Continuous Nerve Research Articles

Proof of Concept for Continuous On-Demand Phrenic Nerve Stimulation to Prevent Diaphragm Disuse during Mechanical Ventilation (STIMULUS): A Phase 1 Clinical Trial.

Proof of Concept for Continuous On-Demand Phrenic Nerve Stimulation to Prevent Diaphragm Disuse during Mechanical Ventilation (STIMULUS): A Phase 1 Clinical Trial.

Continuous nerve block versus thoracic epidural analgesia for post-operative pain of pectus excavatum repair: a systematic review and meta-analysis

Surgery to repair pectus excavatum (PE) is often associated with severe postoperative pain, which can impact the length of hospital stay (LOS). While thoracic epidural analgesia (TEA) has traditionally been used for pain management in PE, its placement can sometimes result in severe neurological complications. Recently, paravertebral block (PVB) and erector spinae plane block (ESPB) have been recommended for many other chest and abdominal surgeries. However, due to the more severe and prolonged pain associated with PE repair, it is still unclear whether continuous administration of these blocks is as effective as TEA. Therefore, we conducted this systematic review and meta-analysis to demonstrate the equivalence of continuous PVB and ESPB to TEA.

Comparison of the analgesic efficacy between arthroscopically placed continuous suprascapular nerve block and ultrasound-guided continuous superior trunk block: a double-blinded randomized controlled trial.

Single-shot suprascapular nerve block and superior trunk block have been reported to provide a non-inferior analgesic effect after shoulder surgery with a lesser incidence of hemidiaphragmatic paresis compared with interscalene brachial plexus block. This study hypothesized that continuous suprascapular nerve block provides non-inferior analgesia with minimal effects on diaphragmatic movement compared with continuous superior trunk block in patients undergoing arthroscopic shoulder surgery. We randomized 100 patients undergoing arthroscopic shoulder surgery between December 2020 and October 2021 into continuous suprascapular nerve block and continuous superior trunk block groups. Before the surgery, patients received either a single-shot superior trunk block or subomohyoid suprascapular nerve block. Thereafter, a superior trunk catheter was inserted by anesthesiologists in patients in the continuous superior trunk block group, and a posterior suprascapular nerve catheter was inserted with arthroscopic assistance during the surgery by surgeon in the continuous suprascapular nerve block group. The primary outcome was the postoperative pain score at postoperative 24 h, and the incidence of hemidiaphragmatic paresis was also compared. Overall, 98 patients were included in the final analysis. The worst and resting pain scores at postoperative 24 h in the continuous suprascapular nerve block group were inferior compared with those in the continuous superior trunk block group in the test with a non-inferiority margin of 1 (worst pain score, mean difference: 0.9, 95% CI 0.1 to 1.7; resting pain score: mean difference: 0.5, 95% CI 0.0 to 1.0). However, the continuous suprascapular nerve block group had a significantly lower incidence of hemidiaphragmatic paresis at postoperative 24 h than the continuous superior trunk block group. Continuous suprascapular nerve block provides statistically inferior analgesia compared to the continuous superior trunk block; however, the continuous suprascapular nerve block had a minimal effect on the phrenic nerve function.

Comparison of continuous pericapsular nerve group (PENG) block versus continuous fascia iliaca compartment block on pain management and quadriceps muscle strength after total hip arthroplasty: a prospective, randomized controlled study

BackgroundThis investigation aimed to evaluate the impact of continuous pericapsular nerve group (PENG) block and continuous fascia iliac compartment block (FICB) on postoperative pain following total hip arthroplasty (THA).MethodsThis prospective, randomized, and controlled trial recruited a cohort of fifty-seven patients with unilateral femoral neck fractures from Xi’an Aerospace General Hospital in northwest China between July 2020 and November 2021. These patients were randomly assigned to two groups: the continuous PENG block group (PENG group, n = 29) and the continuous FICB group (FICB group, n = 28). Under ultrasound guidance, PENG block and FICB procedures were performed prior to spinal anesthesia, utilizing 20 ml of 0.25% ropivacaine for PENG block and 30 ml of 0.25% ropivacaine for FICB. Subsequently, a catheter was inserted. All study participants received a standardized postoperative multimodal analgesic regimen, including intravenous administration of 30 mg Ketorolac tromethamine every eight hours and patient-controlled neural analgesia (PCNA) after surgery. Numerical rating scale (NRS) scores at rest and during exercise were recorded at various time points: prior to block (T0), 30 min post-blockade (T1), and 6 h (T2), 12 h (T3), 24 h (T4), and 48 h (T5) postoperatively. Additional data collected encompassed postoperative quadriceps muscle strength, the time of initial ambulation after surgery, the number of effective PCNA activations, rescue analgesia requirements, and occurrences of adverse events (such as nausea and vomiting, hematoma, infection, catheter detachment, or displacement) within 48 h following surgery.ResultsIn the PENG group, the resting NRS pain scores exhibited lower values at T1, T4, and T5 than those at T0. Furthermore, exercise NRS pain scores at T1-T5 were lower in the PENG group than in the FICB group. Similarly, during the same postoperative period, the PENG group demonstrated enhanced quadriceps strength on the affected side compared to the FICB group. Additionally, the PENG group displayed earlier postoperative ambulation and reduced occurrences of effective PCNA activations and rescue analgesia requirements compared to the FICB group.ConclusionContinuous PENG block exhibited superior analgesic efficacy after THA compared to continuous FICB, promoting recovery of quadriceps strength on the affected side and facilitating early postoperative ambulation.Trial RegistrationThis clinical trial was registered in the China Clinical Trials Center (http://www.chictr.org.cn) on 20/07/2020, with the registration number ChiCTR2000034821.

Ultrasound-guided low-volume continuous cervical sympathetic nerve block for treatment of an electrical storm

In addition to the treatment for complex regional pain syndrome (CRPS), the stellate ganglion block is atreatment option for refractory intermittent ventricular tachycardia (VT). Despite the use of imaging techniques, such as fluoroscopy and ultrasound, numerous side effects and complications have been reported. These are aresult of the complex anatomical site and the volume of injected local anesthetics. This article reports on the catheter placement for continuous block of the cervical sympathetic trunk with high-resolution ultrasound imaging (HRUI) in apatient with intermittent VT. The tip of the cannula was placed on the anterior aspect of the longus colli muscle and 20 mg prilocaine 1% (2 ml) was injected. The VT stopped and a continuous infusion of 1 ml/h ropivacaine 0,2 % was started. Nevertheless, during the next hour the patient developed hoarseness and dysphagia, so that ablock of the recurrent laryngeal nerve and the deep ansa cervicalis (C1-C3) was carried out. The infusion was paused and restarted later with 0.5 ml/h. The spread of the local anesthetic was controlled by ultrasound. Over the next 4days the patient showed no VT or detectable side effects. After implantation of adefibrillator 1day later the patient could then be discharged home on the following day. This case shows that the HRUI can be advantageously used in the catheter placement and also when adjusting the flow rate. In this way the risk of complications and side effects related to the puncture and local anesthetic volume can be reduced.

Comparison of analgesic efficacy between continuous adductor canal nerve block catheter with and without posterior capsular infiltration in patients undergoing unilateral robotic total knee replacement: A retrospective study

Comparison of analgesic efficacy between continuous adductor canal nerve block catheter with and without posterior capsular infiltration in patients undergoing unilateral robotic total knee replacement: A retrospective study

Postoperative Rebound Pain: Our Current Understanding About the Role of Regional Anesthesia and Multimodal Approaches in Prevention and Treatment.

Rebound pain (RP) is a common occurrence after peripheral nerve block placement, especially when blocks are used for orthopedic surgery. This literature review focuses on the incidence and risk factors for RP as well as preventative and treatment strategies. The addition of adjuvants to a block, when appropriate, and starting patients on oral analgesics prior to sensory resolution are reasonable approaches. Using continuous nerve block techniques can provide extended analgesia through the immediate postoperative phase when pain is the most intense. Peripheral nerve blocks (PNBs) are associated with RP, a frequent phenomenon that must be recognized and addressed to prevent short-term pain and patient dissatisfaction, as well as long-term complications and avoidable hospital resource utilization. Knowledge about the advantages and limitations of PNBs allows the anesthesiologists to anticipate, intervene, and hopefully mitigate or avoid the phenomenon of RP.

Ultrasound-Guided Brachial Plexus Block by Costoclavicular Space Approach: A Narrative Review.

In recent years, ultrasound-guided costoclavicular brachial plexus block (CCB) has gained attention as a novel approach for brachial plexus nerve block. Human anatomy studies have identified the costoclavicular space as the area between the midpoint of the clavicle and the first rib. This space accommodates the brachial plexus, axillary arteries, and veins. Its superficial and fixed position makes it a promising option for infraclavicular brachial plexus blockage, providing a safe and reliable analgesic effect. CCB combines the benefits of real-time ultrasound visualization of the nerve block needle, avoidance of peripheral blood vessels, and targeted delivery of local anesthetics to the nerve. Consequently, it significantly reduces the associated complications of other classical approaches such as interscalene brachial plexus block (ISB), supraclavicular brachial plexus block (SCB), lateral sagittal infraclavicular brachial plexus block (LS-ICB), and axillary brachial plexus block. These complications include phrenic paralysis, incomplete brachial plexus block, and pneumothorax. This narrative review examines the literature on brachial plexus block in the costoclavicular space, discussing the anatomical position, the procedure, clinical indications, choice of local anesthetic concentration and volume, and continuous nerve block of CCB. The aim is to provide a basis for future clinical practice and enhanced safety.

Pre-operative sciatic nerve block vs postoperative surgeon-placed perineural stump catheter for prevention of phantom limb pain after below-knee amputation.

Pre-operative sciatic nerve block vs postoperative surgeon-placed perineural stump catheter for prevention of phantom limb pain after below-knee amputation.

Safety of continuous intraoperative vagus nerve neuromonitoring during thyroid surgery.

Continuous intraoperative neuromonitoring has successfully demonstrated to predict impending damage to the recurrent laryngeal nerve, by detecting changes in electromyographic recordings. Despite the apparent benefits associated with continuous intraoperative neuromonitoring, its safety is still a debate. The aim of this study was to investigate the electrophysiological impact of continuous intraoperative neuromonitoring on the vagus nerve. In this prospective study, the amplitude of the electromyographic wave of the vagus nerve-recurrent laryngeal nerve axis was measured both proximally and distally to the stimulation electrode placed upon the vagus nerve. Electromyographic signal amplitudes were collected at three distinct events during the operation: during the dissection of the vagus nerve, before application of the continuous stimulation electrode onto the vagus nerve and after its removal. In total, 169 vagus nerves were analysed, among 108 included patients undergoing continuous intraoperative neuromonitoring-enhanced endocrine neck surgeries. Electrode application resulted in a significant overall decrease in measured proximo-distal amplitudes of -10.94 µV (95 per cent c.i. -17.06 to -4.82 µV) (P < 0.005), corresponding to a mean(s.d.) decrease of -1.4(5.4) per cent. Before the removal of the electrode, the measured proximo-distal difference in amplitudes was -18.58 µV (95 per cent c.i. -28.31 to -8.86 µV) (P < 0.005), corresponding to a mean(s.d.) decrease of -2.50(9.59) per cent. Seven nerves suffered a loss of amplitude greater than 20 per cent of the baseline measurement. In addition to supporting claims that continuous intraoperative neuromonitoring exposes the vagus nerve to injury, this study shows a mild electrophysiological impact of continuous intraoperative neuromonitoring electrode placement on the vagus nerve-recurrent laryngeal nerve axis. However, the small observed differences are negligible and were not associated with a clinically relevant outcome, making continuous intraoperative neuromonitoring a safe adjunct in selected thyroid surgeries.

Intraoperative Neuromonitoring in Vestibular Schwannoma Surgery

Vestibular schwannoma surgery necessitates intraoperative neuromonitoring to secure long-term tumor control by sufficient tumor removal and preservation of neural function. Therein, facial nerve function can be assessed in real-time and quantitatively by intraoperative continuous facial nerve monitoring with repetitive direct stimulation. The ABR and, further, CNAP, are closely monitored for the continuous assessment of the hearing function. In addition, the evoked masseter and extraocular electromyograms, SEP, MEP, and neuromonitoring of the lower cranial nerves are implemented as needed. In this article, we introduce our neuromonitoring techniques during vestibular schwannoma surgery with an illustrative video.

Single-Shot Versus Continuous Nerve Blocks for Pediatric Anterior Cruciate Ligament Reconstruction: Analgesic Efficacy and Postoperative Outcomes

Background: Regional anesthesia is often used to minimize postoperative pain, enable early mobilization, and improve patient/family satisfaction after ACL reconstruction. Little is known about the effects of nerve blocks on patient-reported outcomes and functional outcomes in pediatric ACL reconstruction. This study was performed to compare analgesic efficacy, isokinetic strength testing, and Patient-Reported Outcomes Measurement Information System (PROMIS) scores between single-shot femoral nerve block (SSNB) and femoral nerve catheter (FNC).Methods: Pediatric patients (<18 years old) who underwent primary ACL reconstruction at a tertiary care children's hospital between January 2018 and August 2019 were included. Patients were grouped based on their anesthesia technique (SSNB or FNC) and compared to identify differences in the occurrence of uncontrolled postoperative pain and opioid refills. PROMIS domain scores, active range of motion (AROM), and isokinetic strength testing at multiple timepoints up to 6 months postoperatively were also collected. Linear regression multiple imputation analysis was performed to account for variable outcome measure availability.Results: A total of 78 patients were included (SSNB:42; FNC:36). The groups had similar pain medication needs and pain scores at 1 week postoperatively. The FNC group had significantly longer in-room to incision times (P<0.001), were less likely to return to school by 1 week after surgery (P=0.03), and had lower mobility scores at the 1-week postoperative visit. Patients in the SSNB group had significantly weaker quadriceps function at 3 months (P=0.02), although this difference resolved by the 6-month visit. There were no cases of infection or neuropathy in either group.Conclusion: Our findings indicate that both FNC and SSNB are viable options with similar efficacy for postoperative pain management in pediatric ACL reconstruction. However, we did not find any evidence of superior analgesia with FNC. Additionally, FNC was associated with lower PROMIS mobility scores at 1 week, delayed return to school, and 30 minutes of additional time spent in the operating room. There were no significant differences between groups in terms of function and PROMIS scores at 6 months postoperatively.Level of Evidence: Level III, retrospective cohort studyKey Concepts•Femoral nerve catheter and single-shot femoral blocks are both viable management options for post-ACL reconstruction pain in children and adolescents.•We found that patients who received a femoral nerve block were less likely to return to school and had lower mobility scores at 1 week postoperatively and spent an additional 30 minutes in the operating room.•Both regional anesthesia techniques had similar PROMIS scores and functional outcomes at 6 months postoperatively.

Battery-Free, Wireless, Cuff-Type, Multimodal Physical Sensor for Continuous Temperature and Strain Monitoring of Nerve.

Peripheral nerve injuries cause various disabilities related to loss of motor and sensory functions. The treatment of these injuries typically requires surgical operations for improving functional recovery of the nerve. However, capabilities for continuous nerve monitoring remain a challenge. Herein, a battery-free, wireless, cuff-type, implantable, multimodal physical sensing platform for continuous in vivo monitoring of temperature and strain from the injured nerve is introduced. The thin, soft temperature, and strain sensors wrapped around the nerve exhibit good sensitivity, excellent stability, high linearity, and minimum hysteresis in relevant ranges. In particular, the strain sensor integrated with circuits for temperature compensation provides reliable, accurate strain monitoring with negligible temperature dependence. The system enables power harvesting and data communication to wireless, multiple implanted devices wrapped around the nerve. Experimental evaluations, verified by numerical simulations, with animal tests, demonstrate the feasibility and stability of the sensor system, which has great potential for continuous in vivo nerve monitoring from an early stage to complete regeneration.

Continuous Nerve Block

Continuous Nerve Block

Increased respiratory modulation of cardiovascular control reflects improved blood pressure regulation in pregnancy.

Hypertensive pregnancy disorders put the maternal-fetal dyad at risk and are one of the leading causes of morbidity and mortality during pregnancy. Multiple efforts have been made to understand the physiological mechanisms behind changes in blood pressure. Still, to date, no study has focused on analyzing the dynamics of the interactions between the systems involved in blood pressure control. In this work, we aim to address this question by evaluating the phase coherence between different signals using wavelet phase coherence. Electrocardiogram, continuous blood pressure, electrocardiogram-derived respiration, and muscle sympathetic nerve activity signals were obtained from ten normotensive pregnant women, ten normotensive non-pregnant women, and ten pregnant women with preeclampsia during rest and cold pressor test. At rest, normotensive pregnant women showed higher phase coherence in the high-frequency band (0.15-0.4Hz) between muscle sympathetic nerve activity and the RR interval, blood pressure, and respiration compared to non-pregnant normotensive women. Although normotensive pregnant women showed no phase coherence differences with respect to hypertensive pregnant women at rest, higher phase coherence between the same pairs of variables was found during the cold pressor test. These results suggest that, in addition to the increased sympathetic tone of normotensive pregnant women widely described in the existing literature, there is an increase in cardiac parasympathetic modulation and respiratory-driven modulation of muscle sympathetic nerve activity and blood pressure that could compensate sympathetic increase and make blood pressure control more efficient to maintain it in normal ranges. Moreover, blunted modulation could prevent its buffer effect and produce an increase in blood pressure levels, as observed in the hypertensive women in this study. This initial exploration of cardiorespiratory coupling in pregnancy opens the opportunity to follow up on more in-depth analyses and determine causal influences.

Regional blocks for pain control at the end of life in pediatric oncology.

Pain management at the end of life is a fundamental aspect of care and can improve patients' quality of life. Interventional approaches may be underutilized for pediatric cancer patients. To describe a single institution's 10 years of experience with regional pain management at the end of life in pediatric oncology. A retrospective cohort study of 27 patients with pediatric cancer who died between April 2011 and December 2021 and received continuous nerve block (CNB) catheters or single-shot nerve blocks (SSBs) during their last three months of life. The type of blocks, analgesic efficacy, and palliative care involvement were evaluated. Twenty-two patients (81.5%) had solid tumor diagnoses, including carcinomas, sarcomas, and neuroblastoma. Most (59%) patients received CNB catheters, and 12 patients (44%) received SSBs for pain control. The mean pain score decreases for CNB catheters and SSBs after interventions were -2.5 and -2.8, respectively, on an 11-point scale. Decreases in opioid patient-controlled analgesia dosing requirements were noted in 56% of patients with CNB catheters; likewise, in 25% of patients with SSBs at 24 h and in 8% at 5 days after interventions. Nearly all patients had PC involvement and received care from pain specialists (96% and 93%, respectively). Twenty-three (85%) had physician orders for scope of treatment orders completed before death. Regional pain control interventions can be effective and safe for relieving regional pain and suffering in dying children and young adults. The collaboration between palliative care and pain management specialists at the end of life can help alleviate suffering and improve quality of life.

Ropivacaine pharmacokinetics in the arterial and venous pools after ultrasound-guided continuous thoracic paravertebral nerve block.

Although thoracic paravertebral blockade (TPVB) is employed in thoracic surgery to ensure satisfactory postoperative analgesia, large doses of anesthetics are required and manifestations of local anesthetic systemic toxicity (LAST) may appear. Currently, there are limited data on the pharmacokinetics of ropivacaine after continuous TPVB. The aim of this prospective study was to investigate ropivacaine kinetics, in the arterial and venous pools, after continuous TPVB and assess the risk of LAST. Immediately after induction of general anesthesia, an ultrasound-guided continuous TPVB at T5 or T6 or T7 thoracic level was performed in 18 adult patients subjected to open thoracotomy. A 25-ml single bolus injection of ropivacaine 0.5% was administered through thoracic paravertebral catheter, followed by a 14 ml/h continuous infusion of ropivacaine 0.2% starting at the end of surgery. Quantification of total ropivacaine concentrations was performed using a validated high-performance liquid chromatography method. Population pharmacokinetic models were developed separately for arterial and venous ropivacaine data. The best model was one-compartment disposition with an additional pre-absorption compartment corresponding to thoracic paravertebral space. Gender had a significant effect on clearance, with females displaying lower elimination than males. Some patients had ropivacaine concentrations above the toxic threshold, but none displayed evidence of LAST. Continuous thoracic paravertebral nerve blocks provided adequate postoperative analgesia. Ropivacaine doses at the upper end of clinical use (800 mg/d) did not inflict the manifestations of LAST and provided adequate postoperative pain control. Pharmacokinetic models were developed, and the effect of gender was identified.

Continuous vagus nerve stimulation exerts beneficial effects on rats with experimentally induced Parkinson's disease: Evidence suggesting involvement of a vagal afferent pathway

BackgroundVagus nerve stimulation (VNS) exerts neuroprotective and anti-inflammatory effects in preclinical models of central nervous system disorders, including Parkinson's disease (PD). VNS setting applied for experimental models is limited into single-time or intermittent short-duration stimulation. We developed a VNS device which could deliver continuous stimulation for rats. To date, the effects of vagal afferent- or efferent-selective stimulation on PD using continuous electrical stimulation remains to be determined. ObjectiveTo investigate the effects of continuous and selective stimulation of vagal afferent or efferent fiber on Parkinsonian rats. MethodsRats were divided into 5 group: intact VNS, afferent VNS (left VNS in the presence of left caudal vagotomy), efferent VNS (left VNS in the presence of left rostral vagotomy), sham, vagotomy. Rats underwent the implantation of cuff-electrode on left vagus nerve and 6-hydroxydopamine administration into the left striatum simultaneously. Electrical stimulation was delivered just after 6-OHDA administration and continued for 14 days. In afferent VNS and efferent VNS group, the vagus nerve was dissected at distal or proximal portion of cuff-electrode to imitate the selective stimulation of afferent or efferent vagal fiber respectively. ResultsIntact VNS and afferent VNS reduced the behavioral impairments in cylinder test and methamphetamine-induced rotation test, which were accompanied by reduced inflammatory glial cells in substantia nigra with the increased density of the rate limiting enzyme in locus coeruleus. In contrast, efferent VNS did not exert any therapeutic effects. ConclusionContinuous VNS promoted neuroprotective and anti-inflammatory effect in experimental PD, highlighting the crucial role of the afferent vagal pathway in mediating these therapeutic outcomes.

Lessons learned from the first 15 years of penile transplantation and updates to the Baltimore Criteria.

Since 2006, five penis transplants have been performed worldwide. Mixed outcomes have been reported, and two of the five penile transplants have required explantation. However, the long-term outcomes have been encouraging when compliance is implemented, whether standard induction and triple therapy maintenance, or single therapy maintenance. Follow-up monitoring of transplant recipients has enabled a synthesis of technical considerations for surgical success and has shown stable leukocyte counts and renal function after a donor bone-marrow-based immunomodulatory regimen followed by tacrolimus monotherapy as long as 3 years post-transplant, as well as continuous nerve regeneration of penile allografts 3 years post-transplant. Areas of uncertainty include the ethics of donor-recipient colour mismatch, surveillance for sexually transmitted infections and how to optimize patient compliance. Questions also remain with respect to the long-term immunological sequelae of penile tissue, functional outcomes, psychosocial implications and patient selection. Patient counselling should be modified to mention the possibility of long-term improvement in nerve regeneration and sufficient renal function with single-therapy maintenance, and to build a longitudinal dialogue and partnership between the patient and the multidisciplinary care team regarding the risks of sexually transmitted infection instead of surveillance.

Distal anterior interosseous nerve to ulnar nerve motor branch reverse end-to-side transfer in a case of severe ulnar neuropathy.

Reverse end-to-side (RETS) distal transfer is gaining popularity in cases of proximal nerve damage with the nerve in continuity, allowing the nerve to potentially retain its ability to regenerate and recover. While preserving the original axon pool, RETS could provide an additional pool of motor axons and/or possibly "babysit" the muscle endplates and distal denervated nerve Schwann cells until reinnervation from the original pool occurs. The authors present a video demonstrating anterior subcutaneous transposition of the ulnar nerve at the elbow coupled with a distal anterior interosseous nerve to ulnar nerve RETS in a case of severe posttraumatic ulnar neuropathy at the elbow. The video can be found here: https://stream.cadmore.media/r10.3171/2022.9.FOCVID2282.