Perineural Catheter Research Articles

Continuous interscalene versus phrenic nerve-sparing high-thoracic erector spinae plane block for total shoulder arthroplasty: a randomized controlled trial.

The high-thoracic erector spinae plane block (HT-ESPB) has been reported as an effective analgesic modality for the shoulder region without phrenic nerve palsy. The goal of this study was to compare the HT-ESPB as a phrenic nerve-sparing alternative to an interscalene block for total shoulder arthroplasty. Thirty patients undergoing total shoulder arthroplasty at Stanford Health Care (Palo Alto, CA, USA) were enrolled in a double-blind randomized controlled trial. We randomized 28 patients to receive either an interscalene or HT-ESPB perineural catheter preoperatively; 26 patients were included in the final analysis. The study was powered for the primary outcome of incidence of hemidiaphragmatic paralysis in the postanesthesia care unit (PACU). Other outcome measures included incentive spirometry volume, brachial plexus motor and sensory exams, adverse events, pain scores, and opioid consumption. The incidence of hemidiaphragmatic paralysis in the HT-ESPB catheter group was significantly lower than in the interscalene catheter group (0/12, 0% vs 14/14, 100%; P < 0.001). No statistically significant differences were found in pain scores and opioid consumption (in oral morphine equivalents) between the interscalene and HT-ESPB groups through postoperative day (POD) 2. Nevertheless, the mean (standard deviation) point estimates for opioid consumption for the HT-ESPB group were higher than for the interscalene group in the PACU (HT-ESPB: 24.8 [26.7] mg; interscalene: 10.7 [21.7] mg) and for POD 0 (HT-ESPB: 20.5 [25.0] mg; interscalene: 6.7 [12.0] mg). In addition, cumulative postoperative opioid consumption was significantly higher at POD 0 (PACU through POD 0) in the HT-ESPB group (45.3 [39.9] mg) than in the interscalene group (16.6 [21.9] mg; P = 0.04). This study suggests that continuous HT-ESPB can be a phrenic nerve-sparing alternative to continuous interscalene brachial plexus blockade, although the latter provided superior opioid-sparing in the immediate postoperative period. This was a small sample size study, and further investigations powered to detect differences in analgesic and quality of recovery score endpoints are needed. www. gov (NCT03807505); registered 17 January 2019.

Optimal location for continuous catheter analgesia among the femoral triangle, proximal, or distal adductor canal after total knee arthroplasty: a randomized double-blind controlled trial

BackgroundPain management after total knee arthroplasty is essential to improve early mobilization, rehabilitation, and recovery. Continuous adductor canal (AC) block provides postoperative analgesia while preserving quadriceps strength. However, there have...

Continuous mandibular nerve block as sole analgesia for postoperative pain management after a hemimandibulectomy in a French Bulldog

AbstractA 12‐year‐old French Bulldog presented for a mandibulectomy due to a large ameloblastoma in the left rostral mandibular body. Preoperative pain management consisted of methadone 0.2 mg/kg and a mandibular nerve block with ropivacaine 0.5%. Intraoperatively, an indwelling perineural catheter was placed through the mandibular canal, with the tip placed in the mandibular foramen for postoperative ropivacaine administration. Ropivacaine 0.2% was administered every 6 hours for the first 36 hours without need of any systemic analgesic administration, providing adequate analgesia and allowing for a rapid recovery. The dog was completely alert and responsive in the immediate postoperative period and started eating 12 hours after surgery without any sign of pain or discomfort. No complications were observed during the postoperative period. The perineural catheter was removed after 40 hours and the dog was administered metamizole every 8 hours for analgesia and was discharged 48 hours after surgery.

Comparison of postoperative analgesia with two different doses of dexmedetomidine as an adjuvant to ropivacaine in adductor canal block for unilateral total knee replacement surgery: A randomized double-blinded study.

Multimodal analgesia is used to treat severe postoperative pain (POP) in total knee replacement (TKR) surgery. Adjuvants are used with local anesthetics to improve the quality and duration of pain relief. Studies comparing different doses of dexmedetomidine in adductor canal block (ACB) are sparse to date. This study compares postoperative analgesia with two different doses of dexmedetomidine as an adjuvant to 0.2% ropivacaine in ACB for unilateral TKR. In this prospective, randomized, double-blinded comparative study, sixty patients were divided into two groups: A and B. Postoperatively perineural catheter was inserted and all patients received 0.2% ropivacaine 20 mL bolus followed by an infusion of 0.2% ropivacaine with dexmedetomidine (0.5 µg/Kg in Group A and 1 µg/Kg in Group B) at 8 mL/h. Postoperative pain, motor blockade, rescue analgesia, hemodynamic parameters, sedation, and adverse effects were recorded. Student t, Chi-square, and Mann-Whitney tests were used. Most patients were elderly females (M:15, F:45). Postoperatively, from 2nd to 24th hour, pain score was less in Group B (P < 0.05). The requirement of rescue analgesic was also less in Group B (A:B 330 µg:60 µg; 23%:6%). Motor blockade assessed using modified Bromage scale and sedation using Richmond agitation sedation scale did not show any statistical difference. Dexmedetomidine infusion at 1 µg/Kg is a better adjuvant to 0.2% ropivacaine than 0.5 µg/Kg in ACB. It provides better analgesia without producing sedation, motor blockade, hemodynamic changes, or any adverse effects.

Impact of post- amputation pain syndrome on the results of bone stump formation

Background. To the present day, a high rate of unsatisfactory amputation results still exists. The healing of the bone residual limb, the main support element of the residual limb, is of particular importance. Objective. To study the impact of postamputation pain syndrome on the nature of reparative processes in the bone residual limb. Methods. Three series of experiments were performed on 45 rabbits, 15 in each with mid-third thigh amputation and muscular plasty. In series 1 and 2, a perineural catheter was attached to the sciatic nerve stump during amputation, and mechanical irritation of the nerve was performed daily for 20 minutes in series 1 for 20 days. In series 2, 0.3 ml of 1% lidocaine was injected through the catheter into the circumference of the nerve twice daily for 20 days. Animals of series 3 served as a control. The follow-up periods were 1, 3, 6 months. The study method was histological with infusion of the vessels with ink-gelatin mixture. Results. In series 1, there was a sharp disturbance of the reparative process, which consisted in shape changes, resorption of the cortical diaphyseal plate, stump deformity, absence of bone closure plate formation, and microcirculatory disturbances. In most experiments of the 2nd series, organotypic stumps were formed with normalized microcirculation. In series 3, the results of the residual limb formation were better than in series 1, but worse than in series 2. Conclusion. In the absence of pain syndrome, the bone stump after amputation at the diaphysis level over a period of 1, 3, 6 months retains its cylindrical shape, the structure of the cortical diaphyseal plate, the content of the medullary canal with normal microcirculation, the formation of the bone closure plate, and the completion of the reparative process. The presence of postamputation pain syndrome in the stump distorts the course of the reparative process with the development of pathological remodeling of bone tissue.

Interscalene Block for Analgesia in Orthopedic Treatment of Shoulder Trauma: Single-Dose Liposomal Bupivacaine versus Perineural Catheter

BackgroundInterscalene brachial plexus block is frequently utilized to provide perioperative analgesia to patients undergoing shoulder surgery to optimize recovery, minimize opioid consumption, and decrease overall hospital length of stay. The use of an indwelling perineural interscalene catheter provides extended analgesia and is efficacious in managing severe postoperative pain following major shoulder surgery. Currently, the only alternative to perineural catheters for extended analgesia with interscalene block involves the perineural infiltration of liposomal bupivacaine. However, there is limited published data regarding the overall analgesic effectiveness of using interscalene liposomal bupivacaine in the setting of shoulder surgery.MethodsWe performed a retrospective review of 43 patients in the acute trauma setting who underwent major shoulder surgery and received extended analgesia via perioperative interscalene brachial plexus block with either an indwelling continuous catheter or single-dose liposomal bupivacaine to determine if comparable analgesia can be achieved. The primary outcomes of interest were postoperative pain scores and opioid consumption. Due to the ability to titrate and bolus local anesthetic infusions to a desired clinical effect, we hypothesized that opioid consumption and pain scores would be lower when using the continuous catheter technique.ResultsAfter statistical analysis, our results demonstrated no significant difference between the two techniques in regards to opioid consumption as well as numeric pain scores during the 48-hour postoperative period, but did note a higher rate of complications with patients who received perineural interscalene continuous catheters. Secondary outcomes showed an increase in time required to complete the regional block procedure with the use of indwelling catheters.ConclusionInterscalene brachial plexus block with liposomal bupivacaine may be a viable alternative to indwelling continuous catheters for providing extended analgesia in patients undergoing major shoulder surgery.

Color Doppler ultrasonography of an agitated solution is predictive of accurate catheter placement for a continuous popliteal sciatic nerve block

BackgroundContinuous peripheral nerve catheters (PNCs) have been shown to provide superior postoperative analgesia, decrease opioid consumption, and improve patient satisfaction compared with single injection techniques. In order to achieve success and reliability, accurate catheter positioning is an essential element of PNC placement. An agitated solution of normal saline, D5W, or a local anesthetic solution can be produced by the introduction of air to the injectate, creating air bubbles that can enhance ultrasonographic visualization and possibly improve block success.MethodsEighty-three patients were enrolled. Ultrasound-guided continuous popliteal sciatic nerve blocks were performed by positioning the tip of a Tuohy needle between the tibial and common peroneal branches of the sciatic nerve and threading a catheter. An agitated local anesthetic solution was injected through the catheter, viewed with color Doppler ultrasound and video recorded. A peripheral block score (lower score = greater blockade, range 0-14) was calculated based upon the motor and sensory testing at 10, 20, and 30 min after block completion. The color Doppler agitation coverage pattern for the branches of the sciatic nerve was graded as follows: complete (> 50%), partial (> 0%, ≤ 50%), or none (0%).ResultsThe degree of nerve blockade at 30 min as judged by median (10th, 90th percentile) peripheral block score was significant for partial or complete color Doppler coverage of the sciatic nerve injectate compared to no coverage [3 (0, 7) vs 8 (4, 14); p < 0.01] and block onset was faster (p = 0.03). The block success was higher in groups with partial or complete coverage of the branches of the sciatic nerve vs no coverage (96% vs 70%; p = 0.02).ConclusionsInjection of an agitated solution through a popliteal sciatic perineural catheter is predictive of accurate catheter placement when partial or complete coverage of the sciatic nerve branches is visualized with color Doppler ultrasound.Trial registrationNCT01591603

A Randomized Double-Blind Trial Comparing the Efficacy of Dexamethasone vs. Clonidine as an Adjunct to Ropivacaine in Ultrasound Guided Continuous Interscalene Block for Arthroscopic Shoulder Surgery

Background: Ultrasound-Guided Continuous Interscalene Block (USGCISB) decreases postoperative morbidity following arthroscopic shoulder surgery. Both dexamethasone and clonidine have been shown to prolong the duration of analgesia when added with ropivacaine in peripheral nerve blocks. However, there is no head-to-head comparison between dexamethasone and clonidine as an adjuvant using USG-CISB. Methods: In this randomized double-blinded controlled trial, 60 ASA grade 1-2 patients, 18-65 years, scheduled for arthroscopic shoulder surgery under general Anaesthesia following USG-CISB with perineural catheter using 30 ml of 0.5% ropivacaine were randomly allocated to Group 1 (adjunct dexamethasone 8 mg) or Group 2 (adjunct clonidine 150 μg). Primary outcome was duration of postoperative analgesia, as measured (in min) from the achievement of adequate sensory block till the first bolus of 0.2% ropivacaine by patient controlled regional analgesia. Secondary outcomes were measures of the pain ratings, total postoperative analgesic consumption, patient satisfaction, and adverse effects over 48h postoperatively. Results: The median duration of analgesia in Group 1 was significantly longer than Group 2 (1432 min vs. 751 min; P &lt; 0.001). Median total postoperative analgesic consumption in Group 1 was significantly less than Group 2 (84 ml vs. 120 ml; P &lt; 0.001). Median patient satisfaction score in Group 1 was significantly more than Group 2 (90 vs. 84; P = 0.001). Postoperative adverse effects were few and comparable. Conclusion: Compared to clonidine, dexamethasone significantly prolonged the duration of analgesia, decreased postoperative analgesic consumption, and increased patient satisfaction following USG-CISB when used as an adjunct to ropivacaine for arthroscopic shoulder surgery.

Exploring patients’ experiences of analgesia after major lower limb amputation: a qualitative study

ObjectivesTo explore patient experiences, understanding and perceptions of analgesia following major lower limb amputation.DesignQualitative interview study, conducted as part of a randomised controlled feasibility trial.SettingParticipants were recruited from two general...

Are the Placement, Maintenance, and Removal of Femoral and Sciatic Catheters Associated With Bleeding Complications in Vascular Patients on Antithrombotics? A Single-Center, Retrospective Cohort Study.

Information on the safety of placement, maintenance, and removal of peripheral nerve blocks in the presence of therapeutic or prophylactic antithrombotics is limited to case reports. In this retrospective, descriptive study, we examined the use of femoral and gluteal or subgluteal sciatic perineural catheters in 146 patients on antithrombotics who received lower limb amputation (LLA) above or below the knee at the University of Florida Health Shands Hospital between January 2015 and December 2019. We searched patient surgical records for complications such as bleeding, nerve damage, infection, and hematoma during placement, maintenance, and removal of the perineural catheters. In this cohort of 146 patients on antithrombotics, there was 1 episode of hematoma with an estimated incidence of 1 of 146 (0.68%, 95% confidence interval [CI], 0.02-3.76). This patient developed a hematoma at the location of the femoral catheter and required a blood transfusion. This patient was on aspirin daily and subcutaneous heparin 3 times per day and had a normal coagulation profile during their hospital stay. This report investigates bleeding complications of femoral and sciatic perineural catheters in patients undergoing LLA on antithrombotics. We found that, except for 1 patient, most patients on varying combinations of antithrombotics did not experience bleeding complications related to the femoral and sciatic perineural catheters.

Chronic pain in lower limb amputees: Is there a correlation with the use of perioperative epidural or perineural analgesia?

Chronic pain is common in patients who undergo lower limb amputation. The use of epidural or perineural catheters seems to reduce acute pain after surgery but their effects in a longer follow up are unknown. To evaluate the long-term prevalence of phantom limb sensation (PLS), phantom limb pain (PLP), and residual limb pain (RLP) and their correlation with perioperative use of epidural or perineural catheters. Postal survey. Patients with trans-femoral, trans-tibial or hemi-pelvectomy amputation were asked to partake in the study. The Prosthetic Evaluation Questionnaire was used for the presence of chronic post-surgical pain. Use of catheters was retrieved from medical notes. 57 patients at a mean of 4.4 years follow up were included. PLS was reported in 68.4%, PLP in 63.2 % and RLP in 54.4% of amputees. No correlation was identified between pain syndromes and the presence of individual catheters and the duration of their permanence. The simultaneous use of 2 catheters was related to a lesser presence of PLP. Data on prevalence of PLP, PLS and RLP are consistent with the literature. Favourable effects in PLP reduction in the long term follow up was related to the simultaneous use of two catheters.

Immediate Effects of a Continuous Peripheral Nerve Block on Postamputation Phantom and Residual Limb Pain: Secondary Outcomes From a Multicenter Randomized Controlled Clinical Trial.

We recently reported that a 6-day continuous peripheral nerve block reduced established postamputation phantom pain 3 weeks after treatment ended. However, the immediate effects of perineural infusion (secondary outcomes) have yet to be reported. Participants from 5 enrolling academic centers with an upper or lower limb amputation and established phantom pain received a single-injection ropivacaine peripheral nerve block(s) and perineural catheter insertion(s). They were subsequently randomized to receive a 6-day ambulatory perineural infusion of either ropivacaine 0.5% or normal saline in a double-masked fashion. Participants were contacted by telephone 1, 7, 14, 21, and 28 days after the infusion started, with pain measured using the Numeric Rating Scale. Treatment effects were assessed using the Wilcoxon rank-sum test at each time point. Adjusting for 4 time points (days 1, 7, 14, and 21), P < .0125 was deemed statistically significant. Significance at 28 days was reported using methods from the original, previously published article. Pretreatment average phantom and residual pain scores were balanced between the groups. The day after infusion initiation (day 1), average phantom, and residual limb pain intensity was lower in patients receiving local anesthetic (n = 71) versus placebo (n = 73): median [quartiles] of 0 [0-2.5] vs 3.3 [0-5.0], median difference (98.75% confidence interval [CI]) of -1.0 (-3.0 to 0) for phantom pain (P = .001) and 0 [0-0] vs 0 [0-4.3], and median difference 0.0 (-2.0 to 0.0) for residual limb pain (P < .001). Pain's interference with physical and emotional functioning as measured with the interference domain of the Brief Pain Inventory improved during the infusion on day 1 for patients receiving local anesthetic versus placebo: 0 [0-10] vs 10 [0-40], median difference (98.75% CI) of 0.0 (-16.0 to 0.0), P = .002. Following infusion discontinuation (day 6), a few differences were found between the active and placebo treatment groups between days 7 and 21. In general, sample medians for average phantom and residual limb pain scores gradually increased after catheter removal for both treatments, but to a greater degree in the control group until day 28, at which time the differences between the groups returned to statistical significance. This secondary analysis suggests that a continuous peripheral nerve block decreases phantom and residual limb pain during the infusion, although few improvements were again detected until day 28, 3 weeks following catheter removal.

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

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. 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 10-20mL ropivacaine 0.5% (weight adjusted), the catheters were secured and connected to disposable mechanical infusion pumps with ropivacaine 0.2% (basal infusion rate=6mL/h; weight adjusted (0.2mL/kg/h)). After catheterization, the patients were examined daily, by specially educated acute pain service nurses. Pro re nata (PRN) or fixed boluses (10mL 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. 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 3days (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 10days 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. 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.

Cryoneurolysis and Peripheral Nerve Stimulation: Reply.

We would like to thank our colleagues for their thoughtful letter1 regarding the use of percutaneous peripheral nerve stimulation to treat postoperative pain.2 We agree that combining a local anesthetic–based peripheral nerve block with percutaneous peripheral nerve stimulation will most likely prove the optimal management after painful surgical procedures, although we hesitate to describe it as “novel” given this combination was reported in multiple publications previously.3–6 Several feasibility studies found that the acute pain from orthopedic procedures such as rotator cuff repair frequently required the addition of local anesthetic–based nerve block to percutaneous peripheral nerve stimulation in the recovery room.3–6 Therefore, in a recently completed randomized, double-masked, sham-controlled trial (n = 66), we administered a single-injection ropivacaine peripheral nerve block after ultrasound-guided percutaneous lead insertion in all participants (NCT03481725). While the ropivacaine peripheral nerve block did provide effective postoperative analgesia as our colleagues suggest in their letter, the transition to stimulation during block resolution proved very challenging for the majority of participants—it was not a “smooth” transition from one modality to the next. The problem stems from the finding that current intensity requirements can vary dramatically—and unpredictably—preoperatively and postoperatively,3–6 and that percutaneous peripheral nerve stimulation current can induce pain and muscle contractions with an intensity that is too high.3 Therefore, the pulse generator must be set to a relatively low intensity in the recovery room to ensure that the electrical current does not induce pain and/or contractions during block resolution 4 to 12 h postdischarge (and providing suboptimal analgesia until increased by the patient).We agree with our colleagues that the cost of the available percutaneous peripheral nerve stimulation system may discourage its general adoption and that the (off-label) use of existing stimulating perineural catheters is enticing due to their availability and dramatically lower cost. This possibility certainly deserves investigation. However, we are somewhat pessimistic regarding the probability of providing adequate analgesia using a single stimulating catheter to deliver both perineural local anesthetic and, subsequently, electrical current. In general, perineural catheters must be inserted within the same fascial plane as the target nerve/plexus for adequate local anesthetic administration. In contrast—and as described in our review article—for percutaneous peripheral nerve stimulation, “…the optimal distance from the lead tip to epineurium of the target nerve was consistently 1.0 to 1.5 cm… A relatively remote distance theoretically promotes selective stimulation of the desired larger-diameter myelinated sensory neurons without activating motor or smaller-diameter sensory neurons that induce muscle contraction and discomfort, respectively… In addition, leads placed at this distance from the nerve are less sensitive to small changes in positioning due to movement which is critical in avoiding unpleasant sensations with purposeful muscle contraction.”3 Therefore, at more than 1.0 cm from the target nerve and rarely within the same fascial plane, it is improbable that a perineural local anesthetic infusion would provide significant analgesia.The University of California at San Diego has received funding and product for other research projects of Drs. Ilfeld and Finneran from: Epimed (Farmers Branch, Texas); Infutronics (Natick, Massachusetts); and a manufacturer of percutaneous peripheral nerve stimulation devices, SPR Therapeutics (Cleveland, Ohio).

EFFECTIVENESS OF INTRAOPERATIVE PLACEMENT OF A PERINEURAL NERVE CATHETER IN PATIENT ROAD TO RECOVERY

Post surgical pain after major lower limb amputation is a major problem to the patients recovery. The majority of patients require continuous opioid analgesics and NSAIDs after surgery, which are associated with side-effects. In order to overcome the pain encountered by these patients, we routinely practice intraoperative placement of aNerve catheter along the peripheral nerve stump. The anesthetic medication is used to calm the nerves and overcome pain perceived by the patient. We study the effectiveness of pain control and reduction in the need for oral / parenteral administration of analgesics. This step could potentially reduce post-procedure analgesics usage and other related adverse effects. Methods: A retrospective study and data review of 98 patients who had major lower limb amputation for peripheral vascular disease over a 5-year duration. Intra-operatively, 42 patients had a perineural catheter placement were compared to 56 patients who had oral and parenteral analgesics prescribed to treat post operative pain. The primary outcomes of this studywere the number and quantity of drug needed in the first 4 days postoperatively and swiftness in postoperative recovery to do rehabilitation. Results: 98 major lower-limb amputations were selected. Analysis shows that perineural catheter use was associated with a decreased need for postoperative analgesics and decreased postoperative pain scores at 72 hours. Perineural catheter use led to a 65% reduction inopioid + NSAIDs use during the early postoperative period. Data also suggests the patient tend to fair better in rehabilitation work with nerve catheter placement. Conclusions: Post operative continuous infusions of local anesthetic through nerve catheter are safe and effective in reducing pain post-amputation. The analgesic medications requirement after major lower limb amputation can be significantly lowered so are the complications.

Augmenting conventional regional nerve block with peripheral neuromodulation using a perineural stimulating catheter

Augmenting conventional regional nerve block with peripheral neuromodulation using a perineural stimulating catheter

Clinical effect of normal saline injectate into interscalene nerve block catheters given within one hour of local anesthetic bolus on analgesia and hemidiaphragmatic paralysis

BackgroundPrevious case reports describe the reversal of phrenic nerve blockade from the interscalene nerve block using normal saline injectate washout. This randomized clinical trial aimed to evaluate whether using normal...

Bone stump formation against the background of post-amputation pain syndrome

Introduction: Bone is the basis of the stump. Aim: To study the impact of post-amputation pain syndrome on the nature of reparative processes in the bone residual limb. Material and methods: Three series of experiments were performed on 45 rabbits, 15 in each with mid-third thigh amputation and muscular plasty. In series 1, 2, a perineural catheter was attached to the sciatic nerve stump during amputation, and mechanical irritation of the nerve was performed daily for 20 minutes in series 1 for 20 days. In series 2, 0.3 mL of lidocaine (1%) was injected through the catheter into the circumference of the nerve twice daily for 20 days. Series 3 is a control. The follow-up periods were 1, 3, 6 months. The study method was histological with infusion of the vessels with ink-gelatin mixture. Results and discussion: In series 1, there was a sharp disturbance of the reparative process, which consisted in shape changes, resorption of the cortical diaphyseal plate, fractures, stump deformity, absence of bone closure plate formation, and microcirculatory disturbances. In the overall majority of experiments of series 2, the stumps retained the shape and structure characteristic of diaphysis with normalization of microcirculation. In series 3, the results of the residual limb formation were better than in series1, but worse than in series 2. Conclusions: When the pain syndrome is resolved within 20 days after amputation, a bone stump is formed with an organotypic shape and structure characteristic of the diaphysis, the formation of a compact closure plate of mature bone tissue, normalization of the medullary tissues and blood circulation. In post-amputation pain syndrome, organotypic formation of the residual limb does not occur.

Continuous peripheral nerve block for in-patients with lower limb ischemic pain

OBJECTIVES:Demonstrate that continuous peripheral nerve block (CPNB) may be an alternative with adequate analgesia and a lower incidence of side effects for ischemic pain due peripheral obstructive arterial disease (POAD).METHODS:Retrospective cohort study with 21 patients with POAD, Fontaine IV graded, with foot pain. Patients were submitted to continuous sciatic nerve block (CSNB), through a perineural catheter. Primary outcomes were pain intensity (by numerical rating scale) and opioid consumption (in oral morphine equivalents).RESULTS:During CSNB, pain scores markedly decreased in comparison to the pre-block period.CONCLUSIONS:CPNB may be a good option for ischemic pain treatment in in-patients, as it provides effective pain control with fewer adverse effects.

Low-Cost Techniques for Bilateral Intermittent Transversus Abdominis Plane Block Using Intravenous Cannula Following Cesarean Section

Abstract Transversus abdominis plane (TAP) block was developed as part of multimodal postoperative analgesia for cesarean section (CS) parturient. While continuous TAP block could provide satisfactory analgesia, the cost of the standard perineural catheters may limit its routine application. We present case reports of novel utilization of intravenous (IV) cannula as an alternative to the standard perineural catheters for postoperative intermittent TAP block. The results showed the feasibility and beneficial effect of IV cannula-facilitated TAP block in providing opioid-sparing postoperative acute pain management in CS parturient with minimal complication regarding its off-label application.