Continuous Peripheral Nerve Blockade Research Articles

Peripheral nerve blockade and novel analgesic modalities for ambulatory anesthesia.

Despite peripheral nerve blockade offering analgesic benefits and improving patient satisfaction, it has not been well adopted in ambulatory anesthesia. In this review, we aim to summarize the evidence underlying peripheral nerve blockade, local anesthetic adjuncts, continuous peripheral nerve blockade and novel analgesic modalities, with the objective to provide recommendations on postoperative analgesia optimization after peripheral nerve blockade in an ambulatory setting. Barriers to the widespread use of peripheral nerve blockade in ambulatory anesthesia could include lack of education and training, and increased anesthetic induction time. Strategies that have demonstrated promise to increase duration of action and attenuate rebound pain phenomenon after peripheral nerve blockade include multimodal analgesia, local anesthetic adjuncts and continuous infusion of local anesthetic. Dexamethasone has been demonstrated to be the most effective local anesthetic adjunct. Continuous peripheral nerve blockade is a reasonable alternative but at the expense of additional costs and logistical reorganization. There is currently insufficient data to promote the ambulatory use of liposomal bupivacaine, cryoanalgesia and percutaneous peripheral nerve stimulation. Educational programs and parallel processing may promote peripheral nerve blockade in an ambulatory setting, improving the patient experience in the postoperative period. Intravenous dexamethasone should be considered wherever appropriate as part of a multimodal analgesic strategy to optimize postoperative pain control.

A reliable septum exists between the lateral cord and medial and posterior cords in the costoclavicular region: Clinical and microanatomical considerations in brachial plexus anesthetic blockade.

The ultrasound-guided proximal infraclavicular costoclavicular block (PICB) appears popular but its results are inconsistent. We sought an accurate demonstration of septae formed between the brachial plexus cords. We performed in-plane, lateral-to-medial PICBs on 120 patients and recorded images. Once the most superficial lateral cord component was entered, a 0.4-0.6 mA current was applied to confirm needle placement; 5 ml of local anesthetic (LA) solution was then injected and its spread was observed and recorded. As the needle was advanced, the presence or absence of a hyperechoic linear structure was noted before the deeper compartment was reached, specifically looking for the possible displacement of such a septum. Upon initial scanning, a septum was observed in 67 of the 120 patients (46.2%). However, there was clear displacement of a linear septum between the lateral cord compartment and the medial and posterior cord compartments that prevented spread between the compartments in 94.16% of patients. Piercing the septum evoked motor responses from the medial or posterior cord. The same anatomical regions were studied microanatomically by analyzing cross-sections obtained with the same approach angle as the ultrasound probe. Intraplexus fascial septae that bundled the medial and posterior cords into one compartment and separated them from the lateral cord were demonstrated and confirmed microanatomically. This suggests the need for two separate injections (or two separate catheter placements for continuous peripheral nerve blockade) into the superficial and deep compartments to ensure LA spread around all three cords of the brachial plexus at this level.

Does a catheter over needle system reduce infusate leak in continuous peripheral nerve blockade: a randomised controlled trial.

Continuous peripheral nerve blockade is a common technique in the analgesic management for many procedures. Leakage of local anaesthetic from around the nerve catheter insertion site can increase the chance of catheter dislodgement, risks infective complications, and could divert anaesthetic away from the nerve causing the block to fail. We conducted a randomised controlled trial to assess whether the type of nerve catheter influenced local anaesthetic leak rate. One hundred and ten patients scheduled for elective unilateral total knee arthroplasty were randomised to receive a perineural catheter with either a catheter over needle (CON) system (Pajunk® E-Cath) (PAJUNK® GmbH, Medizintechnologie, Geisingen, Germany), or catheter through needle (CTN) system (Pajunk® SonoLong) (PAJUNK® GmbH, Medizintechnologie, Geisingen, Germany). There was no statistically significant difference in the rate of leaking catheters between groups (CON 1.8% versus CTN 3.7%; <i>P</i>=0.618), however, the overall leak rate was much lower than anticipated from pilot data. The CON system was on average faster to insert (CON 357 seconds versus CTN 482 seconds; <i>P</i>=0.004), but associated with poorer needle visibility under ultrasound (Likert scale 1-5, mean [SD], CON 3.31 [0.96] versus CTN 3.89 [0.84]; <i>P</i>=0.001). All seven instances of inadvertent catheter dislodgement occurred in the CTN group (<i>P</i>=0.006). There was no statistically significant difference between groups in the proportion of patients who had adequate analgesia on day one (CON 80% versus CTN 86.5%; <i>P</i>=0.294) and day two postoperatively (CON 85.5% versus CTN 91.8%; <i>P</i>=0.369). Our findings show the overall leak rate to be very low with both catheter systems; however, the CON system may have advantages in terms of speed of use and rate of inadvertent catheter dislodgement.

Anesthetic requirements measured by bilateral bispectral analysis and femoral blockade in total knee arthroplasty

A continuous peripheral nerve blockade has proved benefits on reducing postoperative morphine consumption; the combination of a femoral blockade and general anesthesia on reducing intraoperative anesthetic requirements has not been studied. The objective of this study was to determine the relevance of timing in the performance of femoral block to intraoperative anesthetic requirements during general anesthesia for total knee arthroplasty. A single-center, prospective cohort study on patients scheduled for total knee arthroplasty, were sequentially allocated to receive 20mL of 2% mepivacaine throughout a femoral catheter, prior to anesthesia induction (Preoperative) or when skin closure started (Postoperative). An algorithm based on bispectral values guided intraoperative anesthetic management. Postoperative analgesia was done with an elastomeric pump of levobupivacaine 0.125% connected to the femoral catheter and complemented with morphine patient control analgesia for 48hours. The Kruskall Wallis and the chi-square tests were used to compare variables. Statistical significance was set at p<0.05. There were 94 patients, 47 preoperative and 47 postoperative. Lower fentanyl and sevoflurane were needed intraoperatively in the Preoperative group; median values and range: 250 (100-600) vs 450 (200-600)μg and 21 (12-48) vs 32 (18-67)mL p=0.001, respectively. There were no differences in the median verbal numeric rating scale values 4 (0-10) vs 3 (0-10); and in median morphine consumption 9 (2-73) vs 8 (0-63)mg postoperatively. A preoperative femoral blockade is useful in decreasing anesthetic requirements in total knee arthroplasty surgery but no added effect in the postoperative analgesic control.

Programmed intermittent peripheral nerve local anesthetic bolus compared with continuous infusions for postoperative analgesia: A systematic review and meta-analysis

Study objective and backgroundThe role of the programmed intermittent bolus (PIB) technique for infusion of local anesthetics in continuous peripheral nerve blockade (CPNB) remains to be elucidated. Randomized controlled trials (RCTs) on PIB versus continuous infusion for CPNB have demonstrated conflicting results and no systematic review or meta-analysis currently exists. We aimed to delineate via systematic review with meta-analysis if there is any analgesic benefit to performing PIB versus continuous infusion for CPNB. DesignWe conducted a systematic review and random-effects meta-analysis of RCTs. Data sourcesWe searched Medline, Embase, and the Cochrane Library without language restriction from inception to 2-May-2017. Eligibility criteriaIncluded RCTs had to compare PIB to continuous infusion in adult surgical patients receiving any upper or lower limb CPNB for postoperative analgesia. VAS pain scores were the primary outcome. The Cochrane Risk of Bias Tool with GRADE methodology was utilized to assess evidence quality. ResultsNine RCTs (448 patients) met the inclusion criteria. Two studies performed upper limb blocks and the rest lower limb blocks. Five RCTs activated the CPNB with long-acting local anesthetic and only five used multi-modal analgesia. PIB modestly reduced VAS pain scores at 6h (−14.2mm; 95%CI −23.5mm to −5.0mm; I2=82.5%; p=0.003) and 12h (−9.9mm; 95%CI −14.4mm to −5.4mm; I2=12.4%; p<0.001), but not at later time points. There were no other meaningful differences in the rest of the outcomes, apart from more residual motor block with PIB (OR 4.27; 95% CI 1.08–16.9; p=0.04; NNTH=8). GRADE scoring ranged from low to very low. ConclusionsThe existing evidence demonstrates that PIB does not meaningfully reduce VAS pain scores in CPNB. This systematic review provides important information about the limitations of existing studies. Future studies should reflect contemporary practice and focus on more painful operations.

Surgical site infection related to use of elastomeric pumps in pectus excavatum repair. Lessons learned from root cause analysis

BackgroundPectus excavatum repair (PEX) is among the most painful thoracic procedures performed. Continuous peripheral nerve blockade (CPNB) is known to be efficacious in optimizing pain control while limiting narcotic use in adult thoracic procedures. It was introduced in May 2015 as a bridge to oral pain control in children undergoing PEX. Consequently, the surgical site infection (SSI) rate increased from 2.7% to 27.7%. MethodsSSI surveillance followed national guidelines. The abrupt increase prompted root cause analysis and cessation of CPNB use. A dynamic systems model of SSI in PEX was developed. Statistical analysis compared SSI outcomes with and without CPNB. ResultsFrom May 2015 to June 2015, 21 PEX were performed; 11 with CPNB. 6 SSIs were observed. Use of CPNB significantly (p=0.008) increased SSI incidence. Haller index, number of bars, usage of Fiberwire®, methicillin resistant S. aureus colonization and length of stay did not differ. Root cause analysis revealed the proximity of CPNB catheters to the wound, the use of CPNB with implanted hardware and a delayed utilization of CPNB catheters to be of concern. ConclusionIntroduction of CPNB coincided with a significant increase in SSI. Further study is needed to assess the safety of CPNB in pediatric PEX. Level of evidenceLevel III treatment study.

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

BackgroundNew 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.MethodsWe 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.ResultsThe 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).ConclusionsAlthough 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.

Anesthetic requirements measured by bilateral bispectral analysis and femoral blockade in total knee arthroplasty

Background and objectivesA continuous peripheral nerve blockade has proved benefits on reducing postoperative morphine consumption; the combination of a femoral blockade and general anesthesia on reducing intraoperative anesthetic requirements has not been studied. The objective of this study was to determine the relevance of timing in the performance of femoral block to intraoperative anesthetic requirements during general anesthesia for total knee arthroplasty. MethodsA single-center, prospective cohort study on patients scheduled for total knee arthroplasty, were sequentially allocated to receive 20mL of 2% mepivacaine throughout a femoral catheter, prior to anesthesia induction (Preoperative) or when skin closure started (Postoperative). An algorithm based on bispectral values guided intraoperative anesthetic management. Postoperative analgesia was done with an elastomeric pump of levobupivacaine 0.125% connected to the femoral catheter and complemented with morphine patient control analgesia for 48hours. The Kruskall Wallis and the chi-square tests were used to compare variables. Statistical significance was set at p<0.05. ResultsThere were 94 patients, 47 preoperative and 47 postoperative. Lower fentanyl and sevoflurane were needed intraoperatively in the Preoperative group; median values and range: 250 (100–600) vs 450 (200–600)μg and 21 (12–48) vs 32 (18–67)mL p=0.001, respectively. There were no differences in the median verbal numeric rating scale values 4 (0–10) vs 3 (0–10); and in median morphine consumption 9 (2–73) vs 8 (0–63)mg postoperatively. ConclusionsA preoperative femoral blockade is useful in decreasing anesthetic requirements in total knee arthroplasty surgery but no added effect in the postoperative analgesic control.

Clinical and microbiological evaluation of epidural and regional anaesthesia catheters in injured UK military personnel

IntroductionThe adoption of regional and epidural analgesia in UK military personnel injured in action during Op HERRICK increased from 2008, in line with structural and environmental developments in the UK...

Successful Ultrasound-Guided Femoral Nerve Blockade and Catheterization in a Patient with Von Willebrand Disease.

Peripheral nerve blockade (PNB) is superior to neuraxial anesthesia and/or opioid therapy for perioperative analgesia in total knee replacement (TKR). Evidence on the safety of PNB in patients with coagulopathy is lacking. We describe the first documented account of continuous femoral PNB for perioperative analgesia in a patient with Von Willebrand Disease (vWD). Given her history of opioid tolerance and after an informative discussion, a continuous femoral PNB was planned for in this 34-year-old female undergoing TKR. A Humate-P intravenous infusion was started and the patient was positioned supinely. Using sterile technique with ultrasound guidance, a Contiplex 18 Gauge Tuohy needle was advanced in plane through the fascia iliaca towards the femoral nerve. A nerve catheter was threaded through the needle and secured without complications. Postoperatively, a levobupivacaine femoral catheter infusion was maintained, and twice daily Humate-P intravenous infusions were administered for 48 hours; enoxaparin thromboprophylaxis was initiated thereafter. The patient was discharged uneventfully on postoperative day 4. Given documentation of delayed, unheralded bleeding from PNB in coagulopathic patients, we recommend individualized PNB in vWD patients. Multidisciplinary team involvement is required to guide factor supplementation and thromboprophylaxis, as is close follow-up to elicit signs of bleeding throughout the delayed postoperative period.

Continuous peripheral nerve catheters in pediatric complex regional pain syndrome.

Continuous peripheral nerve catheters in pediatric complex regional pain syndrome.

The Safety and Effectiveness of Continuous Peripheral Nerve Blockade in Children

The Safety and Effectiveness of Continuous Peripheral Nerve Blockade in Children

Incidence of Failure of Continuous Peripheral Nerve Catheters for Postoperative Analgesia in Upper Extremity Surgery

To explore the incidence of failure of continuous peripheral nerve blockade (CPNB) after upper extremity operations. Patient data regarding postoperative CPNB were retrospectively obtained from our institution's regional anesthesia database. Documented information on the first postoperative day included pain assessment ratings (numerical verbal pain scale, patient-reported breakthrough pain upon perceived return of sensation, appearance of the catheter site, complications, time of return of sensation, day of return of sensation, residual blockade, patient satisfaction with the block, and whether patient would receive the block again). A total of 207 patients received CPNB for postoperative analgesia. The failure rate on the first postoperative day for infraclavicular (133 patients) and supraclavicular (58 patients) CPNB was 19% and 26%, respectively. Interscalene CPNB (16 patients) yielded 3 incidences of failure. No significant difference was found between supraclavicular and infraclavicular block techniques. In addition, no significant differences were found between the incidences of CPNB failures with potentially more painful surgeries involving bone compared with potentially less painful soft tissue procedures. The CPNB technique used for hand surgery postoperative analgesia was associated with nontrivial failure rates. The potential of CPNB failure and resulting breakthrough pain upon recovery from the primary nerve block is important to help establish patient expectations. Therapeutic IV.

Randomised Comparison of an End-Hole, Triple-Hole and Novel Six-Hole Catheter for Continuous Interscalene Analgesia

Epidural analgesia studies and a recent continuous peripheral nerve block study suggest multi-hole perineural catheters perform better than end-hole catheters. Confounding catheter positioning issues limit interpretation of the latter study. One hundred and fifty-six patients receiving an anterolateral interscalene catheter for elective shoulder surgery were randomised to three groups: following out-of-plane ultrasound confirmation of the needle tip immediately lateral to the C5/6 roots, an end-hole (n=52), triple-hole (n=53) or six-hole (n=51) non-stimulating catheter was positioned 3 cm beyond the needle tip. Ropivacaine 0.375% 15 ml was administered preoperatively via the catheter before surgery under general anaesthesia. A ropivacaine 0.2% 2 ml/hour infusion with mandatory six-hourly, and on-demand hourly, 5 ml boluses was continued for >48 hours with tramadol available as rescue. Patients were questioned in the recovery room and at 24 hours for numerical rating pain score (0 to 10), ropivacaine bolus and tramadol consumption. The frequency of recovery room pain was similar between groups (P=0.75) and demonstrated strong evidence for equivalence at the 5% significance level. Neither time to first pain, "average" or "worst" pain during the first 24 hours, ropivacaine bolus or tramadol consumption significantly differed between groups. Catheter threading difficulty was more common for the square-tipped end-hole catheters (end-hole=19% versus triple-hole=6%, six-hole=0%, P >0.001). This study found no evidence to support catheter orifice configuration significantly affecting the quality of continuous peripheral nerve blockade. These findings are in contrast to epidural catheter studies, and suggest that anatomical factors have a significant bearing on whether multi-orifice catheters confer advantage over the single-orifice design.

Continuous peripheral nerve blockade for treatment of chronic wounds: a case report

Continuous peripheral nerve blockade for treatment of chronic wounds: a case report

Tripping Over Perineural Catheters

Tripping Over Perineural Catheters

Catheter Orifice Configuration Influences the Effectiveness of Continuous Peripheral Nerve Blockade

We investigated perineural catheter threading distance and orifice configuration during continuous interscalene analgesia. One hundred fifty-three patients receiving an anterolateral interscalene catheter (catheter needle and nerve/plexus in a similar alignment) for elective shoulder surgery were randomized to 1 of 3 groups: following out-of-plane ultrasound confirmation of the needle tip immediately lateral to the C5/6 roots, a nonstimulating catheter was blindly advanced 0.5 cm (end-hole; n = 50), 2.5 cm (multiorifice; n = 50) or 5 cm (multiorifice; n = 53) beyond the needle tip. Ropivacaine 0.75% + lidocaine 1% (50:50) 20 mL was administered preoperatively via the catheter before surgery under general anesthesia. A ropivacaine 0.2% 2 mL/hr elastomeric infusion with mandatory 6 hourly (and on demand) 5-mL boluses was continued for more than 48 hrs with tramadol available as rescue. Patients were questioned in the recovery room, at 24 and 48 hrs for numerical rating pain score (0-10), ropivacaine bolus, and tramadol consumption. Patients were more frequently pain-free in the recovery room in the multiorifice 2.5 and 5 cm groups compared with the end-hole 0.5 cm group (94%, 91% vs 66%; P < 0.001). During the first 24 hrs, the end-hole group demonstrated an earlier time to first pain (median, 10 vs17, 15 hrs; P < 0.001), higher "average pain" (median, 3 vs 1, 2, P = 0.004), and more ropivacaine bolus (median, 5 vs 3, 3; P < 0.001) and tramadol consumption (P = 0.01). Groups 2.5 and 5 cm did not significantly differ in any outcomes. These results suggest that multiorifice catheters provide superior intermittent bolus continuous peripheral nerve blockade compared with end-hole catheters. For anterolateral approach interscalene catheter placement, there is minimal benefit, either way, to 2.5- or 5-cm blind catheter advancement.

Intravenous Acetaminophen

OPIOIDS are the cornerstone of moderate to severe acute postoperative pain treatment, particularly when the patient is not a candidate for a regional analgesic technique (such as continuous epidural analgesia or peripheral nerve blockade) or is unresponsive to other (nonopioid) analgesics. Adverse effects of opioids, however, often present a major barrier to achieving excellent analgesia. In a systematic review examining opioid-associated adverse effects in postoperative patients, approximately 30% of patients reported an adverse gastrointestinal (nausea, vomiting, ileus, constipation) or central nervous system (sedation, somnolence) effect.

Development of a Complicated Pain Syndrome Following Cyanide Poisoning in a U.S. Soldier

A majority of modern war wounds are caused by blasts and high-energy ballistics. Extremity injuries predominate since modern body armor does not protect these areas due to mobility limitations. A less known and more insidious mechanism of enemy attack among our soldiers involves treachery by the local populace posing as noncombatants. One such recent event involved the contamination of tobacco with cyanide (CN). We describe a case of a soldier with CN intoxication due to ingestion of tobacco purchased from a local merchant. The soldier developed a complex neuropathic pain syndrome and was successfully treated with an inpatient high-dose intravenous ketamine infusion in combination with continuous peripheral nerve blockade.

Continuous Peripheral Nerve Blockade as Postoperative Analgesia for Open Treatment of Calcaneal Fractures

To examine the cost and efficacy of methods of general and regional anesthetic for postoperative pain control after open repair of intra-articular calcaneal fractures. We compared single-injection popliteal fossa blocks and continuous infusion popliteal fossa blocks with drug delivered through a catheter from an infusion pump (CPNB) to general or spinal anesthetic alone in terms of hospital charges, length of hospital stay, and postoperative oral and intravenous narcotic use, antiemetic use, and safety. Retrospective review. University Level I regional trauma center and associated orthopaedic surgery center. Charts were reviewed for all patients undergoing open treatment of calcaneal fractures during a 9-year period. One hundred six of 203 met study inclusion criteria. All patients received either general or spinal anesthetic. Patients additionally received preoperative single-injection popliteal fossa blocks, CPNB, or no regional block. Data were compared from each group for total hospital cost, length of stay, operating room times, narcotic use, postoperative nausea, and hospital readmission. Eighteen patients from the CPNB group who were discharged within 24 hours of surgery were examined in a subgroup analysis of ambulatory treatment. There were no significant differences between the control group and the two regional anesthesia groups in total hospital cost, length of stay, narcotic use, or antiemetic use. However, subgroup analysis demonstrated that ambulatory CPNB patients had significantly lower total hospital costs and narcotic use compared with the remaining CPNB patients. There were no block-related complications. None of the short-stay patients required urgent medical attention or readmission after discharge. CPNB through an infusion pump may allow patients undergoing open treatment of calcaneal fractures to be safely discharged within 24 hours with a concomitant decrease in healthcare costs. These data suggest that this method of postoperative pain management might be applied to other patients with major foot and ankle trauma and/or reconstructive procedures and that wider use of continuous peripheral nerve blocks may lead to a reduction in healthcare costs.