Meta-analysis of randomised controlled trials of perioperative dexmedetomidine to reduce delirium and mortality after cardiac surgery

Effect of perioperative dexmedetomidine on sleep quality in adult patients after noncardiac surgery: A systematic review and meta-analysis of randomized trials

BACKGROUND

Dexmedetomidine may improve sleep quality after surgery, but conflicting results also exist. Herein, we explored the effects of perioperative dexmedetomidine on postoperative sleep quality in adult patients.

METHODS

In this systematic review and meta-analysis, randomized controlled trials investigating the effects of perioperative dexmedetomidine on sleep quality after noncardiac surgery were retrieved from Cochrane Library, PubMed, and EMBASE from inception to January 12, 2023, and updated on March 15, 2024. The Cochrane Collaboration's tool was applied to assess risk of bias. A random-effects model was used for meta-analysis. The primary outcome was the subjective sleep quality score on the first night after surgery.

RESULTS

A total of 29 trials containing 5610 participants were included. The subjective sleep score on the first postoperative night was lower (better) with dexmedetomidine than with placebo (SMD [standardized mean difference] = -0.8, 95% CI -1.1 to -0.6, p<0.00001; I2 = 93%; 22 trials; n = 4611). Sensitivity analysis showed that overall conclusion was not changed (SMD = -0.8, 95% CI -1.1 to -0.5, p<0.00001; I2 = 93%; 14 trials; n = 3846). Results of polysomnographic monitoring showed improved sleep structure with dexmedetomidine on the first night after surgery, as manifested by increased sleep efficiency index and stage N2 sleep and decreased arousal index and stage N1 sleep.

CONCLUSIONS

This systematic review suggests that, among patients who underwent noncardiac surgery, perioperative dexmedetomidine administration may improve early postoperative sleep quality pattern. However, the resulting evidence were of low or very low qualities and further studies are required to confirm our results.

PROSPERO REGISTRATION NUMBER

CRD42023390972.

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.

Dexmedetomidine improves pulmonary outcomes in thoracic surgery under one-lung ventilation: A meta-analysis

INTRODUCTION

Dexmedetomidine improves intrapulmonary shunt in thoracic surgery and minimizes inflammatory response during one-lung ventilation (OLV). However, it is unclear whether such benefits translate into less postoperative pulmonary complications (PPCs). Our objective was to determine the impact of dexmedetomidine on the incidence of PPCs after thoracic surgery.

METHODS

Major databases were used to identify randomized trials that compared dexmedetomidine versus placebo during thoracic surgery in terms of PPCs. Our primary outcome was atelectasis within 7 days after surgery. Other specific PPCs included hypoxemia, pneumonia, and acute respiratory distress syndrome (ARDS). Secondary outcome included intraoperative respiratory mechanics (respiratory compliance [Cdyn]) and postoperative lung function (forced expiratory volume [FEV1]). Random effects models were used to estimate odds ratios (OR).

RESULTS

Twelve randomized trials, including 365 patients in the dexmedetomidine group and 359 in the placebo group, were analyzed in this meta-analysis. Patients in the dexmedetomidine group were less likely to develop postoperative atelectasis (2.3% vs 6.8%, OR 0.42, 95%CI 0.18-0.95, P = 0.04; low certainty) and hypoxemia (3.4% vs 11.7%, OR 0.26, 95%CI 0.10-0.68, P = 0.01; moderate certainty) compared to the placebo group. The incidence of postoperative pneumonia (3.2% vs 5.8%, OR 0.57, 95%CI 0.25-1.26, P = 0.17; moderate certainty) or ARDS (0.9% vs 3.5%, OR 0.39, 95%CI 0.07-2.08, P = 0.27; moderate certainty) was comparable between groups. Both intraoperative Cdyn and postoperative FEV1 were higher among patients that received dexmedetomidine with a mean difference of 4.42 mL/cmH2O (95%CI 3.13-5.72) and 0.27 L (95%CI 0.12-0.41), respectively.

CONCLUSION

Dexmedetomidine administration during thoracic surgery may potentially reduce the risk of postoperative atelectasis and hypoxemia. However, current evidence is insufficient to demonstrate an effect on pneumonia or ARDS.

Prevention of post-operative delirium using an overnight infusion of dexmedetomidine in patients undergoing cardiac surgery: a pragmatic, randomized, double-blind, placebo-controlled trial

BACKGROUND

After cardiac surgery, post-operative delirium (PoD) is acknowledged to have a significant negative impact on patient outcome. To date, there is no valuable and specific treatment for PoD. Critically ill patients often suffer from poor sleep condition. There is an association between delirium and sleep quality after cardiac surgery. This study aimed to establish whether promoting sleep using an overnight infusion of dexmedetomidine reduces the incidence of delirium after cardiac surgery.

METHODS

Randomized, pragmatic, multicentre, double-blind, placebo controlled trial from January 2019 to July 2021. All adult patients aged 65 years or older requiring elective cardiac surgery were randomly assigned 1:1 either to the dexmedetomidine group or the placebo group on the day of surgery. Dexmedetomidine or matched placebo infusion was started the night after surgery from 8 pm to 8 am and administered every night while the patient remained in ICU, or for a maximum of 7 days. Primary outcome was the occurrence of postoperative delirium (PoD) within the 7 days after surgery.

RESULTS

A total of 348 patients provided informed consent, of whom 333 were randomized: 331 patients underwent surgery and were analysed (165 assigned to dexmedetomidine and 166 assigned to placebo). The incidence of PoD was not significantly different between the two groups (12.6% vs. 12.4%, p = 0.97). Patients treated with dexmedetomidine had significantly more hypotensive events (7.3% vs 0.6%; p < 0.01). At 3 months, functional outcomes (Short-form 36, Cognitive failure questionnaire, PCL-5) were comparable between the two groups.

CONCLUSION

In patients recovering from an elective cardiac surgery, an overnight infusion of dexmedetomidine did not decrease postoperative delirium. Trial registration This trial was registered on ClinicalTrials.gov (number: NCT03477344; date: 26th March 2018).

Prophylactic dexmedetomidine use did not decrease the incidence of delirium in patients undergoing cardiac surgery: A meta-analysis

OBJECTIVE

The benefits of prophylactic dexmedetomidine use in patients undergoing cardiac surgery remain controversial. The aim of this meta-analysis was to investigate the short-term clinical outcomes of dexmedetomidine use versus non-dexmedetomidine use.

METHODS

Systematic searches using PubMed, Embase, and the Cochrane Library were carried out for English articles published from inception to 23 September 2021. This was followed by a meta-analysis investigating delirium, the length of delirium, mortality, bradycardia, hypotension, the length of intensive care unit (ICU) and hospital stay, and the duration of mechanical ventilation.

RESULTS

Ten randomized controlled trials (RCTs) totaling 2550 patients were included. In the dexmedetomidine group incidence of delirium was 13.5%, compared with 16.1% in the control group. The risk ratio (RR) for the comparison was 0.69 (95% CI, 0.47 - 1.00; p = .052). In addition, there were no differences in mortality (RR, 0.56; 95% CI, 0.27 - 1.14; p = .109), the incidence of bradycardia (RR, 1.20; 95% CI, 0.91 - 1.57; p = .201), the incidence of hypotension (RR, 0.90; 95% CI, 0.57 - 1.44; p = .674), and the length of delirium mean difference (MD, -0.99; 95% CI, -2.20 to 0.21; p = .106). However, prophylactic dexmedetomidine use significantly reduced the duration of mechanical ventilation (MD, -2.03; 95% CI, -3.35 to -0.70; p = .003), length of ICU stay (MD, -3.17; 95% CI, -5.10 to -1.24; p = .001), and length of hospital stay (MD, -1.76; 95% CI, -2.88 to -0.66; p = .002).

CONCLUSIONS

Prophylactic dexmedetomidine use did not decrease the incidence of delirium in patients undergoing cardiac surgery, but significantly reduced the duration of mechanical ventilation, length of ICU stay, and length of hospital stay.

Effects of Glucocorticoids on Postoperative Neurocognitive Disorders in Adult Patients: A Systematic Review and Meta-Analysis

Background

Postoperative neurocognitive disorders (PNDs) is common among surgical patients, however, the effect of glucocorticoids for preventing PNDs is not clear. This review aims to evaluate the effect of glucocorticoids on the incidence of PNDs in adult patients undergoing surgery.

Methods

The databases of PubMed/Medline, Embase, the Cochrane Library, and Web of science were searched for all available randomized controlled trials (RCTs) from inception to April 30, 2022. RCTs comparing the effect of glucocorticoids with placebo on the incidence of PNDs in adult surgical patients (≥18 years old) were eligible. Subgroup analyses and meta-regressions were performed to evaluate sources of clinical heterogeneity. The level of certainty for main outcomes were assessed by the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology.

Results

Eleven trials with a total of 10,703 patients were identified. Compared with the control group, glucocorticoids did not reduce the incidence of PNDs (RR: 0.84, 95% CI: 0.67 to 1.06, P = 0.13, GRADE = moderate). Secondary analyses for primary outcome did not change the result. In addition, the length of ICU stay was decreased in glucocorticoids group (RR: −13.58, 95% CI: −26.37 to −0.80, P = 0.04, GRADE = low). However, there were no significant differences between groups with regards to the incidence of postoperative infection (RR: 0.94, 95% CI: 0.84 to 1.06, P = 0.30, GRADE = moderate), blood glucose level (RR: 1.05, 95% CI: −0.09 to 2.19, P = 0.07, GRADE = low), duration of mechanical ventilation (RR: −2.44, 95% CI: −5.47 to 0.59, P = 0.14, GRADE = low), length of hospital stay (RR: −0.09, 95% CI: −0.27 to 0.09, P = 0.33, GRADE = moderate) and 30-day mortality (RR: 0.86, 95% CI: 0.70 to 1.06, P = 0.16, GRADE = moderate).

Conclusions

This meta-analysis suggests that perioperative administration of glucocorticoids may not reduce the incidence of PNDs after surgery. The effect of glucocorticoids on decreased length of ICU stay needs further researches. Future high-quality trials using acknowledged criteria and validated diagnostic tools are needed to determine the influence of glucocorticoids on long-term PNDs.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022302262, identifier: CRD42022302262.

Alpha-2-adrenergic receptor agonists for the prevention of delirium and cognitive decline after open heart surgery (ALPHA2PREVENT): protocol for a multicentre randomised controlled trial

INTRODUCTION

Postoperative delirium is common in older cardiac surgery patients and associated with negative short-term and long-term outcomes. The alpha-2-adrenergic receptor agonist dexmedetomidine shows promise as prophylaxis and treatment for delirium in intensive care units (ICU) and postoperative settings. Clonidine has similar pharmacological properties and can be administered both parenterally and orally. We aim to study whether repurposing of clonidine can represent a novel treatment option for delirium, and the possible effects of dexmedetomidine and clonidine on long-term cognitive trajectories, motor activity patterns and biomarkers of neuronal injury, and whether these effects are associated with frailty status.

METHODS AND ANALYSIS

This five-centre, double-blind randomised controlled trial will include 900 cardiac surgery patients aged 70+ years. Participants will be randomised 1:1:1 to dexmedetomidine or clonidine or placebo. The study drug will be given as a continuous intravenous infusion from the start of cardiopulmonary bypass, at a rate of 0.4 µg/kg/hour. The infusion rate will be decreased to 0.2 µg/kg/hour postoperatively and be continued until discharge from the ICU or 24 hours postoperatively, whichever happens first.Primary end point is the 7-day cumulative incidence of postoperative delirium (Diagnostic and Statistical Manual of Mental Disorders, fifth edition). Secondary end points include the composite end point of coma, delirium or death, in addition to delirium severity and motor activity patterns, levels of circulating biomarkers of neuronal injury, cognitive function and frailty status 1 and 6 months after surgery.

ETHICS AND DISSEMINATION

This trial is approved by the Regional Committee for Ethics in Medical Research in Norway (South-East Norway) and by the Norwegian Medicines Agency. Dissemination plans include publication in peer-reviewed medical journals and presentation at scientific meetings.

TRIAL REGISTRATION NUMBER

NCT05029050.

Impact of perioperative inflammation on days alive and at home after surgery

Background

Perioperative inflammation is associated with perioperative complications, including delirium, that are associated with a reduced number of postoperative days alive and at home at 90 days (DAH90). We tested whether inflammation was associated with DAH90 even when adjusting for perioperative factors, and whether inflammation independently was associated with DAH90 when adjusting for delirium.

Methods

We conducted a prospective cohort study of major, non-intracranial surgical patients who were older than 65 yr (n=134). We measured postoperative delirium incidence and severity, and changes in interleukin (IL)-8 and IL-10 in blood plasma. Our primary outcome, DAH90, was analysed using quantile regression.

Results

Before adjusting for delirium, a postoperative day 1 increased IL-8 was associated with fewer DAH90 at the 0.75 quantile (β=-0.082; 95% confidence interval [CI], -0.19 to -0.006) after adjusting for demographic (age and sex) and perioperative factors (cardiovascular surgery, National Surgical Quality Improvement Program risk of death, and operative time). IL-10 was similarly associated with DAH90 at the 0.5 (β=-0.026; 95% CI, -0.19 to -0.001) and 0.75 (β= -0.035; 95% CI, -0.07 to -0.006) quantiles. Neither cytokine was significantly associated with DAH90 once delirium and baseline Trail Making Test B were added to the models.

Conclusions

Perioperative inflammation predicts DAH90, but when delirium is added to the model inflammation loses significance as a predictor, whereas delirium is significant. Targeting perioperative inflammation may reduce delirium and moderate hospital readmission and mortality.

Clinical trial registration

NCT03124303.