Foetal responses to dexmedetomidine in parturients undergoing caesarean section: a systematic review and meta-analysis

Effectiveness of intrathecal dexmedetomidine vs fentanyl as additives to hyperbaric bupivacaine for postoperative analgesia in women undergoing cesarean section: a systematic review protocol

OBJECTIVE

The aim of this review is to compare the effectiveness of intrathecal dexmedetomidine vs fentanyl as additives to hyperbaric bupivacaine in providing postoperative analgesia in patients undergoing cesarean section.

INTRODUCTION

Pain following cesarean section remains a challenge, with limited treatment options due to potential undesirable parturient and neonatal side effects. Intrathecal dexmedetomidine has emerged as a favorable alternative to opioid additives to hyperbaric bupivacaine in prolonging postoperative analgesia, but its effectiveness requires further investigation.

INCLUSION CRITERIA

The review will evaluate studies of patients who underwent cesarean section under spinal anesthesia where dexmedetomidine and fentanyl were compared as intrathecal additives to hyperbaric bupivacaine for postoperative analgesia. This review will consider randomized controlled trials, non-randomized controlled trials, and prospective cohort studies for inclusion. No limits regarding publication date or language will be applied.

METHODS

A preliminary search of PubMed and Cochrane Central Register of Controlled Trials has been conducted to identify relevant index terms and keywords, which will be applied in a second search across PubMed, Cochrane CENTRAL, Scopus, and Embase. Google Scholar, National Library of Medicine (Clinicaltrials.gov), and the World Health Organization International Clinical Trial Registry Platform will be searched to identify unpublished literature. Full-text studies will be subjected to an assessment of methodological quality, and data extraction will be performed independently by 2 reviewers. The results will be presented in both tabular and narrative format and, where possible, pooled into a meta-analysis. A Grading of Recommendations, Assessment, Development and Evaluation (GRADE) Summary of Findings will be created to grade the certainty of evidence of the reported outcomes.

REVIEW REGISTRATION

PROSPERO CRD42022364815.

Effect of dexmedetomidine on oxytocin-induced uterine contraction during optimal caesarean section anaesthesia

Numerous drugs are used during caesarean sections to provide regional and general anaesthesia. Dexmedetomidine has been used in some recent obstetric trials, but there are concerns about postpartum changes in uterine contractions. This study evaluated the effect of dexmedetomidine on oxytocin-induced uterine contractions in women undergoing caesarean section. Sixty women undergoing caesarean section in Lianyungang Second People's Hospital were randomly assigned to dexmedetomidine (group D, n = 30) or saline (group C, n = 30) groups. Equal volumes of saline or dexmedetomidine were administered intravenously (IV). During the intraoperative delivery of the foetus and placenta, oxytocin was administered to promote contractions. Heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP) were compared. The Ramsay scale was used to assess sedation, while the Tsai and Chu methods assessed shivering. Adverse intraoperative events were observed. All variables fluctuated significantly after anaesthesia onset in both groups but were most pronounced in group D. The VAS, Ramsay and shivering scores were significantly lower in group D compared to group C. During rapid IV infusion of oxytocin after foetal delivery, the incidence of nausea, vomiting, chest tightness and hypotension was significantly lower in group D than in group C.

Possibility to use quanadex (dexmedetomidine) for caesarean section in patients with pre-eclampsia

A prospective, double­blind, randomized, con­trolled clinical trial was conducted at the Republican Spe­cialized Scientific and Practical Medical Center of Obstet­rics and Gynecology of the Ministry of Health of the Repub­lic of Uzbekistan. The inclusion criteria for pregnant wom­en in the study was preeclampsia. All women were divided into 2 groups. In group I, premedication was performed on the table with sibazon 5 mg. In group II, starting from the moment of premedication, 0.5 µg/kg of quanadex (Yuriya Pharm) was administered intravenously for 15 minutes. The maintaining dose was 0.5–0.8 µg/kg/h. 0.5 % hyper­baric longocaine heavy was administered intrathecally at the LII–LIV level. Hemodynamics was assessed by echocardi­ography. BAC and electrolytes, lactate, glucose, hematocrit were studied on a gas analyzer “BGA­102” Wondfo (Rain Sen Da), NTproBNP, Cystatin­C, interleukin­6 and protein S­100 were determined on an immunofluorescence ana­lyzer Finecare™ FIA MeterPlus/FS 113 (Wonfo), sedation was assessed using the Richmond scale. Newborns were assessed for Apgar scores in the 1st and 5th minutes.The data obtained showed that patients randomized to the group with dexmedetomidine (Group II) were almost al­ways better able to awaken than patients in the group with sibazon, and were distinguished by better hemodynamic stability, antinociceptive protection for surgical and anes­thetic intervention, without pronounced arterial hypoten­sion and bradycardia. It did not cause significant adverse outcomes in newborns.

Intravenous Dexmedetomidine as an Adjunct to Neuraxial Anesthesia in Cesarean Delivery: A Retrospective Chart Review

Background

Dexmedetomidine is a selective α-2 agonist commonly used for sedation that has been used in obstetric anesthesia for multimodal labor analgesia, postcesarean delivery analgesia, and perioperative shivering. This study evaluated the role of intravenous dexmedetomidine to provide rescue analgesia and/or sedation during cesarean delivery under neuraxial anesthesia.

Methods

We conducted a single-center, retrospective cohort study of all parturients undergoing cesarean delivery under neuraxial anesthesia between December 1, 2018, and November 30, 2019, who required supplemental analgesia during the procedure. Patients were divided into two groups: patients who received intravenous dexmedetomidine (Dexmed group) and patients who received adjunct medications such as fentanyl, midazolam, ketamine, and nitrous oxide (Standard group). Primary outcome was incidence of conversion to general anesthesia.

Results

During the study period, 107 patients received adjunct medications. There was no difference in conversion to general anesthesia between the Dexmed group and the Standard group (6% (4/62) vs. 9% (4/45); p=0.718). In the Dexmed group, the mean dexmedetomidine dose received was 37 μg (range 10 to 140 μg). While the use of inotropic/vasopressor medications was common and similar in both groups, there was an increase in the incidence of bradycardia (Dexmed 15% vs. Standard 2%; p=0.042) but not hypotension (Dexmed 24% vs. Standard 24%; p=1.00) in the Dexmed group.

Conclusion

In patients who required supplemental analgesia for cesarean delivery, those who received dexmedetomidine versus other medications had a similar rate of conversion to general anesthesia, a statistically significant increase in bradycardia, but no difference in the incidence of hypotension.

Effect of intravenous dexmedetomidine and remifentanil on neonatal outcomes after caesarean section under general anaesthesia: A systematic review and meta-analysis

BACKGROUND

Various strategies have been used to mitigate haemodynamic instability during general anaesthesia for caesarean section. However, the safety of these strategies for neonates remains controversial.

OBJECTIVE

To investigate the effects of intravenous dexmedetomidine and remifentanil on neonatal outcomes during caesarean section under general anaesthesia.

DESIGN

Systematic review and meta-analysis of randomised controlled trials.

DATA SOURCES

Databases of PubMed, EMBASE and CENTRAL were searched until March 2020 and updated in February 2021.

ELIGIBILITY CRITERIA

Randomised controlled trials were included if they compared dexmedetomidine and remifentanil infusion on neonatal outcomes after elective caesarean section under general anaesthesia. Primary outcomes were 1 and 5 min Apgar scores. Secondary outcomes were the incidence of neonatal mask ventilation or endotracheal intubation, and pH of the umbilical artery and vein. Studies that did not report primary outcomes were excluded.

RESULTS

Five studies with 258 patients in total were included. The Apgar score at 1 min in the remifentanil group was lower than that in the dexmedetomidine group for both quantitative [weighted mean difference (WMD): 0.75; 95% CI, 0.44 to 1.07; τ2 = 0.00] and categorical outcomes (≥Apgar 7 vs.

CONCLUSION

In our study, Apgar score at 1 min reported using both quantitative and categorical variables were lower in the remifentanil group than in the dexmedetomidine group but TSA showed that these differences were inconclusive for categorical variables. Data for other outcomes were scarce and did not allow any conclusions to be drawn. Thus, further studies with larger numbers of parturients and with neonatal outcomes as a primary endpoint are warranted to clarify the effects of intravenous dexmedetomidine and remifentanil.

TRIAL REGISTRATION

The protocol of this study has been registered in PROSPERO (CRD42019141102).

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MESH Headings

• Anesthesia, General/adverse effects
• Cesarean Section
• Dexmedetomidine/adverse effects
• Female
• Humans
• Infant, Newborn
• Piperidines/adverse effects
• Pregnancy
• Remifentanil

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Affiliation(s)

Myeongjong Lee From the Department of Anesthesiology and Pain Medicine (ML), Research Institute of Medical Science, Konkuk University School of Medicine, Chungju (ML), Department of Anesthesiology and Pain Medicine, Asan Medical Center, University of Ulsan College of Medicine, Songpa-gu, Seoul (HK), Department of Anesthesiology and Pain Medicine, Wonkwang University School of Medicine, Muwang-ro, Iksan (CL) and Department of Anesthesiology and Pain Medicine, Chung-Ang University College of Medicine, Heukseok-ro, Dongjak-gu, Seoul, Republic of Korea (HK)
Hyungtae Kim
Cheol Lee
Hyun Kang

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Intrathecal dexmedetomidine and postoperative pain: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND OBJECTIVE

A systematic review and meta-analysis of randomized controlled trials (RCTs) was undertaken to evaluate the effect of intrathecal dexmedetomidine (DEX) on the duration of postoperative analgesia, postoperative pain scores and incidences of adverse effects.

DATABASES AND DATA TREATMENT

Database search was performed from inception until January 2019. All RCTs analysing acute postoperative pain characteristics after intrathecal DEX administration in adults undergoing spinal anaesthesia for elective surgery were included. The primary outcome was postoperative analgesic duration, defined as the time to first analgesic request. The secondary outcomes included pain scores at 6, 12 and 24 postoperative hours and rates of hypotension, bradycardia, shivering and postoperative nausea and vomiting.

RESULTS

Twenty-four studies comprising a total of 1,460 patients were included. Postoperative analgesic duration was prolonged with intrathecal DEX compared to placebo, with a pooled mean difference (MD) of 191.3 min (95% CI 168.8-213.8). Patients who received intrathecal DEX reported lower Visual Analogue Scale scores at 24 postoperative hours compared with those patients receiving placebo, with a MD (95% CI) of -1.05 (-1.89 to -0.20, p = 0.02). There were no differences in the incidence of adverse effects, except for a lower rate of postoperative shivering in the intrathecal DEX group (pooled relative risk 0.58, 95% CI 0.34-0.98, p = 0.04).

CONCLUSIONS

Compared to placebo, intrathecal DEX prolonged postoperative analgesic duration, reduced 24-hr pain intensity and reduced the incidence of shivering without an increase in other adverse effects.

SIGNIFICANCE

The analgesic role of intrathecal DEX is promising due to its ability to significantly increase postoperative analgesic duration when compared with placebo. Its usage can be considered for patients undergoing surgeries with significant postoperative pain, particularly those intolerant of systemic analgesia. However, the optimal dose for various surgeries as well as its long-term neurological effects warrants further studies.

Fetal and Maternal Responses to Dexmedetomidine Intrathecal Application During Cesarean Section: A Meta-Analysis

Background

Intrathecal dexmedetomidine (DEX) can improve the blockade of spinal anesthesia, but there is no clear conclusion on whether it has an effect on the fetus during cesarean section. Our meta-analysis evaluated the safety and efficacy of intrathecal DEX in cesarean delivery.

Material/Methods

We searched Cochrane, Embase, PubMed, and CBM for eligible studies, and used the Revised Cochrane Risk of Bias Tool (RoB 2.0) to assess the risk of bias of each study. RevMan was used for statistical analyses. We have registered this meta-analysis on PROSPERO (CRD42019120995).

Results

The meta-analysis included 10 RCTs, but only 5 were prospectively registered. The results of preregistration studies, including the 1- or 5-min Apgar score (mean difference [MD], −0.03; 95% confidence intervals [CI], −0.16 to 0.10; P=0.64 or MD, 0.00; 95% CI, −0.09 to 0.09; P=1), the umbilical arterial oxygen or carbon dioxide partial pressure (MD, 0.90; 95% CI, −4.92 to 6.72; P=0.76 or MD, 1.20; 95% CI, −2.06 to 4.46; P=0.47), and the cord blood pH (MD, −0.01; 95% CI, −0.05 to 0.03; P=0.72), showed that intrathecal DEX had no significant difference in neonatal outcomes compared with placebo. In maternal outcomes, intrathecal DEX significantly prolonged postoperative pain-free period and reduced the incidence of postoperative shivering, which did not increase spinal anesthesia-associated adverse effects.

Conclusions

Intrathecal DEX is safe for the fetus during cesarean section and can improve the blockade effects of spinal anesthesia on puerperae.

Effectiveness and safety of intravenous application of dexmedetomidine for cesarean section under general anesthesia: a meta-analysis of randomized trials

Objective

The meta-analysis was conducted to assess the effectiveness and safety of intravenous administration of dexmedetomidine for cesarean section under general anesthesia, as well as neonatal outcomes.

Materials and methods

We searched PubMed, Embase, Cochrane Central Register of Controlled Trials and the China National Knowledge Infrastructure database for relevant randomized controlled trials (RCTs) about the application of intravenous dexmedetomidine under general anesthesia for cesarean section. RevMan 5.3 was used to conduct the meta-analysis of the outcomes of interest.

Results

Eight RCTs involved 376 participants were included in this study. The meta-analysis showed that the mean blood pressure at the time of intubation (weighted mean difference [WMD]: -15.67, 95% CI: -21.21, -10.13, P<0.00001), skin incision (WMD: -12.83, 95% CI -20.53, -5.14, P=0.001), and delivery (WMD: -11.65, 95% CI -17.18, -6.13, P<0.0001) in dexmedetomidine group were significantly lower than that in the control group. The heart rate (HR) at the time of intubation (WMD: -31.41, 95% CI -35.01, -27.81, P<0.00001), skin incision (WMD: -22.32, 95% CI -34.55, -10.10, P=0.0003), and delivery (WMD: -19.07, 95% CI -22.09, -16.04, P<0.00001) were also lower than that in control group. For neonatal parameters, no differences existed in umbilical blood gases at delivery, and Apgar scores at 1 minute (WMD: -0.12, 95% CI -0.37, 0.12, P=0.33) and 5 minutes (WMD: -0.17, 95% CI -0.13, 0.46, P=0.27) among two groups.

Conclusion

Intravenous administration of dexmedetomidine could efficiently attenuate the maternal cardiovascular response during cesarean section, without affecting Apgar score of the neonate.