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.

Development and validation of a nomogram for predicting difficult radial artery cannulation in adult surgical patients.

Background: Radial artery cannulation is an invasive procedure commonly performed in patients in the perioperative time, in the intensive care unit, and in other critical care settings. The current study aimed to explore the preoperative risk factors associated with difficult radial artery cannulation and develop a nomogram model for adult patients undergoing major surgery. This nomogram may optimize preoperative clinical decision-making, thereby reducing the number of puncture attempts and preventing associated complications. Methods: This was a single-center prospective cohort study. Between December 2021 and May 2022, 530 adult surgical patients were enrolled. The patients were randomized into the training and validation cohorts at a ratio of 8:2. Radial artery cannulation was performed before the induction of anesthesia. Univariate and multivariate logistic regression analyses were performed to identify variables that were significantly associated with difficult radial artery cannulation. These variables were then incorporated into the nomogram. The discrimination and calibration abilities of the nomogram were assessed. Results: One hundred and seventy-three (41.7 %) patients in the training cohort had difficult radial artery cannulation. Based on multivariate analysis, the independent risk factors were wrist circumference, anatomical abnormalities, BMI <18.5 kg/m2, grade II hypertension, hypotension, and history of chemotherapy and stroke. The concordance indices were 0.765 (95 % confidence interval [CI]: 0.719-0.812) and 0.808 (95 % CI: 0.725-0.890) in the training and validation cohorts, respectively. The calibration curve showed good agreement between the actual and predicted risks. Conclusions: A preoperative predictive model for difficult radial artery cannulation in adult patients undergoing surgery was developed and validated. This model can provide reliable data for optimizing preoperative clinical decision-making.

Application of Dexmedetomidine as an Opioid Substitute in Opioid-Free Anesthesia: A Systematic Review and Meta-analysis.

BACKGROUND: Opioid-based general anesthesia was previously used to alleviate perioperative pain; however, several complications associated with using anesthesia have raised several concerns. Various studies have investigated the application prospect of using opioid-free general anesthesia, such as dexmedetomidine, as an opioid substitute. OBJECTIVES: We performed a systematic review and meta-analysis to explore and highlight the safety and effectiveness of dexmedetomidine as an opioid substitute for opioid-free anesthesia. STUDY DESIGN: A systematic review and meta-analysis. SETTING: We screened for suitable clinical trials from electronic databases, including "PubMed," "Cochrane Library," "EMBASE," and "Web of Science." Eligible trials were included in this meta-analysis. METHODS: The quality of the screened randomized controlled trials (RCTs) was determined using the risk of bias assessment criteria by the Cochrane Collaboration tool. We used the "Review Manager 5.3" and "Stata 10.0" software to perform the meta-analysis. We evaluated the quality of evidence using the "Grading of Recommendations Assessment, Development, and Evaluation" approach. RESULTS: For the analysis, we included 32 RCTs encompassing 2,509 patients. In the opioid-free group, the 2-hour postoperative pain score of patients (mean difference = -0.53, 95% CI: -1.00, -0.07; P = 0.02, I2=78%) was significantly lower compared to those in the opioid-based group. In addition, several patients required rescue analgesia (risk ratio = 0.70, 95% CI: 0.58, 0.84, P < 0.05, I2 = 71%) and opioids postsurgery. However, the duration of extubation and postanesthesia care unit, as well as the incidences of bradycardia, were high in patients receiving dexmedetomidine as opioid-free general anesthesia. LIMITATIONS: Subgroup analysis for different anesthesia-maintaining drugs had not been conducted. The heterogeneity did not reduce after subgroup analysis. Different doses of dexmedetomidine had not been evaluated. CONCLUSIONS: These findings indicate that opioid-free general anesthesia based on dexmedetomidine could be effective; however, prolonged extubation time and cardiovascular complications are a few risks associated with dexmedetomidine.

Prophylactic effect of exogenous melatonin and melatonin receptor agonists on postoperative delirium in elderly patients: a systemic review and meta-analysis of randomized controlled trials.

BACKGROUND: The prophylactic effect of exogenous melatonin and melatonin receptor agonists (MMRAs) on postoperative delirium (POD) in elderly patients remains controversial. OBJECTIVE: This study aimed to assess the prophylactic effect of MMRAs on POD by conducting a systemic review and meta-analysis of randomized controlled trials (RCTs). METHODS: We systematically searched four electronic databases including PubMed, Web of Science, Cochrane Library, and Embase for the eligible studies up to February 28, 2023. The Cochrane risk of bias tool was used for assessing the risk of bias in the included RCTs. The occurrence of POD was the primary outcome. The quality of evidence was evaluated by Grading of Recommendations Assessment, Development, and Evaluation. RESULTS: A total of 11 RCTs comprising patients (MMRA group: 777 patients and placebo group: 781 patients) were included. The results of the meta-analysis showed that the MMRA group had a lower occurrence of POD than the placebo group (risk ratio = 0.70, 95% confidence interval: 0.51-0.97, P < 0.05, I2 = 59%). The subgroup analysis showed that melatonin significantly reduced the occurrence of POD (moderate-quality evidence), whereas ramelteon and tryptophan had no significant impact (moderate-quality evidence). CONCLUSION: Existing evidence suggested that perioperative use of melatonin can prevent POD in elderly patients.

Postoperative Analgesic Effects of Serratus Anterior Plane Block for Thoracic and Breast Surgery: A Meta-analysis of Randomized Controlled Trials.

BACKGROUND: Postoperative pain is a concern after thoracic and breast surgeries. Recent studies have demonstrated that ultrasound-guided serratus anterior plane block (SAPB) could provide postoperative analgesia. OBJECTIVE: The objective of this systematic review and meta-analysis was to examine the effects of SAPB on postoperative analgesia in thoracic and breast surgery. STUDY DESIGN: A systematic review and meta-analysis of randomized control trials (RCTs). METHODS: We systematically queried the PubMed, Embase, Web of Science, and Cochrane Library online databases from their establishment through Mar 31, 2022. Eligible RCTs were selected for the purpose of conducting the meta-analysis. The risk of bias of the included trials was assessed by Cochrane Review Manager. The level of certainty was examined utilizing the GRADE (Grade of Recommendations Assessment, Development, and Evaluation) scale to determine whether the evidence was of high quality or not. RESULTS: During the process of the meta-analysis, a total of 27 pieces of literature was included in the present research. SAPB significantly reduced the intraoperative opioid consumption (mean difference [MD] = -9.52 mg of morphine equivalent, 95% CI, -15.50 to -3.54; P < 0.01, I2 = 98%) and postoperative pain opioid consumption (MD = -23.12 mg of morphine equivalent, 95% CI, -30.59 to -15.65; P < 0.01, I2 = 100%. Also, patients in the SAPB group had lower pain scores during the first postoperative 24 hours. Furthermore, SAPB attenuated the occurrence of postsurgical nausea and vomiting, as well as chronic postsurgical pain. LIMITATIONS: Double-blinding was not performed in some trials, also some assessors were not blinded; the included sample sizes of eligible trials which reported the incidence of chronic postsurgical pain were relatively small; the comparisons between SAPB and other types of blocks were not performed in our meta-analysis. CONCLUSION: Our findings suggest that SAPB not only relieves acute pain after thoracic and breast surgery, but also reduces the incidence of chronic postsurgical pain.

Ondansetron Reduces the Incidence of Hypotension after Spinal Anaesthesia: A Systematic Review and Meta-Analysis.

Hypotension induced by spinal anaesthesia is a common clinical complication associated with multiple perioperative adverse events. We conducted a systemic review and meta-analysis to confirm whether ondansetron could alleviate hypotension following spinal anaesthesia. PubMed, Embase, Web of Science, and Cochrane Library were searched to identify eligible randomised controlled trials from their respective database inception dates to 30 September 2022. The primary outcome of the meta-analysis was the incidence of hypotension after spinal anaesthesia. The risk of bias in the included studies was evaluated using the revised Cochrane risk of bias tool for randomised trials (RoB 2.0). Grading of Recommendations, Assessment, Development, and Evaluation was applied to assess the level of certainty. A total of 25 studies were included in this research. The meta-analysis revealed that ondansetron significantly decreased the incidence of hypotension (RR = 0.65, 95% CI 0.53−0.80, p < 0.01, I2 = 64%) and bradycardia. In addition, patients treated with ondansetron had a reduced need for vasopressors administration. This study suggests that ondansetron may be recommended as a prophylaxis for hypotension and bradycardia following spinal anaesthesia; the level of evidence was moderate with a high level of heterogeneity.

The efficacy of Shenghua Decoction supplementation after early medical abortion: A meta-analysis of randomized controlled trials.

AIMS: Shenghua Decoction (SHD) is a well-known classic herbal formula documented in traditional Chinese medicine (TCM) that has been widely applied during the postpartum period in Chinese communities for several years. We conducted this systematic review and meta-analysis to explore the influence of SHD as an adjuvant treatment for early medical abortion using a combination of mifepristone followed by misoprostol. METHODS: This systematic review and meta-analysis was reported using 2020 PRISMA guidelines. Eight databases were searched from their establishment to February 28, 2022, for randomized controlled trials (RCTs): PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure, the Chinese BioMedical database, the Chinese Scientific Journal Database, and the Wanfang database. The Grading of Recommendations Assessment, Development, and Evaluation estimated the quality of evidence. RESULTS: Sixteen RCTs involving 3016 patients were included in the meta-analysis. Overall, compared with no treatment as the control group after early medical abortion, patients treated with SHD were associated with a higher complete abortion rate (RR: 1.14; 95% CI: 1.10 - 1.18; P < 0.01, I2 = 26%, moderate quality), lower incomplete abortion rate (RR: 0.31; 95% CI: 0.24 - 0.41; P < 0.01, I2 = 0%, moderate quality), and lower viable pregnancy rate (RR: 0.26; 95% CI: 0.11 - 0.62; P < 0.01, I2 = 0%, moderate quality). Additionally, SHD supplementation was associated with reduced the induction-abortion time, duration of vaginal bleeding and menstrual recovery time. CONCLUSION: Our findings suggest that SHD supplementation may be beneficial for women seeking a medical abortion before the 7-week gestational period and no adverse events in the experimental group were reported. However, the methodological quality of the included RCTs was unsatisfactory, and therefore it is necessary to further verify the effectiveness of SHD using standardized studies of rigorous design.

The effect of magnesium sulfate on emergence agitation in children undergoing general anesthesia: A systematic review and meta-analysis.

STUDY OBJECTIVE: Emergence agitation (EA) is a common complication in pediatric patients after general anesthesia. The effectiveness of magnesium sulfate in decreasing the incidence of EA in children remains controversial. Therefore, a systematic review and meta-analysis was performed to assess the efficacy of magnesium sulfate in preventing EA in pediatric patients following general anesthesia. DESIGN: Systematic review and meta-analysis. SETTING: PubMed, Embase, Web of Science, and Cochrane Library were searched to identify eligible randomized controlled trials from their respective database inception dates to June 30, 2021. PATIENTS: Pediatric patients (< 18 years old) undergoing general anesthesia. INTERVENTIONS: Intravenous administration of magnesium sulfate. MEASUREMENTS: The primary outcome of the meta-analysis was EA incidence. The risk of bias of the included studies was evaluated using the revised Cochrane risk of bias tool for randomized trials (RoB 2.0). Grading of Recommendations, Assessment, Development, and Evaluation was applied to assess the level of certainty. MAIN RESULTS: Eight studies with 635 participants were identified. The forest plot revealed no significant difference in the incidence of EA between patients treated with magnesium sulfate and the control group (risk ratio = 0.69, 95% confidence interval [0.44, 1.07]; P = 0.10, I2 = 74%, moderate level of certainty). Additionally, magnesium sulfate did not reduce postoperative pediatric anesthesia emergence delirium scores but prolonged the emergence time. No significant differences were observed in postoperative complications (nausea, vomiting, laryngospasm, breath-holding, coughing, oxygen desaturation, and cardiac arrhythmias). CONCLUSIONS: Administration of magnesium sulfate during general anesthesia did not affect the occurrence of EA in pediatric patients. However, magnesium sulfate can prolong the emergence time without adverse effects. PROSPERO registration number: CRD42021252924.

Application of controlled low central venous pressure during hepatectomy: A systematic review and meta-analysis.

STUDY OBJECTIVE: Previous studies reported that controlled low central venous pressure (CVP) can reduce blood loss during liver resection. This systematic review and meta-analysis sought to explore the efficacy and safety of low CVP in patients undergoing hepatectomy. DESIGN: A systematic review and meta-analysis of randomized controlled trials (RCTs). REVIEW METHODS: RCTs were searched in PubMed, Embase, Web of Science, Cochrane Library, China National Knowledge Infrastructure, Chinese BioMedical database, Chinese Scientific Journals Database, and Wanfang database from inception to April 30, 2021. Subgroup analyses were performed based on different surgical methods (open hepatectomy vs laparoscopic hepatectomy) and published countries (China vs other countries). The quality of evidence was assessed by Grading of Recommendations, Assessment, Development, and Evaluation. MAIN RESULTS: Eighteen RCTs containing 1285 participants (626 patients in the low CVP group and 659 patients in the control group) were included in this study. The forest plot showed that low CVP effectively reduced blood loss during liver resection compared with the control group (MD = -311.92 mL, 95% CI [-429.03, -194.81]; P < 0.001, I2 = 96%). Furthermore, blood transfusion volume (MD = -158.85 mL, 95% CI [-218.30, -99.40]; P < 0.001, I2 = 55%) and the number of patients requiring transfusion (RR 0.41, 95% CI 0.27-0.65, P < 0.001, I2 = 0%) were decreased in the low CVP group. Subgroup analyses showed similar results. Notably, the alanine transaminase level was significantly lower in the low CVP group during the first five postoperative days. However, no significant differences were observed for other postoperative liver function indicators (aspartate aminotransferase, total bilirubin, serum albumin, and prothrombin time), renal function indicators (blood urea nitrogen and serum creatinine) and perfusion parameters (heart rate, mean arterial pressure, and urine volume). The incidence of complications was similar between the two groups. CONCLUSION: The findings of this study showed that low CVP is effective and safe during hepatectomy. Therefore, this technique is recommended to reduce blood loss during hepatectomy. PROSPERO registration number: CRD42021232829.

Postoperative Analgesic Efficacy of Erector Spinae Plane Block in Patients Undergoing Lumbar Spinal Surgery: A Systematic Review and Meta-Analysis.

Lumbar spine surgery is one of the most widespread types of surgery for treating back and leg pain. However, the postoperative period always presents with severe pain due to the removal of skin, subcutaneous tissues, bones, and ligaments. Patients usually require high doses of opioids to relieve pain during the initial three days after operation, as well as experience drug-related complications and prolonged length of stay in hospital. We found that Erector spinae plane block significantly reduced postoperative opioid consumption and pain scores. The present systematic review revealed that ESPB was effective and safe for postoperative analgesia.

Analgesic effects of erector spinae plane block for patients after breast surgery: a systematic review and meta-analysis.

OBJECTIVE: This meta-analysis investigated the analgesic effects of erector spinae plane block (ESPB) in patients undergoing breast surgery. METHODS: PubMed, Embase, Web of Science, and the Cochrane Library were searched from database establishment to January 31, 2020. Two reviewers independently extracted the data. The primary outcomes were pain scores and opioid consumption during the first 24 hours after surgery. The risk of bias of the included studies was assessed according to the Cochrane Handbook. RESULTS: Six randomized controlled trials of 415 patients were included. Compared with the control value, the pain score was significantly lower in the ESPB group at different time points postoperatively. Patients who underwent ESPB required lower opioid consumption (standardized mean difference = -2.02, 95% confidence interval [CI] = -2.85 to -1.20, I2= 91%. The rates of postoperative nausea (risk ratio [RR] = 0.79, 95% CI = 0.48-1.30, I2 = 47%) and postoperative vomiting (RR = 0.76, 95% CI = 0.30-1.96, I2 = 33%) did not differ between the groups. The quality of evidence was low or very low. CONCLUSIONS: ESPB significantly alleviated pain and reduced opioid consumption after breast surgery. Further research is needed to expand its clinical application.PROSPERO registration number CRD42020167900.

5-HT3 receptor antagonists for the prevention of perioperative shivering undergoing spinal anaesthesia: a systematic review and meta-analysis of randomised controlled trials.

OBJECTIVE: Perioperative shivering (POS) is a common complication in patients undergoing spinal anaesthesia. The present study investigated the efficacy of 5-HT3 receptor antagonists in preventing POS following spinal anaesthesia. DESIGN: Systematic review and meta-analysis. DATA SOURCES: Pubmed, Embase, the Web of Science and Cochrane Library were searched from database establishment on 31 July 2019. ELIGIBILITY CRITERIA: Randomised controlled trials that reported the effects of 5-HT3 receptor antagonists in the prevention of POS in patients after spinal anaesthesia. DATA EXTRACTION AND SYNTHESIS: Two reviewers independently extracted data. The primary outcome of the present study was the incidence of POS. The risk of bias for the included studies was assessed according to the Cochrane Handbook. The quality of primary outcome was evaluated by Grading of Recommendations Assessment, Development and Evaluation. Trial sequential analysis for the primary outcome was performed to reduce the type 1 error caused by repeated meta-analysis and the required information size was calculated. RESULTS: A total of 13 randomised controlled trials consisting of 1139 patients were included. The overall incidence of POS was significantly lower in the 5-HT3 receptor antagonists group (risk ratio 0.31; 95% CI 0.26 to 0.38; p<0.01; I2=0%). Subgroup analysis for different types of 5-HT3 receptor antagonists and timing of administration produced similar results. Also, patients had a lower incidence of postoperative nausea and vomiting after administrating 5-HT3 receptor antagonists. No statistically significant differences in drug-related adverse effects were observed. Grading of Recommendations Assessment, Development and Evaluation revealed a high level of evidence. The cumulative z-curve crossed the trial sequential monitoring boundary. CONCLUSIONS: The present study revealed that prophylactic 5-HT3 receptor antagonists were an effective measure for reducing the incidence of POS in patients after spinal anaesthesia. However, further studies investigating the different types of surgeries are required. PROSPERO REGISTRATION NUMBER: CRD42019148191.

The Efficacy of Traditional Chinese Medicine Shoutai Pill Combined with Western Medicine in the First Trimester of Pregnancy in Women with Unexplained Recurrent Spontaneous Abortion: A Systematic Review and Meta-Analysis.

BACKGROUND: Shoutai Pill (STP), a famous classic herbal formula documented in traditional Chinese medicine (TCM), is widely available in China for treating unexplained recurrent spontaneous abortion (URSA). This systematic review and meta-analysis aims at evaluating the efficacy and safety of STP in the first trimester of pregnancy in women with a history of unexplained recurrent spontaneous abortion. METHODS: The following eight databases were searched from their establishment to Dec 31, 2019, for randomized controlled trials (RCTs): PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), the Chinese BioMedical database (CBM), Chinese Scientific Journal Database (VIP), and the Wanfang database. The quality of evidence was estimated by the Grading of Recommendations Assessment, Development, and Evaluation (GRADE). RESULTS: A total of 12 studies (916 patients) with URSA were contained in this meta-analysis. The forest plot showed that patients treated with Shoutai Pill and western medicine had a significantly lower incidence of early pregnancy loss (RR: 0.42; 95% CI: 0.34-0.52; P < 0.01, I 2 = 0%). Subgroup analysis revealed that different types of TCM syndrome differentiation had the similar results. Also, in the combined group, patients had a lower TCM syndromes and symptoms and serum D-dimer level, while higher incidence of live birth. CONCLUSIONS: Our findings suggest that cotreatment with STP and western medicine might be superior to western medicine alone in the first trimester of pregnancy to prevent miscarriage in women with unexplained recurrent spontaneous abortion, and there was no adverse event in the experimental group reported. However, the methodological quality of included RCTs was unsatisfactory; it is necessary to verify its effectiveness with further more standardized researches of rigorous design.

Efficacy of Traditional Chinese Medicine Tonifying Kidney (Bushen) and Activating Blood (Huoxue) Prescription for Premature Ovarian Insufficiency: A Systematic Review and Meta-Analysis.

OBJECTIVE: We carried out this systematic review and meta-analysis to evaluate the effectiveness of TKABP on POI. METHODS: The following eight databases were searched from the establishment to September 30, 2019, for randomized controlled trials (RCTs): PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), the Chinese BioMedical database (CBM), Chinese Scientific Journal Database (VIP), and the Wanfang database. The quality of evidence was estimated by the Grading of Recommendations Assessment, Development, and Evaluation (GRADE). RESULTS: Twenty-three RCTs involving 1712 patients with POI were included. Compared to hormone therapy (HT) groups, TKABP groups showed a significantly higher total effective rate (RR: 1.10; 95% CI: 1.04-1.17; P < 0.01, I 2 = 32%). In addition, TKABP groups revealed a better improvement in terms of serum follicle-stimulating hormone (FSH) levels, serum estradiol (E2) levels, peak systolic velocity (PSV) of ovarian stromal blood, and Kupperman index (KI) score. However, serum luteinizing hormone (LH) levels and ovarian volume (OV) showed no significant statistical difference. Subgroup analyses showed that herbal paste and 3 months of treatment duration had a greater effect on the improvement of hormone levels. Besides, the occurrence of related adverse events in TKABP groups was lower than that in HT groups. CONCLUSIONS: Our review suggests that TKABP appears to be an effective and safe measure for patients with POI, and the herbal paste may be superior. However, the methodological quality of included RCTs was unsatisfactory, and it is necessary to verify its effectiveness with furthermore standardized researches of rigorous design.

Dexmedetomidine as an adjuvant for single spinal anesthesia in patients undergoing cesarean section: a system review and meta-analysis.

OBJECTIVE: Previous studies reported the effect of dexmedetomidine on intrathecal anesthesia. In this review, we explored the impact of dexmedetomidine as an adjunct for lumbar anesthesia in patients undergoing cesarean section. METHODS: Two authors searched eligible random controlled trials in electronic databases, including PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure, the Chinese BioMedical database, Chinese Scientific Journal Database, and the Wanfang database. RESULTS: Ten trials comprising 970 patients were included in this review. Intrathecal dexmedetomidine significantly reduced the onset time of sensory block (standardized mean difference (SMD), -1.50, 95% confidence interval (CI) -2.15, -0.85, I2 = 92%) and motor block (SMD -0.77, 95% CI -1.50, -0.49, I2 = 60%) and prolonged the block duration time (sensory block: SMD 2.02, 95% CI 1.29, 2.74, I2 = 93%; motor block: SMD 1.90, 95% CI 1.07, 2.74, I2 = 94%). Patients who received dexmedetomidine showed a lower incidence of shivering. No significant difference was reported for the neonatal Apgar score and other complications. CONCLUSION: The use of intrathecal dexmedetomidine during cesarean section can shorten the onset time of spinal anesthesia and enhance the effect of local anesthetic. It has no significant impact on neonates and there were no other adverse events.

Dexmedetomidine in the prevention of postoperative delirium in elderly patients following non-cardiac surgery: A systematic review and meta-analysis.

The efficacy of dexmedetomidine in the prevention of postoperative delirium (POD) remains ambiguous, however, it has been used to reduce the incidence of delirium in elderly patients. Here, we conducted a meta-analysis study for assessing the effects of dexmedetomidine on POD among elderly patients following non-cardiac surgery. A systematic literature search was performed against the PubMed, EMBASE, Cochrane Library, and Web of Science databases, and all relevant literature published till November 30, 2019, were considered. Our analysis included 16 randomised controlled trials conducted with 4534 patients for exploring the effects of dexmedetomidine on POD in elderly patients following non-cardiac surgery. It was observed that the overall incidence of POD was significantly lower in the dexmedetomidine group than in the control group (risk ratio [RR] 0.51, 95% confidence interval [CI] 0.43-0.61, P < .01). Similar results were obtained from subgroup analysis upon comparison of the placebo (RR 0.52, 95% CI 0.41-0.66, P < .01, moderate quality of evidence), propofol-treated (RR 0.55, 95% CI 0.38-0.78, P < .01, low quality of evidence), and midazolam-treated (RR 0.38, 95% CI 0.20-0.71, P < .01, low quality of evidence) groups. Trial sequential analysis revealed that the cumulative z-value superseded the monitoring boundary and reached the required information size. However, patients who received dexmedetomidine had a higher incidence of bradycardia and hypotension. In conclusion, the meta-analysis revealed that dexmedetomidine appears to decrease the risk of POD in elderly patients following non-cardiac surgery. However, as some of the studies were heterogeneous and of low quality, high-quality trials are necessary for drawing more definitive conclusions.