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

Dexmedetomidine improves mitophagy and pyroptosis through the ALKBH5/FUNDC1 axis during epidural-related maternal fever

PURPOSE

Epidural analgesia has emerged as a commonly used method for relieving labor pain. However, epidural-related maternal fever (ERMF) is characterized by a high occurrence rate and can have detrimental consequences for the well-being of both the mother and the fetus. This study aimed to investigate the functional role and underlying mechanism of dexmedetomidine (DEX) in ERMF.

MATERIALS AND METHODS

Ropivacaine (ROP)-induced human umbilical vein endothelial cells (HUVECs) were treated with DEX and/or transfected with ALKBH5 or FUNDC1 overexpression plasmid. qPCR and Western blot were adopted for mitophagy and pyroptosis marker protein detection. Autophagosomes were observed through electron microscopy, Caspase-1/PI double-positive cells were determined using flow cytometry. Inflammation-related factors were quantified using ELISA. The N6-methyladenosine (m6A) modification of FUNDC1 mRNA was examined using methylated RNA immunoprecipitation (MeRIP) and the binding between ALKBH5 and FUNDC1 mRNA was confirmed by RNA immunoprecipitation (RIP).

RESULTS

In ROP-induced HUVECs, there was a significant upregulation in ALKBH5 and FUNDC1, resulting in a notable increase in inflammation, pyroptosis, and mitophagy. The administration of DEX demonstrated the ability to alleviate ROP-induced pyroptosis and promote protective mitophagy. Interestingly, DEX treatment significantly reduced the interaction between ALKBH5 and FUNDC1 mRNA, while simultaneously increasing the m6A level of FUNDC1 mRNA in ROP-treated cells. Moreover, the overexpression of FUNDC1 partially reversed the effects of ALKBH5 overexpression on mitophagy and pyroptosis in HUVECs.

CONCLUSIONS

DEX can promote mitophagy and inhibit pyroptosis through the ALKBH5/FUNDC1 axis in ERMF, indicating its potential as a therapeutic strategy for clinical ERMF treatment.

Effect of epidural dexmedetomidine in single-dose combined with ropivacaine for cesarean section

BACKGROUND

Dexmedetomidine has arousal sedation and analgesic effects. We hypothesize that epidural dexmedetomidine in single-dose combined with ropivacaine improves the experience of parturient undergoing cesarean section under epidural anesthesia. This study is to investigate the effect of 0.5 µg/kg epidural dexmedetomidine combined with epidural anesthesia (EA) in parturients undergoing cesarean section.

METHODS

A total of 92 parturients were randomly divided into Group R (receiveing epidural ropivacaine alone) Group RD (receiveing epidural ropivacaine with 0.5 µg/kg dexmedetomidine). The primary outcome and second outcome will be intraoperative NRS pain scores and Ramsay Sedation Scale.

RESULTS

All 92 parturients were included in the analysis. The NRS were significantly lower in Group RD compared to Group R at all observation timepoint (P > 0.05). Higher Ramsay Sedation Scale was found in Group RD compared to Group R (P < 0.001). No parturient has experienced sedation score of 4 and above. No significant difference regarding the incidence of hypotension, bradycardia and nausea or vomiting, Apgar scores and the overall satisfaction with anesthesia was found between Group R and Group RD (P > 0.05).

CONCLUSION

Epidural dexmedetomidine of 0.5 µg/kg added slightly extra analgesic effect to ropivacaine in EA for cesarean section. The sedation of 0.5 µg/kg epidural dexmedetomidine did not cause mother-baby bonding deficit. Satisfaction with anesthesia wasn't significantly improved by epidural dexmedetomidine of 0.5 µg/kg. No additional side effect allows larger dose of epidural dexmedetomidine attempt.

TRIAL REGISTRATION

This study was registered at www.chictr.org.cn (ChiCTR2000038853).

Comparison of dexmedetomidine and opioids as local anesthetic adjuvants in patient controlled epidural analgesia: a meta-analysis

BACKGROUND

Data on the efficacy and incidence of adverse effects associated with dexmedetomidine (DEX) as a local anesthetic adjuvant for patient-controlled epidural analgesia (PCEA) are inconclusive. This meta-analysis assessed the efficacy and risks of DEX for PCEA using opioids as a reference.

METHODS

Two researchers independently searched PubMed, Embase, Cochrane Library, and China Biology Medicine for randomized controlled trials comparing DEX and opioids as local anesthetic adjuvants in PCEA.

RESULTS

In total, 636 patients from seven studies were included in this meta-analysis. Postoperative patients who received DEX had lower visual analog scale (VAS) scores than those who received opioids at 4-8 h (mean difference [MD]: 0.61, 95% CI [0.45, 0.76], P < 0.001, I2 = 0%), 12 h (MD: 0.85, 95% CI [0.61, 1.09], P < 0.001, I2 = 0%), 24 h (MD: 0.59, 95% CI [0.06, 1.12], P = 0.030, I2 = 82%), and 48 h (MD: 0.54, 95% CI [0.05, 1.02], P = 0.030, I2 = 91%). Additionally, patients who received DEX had a lower incidence of itching (odds ratio [OR]: 2.86, 95% CI [1.18, 6.95], P = 0.020, I2 = 0%) and nausea and vomiting (OR: 6.83, 95% CI [3.63, 12.84], P < 0.001, I2 = 24%). In labor analgesia, no significant differences in neonatal (pH and PaO2 of cord blood, fetal heart rate) or maternal outcomes (duration of labor stage, mode of delivery) were found between the DEX and opioid groups.

CONCLUSIONS

Compared with opioids, using DEX as a local anesthetic adjuvant in PCEA improved postoperative analgesia and reduced the incidence of itching and nausea and vomiting without increasing the incidence of adverse events.

Local Periarticular Infiltration with Dexmedetomidine Results in Superior Patient Well-Being after Total Knee Arthroplasty Compared with Peripheral Nerve Blocks: A Randomized Controlled Clinical Trial with a Follow-Up of Two Years

BACKGROUND

This study aimed to compare local periarticular infiltration (LIA) with ultra-sound guided regional anesthesia (USRA) with ropivacaine and dexmedetomidine as an additive agent in primary total knee arthroplasty (TKA).

METHODS

Fifty patients were randomized into two groups in a 1:1 ratio. Patients in the LIA group received local periarticular infiltration into the knee joint. The USRA group received two single-shot USRA blocks. Functional outcomes and satisfaction (range of movement, Knee Society Knee Score, Western Ontario and McMaster Universities Osteoarthritis Index, Oxford Knee Score, and Forgotten Joint Score), including well-being, were analyzed preoperatively and at five days, six weeks, and one and two years postoperatively.

RESULTS

Functional outcomes did not significantly differ between the two groups at six weeks and one and two years after the implementation of TKA. A moderate correlation was observed in the LIA group regarding well-being and pain on day five. Six weeks postoperatively, the LIA group showed significantly superior well-being but worse pain scores. No differences between the groups in well-being and functional outcomes could be observed one and two years postoperatively.

CONCLUSION

Patients treated with LIA had superior postoperative well-being in the early postoperative phase of up to six weeks. Furthermore, LIA patients had similar functionality compared to patients treated with USRA but experienced significantly more pain six weeks postoperatively. LIA leads to improved short-term well-being, which is potentially beneficial for faster knee recovery. We believe that LIA benefits fast-track knee recovery with respect to improved short-term well-being, higher practicability, and faster application.

The potential value of exosomes as adjuvants for novel biologic local anesthetics

The side effects of anesthetic drugs are a key preoperative concern for anesthesiologists. Anesthetic drugs used for general anesthesia and regional blocks are associated with a potential risk of systemic toxicity. This prompted the use of anesthetic adjuvants to ameliorate these side effects and improve clinical outcomes. However, the adverse effects of anesthetic adjuvants, such as neurotoxicity and gastrointestinal reactions, have raised concerns about their clinical use. Therefore, the development of relatively safe anesthetic adjuvants with fewer side effects is an important area for future anesthetic drug research. Exosomes, which contain multiple vesicles with genetic information, can be released by living cells with regenerative and specific effects. Exosomes released by specific cell types have been found to have similar effects as many local anesthetic adjuvants. Due to their biological activity, carrier efficacy, and ability to repair damaged tissues, exosomes may have a better efficacy and safety profile than the currently used anesthetic adjuvants. In this article, we summarize the contemporary literature about local anesthetic adjuvants and highlight their potential side effects, while discussing the potential of exosomes as novel local anesthetic adjuvant drugs.

Effect of different doses of epidural dexmedetomidine on reducing visceral traction reaction for cesarean section: a double-blind randomized controlled trial

PURPOSE

This study aimed to evaluate the effect of different doses of epidural dexmedetomidine on reducing visceral traction reaction for cesarean section under epidural anesthesia.

METHODS

Nulliparas were randomly allocated to receive epidural ropivacaine alone (group R) or in combination with dexmedetomidine 0.5 μg/kg (group RD0.5), 0.75 μg/kg (group RD0.75), and 1 μg/kg (group RD1) with 46 nulliparas in each group. The primary outcome was intraoperative visceral traction reaction (graded from 0 to 3, with 0 and 3, respectively, regarded as 'no discomfort in stomach or perineum; no nausea, vomiting or intestinal tympanites' and 'serious visceral pain, nausea and vomiting, intestinal tympanites').

RESULTS

Visceral traction reaction was significantly alleviated in group RD0.5, RD0.75, and RD1, respectively, compared to group R while it was comparable among RD groups. Increased Ramsay Sedation Scale and lower incidence of shivering were found in RD groups compared to group R (p < 0.001). None of the primipara has experienced Ramsay Sedation Scale above 4. Higher incidence of thirst was found in group RD0.75 and RD1 compared to group R and RD0.5 (p < 0.001). The Apgar scores at 1 and 5 min of the neonates, onset time to T6 sensory block, maximum sensory block level, the incidence of hypotension, bradycardia and nausea or vomiting were comparable among groups.

CONCLUSION

It is suggested that 0.5 μg/kg epidural dexmedetomidine can be used as adjuvant to epidural ropivacaine during cesarean section, because of its alleviating visceral traction reaction, moderate sedating, and reducing shivering without thirst increase.

Postoperative analgesic effect of dexmedetomidine combined with TPVB applied to open gastrectomy for gastric cancer

OBJECTIVES

This study is aimed to investigate the analgesic effect of combined dexmedetomidine and thoracic paravertebral nerve block (TPVB) on gastric cancer (GC) patients undergoing open gastrectomy.

METHODS

From May 2019 to Nov 2020, a total of 80 GC patients preparing for open gastrectomy were enrolled in our hospital and were divided into the ropivacaine (RO) group and the ropivacaine + dexmedetomidine (RD) group ad libitum. All of the patients underwent TPVB. The characteristics, usage of patient-controlled analgesia (PCA), adverse events, visual analogue scale (VAS) scores, inflammatory cytokines, and T cell subgroups between the two groups were compared.

RESULTS

Patients in the RD group showed the decreased occurrence rate of postoperative adverse events and VAS scores and improved anti-inflammation and immune function. These findings implied that the application of dexmedetomidine in combination with ropivacaine in TPVB has a good postoperative analgesic effect, as well as anti-inflammatory and immune-enhancing effects.

CONCLUSION

Dexmedetomidine as an adjunct analgesic may be potentially applied in clinical practice for GC patients undergoing open gastrectomy.

Postoperative Pain Management in Enhanced Recovery Pathways

Postoperative pain is a common but often inadequately treated condition. Enhanced recovery pathways (ERPs) are increasingly being utilized to standardize perioperative care and improve outcomes. ERPs employ multimodal postoperative pain management strategies that minimize opioid use and promote recovery. While traditional opioid medications continue to play an important role in the treatment of postoperative pain, ERPs also rely on a wide range of non-opioid pharmacologic therapies as well as regional anesthesia techniques to manage pain in the postoperative setting. The evidence for the use of these interventions continues to evolve rapidly given the increasing focus on enhanced postoperative recovery. This article reviews the current evidence and knowledge gaps pertaining to commonly utilized modalities for postoperative pain management in ERPs.

Effect of Epidural Dexmedetomidine as an Adjuvant to Local Anesthetics for Labor Analgesia: A Meta-Analysis of Randomized Controlled Trials

Background

This study aims to determine the analgesic effect and safety of dexmedetomidine as an adjuvant to epidural local anesthetics during labor.

Methods

Randomized controlled trials comparing epidural blocks with or without dexmedetomidine for labor analgesia were comprehensively searched. Review manager 5.4 was used to analyze the extracted data.

Results

Compared with placebo and opioids, dexmedetomidine relieved labor pain of 15 min (P=0.002), 30 min (P=0.01), and 120 min (P=0.02) after block and at the moment of fetal disengagement (P=0.0002), decreased mean arterial pressure of 120 min (P=0.01), heart rate of 30 min (P=0.003), 60 min (P < 0.00001), and 120 min (P < 0.00001) after block, blood loss (P=0.02), and the incidence of nausea/vomiting (P=0.006), and increased the incidence of maternal bradycardia (P=0.04). However, sensitivity analysis only found that the incidence of nausea/vomiting was significantly different. Compared with placebo, dexmedetomidine relieved labor pain of 30 min after block (P < 0.00001) and did not increase the incidences of side effects, but only two studies were enrolled. Compared with opioids, dexmedetomidine decreased the incidence of nausea/vomiting (P=0.002), increased the incidence of maternal bradycardia (P=0.04), and had a similar effect on labor pain relief; however, sensitivity analysis found that significant difference existed only at the incidence of nausea/vomiting. Other outcomes from meta-analysis or subgroup analysis were not different.

Conclusions

Epidural dexmedetomidine has the potential to offer a better analgesic effect than placebo, similar labor pain control to opioids, and has no definite adverse effects on the parturient or fetus, but more high-quality studies are needed to confirm these conclusions.

Effect of dexmedetomidine on hemodynamics in patients undergoing hysterectomy: a meta-analysis and systematic review

Objective

We conducted a meta-analysis and systematic review to evaluate the effects of dexmedetomidine on the hemodynamics of patients undergoing hysterectomy.

Methods

We searched the Medline, Embase, and Cochrane Central Register of Controlled Trials databases for clinical randomized controlled trials (RCTs) that allowed direct or indirect comparisons of hemodynamic indicators. We also searched nine English-language databases up to April 2021 to identify relevant research. The Cochrane risk-of-bias tool for RCTs was applied to assess the methodological quality of the eligible studies. The meta-analysis was conducted using RevMan 5.4 software.

Results

Nine trials were included in this systematic review. The effect of dexmedetomidine on heart rate during surgery was significantly smaller than that of other sedatives. Intraoperative systolic and diastolic blood pressure and mean arterial pressure were more stable in the dexmedetomidine group compared with the control group. The postoperative modified Observer’s Assessment of Alertness Score was also better in the dexmedetomidine compared with the control group.

Conclusions

Dexmedetomidine increases hemodynamic stability in patients undergoing hysterectomy, reduces the cardiovascular stress response during surgery, and effectively prevents postoperative adverse reactions, with good safety.

Effect of Dexmedetomidine on Postoperative Sleep Quality: A Systematic Review

In this article, we conduct a systematic review of the literature to explore the specific role of dexmedetomidine (DEX) on postoperative sleep and its associated mechanisms at present. The electronic database Embase, MEDLINE/PubMed, the Cochrane Library, Web of Science, and Google Scholar were searched. The restriction terms included “dexmedetomidine”, “sleep” and “surgery”. The inclusion criteria were as following: 1) patients 18 years old or older; 2) DEX used in the perioperative period not just for critically ill patients in the intensive care unit (ICU); 3) prospective or retrospective studies. The review articles, conference abstracts, and animal studies were excluded. Out of the 22 articles which met the above criteria, 20 of them were randomized controlled studies and 2 of them were retrospective cohort studies. Infusion of DEX including during the surgery and after surgery at a low or high dose was shown to improve subjective and objective sleep quality, although 2 studies showed there is no evidence that the use of DEX improves sleep quality and 1 showed less sleep efficiency and shorter total sleep time in the DEX group. Other postoperative outcomes evaluated postoperative nausea and vomiting, pain, postoperative delirium bradycardia and hypotension. Outcomes of our systematic review showed that DEX has advantages in improving patients’ postoperative sleep quality. Combined with the use of general anesthetic, DEX provides a reliable choice for procedural sedation.

Dexmedetomidine versus fentanyl as adjuvants to ropivacaine for epidural anaesthesia: A systematic review and meta-analysis

BACKGROUND

Several randomized controlled trials (RCTs) have evaluated the use of dexmedetomidine versus fentanyl as adjuvants to ropivacaine for epidural anaesthesia, yet the results are conflicting. We aimed to conduct this meta-analysis to assess the effects and safety of dexmedetomidine and fentanyl as adjuvants to ropivacaine for epidural anaesthesia.

METHODS

Cochrane Library et al databases were searched from inception to Jan 28, 2020. The synthesised effect sizes were presented as mean difference (MD) or odd of risk (OR) and 95% confidence intervals (95% CI).

RESULTS

Nine RCTs with a total of 672 patients were included. The synthesised results indicated that the mean time to the onset of sensory block (MD: -2.82, 95% CI (-4.84, -0.80)), and the time to maximum motor block (MD: -4.35, 95% CI (-7.31, -1.40)) in dexmedetomidine group was significantly less than that of fentanyl group, while the mean time to rescue analgesia in dexmedetomidine group was significantly increased (MD: 99.13, 95% CI (82.89, 115.37)). The incidence of nausea and vomiting (OR: 0.43, 95% CI (0.29, 0.66)), and shivering (OR: 0.34, 95% CI (0.18, 0.63)) in dexmedetomidine group was significantly reduced, yet the incidence of oral dryness in dexmedetomidine group was significantly increased OR: 5.31, 95% CI (1.69, 16.69)).

CONCLUSIONS

Dexmedetomidine is better than fentanyl as adjuvant to ropivacaine for epidural anaesthesia with better effects and less adverse events.

Comparative study on epidural administration of dexmedetomidine, dexmedetomidine-lidocaine or lidocaine in conscious rabbits

The aim of this study was to compare the cardiorespiratory, arterial blood gas and antinociceptive effects of dexmedetomidine (D), dexmedetomidine-lidocaine (DL) or lidocaine (L) administered epidurally on conscious rabbits. Eight six-month-old male New Zealand rabbits were randomly distributed into three treatments: D (2.5 μg/kg); DL (2.5 μg/kg; 2 mg/kg); and L (2 mg/kg). The drugs were injected epidurally via a catheter. Cardiorespiratory, arterial blood gas and antinociceptive variables were recorded before administration, 5 and 10 min after drug administration, then every 10 min until the animals presented a positive response to nociceptive stimulation of perineal dermatomes. Two animals had permanent paralysis after DL treatment due to hemorrhage and congestion with neuron necrosis in spinal cord segments. There was a reduction in mean arterial pressure in treatment L at 5 and 10 min, compared with the baseline, and in treatment DL at 10-30 min. Increases in pH were observed in treatment D at 5 and 10 min, and in DL at all the times evaluated, compared with the baseline. No alterations were observed in other blood gas or electrolyte variables. Antinociceptive effects were evaluated in the perineal, sacral and lumbar regions, and were restricted to the perineal region following D and L treatment. The antinociceptive effects following DL were greater than D and L alone in all of the regions. L and D promotes short-term antinociceptive effects for up to 15 min and, when used in combination with D, increased the duration and extent of sensory block by up to 45 min.

Effects of different epidural initiation volumes on postoperative analgesia in cesarean section

Background/aim

The aim of this study was to compare the effects of different epidural initiation volumes on postoperative pain scores, analgesic requirements, and side effects in pregnant women administered patient-controlled epidural analgesia (PCEA) for postoperative pain after cesarean sections.

Materials and methods

Eighty-one pregnant women, aged 18–45 years, were included in this randomized, double-blind study. Combined spinal epidural anesthesia was administered for each cesarean section. The patients were divided into 3 groups and different volumes (20 mL, 10 mL, and 5 mL) of the study drug (0.0625% bupivacaine plus 2 μg/mL of fentanyl) were administered 90 min after the spinal block via epidural catheter. The visual analogue scale (VAS) scores at rest and during movement, first PCEA dose time, number of PCEA doses required per hour, total analgesic consumed, and side effects were recorded postoperatively.

Results

There were no statistically significant differences among the groups in terms of the VAS rest and VAS movement scores. The times to the first analgesic dose requirement were longer in Group 10 and Group 20 than in Group 5. The analgesic requirement during the first 2 h was lower in Group 20 than in the other groups.

Conclusions

The PCEA initiations with different volumes provided similar pain scores. However, the 20 mL volume resulted in a lower analgesic dose requirement during the early postoperative period, and it also delayed the requirement for analgesia.

Influence of Epidural Ropivacaine with or without Dexmedetomidine on Postoperative Analgesia and Patient Satisfaction after Thoraco-Lumbar Spine Instrumentation: A Randomized, Comparative, and Double-Blind Study

Study Design

This was a prospective, randomized, and double-blind study.

Purpose

Thoraco-lumbar spine surgery is associated with severe postoperative pain and can cause chronic pain. We aimed to compare the impact of epidural ropivacaine with and without dexmedetomidine on postoperative analgesia after thoracolumbar spine instrumentation wherein an epidural catheter was placed by the surgeon intraoperatively.

Overview of Literature

Very few studies have reported the use of epidural dexmedetomidine in spine surgeries. When used via the epidural route, dexmedetomidine is safe and efficacious and is associated with reduced rescue analgesia consumption, increased duration of analgesia, reduced pain scores, but not with major hemodynamic adverse effects.

Methods

Total 60 American Society of Anesthesiologists I–III adult patients aged 18–65 years who were scheduled to undergo thoraco-lumbar spine instrumentation were randomly allocated into group RD (epidural ropivacaine+dexmedetomidine) or group R (epidural ropivacaine plus saline). We aimed to compare the total rescue analgesic consumption on postoperative day 0, 1, and 2. Moreover, we studied the time to first rescue analgesia with visual analogue scale score <4 and the overall patient satisfaction scores.

Results

There was no difference between the demographic characteristics of the two groups. The mean value of total rescue analgesia consumption was 162.5±68.4 mg in the RD group and 247.5±48.8 mg in the R group. The mean time to first rescue analgesia was 594.6±83.0 minutes in the RD group and 103.6±53.2 minutes in the R group. The mean patient satisfaction score was 4.2±0.7 in the RD group and 3.2±0.6 in the R group. No patient had any respiratory depression or prolonged motor blockade during the postoperative period.

Conclusions

This study demonstrated the superior efficacy, in terms of postoperative analgesia and patient satisfaction scores, of epidural ropivacaine plus dexmedetomidine over that of ropivacaine alone in patients undergoing surgery for thoraco-lumbar spine.

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).

Dexmedetomidine in Enhanced Recovery After Surgery (ERAS) Protocols for Postoperative Pain

PURPOSE OF REVIEW

Effective acute pain management has evolved considerably in recent years and is a primary area of focus in attempts to defend against the opioid epidemic. Persistent postsurgical pain (PPP) has an incidence of up to 30-50% and has negative outcome of quality of life and negative burden on individuals, family, and society. The 2016 American Society of Anesthesiologists (ASA) guidelines states that enhanced recovery after surgery (ERAS) forms an integral part of Perioperative Surgical Home (PSH) and is now recommended to use a multimodal opioid-sparing approach for management of postoperative pain. As such, dexmedetomidine is now being used as part of ERAS protocols along with regional nerve blocks and other medications, to create a satisfactory postoperative outcome with reduced opioid consumption in the Post anesthesia care unit (PACU).

RECENT FINDINGS

Dexmedetomidine, a selective alpha2 agonist, possesses analgesic effects and has a different mechanism of action when compared with opioids. When dexmedetomidine is initiated at the end of a procedure, it has a better hemodynamic stability and pain response than ropivacaine. Dexmedetomidine can be used as an adjuvant in epidurals with local anesthetic sparing effects. Its use during nerve blocks results in reduced postoperative pain. Also, local infiltration of IV dexmedetomidine is associated with earlier discharge from PACU. Perioperative use of dexmedetomidine has significantly improved postoperative outcomes when used as part of ERAS protocols. An in-depth review of the use of dexmedetomidine in ERAS protocols is presented for clinical anesthesiologists.

The effect of dexmedetomidine and midazolam on combined spinal-epidural anesthesia in patients undergoing total knee arthroplasty

Background

Intravenous dexmedetomidine has been reported to potentiate the anesthetic effect of local anesthetics and improve the quality of postoperative analgesia when used as an adjuvant in neuraxial block. We compared the effects of intravenous dexmedetomidine and midazolam for sedation on combined spinal-epidural (CSE) anesthesia.

Methods

This study included 50 patients undergoing total knee arthroplasty. CSE anesthesia was given using 10 mg bupivacaine for all patients. After checking the maximum sensory and motor levels, the patients were randomly allocated into two groups of 25 each to receive intravenous continuous infusion of dexmedetomidine (Group D) or midazolam (Group M) for sedation during surgery. Regression block level, hemodynamic changes, and sedation score were compared between the groups when the patients entered the postanesthetic care unit (PACU). For patient-controlled epidural analgesia, 0.2% levobupivacaine with 650 µg of fentanyl (150 ml in total) was infused at a rate of 1 ml/h, in addition to a 3-ml bolus dose with a 30-min lockout time. The visual analogue scale scores, additional analgesic demand, patient satisfaction, and adverse events between the two groups were also compared postoperatively.

Results

A significant difference was observed in relation to the sensory block level in the PACU (Group D: 6.3 ± 2.1; Group M: 3.2 ± 1.9) (P = 0.002). The motor block level and other outcomes showed no significant intergroup differences.

Conclusions

Intravenous injection of dexmedetomidine, rather than midazolam, for procedural sedation is associated with prolonged sensory block, with comparable incidences of adverse events during CSE anesthesia.

Addition of dexmedetomidine to epidural morphine to improve anesthesia and analgesia for cesarean section

The aim of the present study was to evaluate the effectiveness and safety of the combination of epidural dexmedetomidine and morphine in providing anesthesia during cesarean surgery and analgesia for post-cesarean pain relief when added to epidural ropivacaine. A total of 80 females at term scheduled for elective cesarean delivery were randomly assigned to two groups (n=40/group): In the morphine group (group M), patients received an epidural injection of 0.75% ropivacaine (12 ml) and morphine (2 mg) for surgical anesthesia, and epidural infusion of morphine (2 mg) in 100 ml 0.2% ropivacaine at 2 ml/h for 48-h post-operative analgesia; and in the morphine combined with dexmedetomidine group (group DM), patients received an epidural injection of 0.75% ropivacaine (12 ml) and morphine (2 mg) combined with dexmedetomidine (0.5 µg/kg) for surgical anesthesia, and epidural infusion of morphine (2 mg) and dexmedetomidine (200 µg) in 100 ml 0.2% ropivacaine at 2 ml/h for 48-h post-operative analgesia. The primary outcomes included blockade and analgesic effects, sedation and adverse reactions associated with the drugs. Neonatal outcome was also assessed by determining the Apgar score and umbilical cord blood analysis. There was no significant difference between the groups in the cephalad levels of sensory blockade at 20 min post-injection, or in muscle relaxation scores or pain intensity scores at rest or upon movement at 4, 12, 24 or 48 h post-injection (P>0.05). The maternal patients in the DM group experienced more complete motor blockade at 20 min post-injection, better sedation during surgery and following delivery, and less visceral pain caused by peritoneal traction during surgery and by uterine contraction after delivery, compared with those in group M (P<0.05). The patients in group M had a lower incidence and severity score of post-operative nausea than those in the DM group (P<0.05). There was no significant difference between the groups in terms of Apgar score or umbilical cord blood gas values (P>0.05). In conclusion, epidural dexmedetomidine reduces intra-operative and post-operative visceral pain and produces better sedation during surgery and following delivery, without any significant influence on morphine-associated side effects and post-operative analgesia, in females undergoing elective cesarean section under epidural anesthesia with morphine and ropivacaine (registration number ChiCTR1900027942; retrospectively registered with the Chinese Clinical Registry Center on December 6, 2019).

Clinical effects of epidurally administered dexmedetomidine with or without lidocaine in sheep

BACKGROUND

The aims of this study were evaluate cardiopulmonary, sedative and antinociceptive effects of dexmedetomidine-lidocaine combination via lumbosacral epidural injection in sheep.

METHODS

Six Santa Inês breed sheep, 16±6 months old and weighing 42.2 ± 5.7 kg were used. Sheep were subjected to epidural anaesthesia with three treatments: L, lidocaine (1.2 mg/kg), D, dexmedetomidine (2.5 μg/kg) or DL, dexmedetomidine plus lidocaine (2.5 μg/kg + 1.2 mg/kg). Drugs were injected via pre-placed lumbosacral epidural catheters. Cardiopulmonary, arterial blood gases, electrolytes, degree of sedation and antinociceptive aspects were measured before drug administration (T0) and then at 15, 30, 60 and 120 min after drug injection (T15-T120) in all treatments and at T0 to T240 in DL.

RESULTS

There were significantly increases in PaCO₂ at times T60 and T120 in D, and at T30-T120 in DL, compared to baseline. The antinociceptive effects were observed up to 240 min in DL and 60 min in L, and were more intense in DL. Treatment D provided analgesia only in the perineal region, and only at T15.

CONCLUSION

The combination of DEX with lidocaine produced similar cardiopulmonary changes compared with either drug alone, but with greater and more prolonged antinociceptive effects.

Dexmedetomidine Exerts Brain-Protective Effects Under Cardiopulmonary Bypass Through Inhibiting the Janus Kinase 2/Signal Transducers and Activators of Transcription 3 Pathway

Brain injury is a major complication resulted from cardiopulmonary bypass (CPB). Dexmedetomidine (DEX) has potential brain-protective effects; however, the mechanism is unclear. The aim of this study is to investigate the effect of DEX on brain injury in CPB rats and its mechanism. The levels of interleukin-6 (IL-6), interleukin-10 (IL-10), S100β, and neuron-specific enolase (NSE) were measured by enzyme-linked immunosorbent assay. The hippocampus CA1 region in rats was observed by hematoxylin-eosin staining. Western blot and quantitative real-time polymerase chain reaction were performed to detect related proteins and mRNA expressions in the hippocampus tissues. We found that after CPB, the neuron cells in hippocampus CA1 region of rats were randomly arranged, and that the levels of IL-6, IL-10, S100β, NSE, Cleaved Caspase-3, and Bax were upregulated, while Bal-2 level was downregulated. However, after DEX treatment, the neuron cells arranged in an orderly manner, and the levels of IL-6, IL-10, S100β, NSE, Cleaved Caspase-3, and Bax were downregulated, but Bal-2 level was upregulated. DEX suppressed Janus kinase 2 (JAK2)/signal transducers and activators of transcription 3 (STAT3) pathway activated by CPB, ameliorated CPB-induced brain injury in rats by reducing inflammatory response, and inhibited neuronal apoptosis. The brain-protective effect of DEX may be related to the inhibition of the activation of JAK2/STAT3 pathway.

Subarachnoid and epidural dexmedetomidine for the prevention of post-anesthetic shivering: a meta-analysis and systematic review

Background

Post-anesthetic shivering incurs discomfort to patients or even exacerbates their condition. However, no ideal drug has been well established for preventing post-anesthetic shivering. Currently, subarachnoid and epidural dexmedetomidine have demonstrated to have an anti-shivering effect.

Methods

An electronic search was conducted to identify randomized placebo-controlled trials reporting shivering and then compared subarachnoid and epidural dexmedetomidine with placebo in adults undergoing selective surgery. Data assessment and pooling were analyzed by Review Manager 5.3, STATA 15.0 and GRADE-pro 3.6 software.

Results

Twenty-two studies (1389 patients) were subjected to this meta-analysis. The incidence of post-anesthetic shivering decreased from 20.10% in the placebo group to 10.30% in the dexmedetomidine group (RR, 0.48; 95% CI, 0.39–0.59; Z=6.86, P<0.00001, I²=32%). Non-Indian, epidural-space route and cesarean subgroups indicated a better anti-shivering effect. In the subarachnoid-space route subgroup, a dosage of >5 μg showed significantly superior anti-shivering effects than that of ≤5 μg. Subarachnoid and epidural dexmedetomidine increased the incidence of bradycardia, had no impact on nausea and vomiting, shortened the onset of block and lengthened the duration of block and analgesia. However, its effect on hypotension and sedation remained uncertain. The overall risk of bias was relatively low. The level of evidence was high, and the recommendation of voting results was strong.

Conclusion

Dexmedetomidine as a subarachnoid and epidural adjunct drug could decrease the incidence of post-anesthetic shivering in a dose-dependent manner. However, caution should be taken in patients with original bradycardia.

Comparison of Transforaminal Triamcinolone and Dexmedetomidine in Radicular Low-Back Pain: A Randomized Double-Blind Clinical Trial

Background

Administration of steroids in the lumbar transforaminal block for lumbar radicular pain is considered one of the preferred treatment methods though it is associated with some complications.

Objectives

The effects and side effects of triamcinolone and dexmedetomidine in the lumbar transforaminal block were investigated in the present study.

Methods

In this study, 30 patients, aged 40 - 70 years, suffering from lumbar radicular pain arising from the lumbar disc protrusion were equally divided into two groups of triamcinolone (T) and dexmedetomidine (D). They all underwent lumbar transforaminal blocks. An injection solution of triamcinolone (20 mg) plus ropivacaine (0.2%) and another one containing dexmedetomidine (50 μg) plus ropivacaine (0.2%) were administered in the triamcinolone and dexmedetomidine groups, respectively. Visual Analog Scale (VAS), Oswestry Disability Index (ODI), Straight Leg Raise (SLR or lasègue’s test), and Fasting Blood Sugar (FBS) were measured at 0, 2 weeks, 1, 3, and 6 months post-procedure. The levels of calcium, magnesium, and vitamin D, as well as potential complications, were also evaluated.

Results

Significant differences were found in the VAS and ODI during the measurement times within each group. The VAS and ODI were remarkably different between the dexmedetomidine group and the triamcinolone group. In addition, there were considerable differences in the increased FBS and reduced calcium and vitamin D levels in the triamcinolone group from changes in the dexmedetomidine group.

Conclusions

The lumbar transforaminal block with triamcinolone or dexmedetomidine attenuates the lumbar radicular pain. Further, dexmedetomidine exerts a more potent pain relief effect than triamcinolone.

The impact of dexmedetomidine added to ropivicaine for transversus abdominis plane block on stress response in laparoscopic surgery: a randomized controlled trial

BACKGROUND

Intravenous dexmedetomidine is known to attenuate stress response in patients undergoing laparoscopic surgery. We investigated whether the addition of the highly selective alpha-2 adrenergic agonist dexmedetomidine into ropivacaine for ultrasound-guided transversus abdominis plane block could inhibit stress response during laparoscopic surgery, and determined the optimal dose of dexmedetomidine in it.

METHODS

One hundred and twenty-five patients undergoing laparoscopic gynecological surgery were included in this prospective and randomized double-blind study. Patients received general anesthesia with or without a total of 60 ml of 0.2% ropivacaine in combination with low (0.25 μg/kg), medium (0.50 μg/kg) or high dose (1.0 μg/kg) of dexmedetomidine for the four-quadrant transversus abdominis plane block (n = 25). The primary outcomes were stress marker levels during the operation.

RESULTS

One hundred and twenty patients completed the study protocol. Dexmedetomidine added to ropivacaine for transversus abdominis plane block significantly reduced serum levels of cortisol, norepinephrine, epinephrine, interleukin-6, blood glucose, mean arterial pressure and heart rate in a dose-dependent manner (P < 0.05), accompanied with decreased anesthetic and opioid consumption during the operation (P < 0.05), but the high dose of dexmedetomidine induced higher incidences of bradycardia than low or medium dose of dexmedetomidine (P < 0.05).

CONCLUSION

The addition of dexmedetomidine at the dose of 0.5 μg/kg into ropivacaine for ultrasound-guided transversus abdominis plane block is the optimal dose to inhibit stress response with limited impact on blood pressure and heart rate in patients undergoing laparoscopy gynecological surgery.

TRIAL REGISTRATION

This study was registered at www.chictr.org.cn on November 6th, 2016 (ChiCTR-IOR-16009753).

Comparison of dexmedetomidine or sufentanil combined with ropivacaine for epidural analgesia after thoracotomy: a randomized controlled study

Background

Thoracotomy is frequently accompanied with moderate-to-severe postoperative pain, and excellent pain management is important for early rehabilitation. The purpose of this study is to investigate the effects of dexmedetomidine combined with ropivacaine for epidural analgesia after thoracotomy.

Methods

One hundred and thirty patients undergoing elective lung lobectomy were enrolled in the double-blind study and randomly divided into two groups. Group A received 0.5 µg/mL of dexmedetomidine plus 0.1% ropivacaine for postoperative analgesia, and group B (control group) received 0.5 µg/mL of sufentanil plus 0.1% ropivacaine for postoperative analgesia. Hemodynamic parameters were monitored. Pain intensity at rest was assessed using a visual analog scale (VAS) at 2, 4, 6，8, 12, 24, and 48 hrs postoperatively. Ramsay sedation score (RSS), analgesic consumption, postoperative respiratory depression, nausea and vomiting, pruritus, and bradycardia were recorded.

Results

The VAS values at rest during the postoperative 6–48 hrs were lower in group A than those in group B (P<0.05), and the RSS values were higher in group A during the postoperative 4–48 hrs compared to group B (P<0.05). Side effects were similar between the groups (P>0.05).

Conclusion

Dexmedetomidine combined with ropivacaine may provide better postoperative analgesia and sedative effect in patients undergoing thoracic surgery with fewer side effects. It is superior to sufentanil in analgesic effect during postoperative analgesia after thoracotomy.

Comparison of dexmedetomidine and sufentanil as adjuvants to local anesthetic for epidural labor analgesia: a randomized controlled trial

Background

The epidural dexmedetomidine combined with ropivacaine has been successfully used for labor analgesia. We compared the effects of dexmedetomidine and sufentanil as adjuvants to local anesthetic for epidural labor analgesia.

Methods

Eighty nulliparous women were enrolled in the double-blind study and randomly divided into two groups. Group D received 0.5 µg/mL dexmedetomidine with 0.1% ropivacaine for epidural labor analgesia, and group S (control group) received 0.5 µg/mL sufentanil with 0.1% ropivacaine for labor analgesia. Hemodynamic parameters were monitored. Pain was assessed using a visual analog scale. The onset of epidural analgesia, duration of stages of labor, Ramsay Sedation Scale, blood loss, neonatal Apgar scores, umbilical artery blood pH and adverse effects, such as respiratory depression, nausea, vomiting, pruritus, and bradycardia, were recorded.

Results

Compared with the control group, visual analog scale values after cervical dilation >3 cm were lower in group D (P<0.05) and first-stage labor duration was shorter in group D (378.5±52.6 vs 406.5±58.2, P<0.05). Ramsay Sedation Scale values were higher in group D compared to the control group (2.8±0.6 vs 2.4±0.5, P<0.05). No significant differences in side effects were observed between the groups.

Conclusion

Dexmedetomidine is superior to sufentanil in analgesic effect and duration in first-stage labor during epidural analgesia when combined with 0.1% ropivacaine (www.chictr.org.cn, registration ChiCTR-OPC-16008548).

Dexmedetomidine sedation combined with epidural anesthesia for laparoscopy in a patient with suspected tuberculosis: A case report

RATIONALE

We herein present a case in which satisfactory analgesia and sedation were provided by the combination of epidural anesthesia with dexmedetomidine for exploratory laparoscopy in a patient who was highly suspected to have tuberculosis. This is an optimal anesthesia method to minimize the risk of nosocomial infection, especially in developing countries that lack sterilizers for anesthesia machines.

PATIENT CONCERNS

A 45-year-old woman suspected to have active tuberculosis was scheduled to undergo laparoscopy for definitive diagnosis of a pelvic mass.

DIAGNOSES

Tuberculosis was diagnosed by exploratory laparoscopy.

INTERVENTIONS

The surgery was performed under general anesthesia to prevent pain and discomfort during the procedure. However, ventilation machine used by patients with tuberculosis may have a potential risk of nosocomial infection and need disinfection by a special sterilizer machine even when using a bacterial/viral filter-heat and moisture exchanger. Therefore, the surgery was performed under continuous epidural anesthesia combined with dexmedetomidine.

OUTCOMES

The surgery was successfully completed, and pelvic tubercles were confirmed to be caseous necrotic tissue by pathologic examination. The patient began regular antituberculosis treatment after discharging from the gynecology department.

LESSONS

We conclude that administration of dexmedetomidine combined with epidural anesthesia can provide comfortable sedation for short laparoscopic procedures in patients with suspected tuberculosis. This technique can minimize the risk of nosocomial infection.

Paravertebral dexmedetomidine as an adjuvant to ropivacaine protects against independent lung injury during one-lung ventilation: a preliminary randomized clinical trial

Background

To investigate the effect of paravertebral dexmedetomidine as an adjuvant to ropivacaine on independent lung injury during one-lung ventilation.

Methods

In total, 120 patients who underwent elective radical resection of pulmonary carcinoma were randomly assigned to one of six groups (n = 20): normal saline (C group), ropivacaine (R group), intravenous dexmedetomidine (Div group), 0.5 μg/kg paravertebral dexmedetomidine as an adjuvant to ropivacaine (RD0.5 group), 1.0 μg/kg paravertebral dexmedetomidine as an adjuvant to ropivacaine (RD1.0 group), or 2.0 μg/kg paravertebral dexmedetomidine as an adjuvant to ropivacaine (RD2.0 group).

Patients in the R, Div, RD0.5, RD1.0 and RD2.0 groups underwent a thoracic paravertebral block, and normal saline was administered as a control to C group. Small marginal lung samples next to the tumor were harvested immediately after the tumor tissues were excised.

Lung injury was evaluated as follows: an injury score was determined via light microscopy, and cell apoptosis was determined via a TUNEL assay. TNF-α, IL-6, miRNA-210, HIF-1α, Tom20 and ISCU2 were also detected.

Results

Both intravenous and paravertebral dexmedetomidine attenuated independent lung injury. Downregulation of HIF-1α and miRNA-210 and upregulation of Tom20 and ISCU2 may be the underlying mechanism. No difference was observed between the Div and RD0.5 groups, and no further improvement of lung injury was found in the RD1.0 and RD2.0 groups with increased paravertebral dexmedetomidine doses.

Conclusions

Paravertebral dexmedetomidine as an adjuvant to ropivacaine, which is comparable to intravenous dexmedetomidine, could protect against independent lung injury during one-lung ventilation.

Trial registration

ISRCTN, 13000406; retrospectively registered on 22.05.2018.