardiac mortality was similar between treatment groups (0.8% with α-2 adrenergic agonists versus 1.0% with control; RR 0.86, 95% CI 0.60 to 1.23; participants = 12,525; studies = 5, high quality evidence). The risk of myocardial infarction was probably similar between treatment groups (RR 0.94, 95% CI 0.69 to 1.27; participants = 13,907; studies = 12, moderate quality evidence). There was no associated effect on the risk of stroke (RR 0.93, 95% CI 0.55 to 1.56; participants = 11,542; studies = 7; high quality evidence). Conversely, α-2 adrenergic agonists probably increase the risks of clinically significant bradycardia (RR 1.59, 95% CI 1.18 to 2.13; participants = 14,035; studies = 16) and hypotension (RR 1.24, 95% CI 1.03 to 1.48; participants = 13,738; studies = 15), based on moderate quality evidence.There was insufficient evidence to determine the effect of α-2 adrenergic agonists on all-cause mortality in cardiac surgery (RR 0.52, 95% CI 0.26 to 1.04; participants = 1947; studies = 16) and myocardial infarction (RR 1.01, 95% CI 0.43 to 2.40; participants = 782; studies = 8), based on moderate quality evidence. There was one cardiac death in the clonidine arm of a study of 22 participants. Based on very limited data, α-2 adrenergic agonists may have reduced the risk of stroke (RR 0.37, 95% CI 0.15 to 0.93; participants = 1175; studies = 7; outcome events = 18; low quality evidence). Conversely, α-2 adrenergic agonists increased the risk of bradycardia from 6.4% to 12.0% (RR 1.88, 95% CI 1.35 to 2.62; participants = 1477; studies = 10; moderate quality evidence), but their effect on hypotension was uncertain (RR 1.19, 95% CI 0.87 to 1.64; participants = 1413; studies = 9; low quality evidence).These results were qualitatively unchanged in subgroup analyses and sensitivity analyses.

AUTHORS' CONCLUSIONS

Our review concludes that prophylactic α-2 adrenergic agonists generally do not prevent perioperative death or major cardiac complications. For non-cardiac surgery, there is moderate-to-high quality evidence that these agents do not prevent death, myocardial infarction or stroke. Conversely, there is moderate quality evidence that these agents have important adverse effects, namely increased risks of hypotension and bradycardia. For cardiac surgery, there is moderate quality evidence that α-2 adrenergic agonists have no effect on the risk of mortality or myocardial infarction, and that they increase the risk of bradycardia. The quality of evidence was inadequate to draw conclusions regarding the effects of alpha-2 agonists on stroke or hypotension during cardiac surgery.

Does dexmedetomidine have an antiarrhythmic effect on cardiac patients? A meta-analysis of randomized controlled trials

Background

Cardiac surgery patients often experience several types of tachyarrhythmias after admission to the intensive care unit (ICU), which increases mortality and morbidity. Dexmedetomidine (DEX) is a popular medicine used for sedation in the ICU, and its other pharmacological characteristics are gradually being uncovered.

Purpose

To determine whether DEX has an antiarrhythmic effect after cardiac surgery.

Methods

The three primary databases MEDLINE, Embase (OVID SP) and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched, and all English-language and randomized control-designed clinical publications comparing DEX to control medicines for sedation after elective cardiac surgery were included. Two colleagues independently extracted the data and performed other quality assessments. A subgroup analysis was performed according to the different medicines used and whether cardiopulmonary bypass (CPB) was applied. All tachyarrhythmias that occurred in the atria and ventricles were analyzed.

Results

A total of 1295 patients in 9 studies met the selection criteria among 2587 studies that were screened. After quantitative synthesis, our results revealed that the DEX group was associated with a lower incidence of ventricular arrhythmia (VA, OR 0.24, 95% CI 0.09–0.64, I² = 0%, P = 0.005) than the control group. Subgroup analysis did not reveal a significant difference between the DEX and propofol subgroups (OR 0.13, 95% CI 0.03–0.56, I² = 0%, P = 0.007). Additionally, no difference in the incidence of atrial fibrillation (AF) was observed regardless of the different control medicines (OR 0.82, 95% CI 0.60–1.10, I² = 25%, P = 0.19) or whether CPB was applied.

Conclusions

This meta-analysis revealed that DEX has an antiarrhythmic effect that decreases the incidence of VA compared to other drugs used for sedation following cardiac surgery. DEX may not have an effect on AF, but cautious interpretation should be exercised due to high heterogeneity.

Dexmedetomidine prevents acute kidney injury after adult cardiac surgery: a meta-analysis of randomized controlled trials

BACKGROUND

Dexmedetomidine has been shown to confer direct renoprotection by stabilizing the sympathetic system, exerting anti-inflammatory effects and attenuating ischemia/reperfusion (I/R) injury in preclinical studies. Results from clinical trials of dexmedetomidine on acute kidney injury (AKI) following adult cardiac surgery are controversial.

METHODS

We searched EMBASE, PubMed, and Cochrane CENTRAL databases for randomized controlled trials (RCTs) comparing the renal effect of dexmedetomidine versus placebo or other anesthetic drugs in adult patients undergoing cardiac surgery. The primary outcome was the incidence of AKI. The secondary outcomes were mechanical ventilation (MV) duration, intensive care unit (ICU) stay and hospital length of stay(LOS), and postoperative mortality (in-hospital or within 30 days).

RESULTS

Ten trials with a total of 1575 study patients were selected. Compared with controls, dexmedetomidine significantly reduced the incidence of postoperative AKI [68/788 vs 97/787; odds ratio(OR), 0.65; 95% confidence interval (CI), 0.45-0.92; P = 0.02; I² = 0.0%], and there was no difference between groups in postoperative mortality (4/487 vs 11/483; OR, 0.43; 95% CI, 0.14-1.28; P = 0.13; I² = 0.0%), MV duration [in days; n = 1229; weighted mean difference(WMD), -0.22; 95% CI, -2.04 to 1.70; P = 0.81], ICU stay (in days; n = 1363; WMD, -0.85; 95% CI, -2.14 to 0.45; P = 0.20), and hospital LOS (in days; n = 878; WMD, -0.24; 95% CI, -0.71 to 0.23; P = 0.32).

CONCLUSIONS

Perioperative administration of dexmedetomidine in adult patients undergoing cardiac surgery may reduce the incidence of postoperative AKI. Future trials are needed to determine the dose and timing of dexmedetomidine in improving outcomes, especially in patients with decreased baseline kidney function.

Effects of dexmedetomidine on heart arrhythmia prevention in off-pump coronary artery bypass surgery: A randomized clinical trial

Background

Arrhythmia occurring during and after surgery is one of the major complications in open-heart surgery. Dexmedetomidine is an intravenous alpha-2 agonist and very specific short-acting drug to protect the various organs against ischemic injuries and blood reflow. However, the effect of dexmedetomidine for preventing intraoperative heart arrhythmias has not been recognized.

Objective

This study aimed to determine the effect of dexmedetomidine on the incidence rate of heart arrhythmias and anesthetic required in off-pump coronary artery bypass surgery.

Methods

This randomized clinical trial was conducted on patients who were candidates for off-pump coronary artery bypass referring to Imam Reza Hospital of Mashhad, Iran, from July 2016 through January 2017. The patients were randomly assigned to two groups of intervention (infusion of 0.5 mcg/kg/h dexmedetomidine together with induction followed by infusion of 0.5 mcg/kg/h by the end of the surgery) or control (saline infusion). Mean arterial pressure (MAP) and heart rate (HR) were measured before induction, during surgery operation and ICU admission. Data were analyzed by SPSS version 18 using Chi Square and independent-samples t-test.

Results

A total of 76 patients with a mean age of 59.8 ± 8.2 years (in two groups of 38) were studied. The two groups had no statistically significant difference in terms of background variables. The MAP and HR values before induction, during surgery and ICU admission were significantly higher in the control group than in the intervention group (p=0.001). Out of the studied arrhythmias, the values of PAC (55.2% vs. 15.7%), PVC (81.5% vs. 21.0%), AF (26.3% vs. 7.8%), VTAC (21.0% vs. 2.6%) were significantly lower in dexmedetomidine group (p=0.001).

Conclusion

It seems that dexmedetomidine administration during induction and surgery can cause significant reduction in most of the common arrhythmias in off-pump coronary bypass surgery. The use of dexmedetomidine maintains MAP and HR at significantly lower values, and changes compared to the control group as well as reduces the need for anesthetic compounds.

Trial Registration

The present study has been registered at the Iranian Registry of Clinical Trials (www.IRCT.IR) with a code of IRCT2016072413159N9 before starting the study.

Founding

This study was fully sponsored by the Research Deputy at Mashhad University of Medical Sciences, Iran (grant number 941413).

Cardiothoracic Critical Care

High-value CCC is rapidly evolving to meet the demands of increased patient acuity and to incorporate advances in technology. The high-performing CCC system and culture should aim to learn quickly and continuously improve. CCC demands a proactive, interactive, precise, an expert team, and continuity.

Editor's Choice-The cardiovascular implications of sedatives in the cardiac intensive care unit

Patients admitted to the cardiac intensive care unit frequently develop multi-organ system dysfunction associated with their cardiac disease. In many cases, invasive mechanical ventilation is required, which often necessitates sedation for patient-ventilator synchrony, reduction of work of breathing, and patient comfort. In this paper, we describe the use of common sedatives available in the endotracheally intubated critically ill patient and emphasize the clinical and cardiovascular effects. We review γ-aminobutyric acid agonists such as etomidate, benzodiazepines, and propofol, the centrally acting α₂-agonist dexmedetomidine, and the N-methyl-D-aspartate receptor antagonist ketamine. Additionally, we outline the use of opioids and their role in potentiating other sedatives. We note that some sedatives are associated with increased delirium rates, and emphasize that judicious strategies minimizing sedative use are associated with decreases in morbidity and mortality. We also discuss standardized sedation assessment scales and highlight the importance of sedation weaning. Finally, we offer recommendations for sedation use during therapeutic hypothermia, and discuss the use of adjuvant neuromuscular blocking agents.