Continuous peripheral nerve blocks in acute pain management

Continuous peripheral nerve blocks for pain control after orthopaedic surgery: A prospective study during in-hospital and ambulatory care

BACKGROUND

Continuous peripheral nerve blocks (CPNB) provide an opioid-free alternative for pain control after orthopaedic surgery. However, postdischarge ambulatory patient care and follow-up concerns have prevented CPNB use at home.

OBJECTIVE

To address physicians' concerns about the outpatient use of CPNB.

DESIGN

Prospective, cohort, observational study.

SETTING

Single centre, teaching private hospital in Santiago, Chile, between July 2016 and March 2020.

PATIENTS

We included patients aged at least 18 who underwent orthopaedic surgery using CPNB for postoperative pain management. Patients scheduled simultaneously for non-orthopedic surgery on the same event were excluded.

MAIN OUTCOME MEASURES

Pain scores, opioid use, and complication rates at both in-hospital and at-home sites.

RESULTS

CPNB were provided as an analgesia plan in 497 patients who met inclusion criteria, and 387 (77.87%) were discharged home with this continuous analgesia. At 48 h, 70% of the patients reported no-worse-than-mild pain. Less than 3.1% of patients reported an episode of severe pain, and less than 13% of the patients required opioid rescue medication. Transient neurological symptoms were observed in 13% (95% confidence interval (CI), 10.4 to 16.1) of the patients. No long-term or severe complications were observed. High rates of satisfaction were reached among patients.

CONCLUSION

In-hospital and at-home use of CPNB supervised by a pain service team provides a feasible and safe alternative after orthopaedic surgery, pain control with a low requirement of opioids.

A proof-of-concept study of ultrasound-guided continuous parasacral ischial plane block for postoperative pain control in patients undergoing total knee arthroplasty

BACKGROUND

Continuous peripheral nerve blocks are widely used for anesthesia and postoperative analgesia in lower limb surgeries. The authors aimed to develop a novel continuous sacral plexus block procedure for analgesia during total knee arthroplasty.

METHODS

The study comprised two stages. In Stage I, the authors built upon previous theories and technological innovations to develop a novel continuous sacral plexus block method, ultrasound-guided continuous parasacral ischial plane block (UGCPIPB) and subsequently conducted a proof-of-concept study to assess its effectiveness and feasibility. Stage II involved a historical control study to compare clinical outcomes between patients undergoing this new procedure and those receiving the conventional procedure.

RESULTS

The study observed a 90% success rate in catheter placement. On postoperative day (POD) 1, POD2, and POD3, the median visual analog scale (VAS) scores were 3 (range, 1.5-3.5), 2.5 (1.6-3.2), and 2.7 (1.3-3.4), respectively. Furthermore, 96.3% of the catheters remained in place until POD3, as confirmed by ultrasound. The study revealed a significant increase in skin temperature and peak systolic velocity of the anterior tibial artery on the blocked side compared with those on the non-blocked side. Complications included catheter clogging in one patient and leakage at the insertion site in two patients. In Stage II, the novel technique was found to be more successful than conventional techniques, with a lower catheter displacement rate than the conventional procedure for continuous sciatic nerve block.

CONCLUSION

UGCPIPB proved to be an effective procedure and safe for analgesia in total knee arthroplasty.

CHINESE CLINICAL TRIAL REGISTRY NUMBER

ChiCTR2300068902.

The Effect of Regional Anaesthesia on Free Flap Survival in Lower Extremity Reconstructions

Background

The effect of different modalities of anaesthesia in microvascular free flap surgery has been a topic of ongoing debate. Comparative data to study the effect of general anaesthesia and regional anaesthesia in the form of peripheral nerve blocks (PNBs) on lower extremity free flap survival is lacking to date. This study aims to elucidate the effect of regional anaesthesia on flap survival in lower extremity free flap reconstructions.

Methods

A retrospective cohort study of all patients who underwent free vascularised flap reconstruction of the lower extremities between 2012 and 2021 at the Amsterdam University Medical Centre (UMC), The Netherlands, and between 2019 and 2021 at the Radboud UMC, Nijmegen, The Netherlands. In this cohort, we analysed partial and total flap failures.

Results

In this cohort, 87 patients received a total of 102 microvascular free flap reconstructions of the lower extremity. In 20.5% of these operations, patients received a supplemental PNB. Total flap failure was 23.8% in the regional anaesthesia group compared to 21% in the group with general anaesthesia only (p = 0.779). Operation time was longer for patients with regional anaesthesia (p = 0.057). Length of stay was on average 2 days shorter for patients with supplemental regional anaesthesia (p = 0.716).

Discussion

This is the largest cohort comparing flap survival in patients receiving general anaesthesia to general anaesthesia with a PNB in lower extremity reconstructions to date. We cannot attribute a significant beneficial or detrimental effect of regional anaesthesia to flap survival. High failure rates stress the need for future studies.

How to cite this article

Koster ITS, den Os MM, Rutten MVH, et al. The Effect of Regional Anaesthesia on Free Flap Survival in Lower Extremity Reconstructions. Strategies Trauma Limb Reconstr 2024;19(1):15-20.

Impact of self-coiling catheters for continuous popliteal sciatic block on postoperative pain level and dislocation rate: a randomized controlled trial

Background

Dislocation of catheters within the tissue is a challenge in continuous regional anesthesia. A novel self-coiling catheter design is available and has demonstrated a lower dislocation rate in a cadaver model. The dislocation rate and effect on postoperative pain of these catheters in vivo has yet to be determined and were the subjects of this investigation.

Methods

After ethics committee approval 140 patients undergoing elective distal lower limb surgery were enrolled in this prospective randomized controlled trial. Preoperatively, patients were randomly assigned and received either the conventional (n = 70) or self-coiling catheter (n = 70) for ultrasound-guided popliteal sciatic nerve block in short axis view and by the in-plane approach from lateral to medial. The primary outcome was pain intensity after surgery and on the following three postoperative days. Secondary outcomes investigated were dislocation rate in situ determined by sonography, catheter movement visible from outside, opioid consumption as well as leakage at the puncture site.

Results

All catheters were successfully inserted. The study population of self-coiling catheters had significantly lower mean numeric rating scale values than the reference cohort on the first (p = 0.01) and second postoperative days (p < 0.01). Sonographic evaluation demonstrated, 42 standard catheters (60%) and 10 self-coiling catheters (14.3%) were dislocated in situ within the first three postoperative days. The externally visible movement of the catheters at insertion site did not differ significantly between groups through the third postoperative day. The opioid consumption was significantly lower in the self-coiling catheter group on the day of surgery and on the second and third postoperative days (p = 0.04, p = 0.03 and p = 0.04, respectively).

Conclusion

The self-coiling catheter offers a better postoperative pain control and a lower dislocation rate within the tissue when blocking the popliteal sciatic nerve compared to a conventional catheter. Further trials in large patient cohorts are warranted to investigate the potential beneficial effects of self-coiling catheters for other localisations and other application techniques.

Trial registration

The trial was registered at German Clinical Trials Register (DRKS) on 08/04/2020 (DRKS00020938, retrospectively registered).

Effects of prolonged peri-neural bupivacaine infusion in rat sciatic nerves (axon and myelin)

BACKGROUND/OBJECTIVE

Peripheral-nerve blocks (PNBs) using continuous-infusion of local anesthetics are used to provide perioperative analgesia. Yet little research exists to characterize the histopathological effects of continuous long-duration PNBs. Herein we test the hypothesis that continuous peri-neural bupivacaine infusion (3-day vs. 7-day infusion) contributes to histologic injury in a duration-dependent manner using an in vivo model of rat sciatic nerves.

METHODS

We placed indwelling catheters in 22 rats for infusion with low-dose (0.5mg/kg/hr) bupivacaine or normal saline proximal to the right sciatic nerves for 3 or 7 consecutive days. Hind-limb analgesia was measured using Von-Frey nociceptive testing. At infusion end, rats were sacrificed, bilateral nerves were sectioned and stained with hematoxylin and eosin and CD68 for evaluation of inflammatory response, and eriochrome to assess damage to myelin.

RESULTS

Animals receiving continuous infusion of bupivacaine maintained analgesia as demonstrated by significant decrease (50% on average) in nociceptive response in bupivacaine-infused limbs across time points. Both 7-day saline and bupivacaine-infused sciatic nerves showed significantly-increased inflammation by H&E staining compared to untreated native nerve controls (P = 0.0001, P < 0.0001). Extent of inflammation did not vary significantly based on infusate (7-day saline vs. 7-day bupivacaine P > 0.99) or duration (3-day bupivacaine vs 7-day bupivacaine P > 0.99). No significant change in sciatic nerve myelin was found in bupivacaine-infused animals compared to saline-infused controls, regardless of duration.

CONCLUSIONS

Long-duration (7-day) bupivacaine infusion provided durable post-operative analgesia, yet contributed to equivalent neural inflammation as short duration (3-day) infusion of bupivacaine or saline with no evidence of demyelination.

Comparison of the suprainguinal fascia iliaca compartment block with continuous epidural analgesia in patients undergoing hip surgeries: a retrospective study

Background and objective

Pain control is one of the major concerns after major hip surgeries. Suprainguinal fascia iliaca compartment block (S-FICB) is an alternative analgesic technique that can be considered as an effective and less invasive method than epidural analgesia (EA). In this retrospective study, we compared postoperative analgesic efficacy of single shot ultrasound guided S-FICB and EA after major hip surgery.

Methods

We retrospectively examined 150 patients who underwent major hip surgeries and who received S-FICB or EA. Seventy-two patients submitted to EA and 78 patients who received S-FICB were included and their medical records retrospectively reviewed. Morphine consumptions, VAS scores, and side effects were recorded. Patients under antiplatelet or anticoagulant theraphy were also registered. Morphine consumption and VAS scores were the primary endpoints, succes rate and complications were the secondary endpoints of our study. P-values less than 0.05 were considered statistically significant.

Results

Morphine consumption was lower at the emergence in the EA group but there was no statistically significant difference between the two groups according to total opioid consumption (0 [0-0] vs 0 [0-0]; p = 0.52). There was no difference between VAS scores in the first 18 hours. Hypotension was significantly higher in the EA group (9 vs 21; p = 0.04).

Conclusion

In conclusion, S-FICB can provide comparable analgesia with EA in the early postoperative period after hip surgery but VAS scores were found lower in the EA group than S-FICB group after 18^th hour. Hypotension has occured more frequently in patients receiving EA.

Decreasing leakage during continuous femoral nerve catheter fixation using 2-octyl cyanoacrylate glue (Dermabond®): a randomized controlled trial

BACKGROUND

Continuous peripheral nerve catheters (CPNCs) have been used for postoperative pain relief. A common problem encountered with CPNCs is pericatheter leakage, which can lead to dressing adhesive failure. Frequent dressing changes increase the risk of catheter dislodgement and infections. Adhesive glue is effective in securing the peripheral nerve catheter and decreasing leakage around the catheter insertion site. This study aimed to evaluate the incidence of pericatheter leakage with fixation using 2-octyl cyanoacrylate glue (Dermabond®) as compared to sterile strips.

METHODS

Thirty patients undergoing unilateral total knee arthroplasty (TKA) with continuous femoral nerve catheter for postoperative analgesia were randomized into the catheter fixation with 2-octyl cyanoacrylate glue (Dermabond®) group or the sterile strip group. The primary outcome was the incidence of pericatheter leakage. Secondary outcomes included the frequent of catheter displacement, the difficulty of catheter removal, pain score and patient satisfaction.

RESULTS

The incidence of pericatheter leakage at 24 and 48 h was 0% versus 93 and 0% versus 100% in the Dermabond® and sterile strip groups, respectively (P < 0.001). The incidence of displacement at 24 and 48 h was 6.7% versus 93.3 and 6.7% versus 100% in the Dermabond® and sterile strip, respectively (P < 0.001). There was no difference in numeric rating scale, difficulty of catheter removal, or satisfaction scores between groups.

CONCLUSIONS

Catheter fixation with 2-octyl cyanoacrylate glue (Dermabond®) decreased the incidence of pericatheter leakage, as well as catheter displacement, over 48 h as compared to sterile strip fixation.

TRIAL REGISTRATION

This trial was registered on Thai clinical trial registry: TCTR20200228002 , registered 24 February 2020- Retrospectively registered.

Management of Musculoskeletal Pain: An Update with Emphasis on Chronic Musculoskeletal Pain

Musculoskeletal pain is a challenging condition for both patients and physicians. Many adults have experienced one or more episodes of musculoskeletal pain at some time of their lives, regardless of age, gender, or economic status. It affects approximately 47% of the general population. Of those, about 39–45% have long-lasting problems that require medical consultation. Inadequately managed musculoskeletal pain can adversely affect quality of life and impose significant socioeconomic problems. This manuscript presents a comprehensive review of the management of chronic musculoskeletal pain. It briefly explores the background, classifications, patient assessments, and different tools for management according to the recently available evidence. Multimodal analgesia and multidisciplinary approaches are fundamental elements of effective management of musculoskeletal pain. Both pharmacological, non-pharmacological, as well as interventional pain therapy are important to enhance patient’s recovery, well-being, and improve quality of life. Accordingly, recent guidelines recommend the implementation of preventative strategies and physical tools first to minimize the use of medications. In patients who have had an inadequate response to pharmacotherapy, the proper use of interventional pain therapy and the other alternative techniques are vital for safe and effective management of chronic pain patients.

Bupivacaine Extended-Release Liposomal Injection Versus Bupivacaine HCl for Early Postoperative Pain Control Following Wrist Operations: A Prospective, Randomized Control Trial

PURPOSE

This study evaluated pain control after wrist operations using a long-acting local anesthetic, liposomal bupivacaine, compared with the standard local anesthetic, bupivacaine HCl.

METHODS

Patients undergoing elective carpometacarpal joint arthroplasty and proximal row carpectomy were eligible. Those meeting inclusion criteria were enrolled before surgery and were randomized to receive an intraoperative injection of liposomal bupivacaine or bupivacaine HCl. Primary outcomes included intraoperative and postoperative opioid requirements and pain levels. On the first 4 postoperative days, phone contact assessed pain level by numeric rating scale, number of opioids taken in each 24-hour period, and efficacy of anesthesia and opioid side effects with overall benefit of analgesia score.

RESULTS

Postoperative pain scores for 52 patients measured by numeric rating scale demonstrated that liposomal bupivacaine and bupivacaine HCl were similar for pain control. Pain scores and opioid use were similar during the first 4 postoperative days. Opioid use on day 1 was slightly lower with liposomal bupivacaine. There were no statistically significant differences in any postoperative outcome between groups.

CONCLUSIONS

Liposomal bupivacaine and bupivacaine HCl have similar effects in the treatment of early postoperative pain after trapeziometacarpal suspension arthroplasty and proximal row carpectomy. Neither drug demonstrated a clear advantage in this study.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic II.

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.

Regional Catheters for Outpatient Surgery-a Comprehensive Review

PURPOSE OF REVIEW

This review summarizes and discusses the history of continuous catheter blockade (CCB), its current applications, clinical considerations, economic benefits, potential complications, patient education, and best practice techniques.

RECENT FINDINGS

Regional catheters for outpatient surgery have greatly impacted acute post-operative pain management and recovery. Prior to development, options for acute pain management were limited to the use of opioid pain medications, NSAIDS, neuropathic agents, and the like as local anesthetic duration of action is limited to 4-8 h. Moreover, delivery of opioids post-operatively has been associated with respiratory and central nervous depression, development of opioid use disorder, and many other potential adverse effects. CCB allows for faster recovery time, decreased rates of opioid abuse, and better pain control in patients post-operatively. Outpatient surgical settings continue to focus on efficiency, quality, and safety, including strategies to prevent post-operative nausea, vomiting, and pain. Regional catheters are a valuable tool and help achieve all of the well-established endpoints of enhanced recovery after surgery (ERAS). CCB is growing in popularity with wide indications for a variety of surgeries, and has demonstrated improved patient satisfaction, outcomes, and reductions in many unwanted adverse effects in the outpatient setting.

Local Anesthetic Injection Speed and Common Peroneal Nerve Block Duration: A Randomized Controlled Trial in Healthy Volunteers

BACKGROUND AND OBJECTIVES

The speed of local anesthetic (LA) injections in peripheral regional anesthesia ranges from slow continuous infusions (3-12 mL/h) to rapid manual injections (>7500 mL/h). Optimizing injection speed could augment the spread of LA toward the targeted nerves and influence nerve block characteristics. The objective of this study was to investigate whether injection speed of a single dose of LA affects peripheral nerve block duration.

METHODS

After approval from the Danish Regional Scientific Ethics Committee, we enrolled 60 healthy adult volunteers. We used an ultrasound-guided catheter-based technique to perform a common peroneal nerve block. Participants were randomized to receive 4.0 mL of ropivacaine 0.2% with 1 of 5 injection speeds: 12, 60, 300, 600, or 1800 mL/h. Investigators and participants were blinded to group assignment and intervention. Primary outcome was duration of sensory nerve block defined by insensitivity toward cold. Secondary outcomes were duration of motor nerve block, time to onset of sensory nerve block, and grades of sensory and motor nerve block.Intergroup differences were tested by one-way analysis of variance.

RESULTS

We found no differences in sensory block duration between the 5 groups. Durations were median [range]: 11 [6-14], 12 [9-14], 10.5 [2-15], 11 [8-17], and 12 [9-18] hours, respectively (P = 0.294). In addition, we found no differences in secondary outcomes.

CONCLUSIONS

Injection speed of LA in the range of 12 to 1800 mL/h did not affect common peroneal nerve block duration.

CLINICAL TRIAL REGISTRATION

This study was registered at ClinicalTrials.gov, identifier NCT02801799.

Pectoral Fascial (PECS) I and II Blocks as Rescue Analgesia in a Patient Undergoing Minimally Invasive Cardiac Surgery

INTRODUCTION

Patients undergoing minimally invasive cardiac surgery have the potential for significant pain from the thoracotomy site. We report the successful use of pectoral nerve block types I and II (Pecs I and II) as rescue analgesia in a patient undergoing minimally invasive mitral valve repair.

CASE REPORT

In this case, a 78-year-old man, with no history of chronic pain, underwent mitral valve repair via right anterior thoracotomy for severe mitral regurgitation. After extubation, he complained of 10/10 pain at the incision site that was minimally responsive to intravenous opioids. He required supplemental oxygen because of poor pulmonary mechanics, with shallow breathing and splinting due to pain, and subsequent intensive care unit readmission. Ultrasound-guided Pecs I and II blocks were performed on the right side with 30 mL of 0.2% ropivacaine with 1:400,000 epinephrine. The blocks resulted in near-complete chest wall analgesia and improved pulmonary mechanics for approximately 24 hours. After the single-injection blocks regressed, a second set of blocks was performed with 266 mg of liposomal bupivacaine mixed with bupivacaine. This second set of blocks provided extended analgesia for an additional 48 hours. The patient was weaned rapidly from supplemental oxygen after the blocks because of improved analgesia.

CONCLUSIONS

Pectoral nerve blocks have been described in the setting of breast surgery to provide chest wall analgesia. We report the first successful use of Pecs blocks to provide effective chest wall analgesia for a patient undergoing minimally invasive cardiac surgery with thoracotomy. We believe that these blocks may provide an important nonopioid option for the management of pain during recovery from minimally invasive cardiac surgery.

Development of a Multimodal Analgesia Protocol for Perioperative Acute Pain Management for Lower Limb Amputation

Multimodal analgesia may include pharmacological components such as regional anesthesia, opioid and nonopioid systemic analgesics, nonsteroidal anti-inflammatories, and a variety of adjuvant agents. Multimodal analgesia has been reported for a variety of surgical procedures but not yet for lower limb amputation in vasculopathic patients. Perioperative pain management in these patients presents a particular challenge considering the multiple sources and pathways for acute and chronic pain that are involved, such as chronic ischemic limb pain, postoperative residual limb pain, coexisting musculoskeletal pain, phantom limb sensations, and chronic phantom limb pain. These pain mechanisms are explored and a proposed protocol for multimodal analgesia is outlined taking into account the common patient comorbidities found in this patient population.

Transversus Abdominis Plane Block and Free Flap Abdominal Tissue Breast Reconstruction: Is There a True Reduction in Postoperative Narcotic Use?

INTRODUCTION

The use of the transversus abdominis plane (TAP) block is increasing in abdominally based autologous tissue breast reconstruction as a method to provide postoperative donor site analgesia. The purpose of this study was to evaluate the efficacy of the TAP block in the immediate postoperative period.

METHODS

A retrospective analysis of all patients who underwent autologous microsurgical breast reconstruction over a 2-year period (2013-2015) was conducted. Only patients with an abdominal donor site were included. Patients were grouped based on the presence or absence of TAP blocks. Primary endpoints included patient-reported pain score, daily and total narcotic use during the hospitalization, antiemetic use, as well as complications.

RESULTS

We identified 40 patients that had undergone abdominal-based free flap breast reconstruction and TAP block catheter placement for postoperative analgesia that met inclusion criteria. This group was then compared with a matched cohort of 40 patients without TAP blocks. There were no complications associated with using the TAP catheters. There was no statistically significant difference in postoperative pain scores, daily or total narcotic use during the hospitalization, or antiemetic use between the 2 groups. Although not statistically significant, linear regression analysis identified trends of improved donor site analgesia in select groups, such as unilateral immediate reconstructions, body mass index greater than 30 kg/m, and those without abdominal mesh placed at the time of donor site closure in the TAP block group.

CONCLUSIONS

Constant delivery of local anesthetic through the TAP block appears to be safe; however, it did not reduce narcotic requirements or postoperative pain scores in patients undergoing abdominal-based free flap breast reconstruction.

Exparel/Peripheral Catheter Use in the Ambulatory Setting and Use of Peripheral Catheters Postoperatively in the Home Setting

PURPOSE OF REVIEW

With the increasing number of ambulatory surgeries being performed, regional anesthesia has become an increasingly popular anesthetic modality, and many choices exist to provide efficient, effective quality perioperative analgesia. In this paper, we will review the various regional anesthesia options in addition to the advantages and disadvantages of each. Lastly, we will discuss liposomal bupivicaine, a long acting local anesthetic, and its future role in the anesthesiologist's armamentarium. The aim of the publication is to provide a general overview of regional anesthesia as well as to discuss the advantages and disadvantages of this modality. Additionally, we sought to review the basics of liposomal bupivicaine as well as the relevant literature.

RECENT FINDINGS

The results regarding liposomal bupivicaine are mixed and mainly focuses on local infiltration and intra-articular injections. There are no known studies specifically comparing liposomal bupivicaine to bupivicaine hydrochloride in ultrasound-guided nerve blocks. There is some encouraging data regarding liposomal bupivicaine, but further studies are needed before it is adopted as a mainstay of treatment. In addition to efficacy, additional investigations are needed to evaluate cost as this could be a major impediment to its implementation.

Randomized comparison of popliteal-sciatic perineural catheter tip migration and dislocation in a cadaver model using two catheter designs

BACKGROUND

New catheter-over-needle (CON) technology for continuous peripheral nerve blockade has emerged, but its effect on the risk of perineural catheter tip dislocation is unknown. Less flexible catheters may be more likely to migrate away from the nerve with simulated patient movement. In the present study, we evaluated catheter tip migration between CON catheters and traditional catheter-through-needle (CTN) catheters during ultrasound-guided short-axis in-plane (SAX-IP) insertion.

METHODS

We evaluated the migration of popliteal-sciatic catheters in a prone, unembalmed male cadaver. Thirty catheter placement trials were divided randomly into two groups based on the catheter type: CON or CTN. A single anesthesiology resident placed the catheters by SAX-IP insertion, and the catheters were then examined by ultrasound before and after ipsilateral knee range of motion (ROM) exercises (0°-130° flexion). A blinded expert regional anesthesiologist performed caliper measurements on the ultrasound images before and after the ROM exercises. The primary outcome was the change in distance from the catheter tip to the center of the nerve (cm) between before and after the ROM exercises.

RESULTS

The change in the tip-to-nerve distance (median [10th-90th percentile]) was 0.06 (-0.16 to 0.23) cm for the CTN catheter and 0.00 (-0.12 to 0.69) for the CON catheter (P = 0.663). However, there was a statistically significant increase in dislocation out of the nerve compartment for the CON catheter (4/15; 0/15 for CTN) (P = 0.043).

CONCLUSIONS

Although the use of different catheter designs had no effect on the change in the measured migration distance of popliteal-sciatic catheters, 27% of the CON catheters were dislocated out of the nerve compartment. These results may influence the choice of catheter design when using SAX-IP perineural catheter insertion.

Opioid Usage During Admission in Hip Fracture Patients-The Effect of the Continuous Femoral Nerve Block

INTRODUCTION

The aim of this study was to investigate whether there was a difference in opioid usage during admission for hip fracture patients with continuous femoral nerve block (cFNB) when compared to patients nonfemoral nerve block (nFNB).

METHODS AND MATERIALS

Patients were identified from the local database on all hip fracture patients admitted to Bispebjerg University Hospital, Denmark. Four hundred fifty-six hip fracture patients were included during the period September 2008 to October 2010.

RESULTS

Three hundred sixty-six hip fracture patients had cFNB. The mean time with cFNB was 3.4 days. There were no significant differences in gender, length of stay, time to surgery, mortality rate, in-hospital falls, or resurgery rates during admission between the 2 groups. The nFNB group had an insignificant higher use of morphine as needed during the first 5 days of admission (nFNB: 53.1 mg, 95% confidence interval [CI]: 34.4-71.7; cFNB: 47.7 mg, 95% CI: 40.7-64.3; P = .54) and during the whole admission (cFNB: 34.3 mg, 95% CI: 23.2-45.5; cFNB: 30.3 mg, 95% CI: 26.6-33.0; P = .4). Some 8.47% of the total morphine consumption during admission was morphine as needed for the nFNB group and 9.89% for the cFNB group.

CONCLUSION

Patients with cFNB did only have a marginally lower opioid usage during admission when compared to patients without the block, with no significance between the 2 groups. This could indicate that the cFNB is an ineffective analgesic strategy, especially in the postoperative period, but larger randomized studies are needed in order to clarify this.

An electronic surgical order, undertaking patient education, and obtaining informed consent for regional analgesia before the day of surgery reduce block-related delays

Background

Obtaining patient informed consent for a regional analgesia block on the day of surgery can result in surgical case delays. We hypothesized that implementing a preoperative electronic surgical order, undertaking patient education, and obtaining informed consent for a regional block in our preoperative assessment clinic prior to the day of surgery would reduce surgical case delays attributed to our regional anesthesia pain service and increase the percentage of patients for whom our regional anesthesia pain service was requested to provide a block.

Methods

A prospective two-group time-series design, with a nonrandomized, pre- and post-intervention data collection strategy, was applied. Based upon the surgeons’ newly implemented preoperative electronic outpatient orders, patients were identified by our preoperative assessment clinic staff to receive educational materials. The attending anesthesiologist in the preoperative assessment clinic then obtained written informed consent. Block-related delay and utilization data were analyzed with conventional inferential statistics.

Results

We observed a 14.8% (95% CI: 9.4%, 20.1%; P<0.001) decrease in surgical case delays, attributed to the regional nerve block, in the post- vs pre-intervention group. In addition, there was a 9.9% (95% CI: 4.7%, 15.1%); P<0.001) increase in the proportion of patients for whom a regional nerve block was ordered by our three high-volume orthopedic surgeons in the post- vs pre-intervention time periods.

Conclusion

When performed before the day of surgery, a surgeon’s electronic order, patient education, and informed consent for regional postoperative analgesia can improve patient throughput, thereby reducing block-related operating room delays. The preoperative assessment clinic can serve as a venue to achieve this goal, thereby adding value by decreasing downstream delays on the day of surgery.

Standard preoperative analgesia with or without fascia iliaca compartment block for femoral neck fractures

PURPOSE

To compare the visual analogue score (VAS) for pain in patients with femoral neck fracture who received standard preoperative analgesia with or without fascia iliaca compartment block (FICB).

METHODS

In patients with femoral neck fracture, 69 patients who received standard preoperative analgesia (regular paracetamol 1g 4 times a day, codeine 60 mg 4 times a day, and opioid 10 mg 2 hourly as required) were compared with 50 patients who received standard preoperative analgesia plus FICB. VAS for pain at rest and on movement (hip flexion) was assessed before FICB and 15 minutes, 2 and 8 hours after FICB. The amount of additional opioid required and the incidence of opioid overdose (necessitating administration of naloxone) were determined.

RESULTS

VAS for pain was significantly lower after standard analgesia plus FICB than standard analgesia alone (p=0.001). The analgesic effect (pre-score minus post-score) of standard analgesia plus FICB did not differ between genders (p=0.57) or fracture patterns (p=0.79). 19 (38%) patients with standard analgesia plus FICB required no additional opioid analgesia. Compared with standard analgesia alone, addition of FICB reduced the mean dose of opioid from 6.2 to 2.0 (p=0.001) and the number of opioid overdose from 7.2% to 0% (p=0.001). No patient had any complication following FICB.

CONCLUSION

In patients with femoral neck fracture, FICB reduced the need for additional opioid analgesia and avoided the risk of opioid overdose and respiratory depression.

Multimodal versus Conventional Approach for Postoperative Pain Relief in Oral Cancer Patients

INTRODUCTION

Multimodal analgesia includes regional anaesthesia in the form of nerve block may improve recovery along with optimal rehabilitation and early resumption of day-to-day activity following major surgery. Conventional general anaesthesia consists of premedication, induction, intubation and maintenance.

AIM

The aim of the study is to compare the multimodal versus conventional approach in oral cancer surgery.

MATERIALS AND METHODS

The patients were randomly allocated into three groups, 30 patients in each group using the computer generated random table to one of the following groups: Group A: Fentanyl 1 μg/kg, Group B: Fentanyl 1 μg/kg + bupivacaine local infiltration, Group C: Fentanyl 1 μg/kg + bupivacaine local infiltration + Dexemedetomidine infusion (Loading 0.5 μg/kg, Maintenance 0.2μg/kg/hr).

RESULTS

No significant (p>0.05) difference was found in mean arterial pressure and heart rate at different time intervals among the groups. The VAS was lower in Group C than Group B and A. The ramsay sedation scale was higher in Group C than Group B and A. The rescue analgesic for 24 hour was lower in Group C than Group B and A. The time of first time analgesia requirement was significantly (p=0.001) higher in Group C than Group B and A. The rescue analgesic was significantly (p=0.001) lower in Group C (39.29±19.67) than Group B (68.33±18.49) and A (160.83±35.16).

CONCLUSION

Multimodal analgesia has beneficial haemodynamic effects during oral cancer surgery with reliable postoperative analgesia and sedation and less postoperative complication. Dose of drugs used in our study is not associated with any major adverse effect.

Putting it all together: recommendations for improving pain management in plastic surgical procedures

SUMMARY

The benefits of optimal pain management are well recognized. Nevertheless, treatment of postoperative pain continues to be a major challenge, and inadequate postoperative pain relief remains disturbingly high. One of the reasons for suboptimal pain management may be related to inadequate or improper application of available analgesic therapies. Use of patient-specific and procedure-specific pain management strategies should improve pain control and consequently improve perioperative outcome, including early ambulation, ability to perform rehabilitation activities, and return to activities of daily living. This article discusses the current evidence that should allow improved postoperative pain control with emphasis on the use of procedure-specific pain management.

Regional anesthesia for an upper extremity amputation for palliative care in a patient with end-stage osteosarcoma complicated by a large anterior mediastinal mass

Tumor progression during end-of-life care can lead to significant pain, which at times may be refractory to routine analgesic techniques. Although regional anesthesia is commonly used for postoperative pain care, there is limited experience with its use during home hospice care. We present a 24-year-old male with end-stage metastatic osteosarcoma who required anesthetic care for a right-sided above-the-elbow amputation. The anesthetic management was complicated by the presence of a large mediastinal mass, limited pulmonary reserve, and severe chronic pain with a high preoperative opioid requirement. Intraoperative anesthesia and postoperative pain management were provided by regional anesthesia using an interscalene catheter. He was discharged home with the interscalene catheter in place with a continuous local anesthetic infusion that allowed weaning of his chronic opioid medications and the provision of effective pain control. The perioperative applications of regional anesthesia in palliative and home hospice care are discussed.

A novel suture method to place and adjust peripheral nerve catheters

We have developed a peripheral nerve catheter, attached to a needle, which works like an adjustable suture. We used in‐plane ultrasound guidance to place 45 catheters close to the femoral, saphenous, sciatic and distal tibial nerves in cadaver legs. We displaced catheters after their initial placement and then attempted to return them to their original positions. We used ultrasound to evaluate the initial and secondary catheter placements and the spread of injectate around the nerves. In 10 cases, we confirmed catheter position by magnetic resonance imaging. We judged 43/45 initial placements successful and 42/43 secondary placements successful by ultrasound, confirmed in 10/10 cases by magnetic resonance imaging.

A novel concept for continuous peripheral nerve blocks. Presentation of a new ultrasound-guided device

BACKGROUND

Existing techniques for placing and maintaining the position of peripheral nerve catheters are associated with variable success rates and frequent secondary failures. These factors may affect the clinical efficacy and usefulness of peripheral nerve catheters.

METHODS

We developed a new concept and prototype for ultrasound-guided in-plane positioning and readjustment of peripheral nerve catheters (patent pending). The integrated catheter-needle prototype comprises three parts: a curved needle, a catheter with clear echogenic markings attached to the needle tail and a detachable hub allowing injection of local anesthetic while advancing the needle in the tissue. The system works like a suture and is introduced through the skin, passes in close relation to the nerve and exits through the skin. This allows in-plane ultrasound guidance throughout the procedure both during initial positioning as well as during later in-plane readjustment of the catheter. We tested the system in the popliteal region of two fresh cadavers in a preliminary proof of concept study.

RESULTS

Both initial placement and secondary readjustment were precise, judged by the catheter orifices placed close to the sciatic nerve in the popliteal fossa. Circumferential spread of 3-ml isotonic saline around the sciatic nerve was observed on ultrasound images in both conditions.

CONCLUSION

Preliminary proof of concept of this novel method demonstrates that precise in-plane ultrasound-guided initial placement and secondary in-plane readjustment is possible in fresh cadavers. Future studies should address the clinical efficacy and usefulness of this novel concept.

Impact of peripheral nerve block with low dose local anesthetics on analgesia and functional outcomes following total knee arthroplasty: a retrospective study

OBJECTIVE

While the safety and efficacy of peripheral nerve blocks for postoperative pain management has been established in several well controlled prospective trials, the local anesthetic (LA) concentration and volume used in these studies was associated with a significant increase muscle weakness due to motor nerve block. The purpose of the present retrospective study of patients undergoing total knee arthroplasty was to assess the relative analgesic efficacy and functional outcomes of the low concentration, low volume of LA used in peripheral nerve blocks for postoperative pain management.

METHODS

Twenty-four months of deidentified patient data were extracted from an electronic medical record system. All patients received opioids with or without continuous femoral and sciatic nerve block infusions for postoperative analgesia. Pain (resting and with activity), cumulative opioid and LA use were primary endpoints, participation in physical therapy (PT), muscle strength deficits and length of hospital stay (LOS) were secondary endpoints.

RESULTS

Postoperative pain and opioid use were significantly lower in patients with peripheral nerve blocks (n = 1,329) than those with opioids alone (n = 439). There was no detectable decrease in strength associated with nerve blocks, while a significantly greater proportion of patients with nerve blocks were able to participate in PT on postoperative day 1 (96.4% vs 57.1%). These differences were not due to the impact of the surgeon per se, but whether or not the surgeon used nerve blocks for pain management. There was a small but statistically significant decrease in the average LOS in patients with blocks.

CONCLUSION

This analysis supports the use of low concentration, low volume of LA based peripheral nerve blocks for postoperative pain management.

Setting up an acute pain management service

Successful implementation of an acute pain management service involves a team approach in which team members have clearly defined roles. Clinical protocols are designed to help address common problems and prevent errors. As the complexity of surgery and patients' diseases continues to increase, current knowledge of new analgesic medications, acute pain literature, and skills in regional anesthesia techniques is imperative. Emphasizing a multimodal approach can improve analgesia and decrease opioid-related side effects.

Prehospital administered fascia iliaca compartment block by emergency medical service nurses, a feasibility study

INTRODUCTION

Patients with a proximal femur fracture are often difficult to evacuate from the accident scene. Prehospital pain management for this vulnerable group of patients may be challenging. Multiple co-morbidities, polypharmacy and increased age may limit the choice of suitable analgesics. The fascia iliaca compartment (FIC) block may be an alternative to intravenous analgesics. However this peripheral nerve block is mainly applied by physicians.In the Netherlands, prehospital emergency care is mostly provided by EMS-nurses. Therefore we examined whether well-trained EMS-nurses are able to successfully perform a FIC block in order to ensure timely and appropriate effective analgesia.The study was study was registered in the Netherlands Trial Register (NTR-nr 3824).

METHODS

Ten EMS nurses were educated in the performance of a FIC-block. Indications, technique, side-effects and complications were discussed. Hereafter the trained EMS-nurses staffed ambulance teams were dispatched to patients with a suspicion for a proximal femur fracture. After confirmation of the diagnosis, the block was performed and 0.3 ml/kg lidocaine (10 mg/ml) with adrenaline 5 μg/ml was injected. The quality of pain relief, occurrence of complications and patient satisfaction were evaluated.

RESULTS

In 108 patients a block was performed. One hundred patients could be included. Every EMS nurse performed at least 10 FIC blocks. The block was effective in 96 patients. The initial median (NRS)-pain score decreased after block performance to a score of 6 (after 10 minutes), 4 (after 20 minutes) and 3 (after 30 minutes). At arrival at the Emergency Department the median pain score was 3. Dynamic NRS-pain scores when transferring the patient from the accident scene to the ambulance stretcher, during transportation to the hospital and when transferring the patient to a hospital bed were, 4, 3 and 3.5 respectively. Patient satisfaction was very high. No complications were noted.

CONCLUSION

Additional educated EMS-nurses are able to successfully perform a FIC-block for providing acute pain relief to patients with a suspected proximal femur fracture.

Acute pain management

This article updates acute pain management in ambulatory surgery and proposes a practical three-step approach for reducing the impact and incidence of uncontrolled surgical pain. By identifying at-risk patients, implementing multimodal analgesia, and intervening promptly with rescue therapies, the anesthesiologist may improve outcomes, reduce cost, and optimize the patient's experience and quality of recovery.

The evolution and practice of acute pain medicine

BACKGROUND

In recent years, the field of acute pain medicine (APM) has witnessed a surge in its development, and pain has begun to be recognized not merely as a symptom, but as an actual disease process. This development warrants increased education of residents both in the performance of regional anesthesia as well as in the disease course of acute pain and the biopsychosocial mechanisms that define interindividual variability.

REVIEW SUMMARY

We reviewed the organization and function of the modern APM program. Following a discussion of the nomenclature of acute pain-related practices, we discuss the historical evolution and modern role of APM teams, including the use of traditional, as well as complementary and alternative, therapies for treating acute pain. Staffing and equipment requirements are also evaluated, in addition to the training requirements for achieving expertise in APM. Lastly, we briefly explore future considerations related to the essential role and development of APM.

CONCLUSION

The scope and practice of APM must be expanded to include pre-pain/pre-intervention risk stratification and extended through the phase of subacute pain.

Risk of catheter-associated infection in young hematology/oncology patients receiving long-term peripheral nerve blocks

BACKGROUND

Continuous peripheral nerve blocks (CPNBs) are increasingly used to control postoperative and chronic pain. At our pediatric oncology institution, the duration of CPNBs is often prolonged. The risk of catheter-associated infection with prolonged CPNBs has not been previously investigated.

AIM

We analyzed the incidence of CPNB-related infection and its relation to catheter duration, catheter site, intensive care stay, and antibiotic coverage.

METHODS

All CPNBs placed at our institution between August 1, 2005 and October 31, 2010 were studied. Primary diagnosis and the site, indication, duration, and infectious adverse effects of CPNBs were obtained from our Pain Service QI database. Patients' age and sex, antibiotic administration, and number of days in intensive care were collected from patients' medical records.

RESULTS

The use of 179 catheters in 116 patients was evaluated. Mean age at CPNB placement was 15.1 years (median, 14.7; range, 0.4-26.9). The most frequent indication for CPNB was surgery (89.4%), most commonly orthopedic (78.8%). Mean CPNB duration was 7.2 days (median, 5.0; range, 1-81 days). Two cases (1.12%) of CPNBs developed signs of infection, both associated with femoral catheters. The infections were mild and necessitated catheter removal at days 10 and 13, respectively.

CONCLUSION

Nerve block catheter-associated infections are infrequent at our institution despite prolonged CPNB use. Both patients with infection had femoral catheters and prolonged catheter (≥ 10 days) use.

Potential contamination of the surgical site caused by leakage from an interscalene catheter with the patient in a seated position: a case report

PURPOSE

Continuous catheterized nerve blockade has been used for many years to provide effective analgesia postoperatively. We report a potential complication of interscalene nerve block performed with the traditional catheter-through-needle insertion technique. Specifically, leakage from the catheter insertion site posed a risk of contamination to the sterile surgical field. We also describe an alternative catheter design to overcome this leakage problem.

CLINICAL FEATURES

We present a case of leakage from the catheter insertion site during the course of an interscalene nerve block with the patient in a beach chair position for shoulder arthroplasty. Using the traditional catheter-through-needle technique, an 18G 100-mm Tuohy needle was inserted between the C6 and C7 roots under ultrasound guidance. After confirming the needle tip position, 20 mL of local anesthetic (1% ropivacaine and 0.25% bupivacaine 1:1) were injected. A 20G catheter was then threaded through the Tuohy needle and carefully secured with tape and dressing. In the operating room, leakage from the catheter insertion site started to disturb the adhesives of the surgical drapes and threatened the sterility of the surgical field. The catheter was removed prior to surgery upon the surgeon's request. Upon completion of the operation, a catheter was reinserted using an alternative catheter-over-needle method. Postoperatively, no leakage was seen at or around the catheter entry site.

CONCLUSION

This case report serves as a reminder that leakage from the catheter entry site remains a troublesome and hazardous issue during continuous peripheral nerve block. Leakage from the catheter insertion site often occurs due to the loose fit of the catheter in the larger diameter hole left by the Tuohy needle. We have also shown the successful use of an alternative catheter-over-needle design to minimize the risk of leakage from the catheter entry site. This technique resulted in being particularly vital for shoulder surgery with the patient in the beach chair position.

Liposomal bupivacaine: a review of a new bupivacaine formulation

Many attempts have been made to increase the duration of local anesthetic action. One avenue of investigation has focused on encapsulating local anesthetics within carrier molecules to increase their residence time at the site of action. This article aims to review the literature surrounding the recently approved formulation of bupivacaine, which consists of bupivacaine loaded in multivesicular liposomes. This preparation increases the duration of local anesthetic action by slow release from the liposome and delays the peak plasma concentration when compared to plain bupivacaine administration. Liposomal bupivacaine has been approved by the US Food and Drug Administration for local infiltration for pain relief after bunionectomy and hemorrhoidectomy. Studies have shown it to be an effective tool for postoperative pain relief with opioid sparing effects and it has also been found to have an acceptable adverse effect profile. Its kinetics are favorable even in patients with moderate hepatic impairment, and it has been found not to delay wound healing after orthopedic surgery. More studies are needed to establish its safety and efficacy for use via intrathecal, epidural, or perineural routes. In conclusion, liposomal bupivacaine is effective for treating postoperative pain when used via local infiltration when compared to placebo with a prolonged duration of action, predictable kinetics, and an acceptable side effect profile. However, more adequately powered trials are needed to establish its superiority over plain bupivacaine.

PAPupuncture has localized and long-lasting antinociceptive effects in mouse models of acute and chronic pain

Acupuncture has been used for millennia to treat pain, although its efficacy and duration of action is limited. Acupuncture also has brief (1–2 h) antinociceptive effects in mice and these effects are dependent on localized adenosine A₁ receptor (A₁R) activation. Intriguingly, adenosine 5’-monophosphate (AMP) is basally elevated near acupuncture points. This finding suggested that it might be possible to inhibit nociception for a longer period of time by injecting prostatic acid phosphatase (PAP, ACPP) into acupuncture points. PAP is an ectonucleotidase that dephosphorylates extracellular AMP to adenosine, has a long half-life in vivo and is endogenously found in muscle tissue surrounding acupuncture points. Here, we found that injection of PAP into the popliteal fossa—a space behind the knee that encompasses the Weizhong acupuncture point—had dose- and A₁R-dependent antinociceptive effects in mouse models of acute and chronic pain. These inhibitory effects lasted up to six days following a single injection, much longer than the hour-long inhibition provided by acupuncture. Antinociception could be transiently boosted with additional substrate (AMP) or transiently blocked with an A₁R antagonist or an inhibitor of phospholipase C. This novel therapeutic approach—which we term “PAPupuncture”—locally inhibits pain for an extended period of time (100x acupuncture), exploits a molecular mechanism that is common to acupuncture, yet does not require acupuncture needle stimulation.

Lipid emulsion for local anesthetic systemic toxicity

The accidental overdose of local anesthetics may prove fatal. The commonly used amide local anesthetics have varying adverse effects on the myocardium, and beyond a certain dose all are capable of causing death. Local anesthetics are the most frequently used drugs amongst anesthetists and although uncommon, local anaesthetic systemic toxicity accounts for a high proportion of mortality, with local anaesthetic-induced cardiac arrest particularly resistant to standard resuscitation methods. Over the last decade, there has been convincing evidence of intravenous lipid emulsions as a rescue in local anesthetic-cardiotoxicity, and anesthetic organisations, over the globe have developed guidelines on the use of this drug. Despite this, awareness amongst practitioners appears to be lacking. All who use local anesthetics in their practice should have an appreciation of patients at high risk of toxicity, early symptoms and signs of toxicity, preventative measures when using local anesthetics, and the initial management of systemic toxicity with intravenous lipid emulsion. In this paper we intend to discuss the pharmacology and pathophysiology of local anesthetics and toxicity, and the rationale for lipid emulsion therapy.