Comparison of Dexmedetomidine and Morphine as Adjuvants to Bupivacaine for Epidural Anesthesia in Leg Fracture Surgery: A Randomized Clinical Trial

Adding Ketamine to Epidural Morphine Does Not Prolong Postoperative Analgesia After Lumbar Laminectomy or Discectomy

BACKGROUND

Epidural opioids provide effective postoperative analgesia after lumbar spine surgery. Ketamine has been shown to reduce opioid-induced central sensitization and hyperalgesia. We hypothesized that adding ketamine to epidural opioids would prolong the duration of analgesia and enhance analgesic efficacy after lumbar spine surgery.

METHODS

American Society of Anesthesiologists physical status class I to II patients aged between 18 and 70 years with normal renal function undergoing lumbar laminectomy were recruited into this single-center randomized trial. Patients were randomized to receive either single-dose epidural morphine (group A) or epidural morphine and ketamine (group B) for postoperative analgesia. The primary objective was to compare the duration of analgesia as measured by time to the first postoperative analgesic request. Secondary objectives were the comparison of pain scores at rest and movement, systemic hemodynamics, and the incidence of side effects during the first 24 hours after surgery.

RESULTS

Fifty patients were recruited (25 in each group), of which data from 48 were available for analysis. The mean±SD duration of analgesia was 20±6 and 23±3 hours in group A and group B, respectively ( P =0.07). There were 12/24 (50%) patients in group A and 17/24 (71%) patients in group B who did not receive rescue analgesia during the first 24-hour postoperative period ( P =0.07). Pain scores at rest and movement, systemic hemodynamics, and postoperative complications were comparable between the groups.

CONCLUSIONS

The addition of ketamine to epidural morphine did not prolong the duration of analgesia after lumbar laminectomy.

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.

Dexmedetomidine versus sufentanil as adjuvants to bupivacaine for brachial plexus block during upper extremity surgery: a randomized clinical trial

BACKGROUND

Brachial plexus block (BPB) has been accepted as a reliable alternative for general anesthesia in upper limb surgeries. Adding adjuvant drugs like dexmedetomidine and sufentanil has been shown to have clinical and pharmacologic advantages. In this randomized parallel clinical trial, we aim to compare the effects of these two adjuvants for bupivacaine in BPB.

METHODS

In this double-blinded study, by using computer-assisted block randomization, 40 patients ranged from 20 to 65 years old and scheduled for elective upper limb surgeries were assigned to two equal study groups (n = 20), receiving 1 mL of 5 ..g.mL-1 sufentanil (group S) or 1 mL of 100 ..g.mL-1 dexmedetomidine (group D) in adjunction to 30 mL of 0.5% bupivacaine for supraclavicular BPB under the guidance of ultrasonography. Characteristics of local anesthesia and postoperative analgesia were evaluated (n = 40).

RESULTS

The duration of blocks significantly improved in group S (sensory: estimated median difference (EMD) [95%CI] = 100.0 [70.0...130.0], p < 0.001; motor: EMD [95%CI] = 120.0 [100.0...130.0], p < 0.001). Group S also had significantly longer postoperative analgesia and lower opioid consumption within 24 hours after the surgery (EMD [95%CI] = 4.0 [3.0...7.0], p < 0.001; EMD [95%CI] = -5.0 [-5.0...-5.0], p < 0.001; respectively). None of the patients showed adverse effects concerning vital signs, nausea, or vomiting.

CONCLUSION

Our study showed that during ultrasound-guided supraclavicular BPB, sufentanil is a fairly better choice than dexmedetomidine as an adjuvant for bupivacaine and can provide preferable sensory and motor blocks. No significant side effects were seen in either of the study groups.

Dexmedetomidine or Fentanyl, Which One Is Better as an Adjunct Drug in Epidural Anesthesia and Causes More Postoperative Pain Reduction? A Comparative Study, a Randomized Clinical Trial

Objectives

This study compared dexmedetomidine to fentanyl as an adjunct to ropivacaine for epidural anesthesia in patients undergoing femoral neck fracture surgery.

Methods

A total of 56 patients in two different groups with dexmedetomidine and fentanyl underwent the epidural anesthesia method by ropivacaine. This study compared the onset and duration of sensory block, duration of motor block, visual analog scale (VAS) analgesia, and sedation score. The VAS and hemodynamics (e.g., heart rate and mean arterial pressure) were measured every 5 to 15 minutes, then every 15 minutes to the end of the surgery, and then in the 1st, 2nd, 4th, 6th, 12th, and 24th hours after surgery.

Results

In the fentanyl group, the onset time of the sensory block was longer (P < 0.001), and the duration of the block was shorter than in the dexmedetomidine group (P = 0.045). In the fentanyl group, the onset time of motor block was longer than in the dexmedetomidine group (P < 0.001). The mean highest VAS score for each patient in the dexmedetomidine group was 4.9 ± 0.6, compared to the fentanyl group (5.8 ± 0.9), with a significant difference between the two groups (P < 0.001). The sedation score was higher from the 30th minute (P = 0.01) to the 120th minute (P = 0.04) in the patients of the dexmedetomidine group than in the fentanyl group. Side effects, such as dry mouth, hypotension, and bradycardia, were more common in the dexmedetomidine group, and nausea and vomiting were more common in the fentanyl group; however, there were no differences between the groups. There was no respiratory depression in both groups.

Conclusions

This study presented that dexmedetomidine as an adjuvant in epidural anesthesia for orthopedic femoral fracture surgery shortens the onset time of sensory and motor block, increases analgesia length, and prolongs anesthesia. Sedation with dexmedetomidine is better than fentanyl, with fewer side effects, and more effective as preemptive analgesia.

The Influence of Analgesic Modalities on Postoperative Cancer Recurrence

The potential for cancer cells to grow and to metastasize depends on complex interactions between inflammatory signals and pathways, immune cells, and elements of the stromal tissue in which they invade. Related to the nature of many cancers, the probability of recurrence can potentially be quite high for some patients. Immunology, lifestyle modifications, timing of disease, genetics, age, gender, and race are only a handful of ways the likelihood of cancer recurrence can be influenced. The quantity, or density, of certain immunological cells or factors, plays a role in the propagation of cancer cells. Opioids are often used in cancer patients for acute postoperative and chronic pain management. While they can produce significant pain relief, the type of analgesic utilized is important, as it may influence cancer propagation. In this regard, certain opioids have been found to increase T regulatory cells while suppressing NK cell function. Morphine may promote tumor neovascularization and expansion. Fentanyl administration significantly diminishes NK-cells and CD8+ cytotoxic T-cells. In a recent meta-analysis, propofol-based anesthesia improved both cancer-free survival and overall survival. COX inhibitors have also shown promise in persevering cancer immune function, as in literature involving ketorolac and celecoxib. In summary, inhaled anesthesia and opioids may contribute to a pro-tumor metastasis environment also known as cancer propagation; whereas propofol and COX inhibitors may provide a better alternative to reduce cancer recurrence and propagation.

Novel Local Anesthetics in Clinical Practice: Pharmacologic Considerations and Potential Roles for the Future

The treatment of pain, both acute and chronic, has been a focus of medicine for generations. Physicians have tried to develop novel ways to effectively manage pain in surgical and post-surgical settings. One intervention demonstrating efficacy is nerve blocks. Single-injection peripheral nerve blocks (PNBs) are usually preferred over continuous PNBs, since they are not associated with longer lengths of stay. The challenge of single injection PNBs is their length of duration, which at present is a major limitation. Novel preparations of local anesthetics have also been studied, and these new preparations could allow for extended duration of action of anesthetics. An emerging preparation of bupivacaine, exparel, uses a multivesicular liposomal delivery system which releases medication in a steady, controlled manner. Another extended-release local anesthetic, HTX-011, consists of a combination of bupivacaine and low-dose meloxicam. Tetrodotoxin, a naturally occurring reversible site 1 sodium channel toxin derived from pufferfish and shellfish, has shown the potential to block conduction of isolated nerves. Neosaxitoxin is a more potent reversible site 1 sodium channel toxin also found in shellfish that can also block nerve conduction. These novel formulations show great promise in terms of the ability to prolong the duration of single injection PNBs. This field is still currently in development, and more researchers will need to be done to ensure the efficacy and safety of these novel formulations. These formulations could be the future of pain management if ongoing research continues to prove positive effects and low side effect profiles.

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.

Comparison of Intercostal Nerve Block with Ropivacaine and Ropivacaine-Dexmedetomidine for Postoperative Pain Control in Patients Undergoing Thoracotomy: A Randomized Clinical Trial

Background

Thoracotomy is one of the most painful surgeries, and failure to alleviate patients' pain can have dangerous consequences.

Objectives

This study aimed to evaluate the addition of dexmedetomidine to ropivacaine in the intercostal block for postoperative pain control in patients undergoing thoracotomy.

Methods

In this randomized clinical trial, 74 patients aged 18 to 60 years with ASA class I or II, BMI less than 40, and no severe systemic problems referred to a teaching hospital in Ahvaz to undergo thoracotomy were included in the study and randomly divided into two groups. After surgery, an ultrasound-guided intercostal block was done with ropivacaine (5 cc of 0.25% solution; group R) or ropivacaine (5 cc of 0.25% solution) plus dexmedetomidine (0.5 µg/kg; group RD) per dermatome. Two dermatomes above and two dermatomes below the level of surgical incision were used. Pain, total opioid consumption, length of ICU stays, time to first rescue analgesic, and time to get out of bed were compared between the two groups.

Results

The intercostal block significantly reduced pain in both groups (P < 0.0001). The pain was lower in the RD group than in the R group from six hours after the intervention up to 24 hours after (P < 0.001). The number of patients who needed rescue analgesia at 12 hours was significantly lower in the RD group (P < 0.05). The RD group also had lower total opioid consumption and a longer time to receive the first rescue analgesia (P < 0.01). There was no significant difference between the two groups in the length of hospitalization and the time to get out of bed.

Conclusions

Dexmedetomidine is an effective and safe choice to be used as an adjunct to ropivacaine in ICB, and it extends the duration of analgesia in combination with ropivacaine after thoracotomy.

Endogenous opiates and behavior: 2019

This paper is the forty-second consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2019 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug abuse and alcohol (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).

Effects of Dexmedetomidine as an Analgesic Adjuvant for Surgery of Femur Fracture: A Systematic Review and Meta-Analysis

Patients who undergo surgery of femur fracture suffer the excruciating pain. Dexmedetomidine (DEX) is a unique α2-adrenergic receptor agonist with sedative and analgesic properties, whose efficacy and safety are still unclear for surgery of femur fracture. Randomized controlled trials comparing the effects of addition of DEX to general or local anesthesia in surgery of femur fracture were searched from MEDLINE, EMBASE, and the Cochrane Library database. Patients who received DEX infusion had a significant longer time to rescue analgesia compared with those without DEX coadministration. DEX treatment seemed to reduce the visual analog score; however, the significance did not reach any statistical difference. DEX as an analgesic adjuvant did not reduce the onset of sensory block time, shorten the time to achieve maximum sensory block level, and provide a longer duration of sensory block. The difference in mean sedation scores between 2 groups was not statistically significant. As for adverse effects, DEX therapy significantly increased the rate of hypotension. In conclusion, dexmedetomidine as a local anesthetic adjuvant in femur fracture surgery had a longer duration of rescue analgesia. However, the incidence of hypotension was markedly increased in these patients. It was worth noting that the evidence was of low to moderate quality.

Adjuvant Drugs for Peripheral Nerve Blocks: The Role of Alpha-2 Agonists, Dexamethasone, Midazolam, and Non-steroidal Anti-inflammatory Drugs

Adjuvant drugs for peripheral nerve blocks are a promising solution to acute postoperative pain and the transition to chronic pain treatment. Peripheral nerve blocks (PNB) are used in the brachial plexus, lumbar plexus, femoral nerve, sciatic nerve, and many other anatomic locations for site-specific pain relief. However, the duration of action of a PNB is limited without an adjuvant drug. The use of non-opioid adjuvant drugs for single-shot peripheral nerve blocks (sPNB), such as alpha-2 agonists, dexamethasone, midazolam, and non-steroidal anti-inflammatory drugs, can extend the duration of local anesthetics and reduce the dose-dependent adverse effects of local anesthetics. Tramadol is a weak opioid that acts as a central analgesic. It can block voltage-dependent sodium and potassium channels, cause serotonin release, and inhibit norepinephrine reuptake and can also be used as an adjuvant in PNBs. However, tramadol's effectiveness and safety as an adjuvant to local anesthetic for PNB are inconsistent. The effects of the adjuvants on neurotoxicity must be further evaluated with further studies to delineate the safety in their use in PNB. Further research needs to be done. However, the use of adjuvants in PNB can be a way to help control postoperative pain.

Comparison of Dexmedetomidine and Dexamethasone as Adjuvants to Ultra-Sound Guided Interscalene Block in Arthroscopic Shoulder Surgery: A Double-Blinded Randomized Placebo-Controlled Study

BACKGROUND

Interscalene block is one of the popular methods for decreasing pain and analgesic consumption after shoulder arthroscopic surgeries.

OBJECTIVES

The objective is to compare the analgesic duration of effects of dexmedetomidine and dexamethasone as adjuvants to 0.5% ropivacaine in ultrasound-guided interscalene blocks for arthroscopic shoulder surgery in an ambulatory setting.

METHODS

In this randomized controlled trial, 117 adult patients candidate for ambulatory arthroscopic shoulder surgery under general anesthesia were divided into three groups to perform an ultra-sound guided interscalene block before the surgery. The ropivacaine (control) group received ropivacaine 0.5% 20 mL, group Dexamethasone received ropivacaine 0.5% 20 mL plus 4mg dexamethasone, and group dexmedetomidine received ropivacaine 0.5% 20 mL plus 75 mcg of dexmedetomidine. Time to return of sensory function, of motor function, of first pain sensation, amount of opioid medication consumed at 24 hours and 48 hours post-operatively were measured.

RESULTS

The 24-hour median (25th- 75th percentile) opioid consumption in morphine equivalents was similar between groups 22.5 mg (10 - 30), 15 mg (0 - 30), and 15 mg (0 - 20.6) in the ropivacaine, dexmedetomidine, and dexamethasone groups, respectively (P = 0.130). The median (25th- 75th percentile) 48 hours post-operatively, the median opioid consumption in morphine equivalents was 40 mg (25 - 67.5) in the ropivacaine group, 30 mg (22 - 50.6) in the dexamethasone group, and 52.5 mg (30 - 75) in the dexmedetomidine group (P = 0.278). The median 24-hour pain scores were 6 (5 - 8) in the ropivacaine control group, 7 (5.5 - 8) in the dexamethasone group, and 7 (4 - 9) in the dexmedetomidine group (P = 0.573).

CONCLUSIONS

There was no statistical difference in opioid consumption at 24 and 48 hours post-operatively when comparing dexmedetomidine, dexamethasone, and no adjuvant. However, intraoperative opioid use was significantly lower with dexmedetomidine compared to dexamethasone and plain 0.5% ropivacaine. The safe side effect profile of dexmedetomidine makes it a reasonable alternative as an adjuvant for peripheral nerve blockade when dexamethasone use may be contraindicated.

Adjuvant Drugs for Peripheral Nerve Blocks: The Role of NMDA Antagonists, Neostigmine, Epinephrine, and Sodium Bicarbonate

The potential for misuse, overdose, and chronic use has led researchers to look for other methods to decrease opioid consumption in patients with acute and chronic pain states. The use of peripheral nerve blocks for surgery has gained increasing popularity as it minimizes peripheral pain signals from the nociceptors of local tissue sustaining trauma and inflammation from surgery. The individualization of peripheral nerve blocks using adjuvant drugs has the potential to improve patient outcomes and reduce chronic pain. The major limitations of peripheral nerve blocks are their limited duration of action and dose-dependent adverse effects. Adjuvant drugs for peripheral nerve blocks show increasing potential as a solution for postoperative and chronic pain with their synergistic effects to increase the duration of action and decrease the required dosage of local anesthetic. N-methyl-d-aspartate (NMDA) receptor antagonists are a viable option for patients with opioid resistance and neuropathic pain due to their affinity to the neurotransmitter glutamate, which is released when patients experience a noxious stimulus. Neostigmine is a cholinesterase inhibitor that exerts its effect by competitively binding at the active site of acetylcholinesterase, which prevents the hydrolysis of acetylcholine and subsequently retaining acetylcholine at the nerve terminal. Epinephrine, also known as adrenaline, can potentially be used as an adjuvant to accelerate and prolong analgesic effects in digital nerve blocks. The theorized role of sodium bicarbonate in local anesthetic preparations is to increase the pH of the anesthetic. The resulting alkaline solution enables the anesthetic to more readily exist in its un-ionized form, which more efficiently crosses lipid membranes of peripheral nerves. However, more research is needed to show the efficacy of these adjuvants for nerve block prolongation as studies have been either mixed or have small sample sizes.

Efficacy of Dexmedetomidine Versus Morphine as an Adjunct to Bupivacaine in Caudal Anesthesia for Pediatric Thoracic Surgeries: A Randomized Controlled Trial

Background

Caudal anesthesia is an effective method of pain management, which can be successfully employed to minimize post-thoracotomy pain in pediatric patients. However, its main disadvantage is the short postoperative analgesic period, which can be prolonged by the concurrent administration of one of many adjuvants.

Objectives

This prospective randomized, blinded study aimed to compare the efficacy of dexmedetomidine versus morphine as adjuvants to bupivacaine in caudal anesthesia for thoracic surgeries in pediatric patients.

Methods

Fifty patients were randomly allocated into two equal groups. To achieve caudal epidural block anesthesia, the patients in group M (n = 25) were administered morphine and bupivacaine, while group D (n = 25) received a mixture of dexmedetomidine and bupivacaine. The primary outcome of this study was the postoperative analgesic duration achieved. The secondary outcomes included morphine administration in the first 24 hours following caudal block anesthesia, the face, legs, activity, cry, consolability (FLACC) scale scores, and adverse effects, including vomiting, itching, bradycardia, hypotension, and respiratory depression.

Results

The results showed that patients who had received dexmedetomidine achieved a longer postoperative analgesia as compared to those who had received morphine (P < 0.001). Postoperatively, the heart rate, blood pressure, pain score, and mean consumption of morphine were lower in group D as compared to the group M. There was no significant difference in the adverse effects between the two groups.

Conclusions

The use of dexmedetomidine as an adjuvant to bupivacaine for caudal anesthesia during pediatric thoracic surgeries induced better and prolonged postoperative analgesia as compared to morphine.

Postoperative Pain Management: Role of Dexmedetomidine as an Adjuvant

Collapse

Comparison of Sedation with Dexmedetomidine Alfentanil Versus Ketamine-Alfentanil in Patients Undergoing Closed Reduction of Nasal Fractures

Objectives

To compare the sedative effects of dexmedetomidine alfentanil versus ketamine-alfentanil in patients undergoing closed reduction of nasal fractures on the basis of intraoperative hemodynamic changes, satisfaction of patients and surgeons, and the adverse effects.

Methods

Sixty patients with ASA class 1 or 2 were randomized to either of two groups, a dexmedetomidine alfentanil group (DA group; n = 30) or a ketamine-alfentanil group (KA group; n = 30). Hemodynamic parameters, oxygenation status, adverse events, the satisfaction of patients and surgeons, and postoperative pain scores by visual analog scale (VAS) were recorded at specific time intervals during the trial.

Results

Systolic blood pressure was significantly lower in the DA group than in the KA group from T1 min to T15 min. The duration of the recovery ward stay was longer in the DA group; however, two groups were similar in terms of total anesthesia time and awakening time. Likewise, two groups were similar in terms of the patient and surgeon’s satisfaction, pain scores, and the occurrence of adverse effects.

Conclusions

Both sedation methods were safely performed, and dexmedetomidine-alfentanil is as effective as ketamine-alfentanil in patients undergoing short-term operations such as nasal fracture corrections.