Liposomal bupivacaine peripheral nerve block for the management of postoperative pain

Rectus sheath block for acute pain management after robot-assisted laparoscopic prostatectomy

BACKGROUND

Robot-assisted laparoscopic prostatectomy (RALP) is a favored surgical approach for treating prostate cancer. However, RALP does not decrease postoperative pain significantly despite its minimal invasiveness. The pain associated with robot-assisted surgery is most severe during the immediate postoperative period. We aimed to demonstrate that preoperative rectus sheath block (RSB) can reduce acute pain after RALP.

METHODS

A prospective non-randomized study with two parallel groups was performed from June 2020 to August 2020. A total of 100 patients undergoing RALP were divided into two groups: the RSB group (n = 50) and the non-RSB group (n = 50). Ultrasound-guided RSB was performed preoperatively only in the RSB group. The primary outcome of the study was the visual analog scale (VAS) pain score during coughing (VAS-C) 1 h after surgery. In addition, the VAS pain score at rest (VAS-R) and the VAS-C were assessed up to 24 h after surgery. The doses of postoperative opioids consumed were also recorded.

RESULTS

The RSB group had a significantly lower VAS-C 1 h after RALP (58 [47-73] vs. 74 [63-83] mm, p = 0.001). In addition, the RSB group had significantly lower VAS-R and VAS-C scores, and postoperative opioid requirement, up to 6 h after surgery compared to the non-RSB group. Moreover, the VAS-R was significantly lower in the RSB group than in the non-RSB group 24 h after surgery.

CONCLUSION

Preoperative RSB significantly improved analgesia during the early period after RALP. The long-term analgesic efficacy of RSB needs further study.

Postoperative pain: a review of emerging therapeutic options

INTRODUCTION

Postoperative pain is often managed by opioid medications, even though they carry a risk of adverse effects such as vomiting, constipation, sedation, respiratory depression and physical dependence. Furthermore, opioid use in the healthcare setting has likely contributed to the epidemic. However, the mismanagement of postoperative pain can result in delayed recovery time, impaired physical function, increased risk of morbidity and mortality, chronic pain, and higher healthcare costs.

AREAS COVERED

This review explores emerging therapeutic options and strategies in the management of acute postoperative pain and focuses on opioid-sparing, multimodal analgesia. This includes regional anesthetic techniques, non opioid pharmacotherapy, novel opioids and non-pharmacologic therapy. We have also discussed examples of novel analgesics and formulations which have potential benefits in reducing postoperative pain and opioid use after surgery.

EXPERT OPINION

The development of novel regional anesthesia techniques allows for opioid minimization in increasing number of surgical procedures. This synergizes with the availability of novel non-opioid analgesic adjucts. In addition, several novel opioid drugs have been developed which may be pathway selective and associated with less adverse effect than conventional opioids.

Use of Liposomal Bupivacaine in Pediatric Peripheral Nerve Blocks after Traumatic Amputation

Liposomal bupivacaine has been explored for indications in regional anesthesia, but little has been reported about its use in pediatric patients. In March 2021, the FDA approved an indication for liposomal bupivacaine as an infiltrated local anesthetic in children older than the age of six. Despite this recently expanded indication, the literature lacks reports of use for peripheral nerve blockade in children. We describe a case where liposomal bupivacaine was used for femoral and sciatic nerve blocks in a 5-year-old child with traumatic amputation of his lower leg. Pain control was excellent, with no pain or opioid use reported during the first 62 hours. After the regional anesthesia subsided, the patient required in total 4 oral doses of oxycodone 0.1 mg/kg prior to discharge. The patient did not develop chronic pain or phantom limb syndrome. While liposomal bupivacaine is not currently FDA-approved for peripheral nerve blockade in children, this case highlights a potentially effective use of this drug and possible area for further investigation.

A randomized-controlled trial comparing liposomal bupivacaine, plain bupivacaine, and the mixture of liposomal bupivacaine and plain bupivacaine in transversus abdominus plane block for postoperative analgesia for open abdominal hysterectomies

PURPOSE

Transversus abdominus plane (TAP) blocks are widely used for postoperative analgesia for abdominal surgical procedures. The purpose of this study was to compare the analgesic efficacy of plain bupivacaine, liposomal bupivacaine, and the mixture of plain bupivacaine with liposomal bupivacaine when used in a TAP block.

METHODS

This study was a single centre, prospective, patient-, observer-, and surgeon-blinded, randomized-controlled trial in which 90 patients undergoing an open abdominal hysterectomy with a midline incision were randomized to receive a TAP block with plain bupivacaine (group bupivacaine), liposomal bupivacaine (group liposomal), or a mixture of liposomal bupivacaine and plain bupivacaine (group mixture). Primary outcomes included time to the first rescue opioid analgesic and total opioid consumption during the first 72 postoperative hours. Secondary outcomes included pain scores, patient satisfaction, incidence of hemodynamic instability, presence of local anesthetic systemic toxicity, and length of hospital stay.

RESULTS

The median [interquartile range] time to first opioid was 51 [28-66] min in group bupivacaine, 63 [44-102] min in group liposomal, and 51 [24-84] min in group mixture (P = 0.20). The median [interquartile range] total opioid consumption in the first 72 postoperative hours was 208 [155-270] mg in group bupivacaine, 203 [153-283] mg in group liposomal, and 202 [116-325] mg in group mixture (P = 0.92). There were no significant differences in secondary outcomes between groups.

CONCLUSIONS

In this small study at risk of being under-powered, the mixture of liposomal bupivacaine with plain bupivacaine for TAP block did not improve analgesia compared with either liposomal bupivacaine or plain bupivacaine on their own.

TRIAL REGISTRATION

www.clinicaltrials.gov (NCT03250507); registered 5 April 2017.

Does the performance of lower limb peripheral nerve blocks differ among orthopedic sub-specialties? A single institution experience in 246 patients

OBJECTIVES

Continuous peripheral nerve blocks (cPNBs) have shown promising results in pain management after orthopaedic surgeries. However, they can be associated with some risks and limitations. The purpose of this study is to describe our experience with the cPNBs regarding efficacy and adverse events in patients undergoing orthopedic surgeries on the lower extremity in different subspecialties.

METHODS

This is a prospective cohort study on collected data from perineural catheters for pain management after orthopedic surgeries in lower limbs. Catheters were placed by experienced anesthesiologists using sterile technique. After an initial bolus dose of 10-20 mL ropivacaine 0.5% (weight adjusted), the catheters were secured and connected to disposable mechanical infusion pumps with ropivacaine 0.2% (basal infusion rate = 6 mL/h; weight adjusted (0.2 mL/kg/h)). After catheterization, the patients were examined daily, by specially educated acute pain service nurses. Pro re nata (PRN) or fixed boluses (10 mL bupivacaine 0.25%; weight adjusted) with an upper limit of 4 times/day, were administered if indicated. Patients' demographic data, physiological status, and pre-op intake of opioids and other analgesics were registered. The severity of post-operative pain was assessed with 'Numeric Rating Scale' (NRS) and 'Face, legs, Activity, Cry, Consolability' (FLACC) scale for adults and children, respectively. The need for additional opioids and possible complications were registered.

RESULTS

We included 547 catheters of 246 patients (Range 1-10 catheters per patient). Overall, 115 (21%) femoral, 162 (30%) saphenous, 66 (12%) sciatic, and 204 (37%) popliteal sciatic nerve catheter were used. 452 (83%) catheters were inserted by a primary procedure, 61(11%) catheters employed as a replacement, and 34 catheters (6.2%) used as a supplement. For guiding the catheterization, ultrasound was applied in 451 catheters (82%), nerve stimulator in 90 catheters (16%), and both methods in 6 catheters (1.1%). The median duration a catheter remained in place was 3 days (IQR = 2-5). The proportion of catheters with a duration of two days was 81, 79, 73, and 71% for femoral, sciatic, saphenous, and popliteal nerve, respectively. In different subspecialties, 91% of catheters in wound and amputations, 89% in pediatric surgery, 76% in trauma, 64% in foot and ankle surgery, and 59% in limb reconstructive surgery remained more than two days. During first 10 days after catheterization, the proportion of pain-free patients were 77-95% at rest and 63-88% during mobilization, 79-92% of the patients did not require increased opioid doses, and 50-67% did not require opioid PRN doses. In addition to 416 catheters (76%), which were removed as planned, the reason for catheter removal was leaving the hospital in 27 (4.9%), loss of efficacy in 69 (13%), dislodgement in 23 (4.2%), leakage in 8 (1.5%), and erythema in 4 catheters (0.73%). No major complication occurred.

CONCLUSIONS

After orthopaedic procedures, cPNBs can be considered as an efficient method for improving pain control and minimizing the use of additional opioids. However, the catheters sometimes might need to be replaced to achieve the desired efficacy.

Transversus Abdominis Plane Block With Liposomal Bupivacaine vs. Regular Anesthetics for Pain Control After Surgery: A Systematic Review and Meta-Analysis

Background: Transverse abdominal plane (TAP) blocks are used to provide pain relief after abdominopelvic surgeries. The role of liposomal bupivacaine (LB) for TAP blocks is unclear. Therefore, this study aimed to synthesize evidence on the efficacy of LB vs. regular anesthetics in improving outcomes of TAP block. Methods: PubMed, Science Direct, Embase, Springer, and CENTRAL databases were searched up to July 24, 2020. Studies comparing LB with any regular anesthetic for TAP block for any surgical procedure and reporting total analgesic consumption (TAC) or pain scores were included. Results: Seven studies including five randomized controlled trials (RCTs) were reviewed. LB was compared with regular bupivacaine (RB) in all studies. A descriptive analysis was conducted for TAC due to heterogeneity in data presentation. There were variations in the outcomes of studies reporting TAC. Meta-analysis of pain scores indicated statistically significant reduction of pain with the use of LB at 12 h (MD: -0.89 95% CI: -1.44, -0.34 I2 = 0% p = 0.01), 24 h (MD: -0.64 95% CI: -1.21, -0.06 I2 = 0% p = 0.03), 48 h (MD: -0.40 95% CI: -0.77, 0.04 I2 = 0% p = 0.03) but not at 72 h (MD: -0.37 95% CI: -1.31, 0.56 I2 = 57% p = 0.43). Pooled analysis indicated no difference in the duration of hospital stay between LB and RB (MD: -0.18 95% CI: -0.49, 0.14 I2 = 61% p = 0.27). LB significantly reduced the number of days to first ambulation postsurgery (MD: -0.28 95% CI: -0.50, -0.06 I2 = 0% p = 0.01). Conclusions: Current evidence on the role of LB for providing prolonged analgesia with TAP blocks is unclear. Conflicting results have been reported for TAC. LB may result in a small reduction in pain scores up to 48 h but not at 72 h. Further, high-quality homogenous RCTs are needed to establish high-quality evidence.

Managing rebound pain after regional anesthesia

Rebound pain after regional anesthesia can be defined as transient acute postoperative pain that ensues following resolution of sensory blockade, and is clinically significant, either with regard to the intensity of pain or the impact on psychological well-being, quality of recovery, and activities of daily living. Current evidence suggests that it represents an unmasking of the expected nociceptive response in the absence of adequate systemic analgesia, rather than an exaggerated hyperalgesic phenomenon induced by local anesthetic neural blockade. In the majority of patients, it does not appear to significantly impact cumulative postoperative opioid consumption, quality of recovery, or patient satisfaction, and is not associated with longer-term sequelae such as persistent post-surgical pain. Nevertheless, it must be considered whenever regional anesthesia is incorporated into perioperative management. Strategies to mitigate the impact of rebound pain include routine prescribing of a systemic multimodal analgesic regimen, as well as patient education on appropriate expectations regarding block offset and expected surgical pain, and timely initiation of analgesic medication. Prolonging the duration of action of regional anesthesia with continuous catheter techniques or local anesthetic adjuncts may also help alleviate rebound pain, although further research is required to confirm this.

Analgesic Efficacy of Preemptive Transversus Abdominis Plane Block in Patients Undergoing Laparoscopic Colorectal Cancer Surgery

Despite rapid advancements in laparoscopic surgical devices and techniques, pain remains a significant issue. We examined the efficacy of preemptive transversus abdominis plane (TAP) block for acute postoperative pain in patients undergoing laparoscopic colorectal cancer surgery. We retrospectively analyzed 153 patients who underwent laparoscopic colorectal cancer surgery with or without TAP block; among them, 142 were allocated to the TAP or non-TAP group. We performed between-group comparisons of demographic, clinical, and anesthetic data and pain scores at a postoperative anesthesia care unit (PACU) and at postoperative days 1, 3, and 5. There were no significant between-group differences in demographic and clinical characteristics. The mean arterial pressure, heart rate, and minimum alveolar concentration (MAC) were significantly lower in the TAP group at the start and end of surgery. The post-extubation bispectral index was significantly higher in the TAP group. There were no significant between-group differences in the pain scores and opioid consumption at the PACU or at postoperative days 1, 3, and 5, or in the time to pass flatus, the hospital stay length, and postoperative complications. Preemptive TAP block showed an intraoperative, but not postoperative, analgesic effect, characterized by a low mean arterial pressure, heart rate, and MAC.

The use of extended release bupivacaine with transversus abdominis plane and subcostal anterior quadratus lumborum catheters: A retrospective analysis of a novel technique

Background and Aims

Liposomal bupivacaine (LB) is a formulation of local anesthetic that may exert analgesia over a prolonged period. Anecdotal use of LB suggests benefit and prolonged analgesia when used to supplement infiltration blocks. Our aim was to test the effect of a bolus of LB delivered through a nerve catheter in two types of interfascial plane blocks (transversus abdominis plane and anterior subcostal quadratus lumborum). The effect was evaluated through patient self-reporting of postsurgical pain up to 48 postoperative hours.

Material and Methods

Medical records of adult postoperative patients who received LB in a peripheral nerve catheter were followed retrospectively and analysed for pain scores and spread of dermatomal numbness over 48 h following the postoperative dose. A chart review of patients who qualified between June 2015 and March 2017 was performed, and clinical data were obtained from the institutional Perioperative Health Documentation System.

Results

Pain scores decreased following LB bolus, and all patients reported efficient block analgesia after bolus injection. Dermatomal numbness decreased gradually and was minimal by 48 h following bolus.

Conclusion

LB can be injected through a peripheral nerve catheter to prolong analgesia after catheter removal.

[Stocktaking of local anesthetics 2020]

For decades local anesthetics have proven to be safe and effective drugs in the clinical practice, crucially promoting the enormous achievements in regional anesthesia. Meanwhile, it is a well-known fact that local anesthetics are much more than just "simple" sodium channel blockers. They also interact with numerous other ion channels and subcellular structures, enhancing nerve blockade and resulting in systemic "alternative" effects, which can sometimes even be clinically used. By the simultaneous administration of various adjuvants (e.g., opioids, corticosteroids and α₂-receptor agonists) attempts are made to prolong the time of action of local anesthetics after a single administration in order to achieve the best possible improvement in postoperative analgesia. In this context, ultralong-acting local anesthetics, such as liposomal bupivacaine, which at least theoretically can provide a sensory nerve block for several days, have been developed and clinically introduced. The coming years will show whether these approaches will develop into genuine alternatives to the personnel and cost-intensive continuous nerve blockades.Local anesthetic-induced systemic toxicity is meanwhile rare but still a potentially life-threatening event, frequently resulting from accidental intravascular injection or extensive systemic resorption. Consequently, slow and fractional application of these agents with intermittent aspiration helps to prevent toxic sequelae. If toxic symptoms occur, however, the intravenous infusion of 20% lipid solutions in addition to basic treatment measures can enhance the success of treatment.

Application of TAP Block in Laparoscopic Urological Surgery: Current Status and Future Directions

PURPOSE OF REVIEW

Amid the opioid crisis, postoperative pain management is a major challenge for practitioners. Recent pain management guidelines emphasize the importance of using regional anesthesia as part of opioid-sparing multimodal analgesia. This report aims to review recent evidence regarding the utilization of transversus abdominis plane (TAP) block in minimally invasive urologic surgery.

RECENT FINDINGS

TAP block has been shown to improve early and late pain at rest, and to reduce opioid consumption after minimally invasive surgery. These benefits have indirectly reduced the incidence of postoperative delirium, pneumonia, urinary retention, and falls. Compared to epidural analgesia, TAP block provides similar pain control, has a lower incidence of hypotension, and is associated with a shorter length of stay. Few studies focus specifically on the outcomes of TAP block in minimally invasive urologic surgery. TAP block decreases postoperative pain and reduces opioid consumption without increasing complications. TAP block should be integrated as an indispensable component in enhanced recovery after surgery protocols.

Impact of local administration of various doses of dexmedetomidine on ropivacaine-induced lumbar plexus-sciatic nerve block

The present study aimed to investigate the impact of various doses of dexmedetomidine (DEX) on ropivacaine (ROP)-induced lumbar plexus-sciatic nerve block (LSB). A total of 80 patients who underwent ankle surgery under LSB were divided into group R (applied with 30 ml 5% ROP), Dex1 (30 ml 0.5% ROP + 1 µg/kg DEX), Dex2 (30 ml 0.5% ROP + 1.5 µg/kg DEX) and Dex3 (30 ml 0.5% ROP + 2 µg/kg DEX), with 20 cases in each group. The onset time and duration of sensory and motor block, mean arterial pressure (MAP), heart rate (HR), oxygen saturation, Ramsay score, serum vascular endothelial growth factor (VEGF) level and adverse reactions in the four groups were observed. Results demonstrated that the durations of sensory and motor block in group R were shorter than those in groups Dex1-3 (P<0.01), followed by the sequence of group Dex1<Dex2<Dex3 (P<0.05). MAP and HR in groups Dex1-3 at T2-T5 were significantly lower than those in group R (P<0.01), and HR in group Dex3 at T3 and T4 was significantly lower than that in groups Dex1 and Dex2 (P<0.05). Ramsay scores in groups Dex1-3 at T2-T4 were significantly higher than those in group R (P<0.05). Serum VEGF levels in groups Dex2 and Dex3 at T2-T5 were significantly higher than those in group R (P<0.01). The incidences of over-sedation, bradycardia and dry mouth in group Dex3 were notably higher than those in the other groups. In conclusion, 1.5 µg/kg DEX exhibits a superior effect in improving ROP-induced LSB.

Early recovery following lower limb arthroplasty: Qualitative interviews with patients undergoing elective hip and knee replacement surgery. Initial phase in the development of a patient-reported outcome measure

AIMS AND OBJECTIVES

To explore the patients' perspective of surgery and early recovery when undergoing lower limb (hip or knee) arthroplasty.

BACKGROUND

Lower limb arthroplasty is a commonly performed procedure for symptomatic arthritis, which has not responded to conservative medical treatment. Each patient's perspective of the surgical process and early recovery period impacts on their quality of life.

DESIGN

Open, semistructured qualitative interviews were used to allow for a deeper understanding of the patient perspective when undergoing a hip or knee arthroplasty.

METHODS

Following ethical approval, 30 patients were interviewed between August and November 2016 during the perioperative period while undergoing an elective hip or knee arthroplasty (n = 30). The interviews were performed between the day of surgery and a nine-week postoperative clinic appointment. Data were analysed using an in-depth narrative thematic analysis method. NVivo qualitative data analysis software was used.

RESULTS

Seven main themes evolved from the interviews: "improving function and mobility", "pain", "experiences of health care", "support from others", "involvement and understanding of care decisions", "behaviour and coping" and "fatigue and sleeping".

CONCLUSIONS

The early postoperative recovery period is of vital importance to all surgical patients. This is no different for the orthopaedic patient. However, identifying key self-reported areas of importance from patients can guide clinical focus for healthcare professionals.

RELEVANCE TO CLINICAL PRACTICE

To have specific patient-reported information regarding key areas of importance during the perioperative phase is invaluable when caring for the orthopaedic surgical patient. It gives insight and understanding in to this increasing population group. This study has also served as a starting point in the development of a questionnaire which could be used to assess interventions in the lower limb arthroplasty population. These results will influence both items and content of the questionnaire.

QX-OH/Levobupivacaine: Fixed-dose combination to provide a long-acting postoperative pain of knee surgery in rodents

Although total knee arthroplasty (TKA) is a commonly performed procedure, anesthetic efficacy in post-surgical pain remains an issue. Exparel (45mM liposome bupivacaine), a relatively long-acting local anesthetic, has shown efficacy in blocking peripheral nerve or periarticular infiltration to achieve better post-TKA analgesia. In the present work, we tested whether a fixed-dose combination of QX-OH (35mM) and levobupivacaine (10mM) (QX-OH/LB) could confer longer-lasting pain relief and reduce periarticular tissue toxicity compared to liposome bupivacaine (45mM) after TKA operation. In the sciatic nerve block, the duration of sensory block by QX-OH/LB was 2-fold higher than by liposome bupivacaine (median [25th, 75th percentiles], 9.83 [9.33, 10.83] hours versus 4.83 [4.83, 5] hours; P=0.001). Liposome bupivacaine failed to improve post-surgical travel distance and speed (P=0.373) in rats 6h after TKA surgery (versus saline). Similar results were observed in operated mice treated with liposome bupivacaine. However, QX-OH/LB increased locomotor activities markedly both in rats and mice at 6h post-TKA (P<0.001). In addition, there was no difference in the inflammatory recruitment and articular structural damage among murine models-treated with QX-OH/LB, liposome bupivacaine and saline. In conclusion, we show that QX-OH/LB is a safe and long-lasting anesthetic than liposome bupivacaine in the post-TKA pain management in murine models.

Review of the evidence: best analgesic regimen for shoulder surgery

Multimodal pain management has been advocated in patients experiencing acute pain after surgical procedures due to tissue damage and the subsequent inflammatory response. For patients undergoing shoulder surgeries, studies have definitively shown that interscalene blocks (ISBs) via single-injection or continuous infusion can reduce the total opioid consumption and can lower pain scores after surgery. In some cases, ISBs can be used as the sole anesthetic during shoulder surgeries and spare patients of receiving general anesthesia. However, clinicians should be fully aware of potential pulmonary complications of ISBs and weigh the risk-benefit ratio in patients with limited pulmonary reserve.

Comparison of liposomal bupivacaine infiltration versus interscalene nerve block for pain control in total shoulder arthroplasty: A meta-analysis of randomized control trails

BACKGROUND

This meta-analysis aimed to compare the efficiency and safety of liposomal bupivacaine infiltration and interscalene nerve block for pain control after total shoulder arthroplasty.

METHODS

A systematic search was performed in Medline (1966 to May 2017), PubMed (1966 to May 2017), Embase (1980 to May 2017), ScienceDirect (1985 to May 2017) and the Cochrane Library. Only randomized controlled trials (RCTs) were included. Reported surgical outcomes, including visual analogue scale (VAS) scores, opioid consumption, length of stay, and postoperative adverse effects including the risk of nausea and vomiting. Meta-analysis was performed using Stata 11.0 software.

RESULTS

Four RCTs including 510 patients met the inclusion criteria. The present meta-analysis indicated that there were no significant differences between groups in terms of VAS score at 12 hours (standard mean difference [SMD] = 0.272, 95% CI: -0.150 to 0.695, P = .207), 24 hours (SMD = -0.056, 95% CI: -0.458 to 0.346, P = 0.785), and 48 hours (SMD = 0.183, 95% CI: -0.148 to 0.513, P = .278). Liposomal bupivacaine infiltration groups required an equivalent amount of opioids at postoperative 12 hours (SMD = -0.039, 95% CI: -0.222 to 0.143, P = .672), 24 hours (SMD = 0.046, 95% CI: -0.136 to 0.228, P = .618) and 48 hours (SMD = -0.025, 95% CI: -0.207 to 0.157, P = .785).

CONCLUSION

Liposomal bupivacaine infiltration provides equivalent postoperative pain control compared with interscalene nerve block following total shoulder arthroplasty. Both of them can reduce the consumption of opioids without severe adverse effects. More high-quality RCTs with long follow-up period are necessary for proper comparisons of the efficacy and safety of liposomal bupivacaine infiltration with interscalene nerve block.

Perioperative adjuvant corticosteroids for post-operative analgesia in elective knee surgery - A systematic review

BACKGROUND

Elective knee surgery is performed to reduce chronic pain and improve function in degenerate knees. Treatment of acute post-operative pain is suboptimal in 75% of patients despite multimodal analgesic approaches resulting in higher post-operative opiate consumption. The effect of corticosteroids as an adjunct for post-operative pain control remains undefined.

METHODS

The databases MEDLINE, EMBASE and CENTRAL (Cochrane library) will be searched from their inception to present using broad search criteria for eligible randomised/quasi-randomised controlled trials investigating perioperative corticosteroid adjunctive use in elective knee surgery. Meta-analyses will be conducted according to the recommendations from the Cochrane Handbook for Systematic Reviews of Interventions.

DISCUSSION

This systematic review of the perioperative adjunctive use of corticosteroids will assess the analgesic effects, post-operative nausea and vomiting, opiate consumption, infection rates and time till discharge and assess whether adjunctive corticosteroids should be encouraged in elective knee surgery.

SYSTEMATIC REVIEW REGISTRATION

PROPSERO CRD42016049336.

Pharmacologic Properties of Novel Local Anesthetic Agents in Anesthesia Practice

Therapeutic duration of traditional local anesthetics when used in peripheral nerve blocks is normally limited. This article describes novel approaches to extend the duration of peripheral nerve blocks currently available or in development. Three newer approaches on extending the duration of peripheral nerve blocks include site-1 sodium channel blockers, novel local anesthetics delivery systems, and novel adjuvants of local anesthetics. Compared with plain amide-based and ester-based local anesthetics, alternative approaches show significant promise in decreasing postoperative pain, rescue opioid requirement, hospital length-of-stay, and overall health care cost, without compromising the established safety profile of traditional local anesthetics.

Liposomal bupivacaine infiltration at the surgical site for the management of postoperative pain

BACKGROUND

Despite multi-modal analgesic techniques, acute postoperative pain remains an unmet health need, with up to three quarters of people undergoing surgery reporting significant pain. Liposomal bupivacaine is an analgesic consisting of bupivacaine hydrochloride encapsulated within multiple, non-concentric lipid bi-layers offering a novel method of sustained-release analgesia.

OBJECTIVES

To assess the analgesic efficacy and adverse effects of liposomal bupivacaine infiltration at the surgical site for the management of postoperative pain.

SEARCH METHODS

On 13 January 2016 we searched CENTRAL, MEDLINE, MEDLINE In-Process, Embase, ISI Web of Science and reference lists of retrieved articles. We obtained clinical trial reports and synopses of published and unpublished studies from Internet sources, and searched clinical trials databases for ongoing trials.

SELECTION CRITERIA

Randomised, double-blind, placebo- or active-controlled clinical trials in people aged 18 years or over undergoing elective surgery, at any surgical site, were included if they compared liposomal bupivacaine infiltration at the surgical site with placebo or other type of analgesia.

DATA COLLECTION AND ANALYSIS

Two review authors independently considered trials for inclusion, assessed risk of bias, and extracted data. We performed data analysis using standard statistical techniques as described in the Cochrane Handbook for Systematic Reviews of Interventions, using Review Manager 5.3. We planned to perform a meta-analysis and produce a 'Summary of findings' table for each comparison however there were insufficient data to ensure a clinically meaningful answer. As such we have produced two 'Summary of findings' tables in a narrative format. Where possible we assessed the quality of evidence using GRADE.

MAIN RESULTS

We identified nine studies (10 reports, 1377 participants) that met inclusion criteria. Four Phase II dose-escalating/de-escalating trials, designed to evaluate and demonstrate efficacy and safety, presented pooled data that we could not use. Of the remaining five parallel-arm studies (965 participants), two were placebo controlled and three used bupivacaine hydrochloride local anaesthetic infiltration as a control. Using the Cochrane tool, we judged most studies to be at unclear risk of bias overall; however, two studies were at high risk of selective reporting bias and four studies were at high risk of bias due to size (fewer than 50 participants per treatment arm).Three studies (551 participants) reported the primary outcome cumulative pain intensity over 72 hours following surgery. Compared to placebo, liposomal bupivacaine was associated with a lower cumulative pain score between the end of the operation (0 hours) and 72 hours (one study, very low quality). Compared to bupivacaine hydrochloride, two studies showed no difference for this outcome (very low quality evidence), however due to differences in the surgical population and surgical procedure (breast augmentation versus knee arthroplasty) we did not perform a meta-analysis.No serious adverse events were reported to be associated with the use of liposomal bupivacaine and none of the five studies reported withdrawals due to drug-related adverse events (moderate quality evidence).One study reported a lower mean pain score at 12 hours associated with liposomal bupivacaine compared to bupivacaine hydrochloride, but not at 24, 48 or 72 hours postoperatively (very low quality evidence).Two studies (382 participants) reported a longer time to first postoperative opioid dose compared to placebo (low quality evidence).Two studies (325 participants) reported the total postoperative opioid consumption over the first 72 hours: one study reported a lower cumulative opioid consumption for liposomal bupivacaine compared to placebo (very low quality evidence); one study reported no difference compared to bupivacaine hydrochloride (very low quality evidence).Three studies (492 participants) reported the percentage of participants not requiring postoperative opioids over initial 72 hours following surgery. One of the two studies comparing liposomal bupivacaine to placebo demonstrated a higher number of participants receiving liposomal bupivacaine did not require postoperative opioids (very low quality evidence). The other two studies, one versus placebo and one versus bupivacaine hydrochloride, found no difference in opioid requirement (very low quality evidence). Due to significant heterogeneity between the studies (I2 = 92%) we did not pool the results.All the included studies reported adverse events within 30 days of surgery, with nausea, constipation and vomiting being the most common. Of the five parallel-arm studies, none performed or reported health economic assessments or patient-reported outcomes other than pain.Using GRADE, the quality of evidence ranged from moderate to very low. The major limitation was the sparseness of data for outcomes of interest. In addition, a number of studies had a high risk of bias resulting in further downgrading.

AUTHORS' CONCLUSIONS

Liposomal bupivacaine at the surgical site does appear to reduce postoperative pain compared to placebo, however, at present the limited evidence does not demonstrate superiority to bupivacaine hydrochloride. There were no reported drug-related serious adverse events and no study withdrawals due to drug-related adverse events. Overall due to the low quality and volume of evidence our confidence in the effect estimate is limited and the true effect may be substantially different from our estimate.

Liposomal bupivacaine peripheral nerve block for the management of postoperative pain

BACKGROUND

Postoperative pain remains a significant issue with poor perioperative pain management associated with an increased risk of morbidity and mortality. Liposomal bupivacaine is an analgesic consisting of bupivacaine hydrochloride encapsulated within multiple, non-concentric lipid bi-layers offering a novel method of sustained release.

OBJECTIVES

To assess the analgesic efficacy and adverse effects of liposomal bupivacaine infiltration peripheral nerve block for the management of postoperative pain.

SEARCH METHODS

We identified randomised trials of liposomal bupivacaine peripheral nerve block for the management of postoperative pain. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2016, Issue 1), Ovid MEDLINE (1946 to January Week 1 2016), Ovid MEDLINE In-Process (14 January 2016), EMBASE (1974 to 13 January 2016), ISI Web of Science (1945 to 14 January 2016), and reference lists of retrieved articles. We sought unpublished studies from Internet sources, and searched clinical trials databases for ongoing trials. The date of the most recent search was 15 January 2016.

SELECTION CRITERIA

Randomised, double-blind, placebo- or active-controlled clinical trials of a single dose of liposomal bupivacaine administered as a peripheral nerve block in adults aged 18 years or over undergoing elective surgery at any surgical site. We included trials if they had at least two comparison groups for liposomal bupivacaine peripheral nerve block compared with placebo or other types of analgesia.

DATA COLLECTION AND ANALYSIS

Two review authors independently considered trials for inclusion in the review, assessed risk of bias, and extracted data. We performed analyses using standard statistical techniques as described in the Cochrane Handbook for Systematic Reviews of Interventions, using Review Manager 5. We planned to perform a meta-analysis, however there were insufficient data to ensure a clinically meaningful answer; as such we have produced a 'Summary of findings' table in a narrative format, and where possible we assessed the evidence using GRADE (Grading of Recommendations Assessment, Development and Evaluation).

MAIN RESULTS

We identified seven studies that met inclusion criteria for this review. Three were recorded as completed (or terminated) but no results were published. Of the remaining four studies (299 participants): two investigated liposomal bupivacaine transversus abdominis plane (TAP) block, one liposomal bupivacaine dorsal penile nerve block, and one ankle block. The study investigating liposomal bupivacaine ankle block was a Phase II dose-escalating/de-escalating trial presenting pooled data that we could not use in our analysis.The studies did not report our primary outcome, cumulative pain score between 0 and 72 hours, and secondary outcomes, mean pain score at 12, 24, 48, 72, or 96 hours. One study reported no difference in mean pain score during the first, second, and third postoperative 24-hour periods in participants receiving liposomal bupivacaine TAP block compared to no TAP block. Two studies, both in people undergoing laparoscopic surgery under TAP block, investigated cumulative postoperative opioid dose, reported opposing findings. One found a lower cumulative opioid consumption between 0 and 72 hours compared to bupivacaine hydrochloride TAP block and one found no difference during the first, second, and third postoperative 24-hour periods compared to no TAP block. No studies reported time to first postoperative opioid or percentage not requiring opioids over the initial 72 hours. No studies reported a health economic analysis or patient-reported outcome measures (outside of pain). The review authors sought data regarding adverse events but none were available, however there were no withdrawals reported to be due to adverse events.Using GRADE, we considered the quality of evidence to be very low with any estimate of effect very uncertain and further research very likely to have an important impact on our confidence in the estimate of effect. All studies were at high risk of bias due to their small sample size (fewer than 50 participants per arm) leading to uncertainty around effect estimates. Additionally, inconsistency of results and sparseness of data resulted in further downgrading of the quality of the data.

AUTHORS' CONCLUSIONS

A lack of evidence has prevented an assessment of the efficacy of liposomal bupivacaine administered as a peripheral nerve block. At present there is a lack of data to support or refute the use of liposomal bupivacaine administered as a peripheral nerve block for the management of postoperative pain. Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.