Efficacy of dexmedetomidine as an adjuvant in paravertebral block in breast cancer surgery

Dexmedetomidine as an Adjuvant to Nerve Block for Cancer Surgery: A Systematic Review and Meta-Analysis

Background/Objectives: Our understanding of dexmedetomidine, as an adjuvant to nerve blocks in cancer surgery, is characterized by a current lack of compelling evidence, and it remains unknown whether the potential benefits of use outweigh the risks. The aim of the study was to evaluate the benefit and safety profiles of dexmedetomidine as an adjuvant to nerve blocks in cancer surgery. Methods: Systematic searches were conducted in MEDLINE, ScienceDirect, Cochrane Library, Springer, medRxiv, and Scopus up to 17 May 2024. Risk ratios (RR) for binary outcomes and standardized mean differences (SMDs) for continuous outcomes were quantified. Results: Twenty studies were identified. In breast cancer surgery, the use of dexmedetomidine reduced 24 h total morphine consumption (SMD = -1.99 [95% CI -3.01 to -0.98], p = 0.0001, I2 = 91%, random effects) and prolonged the requirement for morphine rescue analgesia (SMD = 2.98 [95% CI 0.01 to 5.95], p = 0.05, I2 = 98%, random effects). In abdominal cancer surgery, the dexmedetomidine group had lower total sufentanil consumption (SMD = -1.34 [95% CI -2.29 to -0.40], p = 0.005, I2 = 84%, random effects). Dexmedetomidine reduced the VAS score and decreased postoperative nausea and vomiting (PONV). No studies using dexmedetomidine reported serious adverse events. Conclusions: Using dexmedetomidine as an adjuvant to nerve blocks in cancer surgery could lower the VAS pain score and prolong the regional anesthesia duration, which would lead to a decrease in total opioid consumption and possibly contribute to fewer PONV events. Furthermore, the reports of no serious adverse events indicate its good safety profile.

Effect of dexmedetomidine on postoperative nausea and vomiting in female patients undergoing radical thoracoscopic lung cancer resection

Introduction: Postoperative nausea and vomiting (PONV) is a prevalent postsurgical complication. The objective of our study was to compare the effect of different doses of dexmedetomidine on PONV in female patients undergoing radical thoracoscopic lung cancer resection. Methods: A total of 164 female patients undergoing elective thoracoscopic radical lung cancer surgery were enrolled and assigned to one of four groups. Patients received 0.2 μg/kg/h, 0.4 μg/kg/h, 0.8 μg/kg/h dexmedetomidine and normal saline in the Dex1, Dex2, Dex3 and Control groups, respectively. The primary outcome was the incidence of PONV during 48 h postoperatively. The second outcomes included the incidence of PONV and postoperative vomiting (POV) at four time points postoperatively (T1: PACU retention period; T2: PACU discharge to postoperative 12 h; T3: postoperative 12 h-postoperative 24 h; T4: postoperative 24 h-postoperative 48 h), the area under the curve of PONV grade (PONVAUC), PONV grade, POV grade and other postoperative recovery indicators. Results: The incidence of PONV differed among the four groups. The Dex2 group (29.27%) was lower than that in the Dex1 group (61.90%) and Control group (72.50%). The incidence of PONV at T2 in the Dex1 group (11.90%) and Dex2 group (9.76%) was lower than that in the Control group (42.50%). The incidence of PONV at T3 in the Dex2 group (29.27%) was lower than that in the Dex1 group (61.90%) and Control group (62.50%). The PONVAUC was lower in the Dex2 group than in the Control group. The incidence of POV at T3 in the Dex2 and Dex3 groups was lower than that in the Control group. The consumption of remifentanil, norepinephrine, PACU dwell time, VAS scores, postoperative PCA press frequency, and the time for the first postoperative oral intake were different among the four groups. The regression model shows that the Dex2 group is a protective factor for PONV. Conclusion: Dexmedetomidine can reduce the incidence of PONV and accelerate postoperative recovery in female patients undergoing radical thoracoscopic lung cancer resection. Compared with the other two dosages, 0.4 μg/kg/h dexmedetomidine is preferable. Clinical Trial Registration: chictr.org.cn, identifier ChiCTR2300071831.

Efficacy of dexmedetomidine combined with ropivacaine on postoperative analgesia and delirium in elderly patients with total knee arthroplasty

This study aimed to investigate the impact of dexmedetomidine combined with ropivacaine on continuous femoral nerve block (CFNB) in postoperative analgesia and delirium in elderly patients with total knee arthroplasty (TKA). A total of 120 patients who undergone TKA were randomly assigned into group D + R (dexmedetomidine combined with ropivacaine) and group R (only ropivacaine), with 60 cases in each group. The pain scores at rest and exercise at 6 h, 12 h, 24 h, and 48 h postoperatively. The occurrence of delirium on Day 1, Day 2, and Day 3 postoperatively were measured, and the sleep quality was evaluated before surgery, the night of surgery, and 24 h postoperatively to observe the occurrence of postoperative complications. The Visual analogu scale (VAS) of group D + R at 12 h, 24 h, and 48 h postoperatively were lower than those of group R in both rest and exercise states. The incidence of postoperative delirium in group D + R was lower than that in group R on Day 1 and Day 2. Pittsburgh sleep quality index (PSQI) scores in group D + R were lower than those in group R. There was no significant difference in postoperative adverse reactions between the two groups. Dexmedetomidine combined with ropivacaine improves postoperative analgesia and sleep quality, and alleviates the occurrence of postoperative delirium in elderly patients with TKA.

Effectiveness of Surgeon-Performed Paravertebral Block Analgesia for Minimally Invasive Thoracic Surgery: A Randomized Clinical Trial

Importance

In minimally invasive thoracic surgery, paravertebral block (PVB) using ultrasound (US)-guided technique is an efficient postoperative analgesia. However, it is an operator-dependent process depending on experience and local resources. Because pain-control failure is highly detrimental, surgeons may consider other locoregional analgesic options.

Objective

To demonstrate the noninferiority of PVB performed by surgeons under video-assisted thoracoscopic surgery (VATS), hereafter referred to as PVB-VATS, as the experimental group compared with PVB performed by anesthesiologists using US-guided technique (PVB-US) as the control group.

Design, Setting, and Participants

In this single-center, noninferiority, patient-blinded, randomized clinical trial conducted from September 8, 2020, to December 8, 2021, patients older than 18 years who were undergoing a scheduled minimally invasive thoracic surgery with lung resection including video-assisted or robotic approaches were included. Exclusion criteria included scheduled open surgery, any antalgic World Health Organization level greater than 2 before surgery, or a medical history of homolateral thoracic surgery. Patients were randomly assigned (1:1) to an intervention group after general anesthesia. They received single-injection PVB before the first incision was made in the control group (PVB-US) or after 1 incision was made under thoracoscopic vision in the experimental group (PVB-VATS).

Interventions

PVB-VATS or PVB-US.

Main Outcomes and Measures

The primary end point was mean 48-hour post-PVB opioid consumption considering a noninferiority range of less than 7.5 mg of opioid consumption between groups. Secondary outcomes included time of anesthesia, surgery, and operating room occupancy; 48-hour pain visual analog scale score at rest and while coughing; and 30-day postoperative complications.

Results

A total of 196 patients were randomly assigned to intervention groups: 98 in the PVB-VATS group (mean [SD] age, 64.6 [9.5] years; 53 female [54.1%]) and 98 in the PVB-US group (mean [SD] age, 65.8 [11.5] years; 62 male [63.3%]). The mean (SD) of 48-hour opioid consumption in the PVB-VATS group (33.9 [19.8] mg; 95% CI, 30.0-37.9 mg) was noninferior to that measured in the PVB-US group (28.5 [18.2] mg; 95% CI, 24.8-32.2 mg; difference: -5.4 mg; 95% CI, -∞ to -0.93; noninferiority Welsh test, P ≤ .001). Pain score at rest and while coughing after surgery, overall time, and postoperative complications did not differ between groups.

Conclusions and Relevance

PVB placed by a surgeon during thoracoscopy was noninferior to PVB placed by an anesthesiologist using ultrasonography before incision in terms of opioid consumption during the first 48 hours.

Trial Registration

ClinicalTrials.gov Identifier: NCT04579276.

Dexmedetomidine as an Adjuvant in Peripheral Nerve Block

Peripheral nerve block technology is important to balanced anesthesia technology. It can effectively reduce opioid usage. It is the key to enhance clinical rehabilitation as an important part of the multimodal analgesia scheme. The emergence of ultrasound technology has accelerated peripheral nerve block technology development. It can directly observe the nerve shape, surrounding tissue, and diffusion path of drugs. It can also reduce the dosage of local anesthetics by improving positioning accuracy while enhancing the block's efficacy. Dexmedetomidine is a highly selective drug α₂-adrenergic receptor agonist. Dexmedetomidine has the characteristics of sedation, analgesia, anti-anxiety, inhibition of sympathetic activity, mild respiratory inhibition, and stable hemodynamics. Numerous studies have revealed that dexmedetomidine in peripheral nerve blocks can shorten the onset time of anesthesia and prolong the time of sensory and motor nerve blocks. Although dexmedetomidine was approved by the European Drug Administration for sedation and analgesia in 2017, it has not yet been approved by the US Food and Drug Administration (FDA). It is used as a non-label drug as an adjuvant. Therefore, the risk-benefit ratio must be evaluated when using these drugs as adjuvants. This review explains the pharmacology and mechanism of dexmedetomidine, the effect of dexmedetomidine on various peripheral nerve block as an adjuvant, and compare it with other types of adjuvants. We summarized and reviewed the application progress of dexmedetomidine as an adjuvant in nerve block and look forward to its future research direction.

The role of dexmedetomidine as an adjuvant for high-thoracic erector spinae plane block for analgesia in shoulder arthroscopy; a randomized controlled study

BACKGROUND

Management of postoperative pain after shoulder arthroscopy is an important issue. Dexmedetomidine, as an adjuvant, improves nerve block efficacy and decreases postoperative consumption of opioids. As a result, we designed this study to determine if adding dexmedetomidine to an erector spinae plane block (ESPB) that is guided by ultrasound (US) is beneficial for treating immediate postoperative pain following shoulder arthroscopy.

METHODS

This randomized controlled double-blind trial recruited 60 cases 18-65 years old of both sexes, American Society of Anesthesiologists (ASA) physical status I-II, scheduled for elective shoulder arthroscopy. Random allocation of 60 cases was done equally into two groups according to the solution injected in US-guided ESPB at T2 before general anesthetic induction. Group (ESPB): 20 ml 0.25% bupivacaine. Group (ESPB + DEX): 19 ml bupivacaine 0.25% + 1 mL dexmedetomidine 0.5 µg/kg. The primary outcome was The total rescue morphine consumption in the first 24 postoperative hours.

RESULTS

The mean intraoperative fentanyl consumption was significantly lower in the group (ESPB + DEX) compared to the group (ESPB) (82.86 ± 13.57 versus 100.74 ± 35.07, respectively, P = 0.015). The median (IQR) time of the 1^st rescue analgesic request was significantly delayed in the group (ESPB + DEX) compared to group (ESPB) [18.5 (18.25-18.75) versus 12 (12-15.75), P = 0.044]. The number of cases that required morphine was significantly lower in the group (ESPB + DEX) than in the group (ESPB) (P = 0.012). The median (IQR) of total postoperative morphine consumption in 1^st 24 h was significantly lower in the group (ESPB + DEX) compared to the group (ESPB) [0 (0-0) versus 0 (0-3), P = 0.021].

CONCLUSION

The dexmedetomidine as an adjuvant to bupivacaine in ESPB produced adequate analgesia by reducing the intraoperative and postoperative opioid requirements in shoulder arthroscopy.

TRIAL REGISTRATION

This study is registered on ClinicalTrials.gov (NCT05165836; principal investigator: Mohammad Fouad Algyar; registration date: 21/12/ 2021).

Evidence basis for using dexmedetomidine to enhance the quality of paravertebral block: A systematic review and meta-analysis of randomized controlled trials

Background: Dexmedetomidine is considered an adjunct to local anaesthesia (LA) to prolong peripheral nerve block time. However, the results from a previous meta-analysis were not sufficient to support its use in paravertebral block (PVB). Therefore, we performed an updated meta-analysis to evaluate the efficacy of dexmedetomidine combined with LA in PVB.

Methods: We performed an electronic database search from the date of establishment to April 2022. Randomized controlled trials (RCTs) investigating the combination of dexmedetomidine and LA compared with LA alone for PVB in adult patients were included. Postoperative pain scores, analgesic consumption, and adverse reactions were analyzed.

Results: We identified 12 trials (701 patients) and found that the application of dexmedetomidine as a PVB adjunct reduced the postoperative pain severity of patients 12 and 24 h after surgery compared to a control group. Expressed as mean difference (MD) (95% CI), the results were −1.03 (−1.18, −0.88) (p < 0.00001, I² = 79%) for 12 h and −1.08 (−1.24, −0.92) (p < 0.00001, I² = 72%) for 24 h. Dexmedetomidine prolonged the duration of analgesia by at least 173.27 min (115.61, 230.93) (p < 0.00001, I² = 81%) and reduced postoperative oral morphine consumption by 18.01 mg (−22.10, 13.92) (p < 0.00001, I² = 19%). We also found no statistically significant differences in hemodynamic complications between the two groups. According to the GRADE system, we found that the level of evidence for postoperative pain scores at 12 and 24 h was rated as moderate.

Conclusion: Our study shows that dexmedetomidine as an adjunct to LA improves the postoperative pain severity of patients after surgery and prolongs the duration of analgesia in PVB without increasing the incidence of adverse effects.

Efficacy of regional anesthesia techniques for postoperative analgesia in patients undergoing major oncologic breast surgeries: a systematic review and network meta-analysis of randomized controlled trials

BACKGROUND

The optimal regional technique to control pain after breast cancer surgery remains unclear. We sought to synthesize available data from randomized controlled trials comparing pain-related outcomes following various regional techniques for major oncologic breast surgery.

METHODS

In a systematic review and network meta-analysis, we searched trials in PubMed, Embase Scopus, Medline, Cochrane Central and Google Scholar, from inception to 31 July 2020, for commonly used regional techniques. The primary outcome was the 24-hr resting pain score measured on a numerical rating score of 0-10. We used surface under the cumulative ranking curve (SUCRA) to establish the probability of an intervention ranking highest. The analysis was performed using the Bayesian random effects model, and effect sizes are reported as 95% credible interval (Crl). We conducted cluster-rank analysis by combining 24-hr pain ranking with 24-hr opioid use or incidence of postoperative nausea and vomiting.

RESULTS

Seventy-nine randomized controlled trials containing 11 different interventions in 5,686 patients were included. The SUCRA values of the interventions for 24-hr resting pain score were continuous paravertebral block (0.83), serratus anterior plane block (0.76), continuous wound infusion (0.76), single-level paravertebral block (0.68), erector spinae plane block (0.59), modified pectoral block (0.49), intercostal block (0.45), multilevel paravertebral block (0.41), wound infiltration (0.33), no intervention (0.12), and placebo (0.08). When compared with placebo, the continuous paravertebral block (mean difference, 1.26; 95% Crl, 0.43 to 2.12) and serratus anterior plane block (mean difference, 1.12; 95% Crl, 0.32 to 1.9) had the highest estimated probability of decreasing 24-hr resting pain scores. Cluster ranking analysis combining 24-hr resting pain scores and opioid use showed that most regional analgesia techniques were more effective than no intervention or placebo. Nevertheless, wound infiltration and continuous wound infusion may be the least effective active interventions for reducing postoperative nausea and vomiting.

CONCLUSION

Continuous paravertebral block and serratus anterior plane block had a high probability of reducing pain at 24 hr after major oncologic breast surgery. The certainty of evidence was moderate to very low. Future studies should compare different regional anesthesia techniques, including surgeon-administered techniques such as wound infiltration or catheters. Trials comparing active intervention with placebo are unlikely to change clinical practice.

STUDY REGISTRATION

PROSPERO (CRD42020198244); registered 19 October 2020.

Impact of adding opioids to paravertebral blocks in breast cancer surgery patients: A systematic review and meta-analysis

BACKGROUND

Several breast cancer studies have reported the use of adjuvant opioids with the paravertebral block (PVB) to improve outcomes. However, there is no level-1 evidence justifying its use.

AIM

To elucidate if the addition of opioids to PVB improves pain control in breast cancer surgery patients.

METHODS

We conducted an electronic literature search across PubMed, Embase, Scopus, and Google Scholar databases up to October 20, 2020. Only randomized controlled trials (RCTs) comparing the addition of opioids to PVB with placebo for breast cancer surgery patients were included.

RESULTS

Six RCTs were included. Our meta-analysis indicated significantly reduced 24-h total analgesic consumption with the addition of opioids to PVB as compared to placebo [standardized mean difference (SMD) -1.57, 95% confidence interval (CI): -2.93, -0.21, I² = 94%]. However, on subgroup analysis, the results were non-significant for studies using single PVB (SMD: -1.76, 95%CI: -3.65, 0.13 I² = 95.09%) and studies using PVB infusion (SMD: -1.30, 95%CI: -4.26, 1.65, I² = 95.49%). Analysis of single PVB studies indicated no significant difference in the time to first analgesic request between opioid and placebo groups (mean difference -11.28, 95%CI: -42.00, 19.43, I² = 99.39%). Pain scores at 24 h were marginally lower in the opioid group (mean difference -1.10, 95%CI: -2.20, 0.00, I² = 0%). There was no difference in the incidence of postoperative nausea and vomiting between the two groups.

CONCLUSION

Current evidence suggests a limited role of adjuvant opioids with PVB for breast cancer surgery patients. Further homogenous RCTs with a large sample size are needed to clarify the beneficial role of opioids with PVB.

Hertling A. Adding Dexmedetomidine to Bupivacaine in Ultrasound-guided Thoracic Paravertebral Block for Pain Management after Upper Abdominal Surgery: A Double-blind Randomized Controlled Trial

Background

Paravertebral blocks are one of the possible postoperative pain management modalities after laparotomy. Adjuvants to local anesthetics, including alpha agonists, have been shown to lead to better pain relief and increased duration of analgesia.

Objectives

The aim of this study is to examine the effect of adding dexmedetomidine to bupivacaine for ultrasound-guided paravertebral blocks in laparotomy.

Methods

In this double-blind, randomized controlled trial (RCT), we enrolled 42 patients scheduled for T6 to T8 thoracic paravertebral block (TPVB) for analgesia after laparotomy. The patients were randomly assigned into two groups of BD (bupivacaine 2.5 mg/mL 20 mL plus dexmedetomidine 100 µg) and B (bupivacaine 20 mL alone). Following surgery, intravenous fentanyl patient-controlled analgesia was initiated. The numerical rating scale (NRS) for pain, sedation score, total analgesic consumption, time to first analgesic requirement, side effects (such as nausea and vomiting), respiratory depression, and patients’ satisfaction during the first 48 hours of evaluation were compared in the two groups.

Results

Pain scores and mean total analgesic consumption at the first 48 hours in the BD group were significantly lower than Group B (P = 0.03 and P < 0.001, respectively). The time of first analgesic request was significantly longer in BD group (P < 0.001). Sedation scores and side effects did not differ significantly between the two groups.

Conclusions

Adding dexmedetomidine to bupivacaine for TPVB after laparotomy yielded better postoperative pain management without significant complications.

Thoracic Paravertebral Nerve Block with Ropivacaine and Adjuvant Dexmedetomidine Produced Longer Analgesia in Patients Undergoing Video-Assisted Thoracoscopic Lobectomy: A Randomized Trial

Purpose

This study evaluated the postoperative analgesic effect of ultrasound-guided single-point thoracic paravertebral nerve block (TPVB) combined with dexmedetomidine (DEX) in patients undergoing video-assisted thoracoscopic lobectomy.

Methods

Sixty adult patients of the American Society of Anesthesiologists (ASA) I-III were randomly assigned into three groups (n = 20 each). G group: patients received routine general anesthesia; PR group: patients received 0.5% ropivacaine; and PRD group: patients received 0.5% ropivacaine with 1 μg/kg DEX. TPVB was performed in the T5 space before surgery, and then, general anesthesia induction and video-assisted thoracoscopic lobectomy were performed. Analgesics were administered through the patient-controlled analgesia (PCA) device intravenously. The background infusion of each PCA device was set to administer 0.02 μg/kg/h sufentanil, with a lockout time of 15 min, and a total allowable volume is 100 ml.

Results

Compared to PR and G groups, the total sufentanil consumption after operation, the times of analgesic pump pressing, the pain score, and the incidence of postoperative nausea or vomiting in the PRD group were significantly reduced (p < 0.05). Also, the duration of first time of usage of the patient-controlled analgesia (PCA) was longer. The heart rate (HR) and mean arterial pressure (MAP) during operation were lower in the PRD group as compared with the other two groups in most of the time. However, hypotension and arrhythmia occurred in three groups with no statistically significant difference.

Conclusions

A small volume of TPVB with ropivacaine and DEX by single injection produced longer analgesia in patients undergoing video-assisted thoracoscopic lobectomy, reduced postoperative opioids consumption, and the incidence of side effects.

Dexmedetomidine upregulates microRNA-185 to suppress ovarian cancer growth via inhibiting the SOX9/Wnt/β-catenin signaling pathway

Dexmedetomidine (DEX) could serve as an adjuvant analgesic during cancer therapies. Abnormal expression of microRNAs (miRNAs) could lead to cancer development. This study was aimed to explore the roles of DEX in ovarian cancer (OC) development. OC cell lines SKOV3 and HO-8910 were treated with DEX, after which OC development and the miR-185, SOX9, and Wnt/β-catenin pathway were measured. DEX-treated HO-8910 cells were transfected with miR-185 mimic, miR-185 antisense or miR-185 antisense + silenced SOX9 to further measure the OC cell growth. The target relation between miR-185 and SOX9 was identified, and SOX9 and Wnt/β-catenin pathway were protein levels detected after miR-185 transfection. The role of miR-185 in OC in vivo was also measured. Our study found DEX had a dose-dependent inhibition on OC growth, and DEX promoted miR-185 but suppressed SOX9 expression in OC cells. miR-185 targeted SOX9. After interfering with miR-185 expression, HO-8910 cell proliferation, invasion, migration, and apoptosis were affected. SOX9 knockdown repressed OC development and Wnt/β-catenin pathway. The volume, weight, positive rate of Ki67, CyclinD1, p53 and the degree of tumor necrosis were affected by miR-185 expression. This study demonstrated that DEX could inhibit OC development via upregulating miR-185 expression and inactivating the SOX9/Wnt/β-catenin signaling pathway.

Dexmedetomidine as an adjuvant for patients undergoing breast cancer surgery: A meta-analysis

BACKGROUND

The goal of this study was to comprehensively evaluate the analgesic and antiemetic effects of adjuvant dexmedetomidine (DEX) for breast cancer surgery using a meta-analysis.

METHODS

Electronic databases were searched to collect the studies that performed randomized controlled trials. The effect size was estimated by odd ratio (OR) or standardized mean difference (SMD). Statistical analysis was performed using the STATA 13.0 software.

RESULTS

Twelve published studies involving 396 DEX treatment patients and 395 patients with control treatment were included. Pooled analysis showed that the use of DEX significantly prolonged the time to first request of analgesia (SMD = 1.67), decreased the postoperative requirement for tramadol (SMD = -0.65) and morphine (total: SMD = -2.23; patient-controlled analgesia: SMD = -1.45) as well as intraoperative requirement for fentanyl (SMD = -1.60), and lower the pain score at 1 (SMD = -0.30), 2 (SMD = -1.45), 4 (SMD = -2.36), 6 (SMD = -0.63), 8 (SMD = -2.47), 12 (SMD = -0.81), 24 (SMD = -1.78), 36 (SMD = -0.92), and 48 (SMD = -0.80) hours postoperatively compared with the control group. Furthermore, the risks to develop postoperative nausea/vomiting (PONV) (OR = 0.38) and vomiting (OR = 0.54) were significantly decreased in the DEX group compared with the control group. The pain relief at early time point (2, 6, 12, 24 hours postoperatively) and the decrease in the incidence of PONV were especially obvious for the general anesthesia subgroup (P < .05) relative to local anesthesia subgroup (P >.05).

CONCLUSION

DEX may be a favorable anesthetic adjuvant in breast cancer surgery, which could lower postoperative pain and the risk to develop PONV. DEX should be combined especially for the patients undergoing general anesthesia.

Preventing pain after breast surgery: A systematic review with meta-analyses and trial-sequential analyses

BACKGROUND AND OBJECTIVE

The aim of this systematic review was to indirectly compare the efficacy of any intervention, administered perioperatively, on acute and persistent pain after breast surgery.

DATABASES AND DATA TREATMENT

We searched for randomized trials comparing analgesic interventions with placebo or no treatment in patients undergoing breast surgery under general anaesthesia. Primary outcome was intensity of acute pain (up to 6 hr postoperatively). Secondary outcomes were cumulative 24-hr morphine consumption, incidence of postoperative nausea and vomiting (PONV), and chronic pain. We used an original three-step approach. First, meta-analyses were performed when data from at least three trials could be combined; secondly, trial sequential analyses were used to separate conclusive from unclear evidence. And thirdly, the quality of evidence was rated with GRADE.

RESULTS

Seventy-three trials (5,512 patients) tested loco-regional blocks (paravertebral, pectoralis), local anaesthetic infiltrations, oral gabapentinoids or intravenous administration of glucocorticoids, lidocaine, N-methyl-D-aspartate antagonists or alpha2 agonists. With paravertebral blocks, pectoralis blocks and glucocorticoids, there was conclusive evidence of a clinically relevant reduction in acute pain (visual analogue scale > 1.0 cm). With pectoralis blocks, and gabapentinoids, there was conclusive evidence of a reduction in the cumulative 24-hr morphine consumption (> 30%). With paravertebral blocks and glucocorticoids, there was conclusive evidence of a relative reduction in the incidence of PONV of 70%. For chronic pain, insufficient data were available.

CONCLUSIONS

Mainly with loco-regional blocks, there is conclusive evidence of a reduction in acute pain intensity, morphine consumption and PONV incidence after breast surgery. For rational decision making, data on chronic pain are needed.

SIGNIFICANCE

This quantitative systematic review compares eight interventions, published across 73 trials, to prevent pain after breast surgery, and grades their degree of efficacy. The most efficient interventions are paravertebral blocks, pectoralis blocks and glucocorticoids, with moderate to low evidence for the blocks. Intravenous lidocaine and alpha2 agonists are efficacious to a lesser extent, but with a higher level of evidence. Data for chronic pain are lacking.

Intranasal dexmedetomidine combined with local anesthesia for conscious sedation during breast lumpectomy: A prospective randomized trial

Breast lumpectomy is usually performed under general or local anesthesia. To the best of our knowledge, whether conscious sedation with intranasal dexmedetomidine and local anesthesia is an effective anesthetic technique has not been studied. Thus, the present study aimed to investigate the effectiveness of conscious sedation with intranasal dexmedetomidine combined with local anesthesia in breast lumpectomy, and to identify its optimal dose. A prospective randomized, double-blinded, placebo-controlled, single-center study was designed, and patients undergoing breast lumpectomies were recruited based on the inclusion and exclusion criteria. All patients were randomly allocated to four groups: i) Local anesthesia with 0.9% intranasal saline (placebo); local anesthesia with ii) 1 µg.kg⁻¹; iii) 1.5 µg.kg⁻¹; or iv) 2 µg.kg⁻¹ intranasal dexmedetomidine. The sedation status, pain relief, vital signs, adverse events, and satisfaction of patient and surgeon were recorded. Patients in the three dexmedetomidine groups were significantly more sedated and experienced less pain compared with the placebo group 45 min after intranasal dexmedetomidine administration and during 30 min in the post-anesthesia care unit. Patients in the 1.5 µg.kg⁻¹ group were more sedated compared with the 1 µg.kg⁻¹ group (without reaching statistical significance), whereas the 1.5 µg.kg⁻¹ group exhibited a similar level of sedation 45 min after intranasal dexmedetomidine administration compared with the 2 µg.kg⁻¹ group. In addition, patients in the 1 and 1.5 µg.kg⁻¹ group experienced no adverse hemodynamic effects. Patient and surgeon satisfaction were greater in the 1.5 µg.kg⁻¹ group compared with the 1 and 2 µg.kg⁻¹ groups. Taken together, the results of the present study suggested that conscious sedation with intranasal dexmedetomidine and local anesthesia may be an effective anesthetic for breast lumpectomy surgery, and that the optimal dose for intranasal dexmedetomidine administration may be 1.5 µg.kg⁻¹, as it resulted in good sedation and patient satisfaction without adverse effects.

Sleep Disturbances After General Anesthesia: Current Perspectives

The purpose of this article is to review (1) sleep mechanism under general anesthesia, harmful effects of postoperative sleep disturbances; (2) risk factors associated with postoperative sleep disturbances; (3) measures to prevent and improve postoperative sleep disturbances. General anesthesia changes the postoperative sleep structure especially in elderly patients after major surgery and results in a high incidence rate of sleep disturbances. Sleep disturbances produce harmful effects on postoperative patients and lead to a higher risk of delirium, more cardiovascular events, and poorer recovery. Some researchers do propose non-pharmacological treatments such as attention to environmental and psychological factors, application of electroacupuncture (EA) technology and pharmacological treatments are helpful, but larger high-quality clinical trials with longer following-up are needed to further investigate the efficacy and safety.

Efficacy of Dexmedetomidine vs Morphine as an Adjunct in a Paravertebral Block with Bupivacaine in Postoperative Analgesia Following Modified Radical Mastectomy

Objective

To observe the efficacy of dexmedetomidine vs morphine as an adjunct in a paravertebral block (PVB) with bupivacaine in postoperative analgesia following modified radical mastectomy.

Study design

This was a randomized controlled trial performed from June 2018 to August 2019 in the Department of Anesthesia, Bakhtawar Amin Medical and Dental College, Ch. Pervaiz Ellahi Institute of Cardiology, Multan, Gurki Hospital, Services Institute of Medical Sciences, and Sheikh Zayed Hospital, Lahore.

Methodology

Seventy-eight patients were equally divided into group M, which received morphine (3 mg) and group D, which received dexmedetomidine (1 µg/kg), along with 20 cc 0.25% bupivacaine, for PVB. The primary outcome included morphine requirements in the post-anesthesia care unit (PACU). Secondary outcomes included the quality and duration of analgesia, intraoperative doses of fentanyl and propofol, postoperative doses of diclofenac required, postoperative nausea and vomiting (PONV), and the Ramsey sedation score. Data were entered into SPSS version 23 (IBM Corp., Armonk, NY) and analyzed by applying the independent t-test, Mann Whitney U-test, and the chi-square test or Fischer’s exact test, as appropriate. P≤0.05 was considered statistically significant.

Results

The mean time for the first analgesic administration was much shorter in group D as compared to group M (p<0.001). The average doses of ephedrine and morphine used were higher in group D (p-value 0.033 and 0.013, respectively). In the PACU, 33.3% of group D patients as compared to 12.8% of group M patients needed morphine (p=0.032). Postoperatively, diclofenac consumption was higher in group D (p<0.001). Postoperative pain was lower and sedation was higher in group M (p<0.05).

Conclusion

As an adjunct to bupivacaine in PVB for MRM, morphine is superior to dexmedetomidine.

Ultrasound-guided transversus abdominis plane block using ropivacaine and dexmedetomidine in patients undergoing caesarian sections to relieve post-operative analgesia: A randomized controlled clinical trial

Dexmedetomidine, which is a highly selective α2 adrenoreceptor agonist, enhances the analgesic efficacy and prolongs the analgesic duration when administered in combination with local anesthetics. The current study aimed to evaluate the effects of dexmedetomidine combined with ropivacaine in ultrasound-guided transversus abdominis plane (TAP) block on post-operative analgesia following cesarean section (CS). A total of 70 patients scheduled for CS were divided randomly into 2 groups: The ropivacaine (R) group, in which patients were administered bilateral 20 ml 0.3% ropivacaine and 2 ml 0.9% normal saline, and the dexmedetomidine (RD) group, in which patients were administered bilateral 20 ml 0.3% ropivacaine and 2 ml dexmedetomidine (0.5 µg/kg). The primary outcome was pain-free duration, and secondary outcomes included heart rate (HR) and mean blood pressure (MBP) measurements, visual analogue scale (VAS) pain scores, number of patients who required rescue analgesic, time to first request for analgesia and patient satisfaction. There was no significant difference in HR and MBP between the two groups at 1 h post-surgery (P>0.05). However, VAS pain scores decreased at 6 and 8 h post-surgery [2 (1-2) vs. 0 (0-0.25) and 2 (2-3) vs. 0 (0-1), respectively; P<0.05], pain-free duration was prolonged (5.91±1.08 vs. 9.62±1.46 h; P<0.05), the number of patients who required rescue analgesic was reduced (19 vs. 9; P<0.05), the time to first request for analgesia was prolonged (7.10±1.21 vs. 11.60±2.11 h; P<0.05) and patient satisfaction was improved [3.5 (3-4) vs. 4 (4-5); P<0.05] in the RD group compared with the R group. Furthermore, no bradycardia or hypotension was observed. In conclusion, the results of the present study demonstrated that adding 0.5 µg/kg dexmedetomidine to 0.3% ropivacaine used in TAP block in patients undergoing CS prolonged pain-free duration, decreased VAS pain scores, reduced the number of patients who required rescue analgesic, prolonged the time to first request for analgesia and improved the patient satisfaction without serious side effects.

PROSPECT guideline for oncological breast surgery: a systematic review and procedure-specific postoperative pain management recommendations

Analgesic protocols used to treat pain after breast surgery vary significantly. The aim of this systematic review was to evaluate the available literature on this topic and develop recommendations for optimal pain management after oncological breast surgery. A systematic review using preferred reporting items for systematic reviews and meta-analysis guidance with procedure-specific postoperative pain management (PROSPECT) methodology was undertaken. Randomised controlled trials assessing postoperative pain using analgesic, anaesthetic or surgical interventions were identified. Seven hundred and forty-nine studies were found, of which 53 randomised controlled trials and nine meta-analyses met the inclusion criteria and were included in this review. Quantitative analysis suggests that dexamethasone and gabapentin reduced postoperative pain. The use of paravertebral blocks also reduced postoperative pain scores, analgesia consumption and the incidence of postoperative nausea and vomiting. Intra-operative opioid requirements were documented to be lower when a pectoral nerves block was performed, which also reduced postoperative pain scores and opioid consumption. We recommend basic analgesics (i.e. paracetamol and non-steroidal anti-inflammatory drugs) administered pre-operatively or intra-operatively and continued postoperatively. In addition, pre-operative gabapentin and dexamethasone are also recommended. In major breast surgery, a regional anaesthetic technique such as paravertebral block or pectoral nerves block and/or local anaesthetic wound infiltration may be considered for additional pain relief. Paravertebral block may be continued postoperatively using catheter techniques. Opioids should be reserved as rescue analgesics in the postoperative period. Research is needed to evaluate the role of novel regional analgesic techniques such as erector spinae plane or retrolaminar plane blocks combined with basic analgesics in an enhanced recovery setting.

Combination of post-fascia iliaca compartment block and dexmedetomidine in pain and inflammation control after total hip arthroplasty for elder patients: a randomized control study

Objective

This study aims to investigate the efficiency of fascia iliaca compartment block (FICB) combined with dexmedetomidine (DEX) in postoperative and inflammation management for elder patients after total hip arthroplasty.

Methods

The present randomized controlled study included a total of 119 elder patients who received total hip arthroplasty in our hospital from March 2016 to December 2018. These patients were divided into three groups: control group, patients received routine general anesthesia; FICB group, patients received additional FICB after surgery; and combined group, patients received both pre-treatment of DEX and post-treatment of fascia iliaca compartment block. The serum levels of interleukin (IL)-1β, IL-6, and C-reactive protein (CRP) were measured by ELISA. The visual analog scale (VAS) score was measured at 12, 24, 48, and 72 h after surgery, and the patient-controlled intravenous analgesia (PCIA) pressing time within 48 h after surgery was also recorded. The Pittsburgh sleep quality index (PSQI) was used to measure the sleep quality before and at 1 month after surgery.

Results

The VAS scores were significantly lower in patients in the combined group, when compared with the other two groups, at 12, 24, 48, and 72 h after surgery. In addition, the VAS scores at all time points were significantly lower in the FICB group than the control group. The PCIA pressing times were also remarkably lower in the combined group. At 4, 24, 48, and 72 h after surgery, the serum levels of these inflammatory factors were the lowest in the combined group, and the PSQI scores were significantly lower in the combined group, when compared with the other two groups, while the control group had the highest PSQI scores among the three groups. There was no severe side effects and significant difference observed.

Conclusion

FICB combined with DEX reduced the postoperative pain, improved the sleep condition, and decreased the serum levels of inflammatory factors after total hip arthroplasty.

Molecular Basis of Cancer Pain Management: An Updated Review

Pain can have a significantly negative impact on the quality of life of patients. Therefore, patients may resort to analgesics to relieve the pain. The struggle to manage pain in cancer patients effectively and safely has long been an issue in medicine. Analgesics are the mainstay treatment for pain management as they act through various methods on the peripheral and central pain pathways. However, the variability in the patient genotypes may influence a drug response and adverse drug effects that follow through. This review summarizes the observed effects of analgesics on UDP-glucuronosyl (UGT) 2B7 isoenzyme, cytochrome P450 (CYP) 2D6, μ-opioid receptor μ 1 (OPRM1), efflux transporter P-glycoprotein (P-gp) and ATP-binding cassette B1 ABCB1/multiple drug resistance 1 (MDR1) polymorphisms on the mechanism of action of these drugs in managing pain in cancer. Furthermore, this review article also discusses the responses and adverse effects caused by analgesic drugs in cancer pain management, due to the inter-individual variability in their genomes.

Efficacy of dexmedetomidine as an adjuvant to local wound infiltration anaesthesia in abdominal surgery: A meta-analysis of randomised controlled trials

To assess the efficacy and safety of dexmedetomidine (DEX) as an adjuvant to local wound infiltration anaesthesia in abdominal surgery, we conducted this meta-analysis. First, the systematic search strategy was performed on PubMed, Embase, and Cochrane Library and five randomised controlled trials (RCTs) involving 294 patients were included. Then, the outcome data were extracted from the studies and their effect sizes were calculated using Review Manager 5. As a result, the addition of DEX significantly reduced visual analogy scores at 6 hours after surgery (mean difference = -0.53[-0.82, -0.25], P < .001), 12 hours after surgery (mean difference = -0.39 [-0.73, -0.05]; P = .03), and 24 hours after surgery (mean difference = -0.20 [-0.29, -0.11], P < .001) and reduced total analgesic consumption within 24 hours after surgery (mean difference = -4.92 [-9.00, -0.84]; P = .02) compared with placebo groups. However, there was no difference in the incidence of postoperative nausea and vomiting (risk ratio = 0.68 [0.41, 1.14]; P = .14). In summary, DEX as a local anaesthetic adjuvant added for local wound infiltration anaesthesia in abdominal surgery could reduce visual analogy scores and postoperative analgesic consumption without changing incidence of postoperative nausea and vomiting.

Ultrasound-guided continuous serratus anterior plane block: dexmedetomidine as an adjunctive analgesic with levobupivacaine for post-thoracotomy pain. A prospective randomized controlled study

Purpose: The study aimed to evaluate the analgesic efficiency of dexmedetomidine (DEX) when added to levobupivacaine in continuous ultrasound-guided serratus anterior plane block (SAPB) performed at the end of major thoracic surgery.

Methods: This randomized, double-blind trial included 50 adults undergoing thoracic surgery. Continuous SAPB was performed at the end of surgery. Patients were randomized into two groups. Group L (n=25) received levobupivacaine only while Group DL (n=25) received a mixture of levobupivacaine and DEX. All patients received intravenous (IV) paracetamol every 8 hrs. Morphine IV was given according to VAS score of pain as a 5 mg loading dose. The primary outcome measure was postoperative pain intensity. Secondary outcome measures were postoperative morphine consumption and adverse effects.

Results: Analgesia was satisfactory in the two groups up to 24 hrs. VAS score was significantly lower in group DL compared to group L between 6 and 24 hrs postoperatively. Total morphine consumption was significantly lower in group DL compared to group L (p<0.001). Up to 12 hrs postoperatively, sedation score was significantly lower in group DL compared to group L. Afterwards, all patients were fully alert. All values of mean arterial pressure and heart rate were within the clinically accepted ranges. There were no recorded cases of hypotension or bradycardia in the whole studied group.

Conclusions: Continuous SAPB with levobupivacaine plus DEX seems to be a promising analgesic alternative following thoracotomy. Combined with IV paracetamol, this approach provided adequate analgesia and proper sedation.

Trial registration: ISRCTN registry; study ID: ISRCTN35517318

Thoracic Paravertebral Block with Adjuvant Dexmedetomidine in Video-Assisted Thoracoscopic Surgery: A Randomized, Double-Blind Study

Background: The addition of the adjuvant dexmedetomidine to a nerve block improves the quality of the block and reduces perioperative opioid consumption. The aim of this study was to assess the effect of dexmedetomidine as an adjuvant for the thoracic paravertebral block (TPVB) in postoperative pain control after video-assisted thoracoscopic surgery (VATS). Methods: Sixty-six males, aged 15–40 years, with spontaneous pneumothorax scheduled for VATS wedge resection were enrolled. Following surgery, ultrasound-guided TPVB was performed on the T3 and T5 levels with 30 mL of 0.5% ropivacaine, plus adjuvant dexmedetomidine 50 μg or normal saline. The primary outcome was cumulative fentanyl consumption at 24 h. Pain severity, the requirement for additional rescue analgesics, hemodynamic variations, and side effects were also evaluated. Results: Median postoperative cumulative fentanyl consumption at 24 h was significantly lower in the dexmedetomidine group (122.6 (interquartile range (IQR) 94.5–268.0) μg vs. 348.1 (IQR, 192.8–459.2) μg, p-value = 0.001) with a Hodges–Lehman median difference between groups of 86.2 (95% confidence interval (CI), 4.2–156.4) mg. Coughing numeric rating scale (NRS) was lower in the dexmedetomidine group at postoperative 2, 4, 8, and 24 h. However, resting NRS differed significantly only after 4 h postoperative. Conclusions: Dexmedetomidine as an adjunct in TPVB provided effective pain relief and significantly reduced opioid requirement in VATS.

The Effect Of Intraoperative Use Of Dexmedetomidine During The Daytime Operation Vs The Nighttime Operation On Postoperative Sleep Quality And Pain Under General Anesthesia

OBJECTIVES

The aim of our study was to compare the effect of using dexmedetomidine (DEX) during the daytime operation or the nighttime operation under general anesthesia on postoperative sleep quality and pain of patients.

METHODS

Seventy-five patients scheduled for elective laparoscopic abdominal surgeries under general anesthesia were randomly assigned to receive operation in the Day Group (8:00-12:00) and the Night Group (18:00-22:00). The Portable Sleep Monitor (PSM) was performed on the following 3 nights: the night before surgery (Sleep 1), the first night after surgery (Sleep 2), and the third night after surgery (Sleep 3). Postoperative pain scores using visual analogue scoring scale, subjective sleep quality using the Athens Insomnia Scale, total dose of general anesthetics and PCA pump press numbers were also recorded.

RESULTS

Intraoperative administration of DEX for patients in the Day Group could improve sleep quality with a higher sleep efficiency and a lower AIS subjective sleep quality than patients in the Night Group at Sleep 2 (P < 0.001 and P = 0.001, respectively) and Sleep 3 (P < 0.001, respectively). There were marked lower rapid eye movement (REM) sleep and Stable sleep in the Night Group than that in the Day Group at Sleep 2 (P < 0.001 and P = 0.032, respectively) and Sleep 3 (P < 0.001, respectively). Patients in the Day Group have better pain relief and less PCA pump press numbers than patients in the Night Group.

CONCLUSION

Using dexmedetomidine during the daytime operation can better improve postoperative sleep quality and pain than nighttime operation in patients undergoing laparoscopic abdominal surgeries.

Dexmedetomidine combined with local anesthetics in thoracic paravertebral block: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Dexmedetomidine (DEX) improves postoperative pain scores and prolongs the duration of blockage when combined with local anesthetics (LAs) for neuraxial and brachial plexus block; however, there is little information about the effectiveness of DEX as an adjuvant to LAs in paravertebral block (PVB). Therefore, a systematic review and meta-analysis were performed to evaluate the safety and efficacy of DEX combined with LAs in PVB.

METHOD

An electronic database search from inception date to February 2018 was performed. Randomized controlled trials (RCTs) comparing DEX as an adjuvant to LAs with LAs alone for PVB in adult patients were included. Postoperative pain scores, duration of analgesia, cumulative perioperative analgesic consumption, and adverse events were analyzed.

RESULT

We identified 7 trials enrolling 350 patients and found that DEX reduced pain scores at rest by standardized mean differences (SMD) -0.86 cm (95% confidence interval [CI] [-1.55, -0.17], P = .01) and SMD -0.93 cm (95% CI [-1.41, -0.26], P =.008) at postoperative 12 hours and 24 hours, respectively. DEX reduced pain scores while dynamic by SMD -1.63 cm (95% CI [-2.92, -0.34], P =.01) and SMD -1.78 cm (95% CI [-2.66, -0.90], P =.007) for postoperative 12 hours and 24 hours, respectively. DEX extended the duration of analgesia by weighted mean differences (WMD) 201.53 minutes (95% CI [33.45, 369.61], P =.02); and reduced cumulative postoperative analgesic consumption by WMD -7.71 mg (95% CI [-10.64, -4.78], P <.001) and WMD -45.64 mg (95% CI [-69.76, -21.53], P < .001) for 24 hours morphine and 48 hours tramadol subgroups, respectively. DEX also increased the odds of hypotension by odds ratio (OR) 4.40 (95% CI [1.37, 14.17], P = .01); however, there was no statistically significant difference for intraoperative fentanyl consumption and the incidence of the bradycardia.

CONCLUSIONS

DEX combined with LAs in PVB significantly improved postoperative pain scores, prolonged the duration of analgesia, reduced postoperative analgesic consumption, and increased the odds of hypotension. However, we cannot neglect the heterogeneity of the included RCTs. More large-scale prospective studies are needed to further clarify the above conclusions.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number CRD42018090251.

Effects of anesthetic interventions on breast cancer behavior, cancer-related patient outcomes, and postoperative recovery

This narrative review will summarize our current understanding of the effects of perioperative interventions on patients undergoing surgical removal of breast malignancies. It will focus on how different anesthetic agents and perioperative interventions might affect both breast cancer behavior and/or tumor recurrence as well as postoperative recovery. The main objective of this study will be to describe the evidence and critically analyze preclinical and clinical studies on the use of intravenous versus inhaled anesthetic agents, opioids, regional anesthetics, and anesthetic adjuncts in patients undergoing breast cancer resection. We will look both at the evidence regarding cancer-related outcomes and postoperative recovery. A search of PubMed, from inception to May 2017 was performed using Mesh terms Breast Neoplasms [Mesh] OR cancer AND breast AND Anesthesia [Mesh]; "Anesthetics"[Mesh] AND "Breast Neoplasms/surgery"[Mesh]. Although no optimal anesthetic combination has been identified for patients undergoing breast cancer resection, it should be noted that based on the available evidence, an ideal anesthetic in this patient population would involve a combination of TIVA (propofol), regional anesthesia (paravertebral block)), non opioid sedatives (clonidine or dexmedetomidine), and COX-2 inhibition (ketorolac). Based on the current evidence, this combination of anesthetic and analgesic agents has the best chance of improving cancer-related outcomes and postoperative recovery.

Effect of Dexmedetomidine Versus Nalbuphine as an Adjuvant on Paravertebral Block to Manage Postoperative Pain After Mastectomies

Background and Objective

Breast cancer is the commonest cancer in women worldwide. Many patients are frequently admitted to the operating theaters for mastectomies. Thoracic paravertebral block (PVB) is increasingly used as an effective means for post-operative pain relief. The present study aimed at evaluating the effectiveness and safety of dexmedetomidine and nalbuphine as an adjuvant to bupivacaine local anesthetic in thoracic paravertebral block in breast cancer surgeries.

Methods

A total of 60 female patients aged 18 to 78 were included in the study, and ASA I, II, III were scheduled for mastectomy. These patients were unsystematically assigned into three 20-member groups: group PB received bupivacaine (0.3 mL/ kg) + 1 mL (0.9% sodium chloride) normal saline; group PBD received bupivacaine (0.3 mL/kg) + dexmedetomidine 1 μg/kg; and Group PBN received bupivacaine (0.3 mL/kg) and 10 mg (1 mL) nalbuphine. Demographic data, intraoperative SPO₂, ETCO₂, HR, SBP and DBP, pain scores (at rest and movement), and sedation scores were recorded every 30 minutes during the initial 2 hours and 4, 8, 24, and 48 hours from T0. Also, postoperative tramadol consumption, the time to the first analgesic request, and any complications were also recorded.

Results

There were no statistically significant differences among the three groups regarding demographic data, SPO₂, ETCO₂, HR, SBP and DBP intraoperatively. Moreover, no significant difference was found in HR, SBP and DBP postoperatively. Postoperative pain scores were significantly higher in group BP, whether at rest or movement. The sedation was significantly higher in PBD group in the first 12 hours postoperatively. There was a significantly lower postoperative tramadol consumption in PBN group and a significantly longer time to the first analgesic request than other groups. No complications were reported in any group.

Conclusions

Addition of nalbuphine 10 mg as an adjuvant to bupivacaine local anesthetic in PVB improved the quality of the block and decreased postoperative analgesic requirements than the bupivacaine only group and dexmedetomidine and bupivacaine group. However, adding dexmedetomidine to bupivacaine increased the time to the first analgesic request and more sedation than bupivacaine and bupivacaine and nalbuphine.

Endogenous Opiates and Behavior: 2016

This paper is the thirty-ninth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2016 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia, stress and social status, tolerance and dependence, learning and memory, eating and drinking, drug abuse and alcohol, sexual activity and hormones, pregnancy, development and endocrinology, mental illness and mood, seizures and neurologic disorders, electrical-related activity and neurophysiology, general activity and locomotion, gastrointestinal, renal and hepatic functions, cardiovascular responses, respiration and thermoregulation, and immunological responses.

Effects of adding dexamethasone or ketamine to bupivacaine for ultrasound-guided thoracic paravertebral block in patients undergoing modified radical mastectomy: A prospective randomized controlled study

Background and Aims:

Pain after modified radical mastectomy (MRM) has been successfully managed with thoracic paravertebral block (TPVB). The purpose of this study was to evaluate the effect of adding dexamethasone or ketamine as adjuncts to bupivacaine in TPVB on the quality of postoperative analgesia in participants undergoing MRM.

Methods:

This prospective randomised controlled study enrolled ninety adult females scheduled for MRM. Patients were randomised into three groups (30 each) to receive ultrasound-guided TPVB before induction of general anaesthesia. Group B received bupivacaine 0.5% + 1 ml normal saline, Group D received bupivacaine 0.5% + 1 ml dexamethasone (4 mg) and Group K received bupivacaine 0.5% + 1 ml ketamine (50 mg). Patients were observed for 24 h postoperatively to record time to first analgesic demand as a primary outcome, pain scores, total rescue morphine consumption and incidence of complications.

Results:

Group K had significantly longer time to first analgesic demand than group D and control group (18.0 ± 6.0, 10.3 ± 4.5 and 5.3 ± 3.1 hours respectively; P = 0.0001). VAS scores were significantly lower in group D and group K compared to control group at 6h and 12 h postoperative (p 0.0001 and 0.0001 respectively) while group K had lower VAS at 18 hours compared to other two groups (P = 0.0001). Control group showed the highest mean 24 h opioid consumption (8.9 ± 7.9 mg) compared to group D and group K (3.60 ± 6.92 and 2.63 ± 5.24 mg, P = 0.008,0.001 respectively). No serious adverse events were observed.

Conclusion:

Ketamine 50 mg or dexamethasone 4 mg added to bupivacaine 0.5% in TPVB for MRM prolonged the time to first analgesic request with no serious side effects.

Effect of dexmedetomidine as an adjuvant to ropivacaine for wound infiltration in patients undergoing open gastrectomy: A prospective randomized controlled trial

OBJECTIVES

The primary objective of this study was to investigate whether dexmedetomidine could potentiate the analgesic efficacy of ropivacaine, when added to ropivacaine for wound infiltration in patients undergoing open gastrectomy.

METHODS

Fifty patients scheduled for open gastrectomy were divided into 2 equal groups that were received wound infiltration using 20 mL 0.3% ropivacaine plus 2 mL normal saline (group R) or 20 mL 0.3% ropivacaine plus 2 mL 1.0 μg/kg dexmedetomidine (group DR). Visual analogue scale (VAS) pain score, patient-controlled analgesia (PCA) pump press number, sufentanil consumption, postoperative nausea and vomiting (PONV), and wound healing score were recorded.

RESULTS

The VAS pain score were comparable between the 2 groups at the observation time points (P > .05), PCA pump press number and sufentanil consumption were higher in group R than that in group DR at 0 to 2, 2 to 4, 4 to 6 time intervals (P < .05) except for 6 to 8, 8 to 10, 10 to 12 time intervals (P > .05), meanwhile, the 24 hours total sufentanil consumption was also higher in group R than that in group DR (90.4 ± 20.5 vs 79.2 ± 9.4) (P < .05), there were no significant differences in PONV and wound healing score between the 2 groups (P > .05).

CONCLUSIONS

Dexmedetomidine as an adjuvant to ropivacaine for wound infiltration promoted the analgesic efficacy of ropivacaine, reduced sufentanil consumption, and had no effect on wound healing; it could be as an ideal adjuvant which could potentiate the analgesic efficacy of local anesthetics.

Multilevel Thoracic Paravertebral Block Using Ropivacaine With/Without Dexmedetomidine in Video-Assisted Thoracoscopic Surgery

OBJECTIVES

Thoracic paravertebral block (TPVB) is reported to have advantages in postoperative pain management in unilateral thoracic surgeries. Previous studies have demonstrated that dexmedetomidine could be used as an adjuvant to local anesthetics, with the aim of prolonging the duration of neural blockade. However, little is known about whether such a combination could improve the quality of postoperative analgesia compared with local anesthetic only when TPVB is used for patients undergoing video-assisted thoracoscopic surgery (VATS).

DESIGN

A prospective, randomized, controlled study.

SETTING

Single-center university hospital.

PARTICIPANTS

The study included 60 patients undergoing VATS under general anesthesia.

INTERVENTIONS

The patients were allocated randomly into the following 2 groups: 0.375% ropivacaine, 20 mL only (group R, n = 30), and 0.375% ropivacaine, 20 mL plus 1 μg/kg of dexmedetomidine (group RD, n = 30). At the end of surgery, TPVB guided using ultrasound was performed at 4 points-T4-5, T5-6, T6-7, and T7-8-of the surgical side; 5 mL of solution were injected at each point. Postoperatively, the intravenous nonsteroidal anti-inflammatory drug flurbiprofen was used as part of multimodal analgesia.

MEASUREMENTS AND MAIN RESULTS

Pain scores at rest and during coughing were evaluated by a blinded observer in the postanesthesia care unit postoperatively at 1, 2, 4, 8, 12, 24, 36, and 48 hours, and the dermatomal levels of sensory blockade, postoperative requirements for rescue analgesia, adverse events, and patient satisfaction also were recorded. There was a significant reduction in postoperative pain scores at rest starting from the postoperative 8th hour until the 48th hour and during coughing starting at the postoperative 4th hour until the 48th hour in the group RD compared with those in group R (p = 0.043). The dermatomal levels of sensory blockade were comparable in the 2 groups. Patient satisfaction after surgery was significantly higher in the group RD than in group R (p < 0.001). Total consumption of the intravenous rescue analgesic morphine and adverse events were not significantly different between the 2 groups.

CONCLUSIONS

Compared with ropivacaine only, the addition of dexmedetomidine, 1 μg/kg, to local anesthetic for multilevel TPVB in patients undergoing VATS prolonged the duration of postoperative analgesia and improved patient satisfaction without serious side effects when combined with postoperative intravenous nonsteroidal anti-inflammatory drug administration.

Intraoperative use of dexmedetomidine promotes postoperative sleep and recovery following radical mastectomy under general anesthesia

Postoperative sleep disturbance and fatigue following radical mastectomy were high risks for prolonged convalescence in patients with breast cancer. The present study was designed to observe the effect of intraoperative use of dexmedetomidine on postoperative sleep, fatigue and recovery following radical mastectomy under general anesthesia. Forty-seven patients were randomized into two groups that were maintained with propofol/remifentanil/Ringer's solution (Control group), or propofol/remifentanil/Dexmedetomidine (DEX group) for surgery under general anesthesia. During the first night following surgery, patients receiving dexmedetomine spent more time sleeping when compared with those form the Control group. During the first week following operation, when compared with the Control group, patients from the DEX group had a higher score of global 40-item recovery questionnaire on day 3 following operation, and lower 9-question fatigue severity scores on day 3 and day 7 following operation. In conclusion, intraoperative use of dexmedetomidine is sufficient to improve postoperative sleep disorder, promote postoperative recovery. The adverse effect of dexmedetomidine on sleep disturbance might be contributed to its recovery-promoting effect.

Dexmedetomidine Improves Postoperative Patient-Controlled Analgesia following Radical Mastectomy

Acute postoperative pain following radical mastectomy is a high risk for prolonged convalescence and potential persistent pain in patients with breast cancer. The present study was designed to observe the effect of intraoperative use of dexmedetomidine on acute postoperative pain following radical mastectomy under general anesthesia. Forty-five patients were enrolled into the study and divided into two groups that were maintained with propofol/remifentanil/Ringer's solution or propofol/remifentanil/Dexmedetomidine followed by morphine-based patient-controlled analgesia. During the first 24 h following surgery, patients receiving dexmedetomine had lower NRS pain scores, decreased morphine consumption, longer time to first morphine request as well as a trending decreased incidence of adverse effects when compared to those received Ringer's solution. In conclusion, the present study finds that intraoperative use of dexmedetomidine could promote analgesic property of postoperative morphine.

Evaluation of the role of dexmedetomidine in improvement of the analgesic profile of thoracic paravertebral block in thoracic surgeries: A randomised prospective clinical trial

Background and Aims:

Thoracic paravertebral block (TPB) is one of the effective methods for management of post-operative pain in thoracic surgeries. The aim of the study was to evaluate effectiveness of addition of dexmedetomidine to paravertebral block with bupivacaine in improving the postoperative pain relief and pulmonary functions in patients undergoing thoracic surgeries.

Methods:

A prospective randomized double-blinded study was performed on forty patients scheduled for thoracic surgery. A paravertebral catheter was secured under ultrasound guidance preoperatively for all patients. Group B (n = 20) received a bolus dose of 0.25% bupivacaine at 0.3 mL/kg followed by continuous infusion of 0.125% bupivacaine 0.1 mL/kg/h. Group (BD) received a bolus dose of 0.25% bupivacaine + dexmedetomidine 1 μg/kg at 0.3 mL/kg followed by continuous infusion of dexmedetomidine 0.2 μg/kg/h + 0.125% bupivacaine 0.1 mL/kg/h. Anaesthesia technique was standardized for all patients. Postoperatively, all patients were assessed during first 24 hours for intraoperative fentanyl and post-operative morphine requirements, Visual Analogue Scores (VAS) scores at rest and during cough, and postoperative pulmonary functions.

Results:

Post-operative morphine consumption in the first 24 hours and intraoperative fentanyl requirement were significantly less in group BD (2.95 ± 1.986 mg, 80.75 ± 31.551μg respectively) compared to group B (9.85 ± 3.468 mg, 186 ± 39.683 μg respectively). Group BD showed less VAS scores during cough and better postoperative pulmonary functions (P < 0.05).

Conclusion:

Addition of dexmedetomidine to paravertebral bupivacaine in patients undergoing thoracic surgeries provides more effective analgesia with improvement in post-operative pulmonary functions.