Combination of adenosine with prilocaine and lignocaine for brachial plexus block does not prolong postoperative analgesia

The effect of adjuvants added to local anaesthetics for single-injection upper extremity peripheral regional anaesthesia: A systematic review with network meta-analysis of randomised trials

BACKGROUND

Peripheral regional anaesthesia is frequently used for upper extremity surgery. To prolong the duration of analgesia, adjuvants can be added to single-injection local anaesthetics. Despite attempts to compare several adjuvants in pairwise meta-analyses, a comprehensive comparison is still missing.

OBJECTIVE

The objective of this network meta-analysis was to determine the effectiveness of adjuvants in upper extremity peripheral nerve blocks.

DESIGN

A systematic review of randomised controlled trials with network meta-analyses.

DATA SOURCES

A literature search in Embase, CENTRAL, MEDLINE and Web of Science was performed up to March 2023.

ELIGIBILITY CRITERIA

Randomised trials comparing different adjuvants injected perineurally in peripheral upper extremity nerve blocks were eligible. Frequentist network meta-analysis was conducted using a random effects model with physiological saline as the comparator. The primary endpoint was the ratio of means (ROM) of the duration of analgesia.

RESULTS

The review included 242 randomised controlled trials with a total of 17 391 patients. Twenty-eight adjuvants were compared in the largest networks. Most network estimations consisted of a high proportion of direct evidence. Fourteen adjuvants increased the duration of analgesia significantly by the following factors, ROM [95% confidence interval (CI)]: dexamethasone 1.95 (1.79 to 2.13), buprenorphine 1.83 (1.51 to 2.24), butorphanol 1.84 (1.41 to 2.39), potassium chloride 1.89 (1.15 to 3.11), dexmedetomidine 1.70 (1.59 to 1.81), sufentanil 1.70 (1.27 to 2.29), ketorolac 1.68 (1.24 to 2.27), midazolam 1.55 (1.24 to 1.94), tramadol 1.52 (1.32 to 1.75), nalbuphine 1.50 (1.30 to 1.72), morphine 1.43 (1.09 to 1.88), magnesium sulfate 1.42 (1.20 to 1.67), clonidine 1.36 (1.24 to 1.50) and fentanyl 1.23 (1.08 to 1.40). Inconsistency in network meta-analysis was substantial. Overall side effect rates were low with all adjuvants.

CONCLUSION

The best interventions to prolong the duration of analgesia were dexamethasone, followed by dexmedetomidine, opioids, electrolytes, ketorolac and midazolam. There are general concerns about the quality of underlying studies and the risk of publication bias.

TRIAL REGISTRATION

PROSPERO 2018 CRD42018115722.

Adjuvants in pain medicine. Selection of the drug depending on the desired effect – so which drug to choose?

To date, much research has focused on finding the ideal adjuvant for local anesthetics. Each of them can have different effects. In anesthesiology and pain medicine, depending on the purpose, one or another effect may be desirable. For example, in some situations it is desirable to accelerate the onset of action or prolong the duration of the block, in others the desired effect may be a “response to intravascular administration”, it should also be borne in mind that not all adjuvants are allowed for intrathecal administration.

Review of adjuvants to local anesthetics in peripheral nerve blocks: Current and future trends

In recent anesthetic practice, peripheral nerve blocks (PNBs) are used extensively for surgical anesthesia and nonsurgical analgesia. PNBs offer many benefits over other anesthetic techniques in a certain population of patients, and in some specific clinical setting, that may contribute to faster and safer pain relief, increased patient satisfaction, reduced hospital stay, and decreased overall healthcare cost. The technique involves the injection of the anesthetic in the vicinity of a specific nerve or bundle of nerves to block the sensation of pain transmitting to a specific portion of the body. However, the length of analgesia when a single anesthetic is used for PNB may not last long. Therefore, the practice of adding an additional agent called adjuvant has been evolved to prolong the analgesic effect. There are many such adjuvants available that are clinically being used for this purpose imparting great efficacy and safety to the anesthetic process. The adjuvants molecules are generally classified as opioids, alpha-2 agonist, steroids, etc. Most of them are safe to use and show little or no adverse event related to neurotoxicity and tissue damage. Although there is extensive use of such adjuvants in the clinical field, none of the molecules is approved by the FDA and is used as an off-label drug. The risk to benefit ratio must be assessed while using such an agent. This review will try to delineate the basic need of adjuvant in peripheral nerve block and will discuss the advantages and limitations of using different adjuvants and will discuss the future prospect of such application.

Adjunct medications for peripheral and neuraxial anesthesia

Regional and neuraxial anesthesia can provide a safer perioperative experience, greater satisfaction, reduced opioid consumption, and reduction of pain, while minimizing side effects. Ultrasound technology has aided clinicians in depositing local anesthetic medication in precise proximity to targeted peripheral nerves. There are a plethora of adjuvants that have been utilized to prolong local anesthetic actions and enhance effects in peripheral nerve blocks. This manuscript describes the current state of the use of adjuncts, e.g., dexmedetomidine, dexamethasone, clonidine, epinephrine, etc., in regional anesthesia. Additionally, evidence behind dosing and block prolongation is summarized along with patient outcomes, adverse effects, and future directions.

Adenosine for postoperative analgesia: A systematic review and meta-analysis

Purpose

Perioperative infusion of adenosine has been suggested to reduce the requirement for inhalation anesthetics, without causing serious adverse effects in humans. We conducted a meta-analysis of randomized controlled trials evaluating the effect of adenosine on postoperative analgesia.

Methods

We retrieved articles in computerized searches of Scopus, Web of Science, PubMed, EMBASE, and Cochrane Library databases, up to July 2016. We used adenosine, postoperative analgesia, and postoperative pain(s) as key words, with humans, RCT, and CCT as filters. Data of eligible studies were extracted, which included pain scores, cumulative opioid consumption, adverse reactions, and vital signs. Overall incidence rates, relative risk (RR), and 95% confidence intervals (CI) were calculated employing fixed-effects or random-effects models, depending on the heterogeneity of the included trials.

Results

In total, 757 patients from 9 studies were included. The overall effect of adenosine on postoperative VAS/VRS scores and postoperative opioid consumption was not significantly different from that of controls (P >0.1). The occurrence of PONV and pruritus was not statistically significantly different between an adenosine and nonremifentanil subgroup (P >0.1), but the rate of PONV occurrence was greater in the remifentanil subgroup (P <0.01). Time to first postoperative analgesic requirement in the adenosine group was not significantly difference from that of the saline group (SMD = 0.07, 95%CI: −0.28 to 0.41, P = 0.71); but this occurred significantly later than with remifentanil (SMD = 1.10, 95%CI: 2.48 to 4.06, P < 0.01). Time to hospital discharge was not significantly different between the control and adenosine groups (P = 0.78). The perioperative systolic blood pressure was significantly lower in the adenosine than in the control group in the mannitol subgroup (P < 0.01). The incidence of bradycardia, transient first- degree atrioventricular block, and tachycardia was not significantly different between the adenosine and control groups (P > 0.1).

Conclusion

Adenosine has no analgesic effect or prophylactic effect against PONV, but reduce systolic blood pressure and heart rates. Adenosine may benefit patients with hypertension, ischemic heart disease, and tachyarrhythmia, thereby improving cardiac function.

NMDA Receptor Antagonists, Gabapentinoids, α-2 Agonists, and Dexamethasone and Other Non-Opioid Adjuvants: Do They Have a Role in Plastic Surgery?

BACKGROUND

Inadequate pain control and opioid-related adverse effects result in delayed patient recovery and discharge times. Adjuvants help to improve the quality of analgesia and decrease opioid consumption, consequently decreasing opioid-related effects, such as nausea and vomiting, sedation, ileus, and respiratory depression. We review the mechanisms and clinical evidence for nonopioid adjuvants.

METHODS

MEDLINE, EMBASE, and the Cochrane Register were searched for meta-analyses, systematic reviews, and randomized, controlled trials that compared the adjuvants ketamine, gabapentin, pregabalin, dexmedetomidine, clonidine, and dexamethasone with placebo. Keywords used in the search included "plastic surgery," "reconstructive surgery," "opioid," "pain," "analgesia," and the names of each adjuvant. The references of included studies were searched for additional relevant studies.

RESULTS

Ketamine was found in 6 meta-analyses to have a significant reduction in opioid requirements and may reduce the hyperalgesia associated with opioids. This seems to be most beneficial in surgeries where high postoperative pain is expected. Multiple robust trials have demonstrated that the gabapentinoids and α-2 agonists significantly improve quality of analgesia and decrease opioid consumption. Two recent meta-analyses found that a single low-dose of dexamethasone used for postoperative nausea and vomiting prophylaxis may also improve postoperative analgesia. There is also emerging evidence for the use of low-dose naloxone, adenosine, and neuraxial neostigmine and acupuncture as part of a successful multimodal pain management regimen.

CONCLUSIONS

Although there is a lack of studies specifically focused in the plastic and reconstructive surgery patient population, the existing literature provides information about when the above adjuvants are likely to have the greatest impact.

Ultrasound-guided continuous infraclavicular brachial plexus block using bupivacaine alone or combined with adenosine for pain control in upper limb surgery

Introduction:

The infraclavicular brachial plexus block (ICB) is designed to deposit anesthetic high in the plexus, achieving anesthesia of the hand, forearm, elbow, and distal arm. Adenosine is a metabolic intermediate that is involved in nearly all aspects of cell function, including neurotransmission and signal transduction.This study was aimed to show whether addition of adenosine to bupivacaine in ultrasound-guided ICB had an analgesic effect.

Methods:

Sixty adult patients were divided into two equal groups, each group included 30 patients. Group I received infraclavicular bupivacaine 0.325% in a volume of 30 ml. Group II received 30 ml of 0.325% bupivacaine + 12 mg adenosine. The block was maintained with an infusion of 10 ml/h. The following parameters were assessed: Success rate, time of the sensory onset, motor block, visual analog scale (VAS), and amount of i.v. pethidine needed.

Results:

This study showed an analgesic effect of infraclavicular adenosine as evidenced by a statistically significant shorter mean time of onset of the sensory block (16 vs. 20 min, P < 0.05), lower mean VAS score over 48 h (1.7 vs. 2.7, P < 0.05), longer mean time of first parenteral analgesic requirement (299 vs. 255 min, P < 0.05), and lower mean total dose of pethidine needed over 48 h after surgery (25.5 vs. 56.6 mg, P <0.05). All patients got successful infraclavicular block and recovered uneventfully without any sensory or motor deficit.

Conclusion:

Adenosine may provide valuable addition to the therapeutic options in anesthesia and pain management. Further research is required to figure out its exact role

Upper extremity regional anesthesia: essentials of our current understanding, 2008

Brachial plexus blockade is the cornerstone of the peripheral nerve regional anesthesia practice of most anesthesiologists. As part of the American Society of Regional Anesthesia and Pain Medicine's commitment to providing intensive evidence-based education related to regional anesthesia and analgesia, this article is a complete update of our 2002 comprehensive review of upper extremity anesthesia. The text of the review focuses on (1) pertinent anatomy, (2) approaches to the brachial plexus and techniques that optimize block quality, (4) local anesthetic and adjuvant pharmacology, (5) complications, (6) perioperative issues, and (6) challenges for future research.

Adenosine as a Non-Opioid Analgesic in the Perioperative Setting

Adenosine, a ubiquitous metabolic intermediate in the body, is involved in nearly every aspect of cell function, including neuromodulation and neurotransmission. Adenosine A(1) and A(2) receptors are widely distributed in the brain and spinal cord, and are a novel, non-opiate target for pain management. The potential of adenosine as a non-narcotic analgesic in anesthetized patients has been explored in clinical trials, including double-blind studies versus placebo and remifentanil infusion. These studies suggest that, compared to placebo or remifentanil, an intraoperative adenosine infusion stabilizes core hemodynamics and reduces the requirement for anesthesia during surgery. Further, adenosine improves postoperative recovery, as indicated by lower pain scores and less opioid consumption. The safety profile of adenosine has been well characterized based on use of currently approved adenosine products. The most common adverse events associated with its use include flushing, chest discomfort, dyspnea, headache, gastrointestinal discomfort, and lightheadedness. These effects are generally well tolerated and transient. Further studies are warranted to investigate the full potential of adenosine as a non-opioid analgesic in the perioperative setting.

Clinical application of adenosine and ATP for pain control

This review summarizes clinical application of adenosine and adenosine 5'-triphosphate (ATP) in pain conditions. Investigations have been performed in patients with acute perioperative pain or chronic neuropathic pain treated with intravenous adenosine or ATP, or intrathecal adenosine. Characteristic central adenosine A1 receptor-mediated pain-relieving effects have been observed after intravenous adenosine infusion in human inflammation/sensitization pain models and in patients with chronic neuropathic pain. Adenosine compounds, in low doses, can reduce allodynia/hyperalgesia more consistently than spontaneous pain, suggesting that these compounds affect neuronal pathophysiological mechanisms involved in central sensitization. Such pain-relieving effects, which are mostly mediated via central adenosine A1 receptor activation, have a slow onset and long duration of action, lasting usually for hours or days and occasionally for months. With acute perioperative pain, treatment with a low-dose infusion of adenosine compounds and the A1 receptor-mediated central antisensitization mechanisms may play only a minor part in the total perioperative pain experience. By administering sufficient doses of adenosine compounds during surgery, however, significant and long-lasting perioperative pain relief can be achieved via central A1 receptor-mediated antinociceptive/analgesic actions as well as via peripheral A2a or A3 receptor-mediated antiinflammatory actions. Thus, adenosine compounds have significant potential for alleviating various types of pain.