Dexmedetomidine versus midazolam as adjuvants to intrathecal bupivacaine: A clinical comparison

The effect of perioperative benzodiazepine administration on postoperative nausea and vomiting: a systematic review and meta-analysis of randomised controlled trials

BACKGROUND

Despite recent systematic reviews suggesting their benefit for postoperative nausea, vomiting, or both (PONV) prevention, benzodiazepines have not been incorporated into guidelines for PONV prophylaxis because of concerns about possible adverse effects. We conducted an updated meta-analysis to inform future practice guidelines.

METHODS

We included randomised controlled trials (RCTs) of all languages comparing benzodiazepines with non-benzodiazepine comparators in adults undergoing inpatient surgery. Our outcomes were postoperative nausea, vomiting, or both. We assessed risk of bias for RCTs using the Cochrane Risk of Bias tool. We pooled data using a random-effects model and assessed the quality of evidence for each outcome using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach.

RESULTS

We screened 31 413 abstracts and 950 full texts. We included 119 RCTs; 104 were included in quantitative synthesis. Based on moderate certainty evidence, we found that perioperative benzodiazepine administration reduced the incidence of PONV (52 studies, n=5086, relative risk [RR]: 0.77, 95% confidence interval [CI] 0.66-0.89; number needed to treat [NNT] 16; moderate certainty), postoperative nausea (55 studies, n=5916, RR: 0.72, 95% CI 0.62-0.83; NNT 21; moderate certainty), and postoperative vomiting (52 studies, n=5909, RR: 0.74, 95% CI 0.60-0.91; NNT 55; moderate certainty).

CONCLUSIONS

Moderate quality evidence shows that perioperative benzodiazepine administration decreases the incidence of PONV. The results of this systematic review and meta-analysis will inform future clinical practice guidelines.

SYSTEMATIC REVIEW PROTOCOL

The protocol for this systematic review was pre-registered with PROSPERO International Prospective Register of Systematic Reviews (CRD42022361088) and published in BMJ Open (PMID 31831540).

Evaluation of bacterial leakage and marginal adaptation of the bioceramics pulp dressing materials: an invitro study

OBJECTIVE

To compare the sealing ability and marginal adaptation of three calcium silicate-based cement (Biodentine, Pro root MTA, MTA Angelus) using a bacterial leakage model and scanning electron microscope (SEM).

METHODS

Recently extracted lower first premolars were randomly categorized into three experimental groups (n = 15 samples), positive control (n = 5 samples), and negative control group (n = 5 sample). Samples from the experimental groups and positive control group were subject to cavity Class I occlusal preparation followed by modified coronal pulpotomy. Different types of bioceramic dressing material were placed in 3 mm thickness accordingly, group 1 (Biodentine), group 2 (MTA Angelus), and group 3 (ProRoot MTA). No dressing material was placed in the positive control group (group 4). All samples were placed in the incubator for 24 h at 37℃, 100% humidity, for the materials to be completely set. The final restoration was placed using the Z350 resin composite. A double layer of nail varnish was applied over all the sample surfaces except the occlusal site. Whereas the samples' surfaces in the negative control, were completely covered. A 3 mm length was measured from the root apex of the samples from each group, before proceeding with the resection. The bacterial leakage test was performed using Enterococcus faecalis TCC 23,125, and a sample from each experimental group was randomly chosen for SEM. Data analysis was conducted under the One-way ANOVA test, completed by Tukey's post hoc test.

RESULTS

There is a significant difference in sealing ability and marginal adaptation between the groups. (p < 0.05). The study showed that Pro Root MTA had the superior sealing ability and marginal adaptation compared to Biodentine and MTA Angelus.

CONCLUSION

The ProRoot MTA as a coronal pulpotomy pulp dressing material, was found to have a better marginal adaptation and sealing ability compared to three other bioceramics materials. The material would be the better choice during clinical settings and procedures.

Spinal or Intravenous Dexmedetomidine for Spinal Anesthesia with Chloroprocaine in Ambulatory Knee Arthroscopies: A Double-Blind Randomized Trial

Purpose

Chloroprocaine provides spinal anesthesia for day-case surgery lasting up to 40 minutes. Intravenous and spinal dexmedetomidine can prolong spinal anesthesia, but no data are available for the combination with chloroprocaine. This double-blind randomized controlled trial compares chloroprocaine with spinal or intravenous dexmedetomidine regarding block characteristics, micturition, and discharge times.

Patients and Methods

After ethical approval and informed consent, 135 patients scheduled for knee arthroscopy were randomized to receive either 40mg spinal chloroprocaine (Chloro-group), 40mg chloroprocaine with 5 mcg spinal dexmedetomidine (Spinal Dex-group) or 40mg chloroprocaine with 0.5 mcg/kg IV dexmedetomidine (IV DEXgroup). Block characteristics, hemodynamic variables and the use of analgesics were registered. Voiding and discharge times were noted. A scoring system was used for micturition problems and sedation. Transient neurological symptoms (TNS) and other late side effects were evaluated after one week.

Results

Demographic data were similar between groups. Block onset times and intensity of motor block were comparable between groups. The time to L2 and Bromage 1 regression was prolonged in the SpinalDEx-group by approximately 30 minutes compared to the other groups (p < 0.01). First voiding as well as discharge from the hospital was prolonged in the Spinal Dex-group by approximately 40 minutes p < 0.01. There was no significant difference between groups regarding treatment of hypotension, sedation, micturition problems or the use of postoperative analgesics (P > 0.8). One patient experienced TNS.

Conclusion

Intrathecal but not intravenous (0.5 mcg/kg) dexmedetomidine can prolong chloroprocaine (40mg) spinal anesthesia when surgery is expected to last over 40 minutes. Despite a similar incidence of adverse effects, this also led to a postponed hospital discharge time.

Dexmedetomidine as an Analgesic Agent with Neuroprotective Properties: Experimental and Clinical Aspects

Dexmedetomidine (Dexdor or Precedex®) is considered as a sedative agent which is widely used as an adjuvant in general anesthesia and critical care practice. There is extensive evidence indicating its neuroprotective properties especially in various ischemic and hemorrhagic brain injury models of animals. Clinical trials have shown that dexmedetomidine (DEX) can improve the outcome of intensive care unit (ICU) patients. Also, DEX is appropriate as a non-opioid analgesic therapy whenever minimizing opioid-related side effects is necessary. The present article reviews the recent advances in the use of DEX as a neuroprotective agent in both animal and human studies including newest findings about the mechanism of the drug as well as analgesic efficacy of this drug at all perioperative stages. In spite of the beneficial effects of the drug on the nervous system, there are potential adverse effects, such as hypotension and bradycardia, which can be treated pharmacologically and must be taken into consideration by clinicians.

Combination of sufentanil, dexmedetomidine and ropivacaine to improve epidural labor analgesia effect: A randomized controlled trial

Opioids and α2-agonists have been used as epidural adjuvants in local anesthetics for a long time, but the effect of the combination of opioids and α2-agonists as epidural adjuvants is not completely understood. In the present study, the combination of dexmedetomidine (Dex) and sufentanil as adjuvants to ropivacaine for epidural labor analgesia was investigated. A total of 108 parturient women receiving labor epidural analgesia were randomly divided into three groups: i) Group RD received 0.1% ropivacaine + 0.5 µg/ml Dex; ii) Group RS received 0.1% ropivacaine + 0.5 µg/ml sufentanil; and iv) Group RDS received 0.1% ropivacaine + 0.25 µg/ml Dex + 0.25 µg/ml sufentanil. Patients received a 10 ml loading dose followed by a maintenance by patient controlled epidural analgesia. The visual analog scale scores, onset time, local anesthetic requirements, motor blockage and adverse effects were recorded. Group RDS displayed an improved labor analgesia effect compared with Groups RD and RS. Group RDS displayed a shorter onset time compared with Groups RD and RS, and a reduced local anesthetic requirement compared with Group RS. The motor blockage in Groups RDS and RS was significantly lower compared with Group RD, and the incidence of pruritus in Groups RDS and RD was lower compared with Group RS. In conclusion, the combined use of 0.25 µg/ml Dex and 0.25 µg/ml sufentanil as adjuvants to 0.1% ropivacaine for epidural labor analgesia displayed an improved analgesia effect compared with the use of either 0.5 µg/ml sufentanil or 0.5 µg/ml Dex alone. The present study was registered with the Chinese Clinical Trial Registry Center on 23 February, 2018 (registration no. ChiCTR-IOR-1800014943).

Effect of 5-μg Dose of Dexmedetomidine in Combination With Intrathecal Bupivacaine on Spinal Anesthesia: A Systematic Review and Meta-analysis

PURPOSE

Intrathecal dexmedetomidine (DEX) has been used to improve the quality and duration of spinal anesthesia. The aim of this meta-analysis is to evaluate whether intrathecal DEX could prolong the duration of sensory and motor block during spinal anesthesia.

METHODS

We searched PubMed, EMBASE, Web of Science, and the Cochrane Library for randomized controlled trials that investigated the facilitatory effects of intrathecal administration of DEX compared with those of a placebo on spinal anesthesia from inception to April 2019. Sensory and motor block durations, sensory and motor block onset times, time to first analgesic request, and DEX-related adverse effects were evaluated. Results were combined using fixed-effects or random effects modeling when appropriate.

FINDINGS

A total of 1478 patients from 25 clinical studies were included in the analysis. Compared with placebo, intrathecal DEX significantly prolonged the durations of both sensory block (weighted mean difference [WMD] = 134.42 min; 95% CI, 109.71-159.13 min; P < 0.001) and motor block (WMD = 114.27 min; 95% CI, 93.18-135.35 min; P < 0.001). It also hastened the onset of sensory block (WMD = -0.80 min; 95% CI, -1.21 to -0.40; P < 0.001) and motor block (WMD = -1.03 min; 95% CI, -1.51 to -0.56 min; P < 0.001). Furthermore, it delayed the time to first analgesic request (WMD = 216.90 min; 95% CI, 178.90-254.90 min; P < 0.001) and reduced the incidence of shivering (risk ratio [RR] = 0.39; 95% CI, 0.27-0.55; P < 0.001). DEX was associated with increased risk of transient bradycardia (RR = 1.59; 95% CI, 1.07-2.37; P = 0.022) and hypotension (RR = 1.40; 95% CI, 1.04-1.89; P = 0.026) but did not increase the incidence of postoperative nausea and vomiting (RR = 0.87; 95% CI, 0.62-1.24; P = 0.45).

IMPLICATIONS

Intrathecal DEX can prolong the duration of sensory block, the duration of motor block, and the time to first analgesic request associated with spinal anesthesia.

Comparison of the ED50 of intrathecal hyperbaric ropivacaine co-administered with or without intrathecal dexmedetomidine for cesarean section: A prospective, double-blinded, randomized dose-response trial using up-down sequential allocation method

STUDY OBJECTIVE

Studies have showed that intrathecal dexmedetomidine as supplements to local anesthetics can improve the quality of the spinal anesthesia and reduce the local anesthetic requirement of spinal anesthesia for cesarean section. However, the magnitude of this effect has not been fully quantified. Therefore, we conducted the present study to investigate the ED₅₀ of intrathecal hyperbaric ropivacaine with or without dexmedetomidine for cesarean section in healthy parturients. ED₅₀ values obtained were compared to estimate the effect of intrathecal dexmedetomidine versus placebo on ropivacaine requirement.

DESIGN

Single-blinded, prospective, randomized study.

SETTING

Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine.

PATIENTS

Sixty healthy parturients under elective cesarean section with combined spinal-epidural anesthesia were randomized into Group C (intrathecal ropivacaine alone) and Group D (intrathecal ropivacaine + 5 μg dexmedetomidine).

INTERVENTIONS

The dose of intrathecal ropivacaine for the first parturient in both groups was 11 mg. An increment or decrement of 0.5 mg intrathecal ropivacaine was made for the subsequent parturient based on the effective or ineffective response of the previous parturient. Effective dose was defined as a bilateral T6 or above sensory block level was achieved within 15 min after induce of spinal anesthesia and no additional epidural anesthetics was required during surgery. The Dixon and Massay sequential method and Probit regression were applied to calculate the ED₅₀ of intrathecal ropivacaine in both groups.

MEASUREMENTS

Characteristics of spinal anesthesia and side effects were recorded.

MAIN RESULTS

The ED₅₀ of hyperbaric ropivacaine calculated by Dixon and Massay formula was 11.4 mg (95% CI, 11.1-11.7 mg) in Group C, and 9.4 mg (95% CI, 9.0-9.7 mg) in Group D (P < 0.05). While using the Probit regression, the ED₅₀ of intrathecal hyperbaric ropivacaine was 11.1 mg (95% CI, 10.7-11.6 mg) in Group C, and 9.1 mg (95% CI, 8.6-9.5 mg) in Group D. Shivering was less observed in Group D than in Group C (P < 0.05). There was no significant difference in the onset time of sensory block or motor block, the incidence of hypotension, bradycardia, nausea and vomiting, sedation and pruritus between the two groups.

CONCLUSION

Under the conditions of the present study, intrathecal dexmedetomidine (5 μg) reduced the ED₅₀ of intrathecal hyperbaric ropivacaine by approximately 18% for cesarean section in healthy parturients under combined spinal-epidural anesthesia.

Fentanyl vs fentanyl-dexmedetomidine in lumbar foraminotomy surgery

Aim

Lumbar foraminotomy surgery requires a potent opioid with short duration and rapid onset of action. In the present study we intended to compare the efficacy of fentanyl alone vs the combination of dexmedetomidine and fentanyl during lumbar foraminotomy surgery.

Methods

The duration and requirements for first postoperative analgesics, hemodynamic stability, and respective side effects were studied. A prospective, randomized, double blind study of 40 patients (fentanyl group [Fen group] and fentanyl-dexmedetomidine group [Fen-Dex group], n=20 each) scheduled for lumbar foraminotomy surgery under pharmaceutical care intervention was carried out. Patients were classified as class I or II, according to the American Society of Anesthesiologists physical status classification. Patients received intraoperative propofol, sevoflurane, atracurium, and either fentanyl loading dose of 1.0 μg/kg and maintenance infusion dose of 0.2 μg/kg/h in both groups. The patients of the Fen group received normal saline (0.9%) placebo, while the patients of the Fen-Dex group received dexmedetomidine infusion (0.5 μg/kg/h) along with the fentanyl infusion. Postoperative morphine doses were given. Hemodynamic stability, pain, postoperative analgesia requirement, side effects of drugs, and other effects were monitored.

Results

In the Fen-Dex group, the pain score was significantly less than in the Fen group (p<0.05). The time to first postoperative analgesia request was prolonged in the Fen-Dex group compared to the Fen group. On the other hand, requirement of morphine, and postoperative symptoms and episodes of nausea and vomiting were significantly greater in the Fen group than in the Fen-Dex group (p<0.05).

Conclusion

The present study suggests the addition of dexmedetomidine during lumbar foraminotomy surgery at different levels would be beneficial to reduce morphine consumption and any adverse drug reaction.

Comparison of dexmedetomidine and fentanyl as local anesthetic adjuvants in spinal anesthesia: a systematic review and meta-analysis of randomized controlled trials

Purpose

To compare the effects of dexmedetomidine (Dex) and fentanyl as adjuvants to local anesthetics in spinal anesthesia.

Methods

Two researchers independently searched the PUBMED, EMBASE, Cochrane library, and CBM for randomized controlled trials comparing the effects of Dex and fentanyl as adjuvants to local anesthetics for intrathecal injection.

Results

A total of 639 patients from nine studies were included in this meta-analysis. The results showed that Dex resulted in statistically significant longer duration of stable sensory block (mean difference [MD] =27.12; 95% confidence interval [CI] [9.89, 44.34], P<0.01, I²=97%), sensory block (standardized mean difference [SMD] =3.81; 95% CI [2.35, 5.27], P<0.01, I²=97%), motor block (SMD =3.64; 95% CI [2.19, 5.08], P<0.01, I²=97%), and pain free period (SMD =2.98; 95% CI [1.69, 4.27], P<0.01, I²=96%); reducing the incidence of pruritus (relative risk [RR] =0.15; 95% CI [0.06, 0.39], P<0.01, I²=0%) compared with fentanyl. However, the onset of sensory and motor block, the time to peak sensory level, and the incidence of hypotension and bradycardia, and the side effects (nausea, vomiting, shivering and respiratory depression) were not significantly different between Dex and fentanyl.

Conclusion

Compared to fentanyl, Dex as local anesthetics adjuvant in spinal anesthesia prolonged the duration of spinal anesthesia, improved postoperative analgesia, reduced the incidence of pruritus, and did not increase the incidence of hypotension and bradycardia.

Dexmedetomidine in perioperative acute pain management: a non-opioid adjuvant analgesic

Many nociceptive, inflammatory, and neuropathic pathways contribute to perioperative pain. Although opioids have long been a mainstay for perioperative analgesia, other non-opioid therapies, and dexmedetomidine, in particular, have been increasingly used as part of a multimodal analgesic regimen to provide improved pain control while minimizing opioid-related side effects. This article reviews the evidence supporting the preoperative, intraoperative, and postoperative efficacy of dexmedetomidine as an adjuvant, and the efficacy of intravenous, spinal canal, and nerve block analgesia with dexmedetomidine for perioperative acute pain treatment. While there have not been any large-scale clinical trials conducted, the current body of evidence suggests that dexmedetomidine is suitable for use as an adjuvant analgesic at all perioperative stages. However, there are potential adverse effects, such as hypotension and bradycardia, which must be taken into consideration by clinicians.

Efficacy and Safety of Dexmedetomidine as an Adjuvant in Epidural Analgesia and Anesthesia: A Systematic Review and Meta-analysis of Randomized Controlled Trials

BACKGROUND AND OBJECTIVE

Several clinical trials have examined and indicated the usefulness of epidural dexmedetomidine therapy. However, there has been no systematic analysis of the findings of these trials to date. We undertook this systematic review and meta-analysis to investigate the efficacy and safety of epidural dexmedetomidine adjunctive therapy in different surgical procedures.

MATERIALS AND METHODS

We searched EMBASE, PubMed, the Cochrane Library, and the Clinical Trials.gov database to identify randomized controlled trials investigating the effects of epidural dexmedetomidine adjunctive therapy. The article search was conducted without language or date restrictions. The date of the last search was 27 July 2016. The mean differences (MD) or standardized mean differences (SMD) with 95% confidence intervals (CIs) were calculated for continuous variables, and risk ratios (RRs) were presented for dichotomous outcomes. Heterogeneity was assessed using τ ², χ ² and I ² analyses.

RESULTS

Twelve randomized controlled trials were included in the final analysis. Compared with the control treatment, epidural dexmedetomidine administration prolonged the duration of analgesia (P < 0.0001), reduced the time to sensory block (P = 0.002), decreased the requirement for rescue analgesia (P < 0.00001) and achieved a significantly higher sedation score (P < 0.0001). Although dexmedetomidine adjunctive therapy did not affect mean arterial pressure (P = 0.33), systolic blood pressure (P = 0.32) or diastolic blood pressure (P = 0.28), it significantly lowered heart rate (P = 0.0009). Symptoms indicative of hypotension and bradycardia events were more common in the dexmedetomidine group, but the difference in the overall risk of hypotension and bradycardia was statistically insignificant (P > 0.05) in comparison with that reported for the control therapies. Furthermore, dexmedetomidine effectively reduced post-operative pain (P = 0.03), whilst the occurrence of other side effects, such as pruritus, dizziness, dry mouth, nausea and vomiting did not differ significantly from that reported for the control therapies, except the risk of shivering was significantly higher with control therapies (P = 0.03).

CONCLUSION

This systematic review and meta-analysis demonstrates that dexmedetomidine as an adjuvant in epidural procedures is generally safe and well tolerated. Furthermore, dexmedetomidine acted synergistically and provided an improved sedation and analgesic profile.

Intrathecal Dexmedetomidine Alleviates Shivering during Cesarean Delivery under Spinal Anesthesia

Shivering associated with spinal anesthesia during Cesarean delivery is an uncomfortable experience for the parturient, which may also cause adverse effects. In this prospective, randomized, double-blind, placebo-controlled study, we sought to evaluate the effect of intrathecal dexmedetomidine, administered as an adjunct to hyperbaric bupivacaine for Cesarean delivery, on the incidence and severity of shivering associated with spinal anesthesia. Patients undergoing Cesarean delivery were randomly allocated to three groups of 30 patients each. Experimental treatments were added to hyperbaric bupivacaine as follows: Patients in group I (control) were administered isotonic saline. Patients in groups II and III received dexmedetomidine (2.5, 5 µg, respectively), mixed with isotonic saline. Shivering was observed in 11, 10 and 2 patients in groups I, II and III, respectively. The incidence of shivering in group III was significantly lower than that in groups I (p=0.005) and II (p=0.01). The severity of shivering was significantly different between the three groups (p=0.01). There were no significant inter-group differences with respect to mean arterial pressure and heart rate at any time point after administration of intrathecal local anesthesia (p>0.05). Intrathecal dexmedetomidine (5 µg) administered as an adjunct to hyperbaric bupivacaine during Cesarean delivery significantly reduced the incidence and intensity of shivering associated with spinal anesthesia.