Efficacy of Serratus Anterior Plane Block Using Bupivacaine/ Magnesium Sulfate Versus Bupivacaine/ Nalbuphine for Mastectomy: A Randomized, Double-Blinded Comparative Study

A meta‐analysis showing the quantitative evidence base of perineural nalbuphine for wound pain from upper‐limb orthopaedic trauma surgery

The adjuvant effectiveness of nalbuphine in context of brachial plexus block (BPB) in patients undergoing upper-limb orthopaedic trauma surgery has remained uncertain. The purpose of this meta-analysis was to evaluate the analgesic benefit of mixing nalbuphine into local anaesthetics in BPB for wound pain from upper-limb trauma surgery. Primary outcome was the duration of analgesia. Seventeen trials (1104 patients) were analysed. Patients receiving nalbuphine have an increased weighted mean difference (WMD) 95% confidence interval of the duration of analgesia by 186.91 minutes (133.67 to 240.16) (P < 0.001). Compared to placebo, nalbuphine shorten the onset time of sensory and motor block by WMD of 2.59 (1.27 to 3.92) and 3.06 minutes (1.65 to 4.48) (P < 0.001), respectively. Meanwhile, nalbuphine prolonged the durations of sensory and motor block (P < 0.001). Qualitative and quantitative synthesis revealed no differences with regard to the outcomes related to side-effects. There is moderate-quality evidence that the addition of nalbuphine to local anaesthetics for BPB in patients undergoing upper-limb orthopaedic trauma surgery significantly prolongs the duration of analgesia, while preserving a similar safety-profile compared with local anaesthetics alone. However, these benefits should be further weighed against nalbuphine-related neurological safety in future studies.

Endogenous opiates and behavior: 2020

This paper is the forty-third consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2020 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).

Comparing the Effect of Classical and Modified Thoracolumbar Interfascial Plane Block on Postoperative Pain and IL-6 Level in Posterior Lumbar Decompression and Stabilization Surgery

Background: Ultrasound (US)-guided classical and modified thoracolumbar interfascial plane (TLIP) blocks are often used to provide adequate analgesia after lumbar spinal surgery. Postoperative pro-inflammatory interleukin 6 (IL-6) blood concentrations after lumbar spine surgery are related to postoperative pain and inflammation. Objectives: The purpose of this prospective randomized parallel controlled study was to assess postoperative pain and serum levels of pro-inflammatory IL-6 after posterior lumbar decompression and stabilization surgery with a classical and modified technique of TLIP block. Methods: This prospective randomized, single-blinded controlled pilot study was conducted on eight patients who will undergo posterior lumbar decompression and stabilization surgery. After obtaining the ethical approval and an informed consent, all subjects were randomly allocated into the classic TLIP group and the modified TLIP group. Following general anesthesia induction, 20 mL bupivacaine 0.25% was injected on each side in interfascialis plane between m. longissimus and m. iliocostalis in modified TLIP group and between m. multifidus and m. longissimus in classical TLIP group. Intraoperative hemodynamic (blood pressure and heart rate) and noxious stimulation response level (qNOX), postoperative IL-6 level, 24-hour morphine consumption, and numerical rating score were recorded and analyzed. Results: The median of IL-6 level was found to be lower in the modified TLIP group 12 hours postoperatively compared to classic TLIP (29.91 (8.56 – 87.61) vs. 46.87 (2.87 – 92.35)). The mean Numerical Rating Scale (NRS) in the modified TLIP block was comparable with the classic TLIP group, although it was lower than the classic TLIP group (2.75 ± 1.5 vs. 3.75 ± 1.7 at 6 hours and 3.5 ± 1.3 vs. 4 ± 1.6 12 hours postoperatively). However, there was no difference in intraoperative hemodynamic, Qnox value, and total postoperative morphine consumption between the two groups. Conclusions: Our study showed that modified TLIP block resulted in lower IL-6 level and NRS 12 hours postoperatively compared to classical TLIP block. However, there were no differences in total postoperative morphine consumption between the two groups.

Evaluation of the Effects of Oral Magnesium Sachet on the Prevention of Spinal Anesthesia-Induced Headache After Cesarean Section: A Randomized Clinical Trial

Background: Post-dural puncture headache (PDPH) is a common complication of spinal anesthesia. It often goes away after a few days but may be more severe in some patients and persists for weeks. Objectives: This study aimed to evaluate the effect of oral magnesium on the prevention of PDPH after cesarean section for the first time. Methods: In this double-blind, randomized clinical trial, 100 candidates for elective cesarean section under spinal anesthesia were randomly divided into 2 groups: (i) the intervention group that received 300 mg of oral magnesium powder and (ii) the control group that received starch powder. The frequency and severity of headache and amount of analgesic consumption in both groups were measured 1, 2, and 3 days after cesarean section. Data were analyzed using SPSS version 22 at 95% CI. Results: The frequency of PDPH 1, 2, and 3 days after surgery was 8% vs 24% (P = 0.029), 10% vs 26% (P = 0.039), and 12% vs 18% (P = 0.401) in the intervention and control groups, respectively. The mean and SD of pain severity was 0.52 ± 1.83 vs 1.5 ± 2.84 (P = 0.03) on the first day, 0.70 ± 2.19 vs 1.58 ± 2.86 (P = 0.05) on the second day, and 0.82 ± 2.32 vs 1.18 ± 2.62 on the third day (P = 0.43) in the intervention and control groups, respectively. Although more patients in the control group received rescue analgesia, no significant difference was seen between the 2 study groups. Conclusions: In women candidates for cesarean section, oral administration of 300 mg magnesium 2 hours before surgery significantly reduces the frequency and severity of PDPH, but its impact on reducing analgesic consumption is not significant.

Anesthetic Conversion of Preexisting Labor Epidural Analgesia for Emergency Cesarean Section and Efficacy of Levobupivacaine with or Without Magnesium Sulphate: A Prospective Randomized Study

Background: For pregnant women who require an emergency cesarean section (CS), extending labor epidural analgesia as quickly as feasible to good quality anesthesia is a critical issue. This indicates the presence of functional labor epidural analgesia and reduces the need for general anesthesia. Addition of magnesium increases anesthetic and analgesic qualities of epidural anesthesia. Objectives: The purpose of this trial was to assess the role of adding magnesium sulfate (MgSO4) with levobupivacaine to speed up the conversion of labor epidural analgesia into enough anesthesia for emergency CS. Methods: Fifty parturients were randomly assigned to receive 19.5 mL of levobupivacaine 0.5% with either 0.5 mL of normal saline 0.9% (Group I) or 0.5 mL of MgSO4 10% (Group II) after receiving labor epidural analgesia. We documented the onset of block (loss of pinprick to T6), number of patients needing additional analgesia, the time needed for sensory and motor blockade to recover, and the adverse effects. Results: The frequency of patients receiving intraoperative supplements was comparable in the study groups (P = 0.491), although the onset of the block was faster in Group II than in Group I (P = 0.000*). Group II took substantially longer to recover from sensory and motor blockade than Group I (P = 0.001* and P = 0.001*, respectively). In both groups, the occurrence of adverse events was similar. Conclusions: Adding 50 mg of MgSO4 to levobupivacaine 0.5% accelerated the epidural top, and both sensory onset and motor blocks period were prolonged as compared to levobupivacaine alone when extending epidural analgesia for emergency CS.

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.

Management of pain using magnesium sulphate: A narrative review

Pain is one of the most complex and unpleasant sensory and emotional human experiences. Pain relief continues to be a major medical challenge. The application of systemic opioid and regional analgesia techniques has facilitated a decrease in the occurrence and gravity of pain. Magnesium has an evolving role in pain management. Magnesium sulphate (MgSO4), the pharmacological form of magnesium, is a physiological voltage-dependent blocker of N-methyl-D-aspartate (NMDA)-coupled channels. In terms of its antinociceptive role, magnesium blocks calcium influx, which inhibits central sensitization and decreases preexisting pain hypersensitivity. These properties have encouraged the research of magnesium as an adjuvant agent for intra- and post-operative analgesia. Moreover, the mentioned magnesium impacts are also detected in patients with neuropathic pain. Intravenous magnesium sulphate, followed by a balanced analgesia, decreases opioid consumption. This review has focused on the existing evidence concerning the role of magnesium sulphate in pain management in situations including neuropathic pain, postherpetic neuralgia, trigeminal neuralgia, migraine, and post-operative pain. Additional studies are required to improve the use of magnesium sulphate for pain to increase the quality of life of patients.

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.

Pain Control After Mastectomy in Transgender Patients: Ultrasound-guided Pectoral Nerve Block II Versus Conventional Intercostal Nerve Block: A Randomized Clinical Trial

Background

Mastectomy is sometimes performed in transgender patients, which may damage the regional nerves such as the pectoral and intercostobrachial nerves, leading to postoperative pain. An ultrasound-guided nerve block can be used to track and block the nerves properly.

Objectives

This study aimed to compare the ultrasound-guided type-II pectoral nerve block with the blind (conventional) intercostal nerve block (ICNB) for pain control after breast tissue reconstruction surgery in transgender patients.

Methods

In the present single-blind randomized clinical trial, 47 patients were randomly divided into two groups: (A) Ultrasound-guided type-II pectoral nerve block (n = 23) and (B) blind intercostal nerve block (n = 24). After nerve block in both groups, pain intensity at 3, 6, 12, and 24 hours after surgery, upper limb paresthesia, frequency of nausea and vomiting, shortness of breath, hematoma, and the length of hospital stay were assessed.

Results

Patients who received the ultrasound-guided type-II pectoral nerve block had a greater reduction in pain intensity (24 h after surgery), opioid use (24 h after surgery), nausea, vomiting, and hospital stay than those who received ICNB, whereas the recovery time did not differ between the study groups.

Conclusions

The pectoral nerve block under ultrasound guidance, compared to the intercostal nerve block, in transgender patients can reduce the required dosage of opioids within 24 hours, pain intensity within 24 hours after surgery, the incidence of postoperative nausea, and vomiting, and the hospital stay of patients.

Efficacy of Ultrasound-Guided Serratus Anterior Plane Block for Postoperative Analgesia in Patients Undergoing Breast Surgery: A Systematic Review and Meta-Analysis of Randomised Controlled Trials

Objective

Serratus anterior plane block (SAPB) provides effective thoracic analgesia. This systematic review and meta-analysis was conducted to assess the safety and efficacy of SAPB for postoperative analgesia after breast surgery.

Methods

A systematic literature search was performed using Embase, PubMed, Web of Science, and the Cochrane Library for eligible randomised controlled trials. The primary outcomes involved the administration of intraoperative and postoperative opioids. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach was used for rating the quality of evidence for making recommendations.

Results

Overall, 13 studies comprising 826 patients met the inclusion criteria (412 in the SAPB group and 414 in the control group). Patients treated with SAPB exhibited a significantly lower postoperative opioid consumption (mean difference, −38.51 mg of oral morphine equivalent; 95% confidence interval (CI), −60.97 to −16.05; P < 0.01; I² = 100%), whereas no difference was observed in the intraoperative opioid consumption (mean difference, −9.85 mg of oral morphine equivalent; 95% CI, −19.52 to −0.18; P=0.05; I² = 94%). In addition, SAPB significantly decreased the occurrence of postoperative nausea and vomiting (risk ratio, 0.32; 95% CI, 0.19–0.55; P < 0.05;I² = 38%) and reduced pain scores during the postoperative period (1 h: standardised mean difference (SMD), −1.23; 95% CI, −2.00 to −0.45; I² = 92%; 2 h: SMD, −0.71; 95% CI, −1.00 to −0.41; I² = 48%; 4 h: SMD, −1.52; 95% CI, −2.77 to −0.27; I² = 95%; 6 h: SMD, −0.80; 95% CI, −1.51 to −0.08; I² = 81%; 8 h: SMD, −1.12; 95% CI, −1.98 to −0.27; I² = 92%; 12 h: SMD, −0.78; 95% CI, −1.21 to −0.35; I² = 83%; and 24 h: SMD, −0.71; 95% CI, −1.20 to −0.23; I² = 87%; P < 0.05 for all).

Conclusion

SAPB was safe and effective after breast surgery to relieve postsurgical pain. However, additional well-developed trials are required to validate these findings.

Full Opioid Agonists and Tramadol: Pharmacological and Clinical Considerations

Opioids are mu receptor agonists and have been an important part of pain treatment for thousands of years. In order to use these drugs appropriately and successfully in patients, whether to control pain, to treat opiate-induced side effects, or opiate withdrawal syndromes, a solid understanding of the pharmacology of such drugs is crucial. The most recognized full agonist opioids are heroin, morphine, codeine, oxycodone, meperidine, and fentanyl. Phenanthrenes refer to a naturally occurring plant-based compound that includes three or more fused rings. The opioids derived from the opium plant are phenanthrene derivatives, whereas most synthetic opioids are simpler molecules that do not have multiple rings. Methadone acts as a synthetic opioid analgesic similar to morphine in both quality and quantity; however, methadone lasts longer and in oral form, has higher efficacy, and is considered a diphenylheptane. Fentanyl is a strong synthetic phenylpiperdine derivative that exhibits activity as a mu-selective opioid agonist approximately 50 to 100 times more potent than morphine. Meperidine is another medication which is a phenylpiperdine. Tramadol is considered a mixed-mechanism opioid drug, as it is a centrally acting analgesic that exerts its effects via binding mu receptors and blocking the reuptake of monoamines. Some of the most common adverse effects shared among all opioids are nausea, vomiting, pruritus, addiction, respiratory depression, constipation, sphincter of Oddi spasm, and miosis (except in the case of meperidine). Chronic opioid usage has also established a relationship to opioid-induced hypogonadism and adrenal suppression. Physicians must be stewards of opioid use and use opioids only when necessary.

Utilization of Magnesium for the Treatment of Chronic Pain

Context

The International Association for the Study of Pain (IASP) defines chronic pain as pain that persists or recurs for longer than 3 months. Chronic pain has a significant global disease burden with profound effects on health, quality of life, and socioeconomic costs.

Evidence Acquisition

Narrative review.

Results

There are several treatment options, including pharmacological therapy, physical rehabilitation, psychological therapies, and surgical interventions, for chronic pain management. Magnesium has been FDA-approved for several indications including hypomagnesemia, arrhythmia, prevention of seizures in eclampsia/preeclampsia, and constipation. Magnesium has been used for numerous off-label uses, notably for acute and chronic pain management. The mechanism of magnesium in pain management is primarily through its action as a voltage-gated antagonist of NMDA receptors, which are involved in pain transduction.

Conclusions

This narrative review will focus on the current evidence and data surrounding the utilization of magnesium as a treatment option for chronic pain.