What is the place of clonidine in anesthesia? Systematic review and meta-analyses of randomized controlled trials

Adjuvant Analgesics in Acute Pain - Evaluation of Efficacy

PURPOSE OF THE REVIEW

Acute postoperative pain impacts a significant number of patients and is associated with various complications, such as a higher occurrence of chronic postsurgical pain as well as increased morbidity and mortality.

RECENT FINDINGS

Opioids are often used to manage severe pain, but they come with serious adverse effects, such as sedation, respiratory depression, postoperative nausea and vomiting, and impaired bowel function. Therefore, most enhanced recovery after surgery protocols promote multimodal analgesia, which includes adjuvant analgesics, to provide optimal pain control. In this article, we aim to offer a comprehensive review of the contemporary literature on adjuvant analgesics in the management of acute pain, especially in the perioperative setting. Adjuvant analgesics have proven efficacy in treating postoperative pain and reducing need for opioids. While ketamine is an established option for opioid-dependent patients, magnesium and α2-agonists have, in addition to their analgetic effect, the potential to attenuate hemodynamic responses, which make them especially useful in painful laparoscopic procedures. Furthermore, α2-agonists and dexamethasone can extend the analgesic effect of regional anesthesia techniques. However, findings for lidocaine remain inconclusive.

Intraoperative clonidine in endometriosis and spine surgery: A protocol for two randomised, blinded, placebo-controlled trials

BACKGROUND

A high proportion of patients who undergo surgery continue to suffer from moderate to severe pain in the early postoperative period despite advances in pain management strategies. Previous studies suggest that clonidine, an alpha2 adrenergic agonist, administered during the perioperative period could reduce acute postoperative pain intensity and opioid consumption. However, these studies have several limitations related to study design and sample size and hence, further studies are needed.

AIM

To investigate the effect of a single intravenous (IV) dose of intraoperative clonidine on postoperative opioid consumption, pain intensity, nausea, vomiting and sedation after endometriosis and spine surgery.

METHODS

Two separate randomised, blinded, placebo-controlled trials are planned. Patients scheduled for endometriosis (CLONIPAIN) will be randomised to receive either 150 μg intraoperative IV clonidine or placebo (isotonic saline). Patients undergoing spine surgery (CLONISPINE) will receive 3 μg/kg intraoperative IV clonidine or placebo. We aim to include 120 patients in each trial to achieve power of 90% at an alpha level of 0.05.

OUTCOMES

The primary outcome is opioid consumption within the first three postoperative hours. Secondary outcomes include pain intensity at rest and during coughing, nausea, vomiting and sedation within the first two postoperative hours and opioid consumption within the first six postoperative hours. Time to discharge from the PACU will be registered.

CONCLUSION

This study is expected to provide valuable information on the efficacy of intraoperative clonidine in acute postoperative pain management in patients undergoing endometriosis and spine surgery.

A Comparative Study of the Antiemetic Effects of α2-Adrenergic Receptor Agonists Clonidine and Dexmedetomidine against Diverse Emetogens in the Least Shrew (Cryptotis parva) Model of Emesis

In contrast to cats and dogs, here we report that the α2-adrenergic receptor antagonist yohimbine is emetic and corresponding agonists clonidine and dexmedetomidine behave as antiemetics in the least shrew model of vomiting. Yohimbine (0, 0.5, 0.75, 1, 1.5, 2, and 3 mg/kg, i.p.) caused vomiting in shrews in a bell-shaped and dose-dependent manner, with a maximum frequency (0.85 ± 0.22) at 1 mg/kg, which was accompanied by a key central contribution as indicated by increased expression of c-fos, serotonin and substance P release in the shrew brainstem emetic nuclei. Our comparative study in shrews demonstrates that clonidine (0, 0.1, 1, 5, and 10 mg/kg, i.p.) and dexmedetomidine (0, 0.01, 0.05, and 0.1 mg/kg, i.p.) not only suppress yohimbine (1 mg/kg, i.p.)-evoked vomiting in a dose-dependent manner, but also display broad-spectrum antiemetic effects against diverse well-known emetogens, including 2-Methyl-5-HT, GR73632, McN-A-343, quinpirole, FPL64176, SR141716A, thapsigargin, rolipram, and ZD7288. The antiemetic inhibitory ID50 values of dexmedetomidine against the evoked emetogens are much lower than those of clonidine. At its antiemetic doses, clonidine decreased shrews' locomotor activity parameters (distance moved and rearing), whereas dexmedetomidine did not do so. The results suggest that dexmedetomidine represents a better candidate for antiemetic potential with advantages over clonidine.

Non-Opioid Analgesics and Adjuvants after Surgery in Adults with Obesity: Systematic Review with Network Meta-Analysis of Randomized Controlled Trials

Background/Objectives: Managing postoperative pain in patients with obesity is challenging. Although using a combination of pain relief methods is recommended for these patients, the true effectiveness of various intravenous non-opioid analgesics and adjuvants in multimodal anesthesia needs to be better defined. Methods: A systematic review and network meta-analysis was performed to evaluate the efficacy of nonsteroidal anti-inflammatory drugs (NSAIDs), acetaminophen, ketamine, α-2 agonists, lidocaine, magnesium, and oral gabapentinoids in adult surgical patients with obesity. The analysis aimed to compare these treatments to a placebo/no treatment or alternative analgesics, with a primary focus on postoperative pain and secondary endpoints including rescue analgesia, postoperative nausea and vomiting (PONV), and recovery quality. English-language randomized controlled trials across PubMed, Scopus, Web of Science, CINAHL, and EMBASE were considered. Quality and evidence certainty were assessed with the RoB 2 tool and GRADE, and data was analyzed with R software. Results: NSAIDs, along with acetaminophen, lidocaine, α-2 agonists, ketamine, and oral gabapentinoids, effectively reduce early postoperative pain. NSAIDs, particularly ibuprofen, as well as acetaminophen, ketamine, and lidocaine, also show benefits in later postoperative stages. Intravenous non-opioid analgesics and adjuvants show some degree of benefit in reducing PONV and the need for rescue analgesic therapy when using α-2 agonists alone or combined with oral gabapentinoids, notably decreasing the likelihood of PONV. Ketamine, lidocaine, and α-2 agonists are shown to enhance postoperative recovery and care quality. Conclusions: Intravenous non-opioid analgesics and adjuvants are valuable in multimodal anesthesia for pain management in adult surgical patients suffering from obesity.

Intraoperative pharmacologic opioid minimisation strategies and patient-centred outcomes after surgery: a scoping review

BACKGROUND

Postoperative patient-centred outcome measures are essential to capture the patient's experience after surgery. Although a large number of pharmacologic opioid minimisation strategies (i.e. opioid alternatives) are used for patients undergoing surgery, it remains unclear which strategies are most promising in terms of patient-centred outcome improvements. This scoping review had two main objectives: (1) to map and describe evidence from clinical trials assessing the patient-centred effectiveness of pharmacologic intraoperative opioid minimisation strategies in adult surgical patients, and (2) to identify promising pharmacologic opioid minimisation strategies.

METHODS

We searched MEDLINE, Embase, CENTRAL, Web of Science, and CINAHL databases from inception to February 2023. We included trials investigating the use of opioid minimisation strategies in adult surgical patients and reporting at least one patient-centred outcome. Study screening and data extraction were conducted independently by at least two reviewers.

RESULTS

Of 24,842 citations screened for eligibility, 2803 trials assessed the effectiveness of intraoperative opioid minimisation strategies. Of these, 457 trials (67,060 participants) met eligibility criteria, reporting at least one patient-centred outcome. In the 107 trials that included a patient-centred primary outcome, patient wellbeing was the most frequently used domain (55 trials). Based on aggregate findings, dexmedetomidine, systemic lidocaine, and COX-2 inhibitors were promising strategies, while paracetamol, ketamine, and gabapentinoids were less promising. Almost half of the trials (253 trials) did not report a protocol or registration number.

CONCLUSIONS

Researchers should prioritise and include patient-centred outcomes in the assessment of opioid minimisation strategy effectiveness. We identified three potentially promising pharmacologic intraoperative opioid minimisation strategies that should be further assessed through systematic reviews and multicentre trials. Findings from our scoping review may be influenced by selective outcome reporting bias.

STUDY REGISTRATION

OSF - https://osf.io/7kea3.

Effect of esketamine-based opioid-sparing anesthesia strategy on postoperative pain and recovery quality in patients undergoing total laparoscopic hysterectomy: A randomized controlled trail

Objective

Opioid-sparing anesthesia reduces intraoperative use of opioids and postoperative adverse reactions. The current study investigated the effect of esketamine-based opioid-sparing anesthesia on total laparoscopic hysterectomy patients' recovery.

Methods

Ninety patients undergoing total laparoscopic hysterectomy were randomly assigned to esketamine-based group (group K) or opioid-based group (group C). The allocation to groups was unknown to patients, surgeons, and postoperative medical staff. The inability to implement blinding for anesthesiologists was due to the distinct procedures followed by the various groups while administering drugs. The QoR-40 and VAS were used to measure recovery quality. Postoperative adverse events, perioperative opioid consumption, and intraoperative hemodynamics were secondary endpoints.

Results

There was an absence of notable discrepancy in the baseline data observed between the two groups. The QoR-40 scores exhibited greater values in group K when compared to group C on the first day following the surgical procedure (160.91 ± 9.11 vs 151.47 ± 8.35, respectively; mean difference 9.44 [95 %CI: 5.78-13.11]; P < 0.01). Within 24 h of surgery, the VAS score of group K was lower at rest and during movement. (P < 0.05 for each). Group K had much lower rates of nausea and vomiting within 24 h of surgery. (P < 0.05 for each). Group K received significantly lower total doses of sufentanil and remifentanil than group C. (17.28 ± 2.59 vs 43.43 ± 3.52; 0.51 ± 0.15 vs 1.24 ± 0.24). The proportion of patients who used ephedrine in surgery was higher in group C than in group K (P < 0.05).

Conclusions

Esketamine-based opioid-sparing anesthesia strategy is feasible and enhanced recuperation following surgery by decreasing adverse effects associated with opioids and pain scores compared to an opioid-based anesthetic regimen.

Dexmedetomidine and clonidine in palliative medicine: multicentric qualitative evaluation

OBJECTIVES

Alpha-2 agonists have analgesic and sedative properties that can prove interesting in palliative care. The main objective of this study was to describe the use of clonidine and dexmedetomidine in palliative care units (PCU). The secondary objective was to identify physicians' perspectives and attitudes toward alpha-2-agonists.

METHODS

International multicentric qualitative survey of prescribing characteristics and attitudes towards alpha-2 agonist. All 159 PCUs in France, Belgium and French-speaking Switzerland were contacted, and 142 physicians answered the questionnaire (31% participation).

RESULTS

20% of the practitioners surveyed prescribe these molecules are mainly for analgesic and sedative indications. There was considerable heterogeneity in the modalities and dosages of administration. The use of clonidine is more frequent and common in Belgium, while dexmedetomidine is only used in France. There is a high level of satisfaction among practitioners who use these molecules, with the desire of the majority of respondents to obtain additional studies and information on alpha-2-agonists.

CONCLUSION

Alpha-2 agonists are little known and little prescribed by French-speaking palliative care physicians but are of interest because of their potential in this field. Phase 3 studies could justify the use of these molecules in palliative situations and would contribute to harmonising professional practices.

How to Modulate Peripheral and Central Nervous System to Treat Acute Postoperative Pain and Prevent Pain Persistence

Chronic postoperative pain (CPSP) is a major issue after surgery, which may impact on patient's quality of life. Traditionally, CPSP is believed to rely on maladaptive hyperalgesia and risk factors have been identified that predispose to CPSP, including acute postoperative pain. Despite new models of prediction are emerging, acute pain is still a modifiable factor that can be challenged with perioperative analgesic strategies. In this review we present the issue of CPSP, focusing on molecular mechanism underlying the development of acute and chronic hyperalgesia. Also, we focus on how perioperative strategies can impact directly or indirectly (by reducing postoperative pain intensity) on the development of CPSP.

Pain in Colorectal Surgery: How Does It Occur and What Tools Do We Have for Treatment?

Pain is a complex entity with deleterious effects on the entire organism. Poorly controlled postoperative pain impacts the patient outcome, being associated with increased morbidity, inadequate quality of life and functional recovery. In the current surgical environment with less invasive surgical procedures increasingly being used and a trend towards rapid discharge home after surgery, we need to continuously re-evaluate analgesic strategies. We have performed a narrative review consisting of a description of the acute surgical pain anatomic pathways and the connection between pain and the surgical stress response followed by reviewing methods of multimodal analgesia in colorectal surgery found in recent literature data. We have described various regional analgesia techniques and drugs effective in pain treatment, emphasizing their advantages and concerns. We have also tried to identify present knowledge gaps requiring future research. Our review concludes that surgical pain has peculiarities that make its management complex, implying a consistent, multimodal approach aiming to block both peripheral and central pain pathways.

Effectiveness of the oral Clonidine as a pre-anesthetic medicine for thyroidectomy surgery; A randomized clinical trial

Introduction

Hemodynamic disturbance is a common problem in patients undergoing thyroid surgery. It may be due to episodic increases in thyroid hormones (thyroid storm) or stimulation of the carotid sinus baroreflex. The aim of the present study was to investigate effectiveness of the pre-operative oral Clonidine on reducing these hemodynamic changes during total thyroidectomy surgery.

Methods

In a prospective, randomized, double-blind study, 80 patients scheduled for elective total thyroidectomy were randomized to receive either 0.2 mg Clonidine (n=40) or a matched placebo (n=40) orally sixty minutes before entering the operating room. Hemodynamic variables, the duration of surgery, estimated amount of blood loss and the dose of administered remifentanil were recorded for further analysis.

Results

Oral Clonidine was found to be significantly better in maintaining stable hemodynamics compared to the control group. Also, In the Clonidine group, the estimated amount of blood loss (110.4±10 ml vs. 182.2±11.4 mL, P=0.04), duration of the surgery (78.26±55.2 min vs. 105.16±61.75 min, P=0.027) and administered dose of remifentanil (26.67±6.6 μg vs. 216.2±14.8 μg, P=0.01) were also significantly lower than the control group.

Conclusion

Pre-operative administration of 0.2 mg oral Clonidine in patients undergoing total thyroidectomy results in improved perioperative hemodynamic stability and reduced response to perioperative stress.

Multimodal Analgesia Bundle and Postoperative Opioid Use Among Patients Undergoing Colorectal Surgery

Importance

A key objective in contemporary surgery is to reduce or eliminate the usage of opioids to minimize gastrointestinal adverse effects, fatigue, and long-term opioid dependency.

Objectives

To evaluate the association of the implementation of a care bundle of 3 opioid-sparing interventions with the amount of opioids consumed postoperatively among patients undergoing major abdominal surgery and to examine the respective associations of the 3 components.

Design, Setting, and Participants

This retrospective cohort study was performed at Ersta Hospital, an elective teaching hospital in Stockholm, Sweden. All patients undergoing major colorectal surgery between January 1, 2016, through December 31, 2019, were included. Data analysis was conducted from February 1, 2020, to May 30, 2022.

Exposures

A care bundle consisting of an individualized opioid regimen, regular gabapentinoids, and clonidine as a rescue analgesic was gradually introduced early in the study period.

Main Outcomes and Measures

Amount of in-hospital administered intravenous and oral opioids on the day of surgery and the first 5 postoperative days (morphine milligram equivalents [MME]). The association between exposure and outcome was examined using multivariable linear regression.

Results

Overall, 842 patients had major colorectal surgery in the study period (mean [SD] age, 64.6 [15.5] years; 421 [50%] men). Median (range) opioid usage decreased from 75 (0-796) MME in 2016 to 22 (0-362) MME in 2019 (P < .001), and the proportion of patients receiving 45 MME or less increased from 35% to 66% (P < .001). On multivariable analysis (F5, 836 = 57.5; P < .001), an individualized opioid strategy (β = -11.6; SE = 3.8; P = .003), the use of gabapentin (β = -39.1; SE = 4.5; P < .001), and increasing age (β = -1.0; SE = 0.11; P < .001) were associated with less opioid consumption, while the use of clonidine was associated with more opioid intake (β = 11.6; SE = 3.6; P = .001).

Conclusions and Relevance

In this cohort study of 842 patients undergoing colorectal surgery, a care bundle consisting of an individualized opioid regimen, regular gabapentin, and clonidine as a rescue analgesic was found to be associated with a significant decrease in opioids consumed postoperatively. Regular gabapentin and an individualized opioid regimen were particularly strongly associated with this decrease and should be further evaluated as components of multimodal, opioid-free postoperative analgesia.

Adjuvants for balanced anesthesia in ambulatory surgery

Balanced anesthesia relies on the simultaneous administration of different drugs to attain an anesthetic state. The classic triad of anesthesia is a combination of a hypnotic, an analgesic, and a neuromuscular blocker. It is predominantly the analgesic pillar of this triad that became more and more supported by adjuvant therapy. The aim of this approach is to evolve into an opioid-sparing technique to cope with undesirable side effects of the opioids and is fueled by the opioid epidemic. The optimal strategy for balanced general anesthesia in ambulatory surgery must aim for a transition to a multimodal analgesic regimen dealing with acute postoperative pain and ideally reduce the most common adverse effects patients are faced with at home; sore throat, delayed awakening, memory disturbances, headache, nausea and vomiting, and negative behavioral changes. Over the years, this continuum of "multimodal general anesthesia" adopted many drugs with different modes of action. This review focuses on the most recent evidence on the different adjuvants that entered clinical practice and gives an overview of the different mechanisms of action, the potential as opioid-sparing or hypnotic-sparing drugs, and the applicability specifically in ambulatory surgery.

Perioperative opioids: a narrative review contextualising new avenues to improve prescribing

Opioids have dominated the management of perioperative pain in recent decades with higher doses than ever before used in some circumstances. Through the expanding use of opioids, growing research has highlighted their associated side-effects and the intertwined phenomena of acute withdrawal syndrome, opioid tolerance, and opioid-induced hyperalgesia. With multiple clinical guidelines now endorsing multimodal analgesia, a diverse array of opioid-sparing agents emerges and has been studied to variable degrees, including techniques of opioid-free anaesthesia. It remains unclear to what extent such methods should be adopted, yet current evidence does suggest dependence on opioids as the primary perioperative analgesic might not meet the principles of 'rational prescribing' as described by Maxwell. In this narrative review we describe how, using current evidence, a patient-centred rational-prescribing approach can be applied to opioids in the perioperative period. To contextualise this approach, we discuss the historical adoption of opioids in anaesthesia, our growing understanding of associated side-effects and emerging strategies of opioid-sparing and opioid-free anaesthesia. We discuss avenues and challenges for improving opioid prescribing to limit persistent postoperative opioid use and how these may be incorporated into a rational-prescribing approach.

Opioid-Sparing Techniques in Orthopedic Anesthesia-One Step to Opioid-Free Anesthesia?

Opioid-free anesthesia is a multimodal anesthesia aimed at avoiding the negative impact of intraoperative opioid on patient's postoperative outcomes. It is based on the physiology of pathways involved in intraoperative nociception. It has been shown to be feasible but the literature is still scarce on the clinically meaningful benefits as well as on the side effects and/or complications that might be associated with it. Moreover, most studies involved abdominal and/or bariatric surgery. Procedure-specific studies are lacking, especially in orthopedics.

Use of clonidine in the treatment of Irukandji syndrome: A 4-year retrospective cohort study on safety, efficacy and clinical utility

OBJECTIVE

Irukandji syndrome (IS) is an extremely painful condition that causes a significant catecholamine surge and sympathetic autonomic response related to the envenomation from certain types of jellyfish. Current management involves intravenous fluids, magnesium sulphate and large doses of opioids for symptom control. Clonidine, a centrally acting alpha-2 agonist, is often used as an analgesic adjunct to reduce opioid requirements in acute pain. The present study explores the safety and efficacy of clonidine in reducing opioid requirements in IS.

METHODS

All patients diagnosed with IS at Cairns Hospital between 1 March 2016 and 30 April 2020, and participants from the Magnesium in Irukandji Study Trial, were included in this retrospective study (n = 114). Cases were separated into two groups depending on whether or not they received clonidine, and subsequently analysed according to pre- and post-intervention opioid requirements, clonidine dose administered and adverse effects.

RESULTS

Notably, 39 patients with IS received ≥1 mcg/kg clonidine and the remaining 75 did not. There was no difference in oral morphine equivalent daily dose (oMEDD) between groups before clonidine administration; however, there was a significant reduction in oMEDD required after patients received clonidine (26.1 mg; 95% CI 4.6-47.7) compared with those who did not (66.6 mg; 95% CI 56.9-86.1) (F = 8.722, df = 1 × 224, P = 0.003). One episode of hypotension occurred following the intervention.

CONCLUSION

Patients with IS who received clonidine required significantly lower opioid requirements than those who did not receive clonidine. Clonidine was safe to administer and should be considered early when treating IS. The optimal clonidine dose remains unclear and requires prospective studies to validate our findings.

Oral clonidine as a pre-anesthetic medication in hair transplantation surgery-A pilot study

BACKGROUND

Hair transplantation (HT) is a safe and rewarding procedure for a patient as well as the surgeon. Clonidine may be a good adjuvant in HT because of its analgesic, anxiolytic, and sedative effects.

OBJECTIVE

To study efficacy of Clonidine as a preoperative medication in HT.

METHODS & MATERIALS

The study was a prospective trial of 46 consecutive patients who underwent HT between January and May 2017. Patients with normal vital parameters on arrival were given Tab clonidine (0.1 mg) 30 min before starting of the procedure [Clonidine group (n = 30)]; rest were included in the control group (n = 16). Vitals were monitored every 30 min during surgery until the end. Patients were assessed for pain, level of sedation during surgery and for postoperative analgesia.

RESULT

All patients who received clonidine, except one, were comfortable and experienced no pain throughout the duration of surgery; nine went into deep sleep. Of the 16 patients in the control group, no patients reported deep sleep, 3 felt restless, and 4 had mild pain. There were no untoward effects in both groups.

CONCLUSION

Our study suggests that clonidine is useful as a pre-anesthetic medication in HT. However, this is a pilot study and further larger studies are needed.

Perioperative Buprenorphine Management: A Multidisciplinary Approach

Buprenorphine formulations (including buprenorphine/naloxone) are effective treatments of pain and opioid use disorder (OUD). Historically, perioperative management of patients prescribed buprenorphine involved abstinence from buprenorphine sufficient to allow for unrestricted mu-opioid receptor availability to full agonist opioid (FAO) treatment. Evidence is mounting that a multimodal analgesic strategy, including simultaneous administration of buprenorphine and FAO, nonopioid adjuncts such as acetaminophen and nonsteroidal anti-inflammatory drugs, and regional anesthesia, is a safe and effective perioperative strategy for the patient prescribed long-term buprenorphine treatment of OUD. This strategy will likely simplify management and more seamlessly provide continuous buprenorphine treatment of OUD after hospital discharge.

[Inhalational anesthetics]

Inhalational anesthetics have been used for induction and maintenance of general anesthesia for more than 150 years. All of the currently used inhalational anesthetics are chlorinated and fluorinated derivatives of ether. Dosing is carried out using the minimal alveolar concentration (MAC) concept. The pharmacokinetic properties of the various inhalational anesthetics are governed by the specific distribution coefficients. Mechanisms of action include specific modulations of various receptors of the central nervous system as well as an unspecific interaction with the cell membrane. Organ toxicity of modern inhalational anesthetics is considered to be minimal. The role of inhalational anesthetics in the context of postoperative nausea and vomiting (PONV) has been reassessed in recent years. The superiority of inhalational anesthetics over intravenous hypnotics with respect to intraoperative awareness is undisputed. The organ protective mechanism of preconditioning is an exclusive property of inhalational anesthetics among all the currently available hypnotics.

Efficacy of Local Anesthetic Wound Infiltration in Temporomandibular Joint Ankylosis Surgery for Control of Postoperative Pain: A Prospective, Randomized Controlled, and Double-Blinded Trial

PURPOSE

This study aimed to compare the analgesic efficacy of wound infiltration with ropivacaine alone or with adjuvants clonidine or dexamethasone for postoperative pain in temporomandibular joint ankylosis (TMJA) surgery.

MATERIALS AND METHODS

The investigators implemented a randomized controlled trial with 3 parallel groups, among the patients of bilateral TMJA visiting the maxillofacial surgery unit between March 12, 2015 and February 5, 2017. At the completion of surgery, wound infiltration was done with 0.25% of ropivacaine (R group), 0.25% of ropivacaine with 0.5 mcg/kg of clonidine (RC group), 0.25% of ropivacaine with 0.1 mg/kg of dexamethasone (RD group), and 0.2 mL/kg of drug volume on each side. The primary outcome variables were total opioid consumption (fentanyl in micrograms/kilogram) and visual analog scale for pain at rest and movement for 24 hours after surgery. The secondary outcome variables were time (minutes) to first rescue analgesic requirement and patient satisfaction scores. The patients, surgeons, and anesthesiologists collecting the data were blinded to the group allocation. Continuous and qualitative data were summarized using mean (standard deviation) and frequency distribution, respectively.

RESULTS

About 45 patients were randomized into 3 equal groups. Mean age of the sample was 17.6 ± 8.04 years (males = 24 [53%]; females = 21 [47%]). Surgery for TMJA included gap arthroplasty (n = 17), interpositional arthroplasty (n = 24), and total TMJ replacement (n = 4). Total fentanyl (micrograms) consumption during 24 hours was comparable between all the 3 groups and statistically not significant (P = .40). The pain scores (visual analog scale at rest and movement) were comparable at all time points. No significant difference was noted for time to first rescue analgesic requirement (P = .31). Patient satisfaction was higher in RC group as compared with R group (P = .009). No adverse effects were noted in any group.

CONCLUSIONS

Within the confines of the sample size and the absence of power calculation, the study implies that wound infiltration with ropivacaine was as efficacious as when mixed with adjuvants, either clonidine or dexamethasone, for control of postoperative pain for 24 hours.

Management strategies for the treatment and prevention of postoperative/postdischarge nausea and vomiting: an updated review

Postoperative nausea and vomiting (PONV) and postdischarge nausea and vomiting (PDNV) remain common and distressing complications following surgery. The routine use of opioid analgesics for perioperative pain management is a major contributing factor to both PONV and PDNV after surgery. PONV and PDNV can delay discharge from the hospital or surgicenter, delay the return to normal activities of daily living after discharge home, and increase medical costs. The high incidence of PONV and PDNV has persisted despite the introduction of many new antiemetic drugs (and more aggressive use of antiemetic prophylaxis) over the last two decades as a result of growth in minimally invasive ambulatory surgery and the increased emphasis on earlier mobilization and discharge after both minor and major surgical procedures (e.g. enhanced recovery protocols). Pharmacologic management of PONV should be tailored to the patient’s risk level using the validated PONV and PDNV risk-scoring systems to encourage cost-effective practices and minimize the potential for adverse side effects due to drug interactions in the perioperative period. A combination of prophylactic antiemetic drugs with different mechanisms of action should be administered to patients with moderate to high risk of developing PONV. In addition to utilizing prophylactic antiemetic drugs, the management of perioperative pain using opioid-sparing multimodal analgesic techniques is critically important for achieving an enhanced recovery after surgery. In conclusion, the utilization of strategies to reduce the baseline risk of PONV (e.g. adequate hydration and the use of nonpharmacologic antiemetic and opioid-sparing analgesic techniques) and implementing multimodal antiemetic and analgesic regimens will reduce the likelihood of patients developing PONV and PDNV after surgery.

Opioid free anesthesia: evidence for short and long-term outcome

The introduction of synthetic opioids in clinical practice played a major role in the history of anesthesiology. For years, anesthesiologists have been thinking that opioids are needed for intraoperative anesthesia. However, we now know that opioids (especially synthetic short-acting molecules) are definitely not ideal analgesics and may even be counterproductive, increasing postoperative pain. As well, opioids have revealed important drawbacks associated to poor perioperative outcomes. As a matter of fact, efforts in postoperative pain management in the last 30 years were driven by the idea of reducing/eliminating opioids from the postoperative period. However, a modern concept of anesthesia should eliminate opioids already intra-operatively towards a balanced, opioid-free approach (opioid-free anesthesia - OFA). In OFA drugs and techniques historically proven for their efficacy are combined in rational and defined protocols. They include ketamine, alpha-2 agonists, lidocaine, magnesium, anti-inflammatory drugs and regional anesthesia. Promising results have been obtained on perioperative outcome. For sure, analgesia is not reduced with OFA, but it is effective and with less opioid-related side effects. These benefits may be of particular importance in some high-risk patients, like OSAS, obese and chronic opioid-users/abusers. OFA may also increase patient-reported outcomes; despite it is difficult to specifically rule out the effect of intraoperative opioids. Finally, few data are available on long-term outcomes (persistent pain and opioid abuse, cancer outcome). New studies and data are required to elaborate the optimal approach for each patient/surgery, but interest and publication are increasing and may open the road to the wider adoption of OFA.

Safety and efficacy of clonidine on postoperative vomiting and pain in pediatric ophthalmic surgery: A systematic review and meta-analysis

BACKGROUND

Postoperative vomiting and pain are common, unpleasant phenomena in pediatric patients undergoing ophthalmic surgery. Clonidine has antiemetic and analgesic properties and thus may be used as premedication to reduce postoperative vomiting and pain.

AIM

To assess whether clonidine premedication may safely decrease postoperative vomiting and postoperative pain in pediatric patients who received an ophthalmic surgery.

METHODS

We systematically searched PubMed, EMBASE, Cochrane Library, and Scopus databases from their inception to September 2018. Randomized clinical trials comparing clonidine premedication with a placebo or an active comparator that investigated postoperative vomiting or postoperative pain in pediatric patients undergoing ophthalmic surgery were included. The primary outcome was postoperative vomiting. The secondary outcome was postoperative pain. We also evaluated the safety of clonidine premedication by tracking hemodynamic instability associated with its use.

RESULTS

Ten studies with 979 patients were eligible for inclusion. Clonidine achieved a significantly lower incidence of postoperative vomiting within 6 hours postoperatively, 6-24 hours postoperatively, and at the end of the study (risk difference: -0.15; 95% confidence interval: -0.32 to -0.05; risk difference: -0.15; 95% confidence interval: -0.29 to 0.01; and risk difference: -0.23; 95% confidence interval: -0.34 to -0.12, respectively) than placebo. For the subgroup of patients who received strabismus surgery, clonidine produced a lower incidence of postoperative vomiting than placebo (risk difference: -0.19; 95% confidence interval: -0.29 to -0.05). Compared to benzodiazepine, clonidine achieved a lower incidence of postoperative vomiting at the end of the study (risk difference: -0.19; 95% confidence interval: -0.31 to -0.07); the effect was only observed in patients receiving clonidine 4 μg/kg. Furthermore, children receiving clonidine had lower postoperative pain scores, lower analgesic requirements, and more of them were pain-free compared to those who received a placebo. No patient using clonidine had any major hemodynamic instability.

CONCLUSION

Compared to placebo or benzodiazepine, clonidine premedication was effective in reducing postoperative vomiting in pediatric patients undergoing ophthalmic surgery. Clonidine premedication also provided more reduction in postoperative pain when compared to placebo. The use of clonidine premedication was not associated with adverse hemodynamic events.

Clonidine in pediatric anesthesia: the new panacea or a drug still looking for an indication?

PURPOSE OF REVIEW

Clonidine, an α2-receptor agonist is a widely used drug in pediatrics with a large scope of indications ranging from prevention of postoperative emergence agitation, analgesia, anxiolysis, sedation, weaning to shivering. In the era of 'opioid-free' medicine with much attention be directed toward increasing problems with opioid use, clonidine due to its global availability, low cost and safety profile has become an even more interesting option.

RECENT FINDINGS

Increasing evidence from randomised clinical trials support the use of clonidine in healthy children in the perioperative setting. Clonidine appears to significantly reduce postoperative emergence agitation, opioid consumption, shivering, nausea and vomiting. In addition, emerging evidence support the use of clonidine for sedation of critically ill children in ICUs. In this review, the current evidence for clonidine in pediatrics is described and analyzed including a meta-analysis for prevention of emergence agitation.

SUMMARY

Clonidine appears a safe and beneficial drug with moderate to high-quality evidence supporting its use in pediatric anesthesia. However, for some indications and populations such as children younger than 12 months old and those with hemodynamic instability, there is an urgent need for high-quality trials.

American Society for Enhanced Recovery and Perioperative Quality Initiative Joint Consensus Statement on Perioperative Opioid Minimization in Opioid-Naïve Patients

Surgical care episodes place opioid-naïve patients at risk for transitioning to new persistent postoperative opioid use. With one of the central principles being the application of multimodal pain interventions to reduce the reliance on opioid-based medications, enhanced recovery pathways provide a framework that decreases perioperative opioid use. The fourth Perioperative Quality Initiative brought together a group of international experts representing anesthesiology, surgery, and nursing with the objective of providing consensus recommendations on this important topic. Fourth Perioperative Quality Initiative was a consensus-building conference designed around a modified Delphi process in which the group alternately convened for plenary discussion sessions in between small group discussions. The process included several iterative steps including a literature review of the topics, building consensus around the important questions related to the topic, and sequential steps of content building and refinement until agreement was achieved and a consensus document was produced. During the fourth Perioperative Quality Initiative conference and thereafter as a writing group, reference applicability to the topic was discussed in any area where there was disagreement. For this manuscript, the questions answered included (1) What are the potential strategies for preventing persistent postoperative opioid use? (2) Is opioid-free anesthesia and analgesia feasible and appropriate for routine operations? and (3) Is opioid-free (intraoperative) anesthesia associated with equivalent or superior outcomes compared to an opioid minimization in the perioperative period? We will discuss the relevant literature for each questions, emphasize what we do not know, and prioritize the areas for future research.

Skin/Muscle Incision and Retraction Induces Evoked and Spontaneous Pain in Mice

Background

Surgery is a frequent cause of persistent pain. Unrelieved chronic postsurgical pain causes unnecessary patient suffering and discomfort and usually leads to psychological complications. The rat model of skin/muscle incision and retraction (SMIR) with decreased paw withdrawal thresholds developed by Flatters was usually used to investigate the underlying mechanism of chronic postsurgical pain.

Objectives

The aim of our study was to develop a new mice model of SMIR for further investigation with transgenic mice and so on and to evaluate the analgesic effects of clonidine and gabapentin on pain behavior with this new mice model.

Methods

Male C57BL/6 mice were anesthetized, and a 1.0-1.3 cm incision was made in the skin of the medial thigh approximately 3 mm medial to the saphenous vein to reveal the muscle of the thigh. The paw withdrawal threshold (PWT) to mechanical stimuli and the paw withdrawal latency to heat stimuli were measured before and after SMIR. Furthermore, the PWT to mechanical stimuli and conditioned place preference (CPP) was measured before and after the systemic injection of clonidine and gabapentin.

Results

SMIR-evoked mechanical hypersensitivity in mice began on day 1 after the procedure, prominent between days 1 and 10 after the procedure, persisted at least until day 14, and disappeared on day 18 after the procedure. However, the mice model of SMIR did not evoke significant heat hypersensitivity. Systemic injection of clonidine and gabapentin raised the PWT in the SMIR mice dose-dependently. Compared with the mice that underwent the sham operation, mice of SMIR spent a longer time in the clonidine-paired chamber than those of NS, while the gabapentin-paired chamber has no difference with that of NS in the CPP paradigm.

Conclusion

These data suggested that the mice model of SMIR demonstrated a persistent pain syndrome, including evoked pain and spontaneous pain. Clonidine and gabapentin could relieve mechanical hypersensitivity dose-dependently simultaneously. However, clonidine but not gabapentin could alleviate the spontaneous pain of SMIR in the mice model.

Opioid Use in the Postoperative Arena: Global Reduction in Opioids After Surgery Through Enhanced Recovery and Gynecologic Surgery

Enhanced recovery programs aim to reduce surgical stress to improve the patient perioperative experience. Through a combination of multimodal analgesia and maintaining a physiological state, postoperative recovery is improved. Many analgesic adjuncts are available that improve postoperative pain control and limit opioid analgesia requirements. Adjuncts are often used in combination, but different interventions may be incorporated for patient-specific and procedure-specific needs. Postoperative pain control can be optimized by continuing nonopioid adjuncts, and prescribing opioid analgesia to address breakthrough pain. Prescribing practices should balance optimizing pain relief, minimizing the risk of chronic pain, while limiting the potential for opioid misuse.

Beyond Opioids for Pain Management in Adult Critically Ill Patients

Critically ill patients commonly experience pain, and the provision of analgesia is an essential component of intensive care unit (ICU) care. Opioids are the mainstay of pain management in the ICU but are limited by their adverse effects, risk of addiction and abuse, and recent drug shortages of injectable formulations. A multimodal analgesia approach, utilizing nonopioid analgesics as adjuncts to opioid therapy, is recommended since they may modulate the pain response and reduce opioid requirements by acting on multiple pain mediators. Nonopioid analgesics discussed in detail in this article are acetaminophen, α-2 receptor agonists, gabapentinoids, ketamine, lidocaine, and nonsteroidal anti-inflammatory drugs. This literature review describes the clinical pharmacology, supportive ICU and relevant non-ICU data, and practical considerations associated with the administration of nonopioid analgesics in critically ill adult patients.

Regional anesthesia to ameliorate postoperative analgesia outcomes in pediatric surgical patients: an updated systematic review of randomized controlled trials

Regional anesthesia is becoming increasingly popular among anesthesiologists in the management of postoperative analgesia following pediatric surgery. The main objective of this review was to systematically evaluate the last 5 years of randomized controlled trials on the role of regional anesthesia techniques in alleviating postoperative pain associated with various pediatric surgical procedures. Forty studies on 2,408 pediatric patients were evaluated. The majority of the articles published from 2013 to 2017 reported that the use of regional anesthesia minimized postoperative pain and reduced opioid consumption. Only a few surgical procedures (cholecystectomy, inguinal hernia repair, and non-laparoscopic major abdominal surgery) reported no significant difference in the postoperative pain relief compared with the standard anesthetic management. The growing number of randomized controlled trials in the pediatric literature is very promising; however, additional confirmation is needed to reinforce the use of specific regional anesthesia techniques to provide optimal postoperative pain relief for a few surgical procedures (reconstructive ear surgery, chest wall deformity, hypospadias, umbilical hernia, cleft palate repair) in pediatric patients. More randomized controlled trials are needed to establish regional anesthesia as an essential component of postoperative analgesia management in children.

Repurposing Valproate, Enteral Clonidine, and Phenobarbital for Comfort in Adult ICU Patients: A Literature Review with Practical Considerations

Provision of adequate sedation is a fundamental part of caring for critically ill patients. Propofol, dexmedetomidine, and benzodiazepines are the most commonly administered sedative medications for adult patients in the intensive care unit (ICU). These agents are limited by adverse effects, need for a monitored environment for safe administration, and lack of universal effectiveness. Increased interest has recently been expressed about repurposing older pharmacologic agents for patient comfort in the ICU. Valproate, enteral clonidine, and phenobarbital are three agents with increasing evidence supporting their use. Potential benefits associated with their utilization are cost minimization and safe administration after transition out of the ICU. This literature review describes the historical context, pharmacologic characteristics, supportive data, and practical considerations associated with the administration of these agents for comfort in critically ill adult patients.

Effect of clonidine on the efficacy of lignocaine local anesthesia in dentistry: A systematic review and meta-analysis of randomized, controlled trials

Alternatives to adrenaline with lignocaine local anesthesia, such as clonidine, have been trialed in various randomized, controlled trials. Therefore, the aim of the present systematic review was to compile the available evidence on using clonidine with lignocaine for dental anesthesia. Electronic databases were searched for eligible studies. A data-extraction form was created, extracted data were analyzed using non-Cochrane mode in RevMan 5.3 software. Heterogeneity between the studies were assessed using the forest plot, I² statistics (where >50% was considered to have moderate-to-severe heterogeneity), and χ² -test. Random-effects models were used because of moderate heterogeneity. Five studies were included for the final review. While clonidine was found to significantly shorten the onset of local anesthesia when measured subjectively, no significant difference was observed objectively. No significant difference was observed in the duration and postoperative analgesia. Stable hemodynamic parameters within the safe range were observed postoperatively when clonidine was used. Clonidine could be considered as an alternative to adrenaline in cases of contraindications to adrenaline, such as like cardiac abnormalities, hypertension, and diabetes.

Clonidine as a preoperative sedative

The purpose of this study was to -examine the use of oral clonidine as a preoperative sedative prior to parenteral moderate sedation. Initially, four patients were given 0.2 mg oral clonidine but reduced to 0.1 mg clonidine due to -significant drops in blood pressure. Oral clonidine doses of 0.1 mg were then given to 19 patients preoperatively. In all these patients, blood pressure measurements decreased, but there were no significant differences in amounts of sedative agents needed in the clonidine group and the control group (N = 80). The conclusions reached suggest that clonidine has an advantage over other preoperative sedation agents in anxious patients exhibiting hypertension and tachycardia. However, the preop ideal dose required to reduce the amount of sedative drugs used as well as provide anxiolysis remains unknown. In further studies, different doses should be explored to determine what dosage of clonidine may offer hemodynamic protection as well as decrease sedative drugs needed.