Treatment of Post-Latissimus Dorsi Flap Breast Reconstruction Pain With Continuous Paravertebral Nerve Blocks: A Retrospective Review.

ObjectivesThe addition of a perioperative continuous paravertebral nerve block (cPVB) to a single-injection thoracic paravertebral nerve block (tPVB) has demonstrated improved analgesia in breast surgery. However, its use following isolated post-mastectomy reconstruction using a latissimus dorsi flap (LDF) has not previously been examined.MethodsWe performed a retrospective review of patients who underwent salvage breast reconstruction with a unilateral LDF by a single surgeon. Preoperatively, all patients received a single-injection tPVB with 0.5% ropivacaine. Additionally, patients had the option for catheter placement to receive a continuous 0.2% ropivacaine infusion with intermittent boluses. Infusions commenced in the recovery room and the catheters were removed on the morning of discharge. The primary endpoint was the mean pain numeric rating scale (NRS) scores for the 24-hour period beginning at 7:00 on post-operative day 1.ResultsA total of 22 patients were included in this study (11-cPVB and 11-tPVB). The mean NRS pain score of cPVB patients (3.5 (standard deviation (SD) 1.8) was lower than that of the single-injection tPVB patients (4.4 (SD 2.1), however this difference was not statistically significant (P = 0.31). The length of hospital stay and opioid use was not statistically different between groups.ConclusionsPatients receiving a cPVB in addition to tPVB after LDF reconstruction experienced similar pain to those receiving tPVB alone. A larger, randomized clinical trial is warranted to fully determine the benefits of using cPVB in addition to tPVB for this procedure

Treatment of Post-Latissimus Dorsi Flap Breast Reconstruction Pain With Continuous Paravertebral Nerve Blocks: A Retrospective Review.

ObjectivesThe addition of a perioperative continuous paravertebral nerve block (cPVB) to a single-injection thoracic paravertebral nerve block (tPVB) has demonstrated improved analgesia in breast surgery. However, its use following isolated post-mastectomy reconstruction using a latissimus dorsi flap (LDF) has not previously been examined.MethodsWe performed a retrospective review of patients who underwent salvage breast reconstruction with a unilateral LDF by a single surgeon. Preoperatively, all patients received a single-injection tPVB with 0.5% ropivacaine. Additionally, patients had the option for catheter placement to receive a continuous 0.2% ropivacaine infusion with intermittent boluses. Infusions commenced in the recovery room and the catheters were removed on the morning of discharge. The primary endpoint was the mean pain numeric rating scale (NRS) scores for the 24-hour period beginning at 7:00 on post-operative day 1.ResultsA total of 22 patients were included in this study (11-cPVB and 11-tPVB). The mean NRS pain score of cPVB patients (3.5 (standard deviation (SD) 1.8) was lower than that of the single-injection tPVB patients (4.4 (SD 2.1), however this difference was not statistically significant (P = 0.31). The length of hospital stay and opioid use was not statistically different between groups.ConclusionsPatients receiving a cPVB in addition to tPVB after LDF reconstruction experienced similar pain to those receiving tPVB alone. A larger, randomized clinical trial is warranted to fully determine the benefits of using cPVB in addition to tPVB for this procedure

Nitrogen, phosphorus co-doped holey rGO as a cathode material for Li-ion capacitors (LICs)

Graphene-based materials are considered as ideal cathode materials for lithium-ion capacitors (LICs). However, the ion-accessible surface area of graphene is restricted by the restacking of graphene nanosheets, resulting in a limited specific capacity. Fabricating porous graphene with an appropriate pore structure and introducing heteroatom doping can improve the capacity of graphene and increase the energy outputs of graphene-based LICs. Herein, we use an easy and low-cost hydrothermal method to create a 3D nitrogen and phosphorus co-doped holey rGO (NPHG) aerogel. In a half-cell system, NPHG delivers a specific capacity of ∼120 mAh/g at 0.1 A/g and maintains 92% of its initial capacity after 1000 cycles at 1 Ag−1. Moreover, when used as a cathode with a pre-lithiated nitrogen-doped rGO-siloxene (NGSil-4) anode to construct an NGSil-4//NPHG LIC, a high energy density of 145.86 Wh Kg−1 is obtained at a power density of 200.2 W Kg−1, while retaining 15.35 Wh Kg−1 at 14550 W Kg−1.This work demonstrates the great potential of NPHG cathodes, with the integration of the appropriate porosity and N and P co-doping using a simple and low cost hydrothermal method, for high-performance LICs.</p

Continuous Popliteal-Sciatic Blocks for Postoperative Analgesia: Traditional Proximal Catheter Insertion Superficial to the Paraneural Sheath Versus a New Distal Insertion Site Deep to the Paraneural Sheath.

We tested the hypothesis that during a continuous popliteal-sciatic nerve block, postoperative analgesia is improved with the catheter insertion point "deep" to the paraneural sheath immediately distal to the bifurcation between the tibial and common peroneal branches, compared with the traditional approach "superficial" to the paraneural sheath proximal to the bifurcation. The needle tip location was determined to be accurately located with a fluid bolus visualized with ultrasound; however, catheters were subsequently inserted without a similar fluid injection and visualization protocol (visualized air injection was permitted and usually implemented, but not required per protocol). The average pain (0-10 scale) the morning after surgery for subjects with a catheter inserted at the proximal subparaneural location (n = 31) was a median (interquartile) of 1.5 (0.0-3.5) vs 1.5 (0.0-4.0) for subjects with a catheter inserted at the distal supraparaneural location (n = 32; P = .927). Secondary outcomes were similarly negative

Continuous Popliteal-Sciatic Blocks for Postoperative Analgesia: Traditional Proximal Catheter Insertion Superficial to the Paraneural Sheath Versus a New Distal Insertion Site Deep to the Paraneural Sheath.

We tested the hypothesis that during a continuous popliteal-sciatic nerve block, postoperative analgesia is improved with the catheter insertion point "deep" to the paraneural sheath immediately distal to the bifurcation between the tibial and common peroneal branches, compared with the traditional approach "superficial" to the paraneural sheath proximal to the bifurcation. The needle tip location was determined to be accurately located with a fluid bolus visualized with ultrasound; however, catheters were subsequently inserted without a similar fluid injection and visualization protocol (visualized air injection was permitted and usually implemented, but not required per protocol). The average pain (0-10 scale) the morning after surgery for subjects with a catheter inserted at the proximal subparaneural location (n = 31) was a median (interquartile) of 1.5 (0.0-3.5) vs 1.5 (0.0-4.0) for subjects with a catheter inserted at the distal supraparaneural location (n = 32; P = .927). Secondary outcomes were similarly negative

Ambulatory continuous peripheral nerve blocks to treat postamputation phantom limb pain: a multicenter, randomized, quadruple-masked, placebo-controlled clinical trial

Phantom limb pain is thought to be sustained by reentrant neural pathways, which provoke dysfunctional reorganization in the somatosensory cortex. We hypothesized that disrupting reentrant pathways with a 6-day-long continuous peripheral nerve block reduces phantom pain 4 weeks after treatment. We enrolled patients who had an upper- or lower-limb amputation and established phantom pain. Each was randomized to receive a 6-day perineural infusion of either ropivacaine or normal saline. The primary outcome was the average phantom pain severity as measured with a Numeric Rating Scale (0-10) at 4 weeks, after which an optional crossover treatment was offered within the following 0 to 12 weeks. Pretreatment pain scores were similar in both groups, with a median (interquartile range) of 5.0 (4.0, 7.0) for each. After 4 weeks, average phantom limb pain intensity was a mean (SD) of 3.0 (2.9) in patients given local anesthetic vs 4.5 (2.6) in those given placebo (difference [95% confidence interval] 1.3 [0.4, 2.2], P = 0.003). Patients given local anesthetic had improved global impression of change and less pain-induced physical and emotional dysfunction, but did not differ on depression scores. For subjects who received only the first infusion (no self-selected crossover), the median decrease in phantom limb pain at 6 months for treated subjects was 3.0 (0, 5.0) vs 1.5 (0, 5.0) for the placebo group; there seemed to be little residual benefit at 12 months. We conclude that a 6-day continuous peripheral nerve block reduces phantom limb pain as well as physical and emotional dysfunction for at least 1 month

Proximal Versus Distal Continuous Adductor Canal Blocks: Does Varying Perineural Catheter Location Influence Analgesia? A Randomized, Subject-Masked, Controlled Clinical Trial.

BACKGROUND:A continuous adductor canal block provides analgesia after surgical procedures of the knee. Recent neuroanatomic descriptions of the thigh and knee led us to speculate that local anesthetic deposited in the distal thigh close to the adductor hiatus would provide superior analgesia compared to a more proximal catheter location. We therefore tested the hypothesis that during a continuous adductor canal nerve block, postoperative analgesia would be improved by placing the perineural catheter tip 2-3 cm cephalad to where the femoral artery descends posteriorly to the adductor hiatus (distal location) compared to a more proximal location at the midpoint between the anterior superior iliac spine and the superior border of the patella (proximal location). METHODS:Preoperatively, subjects undergoing total knee arthroplasty received an ultrasound-guided perineural catheter inserted either in the proximal or distal location within the adductor canal in a randomized, subject-masked fashion. Subjects received a single injection of lidocaine 2% via the catheter preoperatively, followed by an infusion of ropivacaine 0.2% (8 mL/h basal, 4 mL bolus, 30 minutes lockout) for the study duration. After joint closure, the surgeon infiltrated the entire joint using 30 mL of ropivacaine (0.5%), ketorolac (30 mg), epinephrine (5 μg/mL), and tranexamic acid (2 g). The primary end point was the median level of pain as measured on a numeric rating scale (NRS) during the time period of 8:00 AM to 12:00 PM the day after surgery. RESULTS:For the primary end point, the NRS of subjects with a catheter inserted at the proximal location (n = 24) was a median (10th, 25th-75th, 90th quartiles) of 0.5 (0.0, 0.0-3.2, 5.0) vs 3.0 (0.0, 2.0-5.4, 7.8) for subjects with a catheter inserted in the distal location (n = 26; P = .011). Median and maximum NRSs were lower in the proximal group at all other time points, but these differences did not reach statistical significance. There were no clinically relevant or statistically significant differences between the treatment groups for any other secondary end point, including opioid consumption and ambulation distance. CONCLUSIONS:For continuous adductor canal blocks accompanied by intraoperative periarticular local anesthetic infiltration, analgesia the day after knee arthroplasty is improved with a catheter inserted at the level of the midpoint between the anterior superior iliac spine and the superior border of the patella compared with a more distal insertion closer to the adductor hiatus

Proximal Versus Distal Continuous Adductor Canal Blocks: Does Varying Perineural Catheter Location Influence Analgesia? A Randomized, Subject-Masked, Controlled Clinical Trial.

BACKGROUND:A continuous adductor canal block provides analgesia after surgical procedures of the knee. Recent neuroanatomic descriptions of the thigh and knee led us to speculate that local anesthetic deposited in the distal thigh close to the adductor hiatus would provide superior analgesia compared to a more proximal catheter location. We therefore tested the hypothesis that during a continuous adductor canal nerve block, postoperative analgesia would be improved by placing the perineural catheter tip 2-3 cm cephalad to where the femoral artery descends posteriorly to the adductor hiatus (distal location) compared to a more proximal location at the midpoint between the anterior superior iliac spine and the superior border of the patella (proximal location). METHODS:Preoperatively, subjects undergoing total knee arthroplasty received an ultrasound-guided perineural catheter inserted either in the proximal or distal location within the adductor canal in a randomized, subject-masked fashion. Subjects received a single injection of lidocaine 2% via the catheter preoperatively, followed by an infusion of ropivacaine 0.2% (8 mL/h basal, 4 mL bolus, 30 minutes lockout) for the study duration. After joint closure, the surgeon infiltrated the entire joint using 30 mL of ropivacaine (0.5%), ketorolac (30 mg), epinephrine (5 μg/mL), and tranexamic acid (2 g). The primary end point was the median level of pain as measured on a numeric rating scale (NRS) during the time period of 8:00 AM to 12:00 PM the day after surgery. RESULTS:For the primary end point, the NRS of subjects with a catheter inserted at the proximal location (n = 24) was a median (10th, 25th-75th, 90th quartiles) of 0.5 (0.0, 0.0-3.2, 5.0) vs 3.0 (0.0, 2.0-5.4, 7.8) for subjects with a catheter inserted in the distal location (n = 26; P = .011). Median and maximum NRSs were lower in the proximal group at all other time points, but these differences did not reach statistical significance. There were no clinically relevant or statistically significant differences between the treatment groups for any other secondary end point, including opioid consumption and ambulation distance. CONCLUSIONS:For continuous adductor canal blocks accompanied by intraoperative periarticular local anesthetic infiltration, analgesia the day after knee arthroplasty is improved with a catheter inserted at the level of the midpoint between the anterior superior iliac spine and the superior border of the patella compared with a more distal insertion closer to the adductor hiatus