Peripheral nerve blocks of wrist and finger flexors can increase hand opening in chronic hemiparetic stroke

Introduction

Hand opening is reduced by abnormal wrist and finger flexor activity in many individuals with stroke. This flexor activity also limits hand opening produced by functional electrical stimulation (FES) of finger and wrist extensor muscles. Recent advances in electrical nerve block technologies have the potential to mitigate this abnormal flexor behavior, but the actual impact of nerve block on hand opening in stroke has not yet been investigated.

Methods

In this study, we applied the local anesthetic ropivacaine to the median and ulnar nerve to induce a complete motor block in 9 individuals with stroke and observed the impact of this block on hand opening as measured by hand pentagonal area. Volitional hand opening and FES-driven hand opening were measured, both while the arm was fully supported on a haptic table (Unloaded) and while lifting against gravity (Loaded). Linear mixed effect regression (LMER) modeling was used to determine the effect of Block.

Results

The ropivacaine block allowed increased hand opening, both volitional and FES-driven, and for both unloaded and loaded conditions. Notably, only the FES-driven and Loaded condition's improvement in hand opening with the block was statistically significant. Hand opening in the FES and Loaded condition improved following nerve block by nearly 20%.

Conclusion

Our results suggest that many individuals with stroke would see improved hand-opening with wrist and finger flexor activity curtailed by nerve block, especially when FES is used to drive the typically paretic finger and wrist extensor muscles. Such a nerve block (potentially produced by aforementioned emerging electrical nerve block technologies) could thus significantly address prior observed shortcomings of FES interventions for individuals with stroke.

Ultrasound-Guided Percutaneous Peripheral Nerve Stimulation of C2 Dorsal Root Ganglion for the Treatment of Refractory Atypical Facial Pain: A Technical Report and Case Series

BACKGROUND

Chronic craniofacial pain can be difficult to manage clinically. This technical report documents the peripheral nerve stimulation of the C2 dorsal root ganglion as an effective modality to treat refractory atypical facial pain.

MATERIALS AND METHODS

In this case series, three patients with chronic refractory atypical facial pain and p >50% pain relief following diagnostic C2 dorsal root ganglion blockade underwent ultrasound-guided percutaneous placement of a peripheral nerve stimulator adjacent to the C2 dorsal root ganglion. Patients were then observed clinically and monitored for improvement in symptoms and adverse events.

RESULTS

Three patients underwent peripheral nerve stimulator placement. At follow-up, there were no reported adverse events, and all patients reported satisfactory improvement in pain.

CONCLUSION

The neuromodulation of C2 dorsal root ganglion via ultrasound-guided percutaneously implanted peripheral nerve stimulator is a novel and potentially effective approach for the management of chronic refractory craniofacial pain.

Standardizing nomenclature in regional anesthesia: an ASRA-ESRA Delphi consensus study of upper and lower limb nerve blocks

BACKGROUND

Inconsistent nomenclature and anatomical descriptions of regional anesthetic techniques hinder scientific communication and engender confusion; this in turn has implications for research, education and clinical implementation of regional anesthesia. Having produced standardized nomenclature for abdominal wall, paraspinal and chest wall regional anesthetic techniques, we aimed to similarly do so for upper and lower limb peripheral nerve blocks.

METHODS

We performed a three-round Delphi international consensus study to generate standardized names and anatomical descriptions of upper and lower limb regional anesthetic techniques. A long list of names and anatomical description of blocks of upper and lower extremities was produced by the members of the steering committee. Subsequently, two rounds of anonymized voting and commenting were followed by a third virtual round table to secure consensus for items that remained outstanding after the first and second rounds. As with previous methodology, strong consensus was defined as ≥75% agreement and weak consensus as 50%-74% agreement.

RESULTS

A total of 94, 91 and 65 collaborators participated in the first, second and third rounds, respectively. We achieved strong consensus for 38 names and 33 anatomical descriptions, and weak consensus for five anatomical descriptions. We agreed on a template for naming peripheral nerve blocks based on the name of the nerve and the anatomical location of the blockade and identified several areas for future research.

CONCLUSIONS

We achieved consensus on nomenclature and anatomical descriptions of regional anesthetic techniques for upper and lower limb nerve blocks, and recommend using this framework in clinical and academic practice. This should improve research, teaching and learning of regional anesthesia to eventually improve patient care.

Setting up regional diagnostic reference levels for pediatric interventional cardiology in Latin America and the Caribbean countries: preliminary results and identified challenges

The goal of the present study was to propose a set of preliminary regional diagnostic reference levels (DRLs) for pediatric interventional cardiology (IC) procedures in Latin America and the Caribbean countries, classified by age and weight groups. The study was conducted in the framework of the Optimization of Protection in Pediatric Interventional Radiology in Latin America and the Caribbean program coordinated by the World Health Organization and the Pan American Health Organization in cooperation with the International Atomic Energy Agency. The first step of the program was focused on pediatric IC. Dose data from diagnostic and therapeutic procedures were collected between December 2020 and December 2021. Regional DRLs were set as the third quartile of patient dose data (kerma area product) collected in 18 hospitals from 10 countries in an initial sample of 968 procedures. DRLs were set for four age bands and five weight ranges. The values obtained for the four age bands (<1 yr, 1 to <5 yr, 5 to <10 yr and 10 to <16 yr) were 2.9, 6.1, 8.8 and 14.4 Gy cm²for diagnostic procedures, and 4.0, 5.0, 10.0 and 38.1 Gy cm²for therapeutic procedures, respectively. The values obtained for the five weight bands (<5 kg, 5 to <15 kg, 15 to <30 kg, 30 to <50 kg and 50 to <80 kg) were 3.0, 4.5, 8.1, 9.2 and 26.8 Gy cm²for diagnostic procedures and 3.7, 4,3, 7.3, 16.1 and 53.4 Gy cm²for therapeutic procedures, respectively. While initial data were collected manually as patient dose management systems (DMSs) were not available in most of the hospitals involved in the program, a centralized automatic DMS for the collection and management of patient dose indicators has now been introduced and is envisaged to increase the sample size. The possibility of alerting on high dose values and introducing corrective actions will help in optimization.

Pain, Analgesic Use, and Patient Satisfaction With Spinal Versus General Anesthesia for Hip Fracture Surgery : A Randomized Clinical Trial

BACKGROUND

The REGAIN (Regional versus General Anesthesia for Promoting Independence after Hip Fracture) trial found similar ambulation and survival at 60 days with spinal versus general anesthesia for hip fracture surgery. Trial outcomes evaluating pain, prescription analgesic use, and patient satisfaction have not yet been reported.

OBJECTIVE

To compare pain, analgesic use, and satisfaction after hip fracture surgery with spinal versus general anesthesia.

DESIGN

Preplanned secondary analysis of a pragmatic randomized trial. (ClinicalTrials.gov: NCT02507505).

SETTING

46 U.S. and Canadian hospitals.

PARTICIPANTS

Patients aged 50 years or older undergoing hip fracture surgery.

INTERVENTION

Spinal or general anesthesia.

MEASUREMENTS

Pain on postoperative days 1 through 3; 60-, 180-, and 365-day pain and prescription analgesic use; and satisfaction with care.

RESULTS

A total of 1600 patients were enrolled. The average age was 78 years, and 77% were women. A total of 73.5% (1050 of 1428) of patients reported severe pain during the first 24 hours after surgery. Worst pain over the first 24 hours after surgery was greater with spinal anesthesia (rated from 0 [no pain] to 10 [worst pain imaginable]; mean difference, 0.40 [95% CI, 0.12 to 0.68]). Pain did not differ across groups at other time points. Prescription analgesic use at 60 days occurred in 25% (141 of 563) and 18.8% (108 of 574) of patients assigned to spinal and general anesthesia, respectively (relative risk, 1.33 [CI, 1.06 to 1.65]). Satisfaction was similar across groups.

LIMITATION

Missing outcome data and multiple outcomes assessed.

CONCLUSION

Severe pain is common after hip fracture. Spinal anesthesia was associated with more pain in the first 24 hours after surgery and more prescription analgesic use at 60 days compared with general anesthesia.

PRIMARY FUNDING SOURCE

Patient-Centered Outcomes Research Institute.

Spinal Anesthesia or General Anesthesia for Hip Surgery in Older Adults

BACKGROUND

The effects of spinal anesthesia as compared with general anesthesia on the ability to walk in older adults undergoing surgery for hip fracture have not been well studied.

METHODS

We conducted a pragmatic, randomized superiority trial to evaluate spinal anesthesia as compared with general anesthesia in previously ambulatory patients 50 years of age or older who were undergoing surgery for hip fracture at 46 U.S. and Canadian hospitals. Patients were randomly assigned in a 1:1 ratio to receive spinal or general anesthesia. The primary outcome was a composite of death or an inability to walk approximately 10 ft (3 m) independently or with a walker or cane at 60 days after randomization. Secondary outcomes included death within 60 days, delirium, time to discharge, and ambulation at 60 days.

RESULTS

A total of 1600 patients were enrolled; 795 were assigned to receive spinal anesthesia and 805 to receive general anesthesia. The mean age was 78 years, and 67.0% of the patients were women. A total of 666 patients (83.8%) assigned to spinal anesthesia and 769 patients (95.5%) assigned to general anesthesia received their assigned anesthesia. Among patients in the modified intention-to-treat population for whom data were available, the composite primary outcome occurred in 132 of 712 patients (18.5%) in the spinal anesthesia group and 132 of 733 (18.0%) in the general anesthesia group (relative risk, 1.03; 95% confidence interval [CI], 0.84 to 1.27; P = 0.83). An inability to walk independently at 60 days was reported in 104 of 684 patients (15.2%) and 101 of 702 patients (14.4%), respectively (relative risk, 1.06; 95% CI, 0.82 to 1.36), and death within 60 days occurred in 30 of 768 (3.9%) and 32 of 784 (4.1%), respectively (relative risk, 0.97; 95% CI, 0.59 to 1.57). Delirium occurred in 130 of 633 patients (20.5%) in the spinal anesthesia group and in 124 of 629 (19.7%) in the general anesthesia group (relative risk, 1.04; 95% CI, 0.84 to 1.30).

CONCLUSIONS

Spinal anesthesia for hip-fracture surgery in older adults was not superior to general anesthesia with respect to survival and recovery of ambulation at 60 days. The incidence of postoperative delirium was similar with the two types of anesthesia. (Funded by the Patient-Centered Outcomes Research Institute; REGAIN ClinicalTrials.gov number, NCT02507505.).

American Society of Regional Anesthesia and Pain Medicine expert panel recommendations on point-of-care ultrasound education and training for regional anesthesiologists and pain physicians-part II: recommendations

Point-of-care ultrasound (POCUS) is a critical skill for all regional anesthesiologists and pain physicians to help diagnose relevant complications related to routine practice and guide perioperative management. In an effort to inform the regional anesthesia and pain community as well as address a need for structured education and training, the American Society of Regional Anesthesia and Pain Medicine Society (ASRA) commissioned this narrative review to provide recommendations for POCUS. The recommendations were written by content and educational experts and were approved by the guidelines committee and the Board of Directors of the ASRA. In part II of this two-part series, learning goals and objectives were identified and outlined for achieving competency in the use of POCUS, specifically, airway ultrasound, lung ultrasound, gastric ultrasound, the focus assessment with sonography for trauma exam, and focused cardiac ultrasound, in the perioperative and chronic pain setting. It also discusses barriers to POCUS education and training and proposes a list of educational resources. For each POCUS section, learning goals and specific skills were presented in the Indication, Acquisition, Interpretation, and Medical decision-making framework.

American Society of Regional Anesthesia and Pain Medicine expert panel recommendations on point-of-care ultrasound education and training for regional anesthesiologists and pain physicians-part I: clinical indications

Point-of-care ultrasound (POCUS) is a critical skill for all regional anesthesiologists and pain physicians to help diagnose relevant complications related to routine practice and guide perioperative management. In an effort to inform the regional anesthesia and pain community as well as address a need for structured education and training, the American Society of Regional Anesthesia and Pain Medicine (ASRA) commissioned this narrative review to provide recommendations for POCUS. The guidelines were written by content and educational experts and approved by the Guidelines Committee and the Board of Directors of the ASRA. In part I of this two-part series, clinical indications for POCUS in the perioperative and chronic pain setting are described. The clinical review addresses airway ultrasound, lung ultrasound, gastric ultrasound, the focus assessment with sonography for trauma examination and focused cardiac ultrasound for the regional anesthesiologist and pain physician. It also provides foundational knowledge regarding ultrasound physics, discusses the impact of handheld devices and finally, offers insight into the role of POCUS in the pediatric population.

Thoracoscopic lung biopsy under regional anesthesia for interstitial lung disease

BACKGROUND

Interstitial lung disease (ILD) management guidelines support lung biopsy-guided therapy. However, the high mortality associated with thoracoscopic lung biopsy using general anesthesia (GA) in patients with ILD has deterred physicians from offering this procedure and adopt a diagnostic approach based on high-resolution CT. Here we report that thoracoscopy under regional anesthesia could be a safer alternative for lung biopsy and effectively guide ILD treatment.

METHODS

This was a single-center retrospective review of prospectively maintained database and consisted of patients who underwent thoracoscopic lung biopsy between March 2016 and March 2018. Patients were divided into two groups: (A) GA, and (B) regional anesthesia using monitored anesthesia care (MAC) and thoracic epidural anesthesia (TEA).

RESULTS

During the study period, 44 patients underwent thoracoscopic lung biopsy. Of these, 15 underwent MAC/TEA. There were no significant differences between the two groups with regard to pulmonary function test and clinicodemographic profile. However, operative time and hospital stay were shorter in MAC/TEA group (32.5±18.5 min vs 50.8±18.4; p=0.004, 1.0±1.3 days vs 10.0±34.7 days; p<0.001, respectively). Eight patients in the GA group, but none in the MAC/TEA group, experienced worsening of ILD after lung biopsy (p=0.03). Additionally, one patient in the GA group died due to acute ILD worsening. No cases of MAC/TEA group had to be converted to GA. In all cases a pathological diagnosis could be made.

CONCLUSIONS

Thoracoscopy using regional anesthesia might be a safer alternative to lung biopsy in patients with ILD.

Technical considerations for approaches to the ultrasound-guided maxillary nerve block via the pterygopalatine fossa: a literature review

Background and objectives

Blockade of the trigeminal nerve and its branches is an effective diagnostic tool and potential treatment of facial pain. Ultrasound-guided injections in the pterygopalatine fossa (PPF) to block the trigeminal nerve divisions and sphenopalatine ganglion have been described but a consensus has yet to be reached over the ideal approach. We sought to delineate and compare the various approaches to the ultrasound-guided trigeminal divisions blockade via the PPF.

Methods

The literature search was performed by searching the National Library of Medicine’s PubMed database, the Cochrane Database of Systematic Reviews and Google Scholar within the date range of January 2009–March 2019 for keywords targeted toward “trigeminal nerve,” “maxillary nerve,” or “pterygopalatine fossa,” “ultrasound,” and “nerve block,” using an English language restriction. Six papers were included in the final review: one prospective double-blinded randomized controlled trial, one prospective descriptive study, one case series, two case reports, and one cadaveric study.

Results

There are three main approaches to the ultrasound-guided trigeminal nerve branches blockade via the PPF: anterior infrazygomatic in-plane, posterior infrazygomatic in-plane, and suprazygomatic out-of-plane approaches. Each showed injectate spread to the PPF in cadaver, adult and pediatric patients, respectively.1–5 Injectate used varied from 3 to 5 mL to 0.15 mL/kg.

Conclusions

These studies demonstrated that the PPF is a readily accessible target for the ultrasound-guided maxillary nerve block via three main approaches.2 The ideal approach is yet to be determined and must be further explored.

Ultrasound-Guided Pulsed Radiofrequency of C2 Dorsal Root Ganglion as Adjuvant Treatment for Chronic Headache Disorders: A Case Report

Cluster headaches are characterized by unilateral sudden onset of intense, brief, sharp pain along the side of the face around the eye. Patients often can have symptoms that are resistant to medications, nerve blocks, and surgical treatments. There is increasing evidence of anatomical and functional connections between the trigeminal and occipital nerves. We present a patient with cluster headache presenting with chronic ipsilateral facial pain with nasal congestion and left eye pain who achieved sustained pain relief with an ultrasound-guided injection into the pterygopalatine fossa in conjunction with an ultrasound-guided pulsed radiofrequency ablation procedure involving the C2 dorsal root ganglion.

Percutaneous 60-day peripheral nerve stimulation implant provides sustained relief of chronic pain following amputation: 12-month follow-up of a randomized, double-blind, placebo-controlled trial

INTRODUCTION

Peripheral nerve stimulation (PNS) has historically been used to treat chronic pain, but generally requires implantation of a permanent system for sustained relief. A recent study found that a 60-day PNS treatment decreases post-amputation pain, and the current work investigates longer-term outcomes out to 12 months in the same cohort.

METHODS

As previously reported, 28 traumatic lower extremity amputees with residual and/or phantom limb pain were randomized to receive 8 weeks of PNS (group 1) or 4 weeks of placebo followed by a crossover 4 weeks of PNS (group 2). Percutaneous leads were implanted under ultrasound guidance targeting the femoral and sciatic nerves. During follow-up, changes in average pain and pain interference were assessed using the Brief Pain Inventory-Short Form and comparing with baseline.

RESULTS

Significantly more participants in group 1 reported ≥50% reductions in average weekly pain at 12 months (67%, 6/9) compared with group 2 at the end of the placebo period (0%, 0/14, p=0.001). Similarly, 56% (5/9) of participants in group 1 reported ≥50% reductions in pain interference at 12 months, compared with 2/13 (15%, p=0.074) in group 2 at crossover. Reductions in depression were also statistically significantly greater at 12 months in group 1 compared with group 2 at crossover.

CONCLUSIONS

This work suggests that percutaneous PNS delivered over a 60-day period may provide significant carry-over effects including pain relief, potentially avoiding the need for a permanently implanted system while enabling improved function in patients with chronic pain.

TRIAL REGISTRATION NUMBER

NCT01996254.

Percutaneous peripheral nerve stimulation for the treatment of chronic neuropathic postamputation pain: a multicenter, randomized, placebo-controlled trial

BACKGROUND AND OBJECTIVES

Chronic neuropathic pain is a common challenging condition following amputation. Recent research demonstrated the feasibility of percutaneously implanting fine-wire coiled peripheral nerve stimulation (PNS) leads in proximity to the sciatic and femoral nerves for postamputation pain. A multicenter, double-blinded, randomized, placebo-controlled study collected data on the safety and effectiveness of percutaneous PNS for chronic neuropathic pain following amputation.

METHODS

Twenty-eight lower extremity amputees with postamputation pain were enrolled. Subjects underwent ultrasound-guided implantation of percutaneous PNS leads and were randomized to receive PNS or placebo for 4 weeks. The placebo group then crossed over and all subjects received PNS for four additional weeks. The primary efficacy endpoint evaluated the proportion of subjects reporting ≥50% pain reduction during weeks 1-4.

RESULTS

A significantly greater proportion of subjects receiving PNS (n=7/12, 58%, p=0.037) demonstrated ≥50% reductions in average postamputation pain during weeks 1-4 compared with subjects receiving placebo (n=2/14, 14%). Two subjects were excluded from efficacy analysis due to eligibility changes. Significantly greater proportions of PNS subjects also reported ≥50% reductions in pain (n=8/12, 67%, p=0.014) and pain interference (n=8/10, 80%, p=0.003) after 8 weeks of therapy compared with subjects receiving placebo (pain: n=2/14, 14%; pain interference: n=2/13, 15%). Prospective follow-up is ongoing; four of five PNS subjects who have completed 12-month follow-up to date reported ≥50% pain relief.

CONCLUSIONS

This work demonstrates that percutaneous PNS therapy may provide enduring clinically significant pain relief and improve disability in patients with chronic neuropathic postamputation pain.

TRIAL REGISTRATION NUMBER

NCT01996254.

Transversus Abdominis Plane Blockade as Part of a Multimodal Postoperative Analgesia Plan in Patients Undergoing Radical Cystectomy

Background:

Radical cystectomy (RC) is a morbid procedure with frequent complications that may benefit from implementation of an enhanced recovery after surgery (ERAS) protocol.

Objective:

To examine the benefits of a multimodal analgesic plan that uses continuous transversus abdominis plane (TAP) blockade as part of an ERAS protocol after RC.

Methods:

A retrospective comparison of consecutive patients undergoing RC over a 4-year period was conducted. Patients were designated as having surgery either before or after implementation of an ERAS protocol. A major component of the ERAS protocol was a multi-modal analgesia plan with TAP blockade. Patient demographics, comorbidities, operative details, and outcomes, including days to flatus, bowel movement (BM), narcotic usage, and length of stay (LOS) were compared.

Results:

In total, 171 patients were included: 100 pre-ERAS and 71 ERAS. There were no differences in age, smoking status, operative approach, or diversion type. The patients in the ERAS cohort were less likely to be male, had a higher median BMI, and more likely to have received neoadjuvant chemotherapy. Total and early postoperative narcotic use were lower in the ERAS cohort: 89 vs. 336 mg (p < 0.001) and 62 vs 203 mg (p = 0.001), respectively. The ERAS cohort had fewer days to flatus (3 vs. 4, p < 0.001) and fewer days to bowel movement (4 vs. 5, p < 0.001). Median LOS was shorter in the ERAS cohort (7 vs. 8.5d, p = 0.001). There were no differences in complications or readmission rates between the two cohorts.

Conclusions:

TAP blockade as part of an ERAS multi-modal pain plan is associated with low narcotic usage, and significant improvement in time to flatus, BM, and LOS compared to traditional post-RC pain management.

Ultrasound-Guided Pulsed Radiofrequency Application via the Pterygopalatine Fossa: A Practical Approach to Treat Refractory Trigeminal Neuralgia

Although pharmacological therapy is the primary treatment modality for trigeminal neuralgia associated pain, ineffective analgesia and dose limiting side effects often prompt patients to seek alternative pharmacological solutions such as interventional nerve blockade. Blockade of the Gasserian ganglion or its branches is an effective analgesic procedure for trigeminal neuralgia, traditionally performed using fluoroscopy or CT imaging. Ultrasonography allows point of care and real time visualization of needle placement within the surrounding anatomical structures. The use of ultrasonography with pulsed radiofrequency therapy for trigeminal neuralgia has not been reported. Our case is a 66-year-old male suffering from trigeminal neuralgia for 4 years that was refractory to pharmacologic therapy. Neurological examination was normal with no sensory deficit. Imaging showed no vascular compression or mass involving the trigeminal nerve. A diagnostic ultrasound-guided trigeminal nerve block via the pterygopalatine fossa with 4 mL of bupivacaine 0.25% and 4 mg dexamethasone provided immediate pain relief (100%) with sustained analgesia >50% at 2 weeks. Pain relief was not sustained at one month, with return to pretreatment symptoms. A series of injections were performed with similar intermittent analgesic effectiveness. The decision was made that the patient was a suitable candidate for pulsed radiofrequency application in the pterygopalatine fossa. We successfully used an alternative approach through the pterygopalatine fossa to treat trigeminal neuralgia using ultrasound guidance in an office setting. Our case demonstrates the utility of ultrasound-guidance pulsed radiofrequency treatment in the pterygopalatine fossa as a potential alternative to other percutaneous techniques for patients with medical refractory trigeminal neuralgia.

Ultrasound-guided trigeminal nerve block via the pterygopalatine fossa: an effective treatment for trigeminal neuralgia and atypical facial pain

BACKGROUND

Patients presenting with facial pain often have ineffective pain relief with medical therapy. Cases refractory to medical management are frequently treated with surgical or minimally invasive procedures with variable success rates. We report on the use of ultrasound-guided trigeminal nerve block via the pterygopalatine fossa in patients following refractory medical and surgical treatment.

OBJECTIVE

To present the immediate and long-term efficacy of ultrasound-guided injections of local anesthetic and steroids in the pterygopalatine fossa in patients with unilateral facial pain that failed pharmacological and surgical interventions.

SETTING

Academic pain management center.

STUDY DESIGN

Prospective case series.

METHODS

Fifteen patients were treated with ultrasound-guided trigeminal nerve block with local anesthetic and steroids placed into the pterygopalatine fossa.

RESULTS

All patients achieved complete sensory analgesia to pin prick in the distribution of the V2 branch of the trigeminal nerve and 80% (12 out of 15) achieved complete sensory analgesia in V1, V2, V3 distribution within 15 minutes of the injection. All patients reported pain relief within 5 minutes of the injection. The majority of patients maintained pain relief throughout the 15 month study period. No patients experienced symptoms of local anesthetic toxicity or onset of new neurological sequelae.

LIMITATIONS

Prospective case series.

CONCLUSION

We conclude that the use of ultrasound guidance for injectate delivery in the pterygopalatine fossa is a simple, free of radiation or magnetization, safe, and effective percutaneous procedure that provides sustained pain relief in trigeminal neuralgia or atypical facial pain patients who have failed previous medical interventions.

Nerve block of the infrapatellar branch of the saphenous nerve in knee arthroscopy: a prospective, double-blinded, randomized, placebo-controlled trial

BACKGROUND

With the rising use of outpatient knee arthroscopy over the past decade, interest in peripheral nerve blocks during arthroscopy has increased. Femoral nerve blocks are effective but are associated with an inherent risk of the patient falling postoperatively because of quadriceps weakness. We studied blocks of the infrapatellar branch of the saphenous nerve, which produce analgesia in the knee that is similar to that resulting from a femoral nerve block but without associated quadriceps weakness.

METHODS

Thirty-four patients were enrolled into each arm of this prospective, randomized, double-blinded trial comparing 10 mL of 0.25% bupivacaine used as a block of the infrapatellar branch of the saphenous nerve with a placebo during simple knee arthroscopy. Immediate outcome measures included Numeric Rating Scale (NRS) pain scores (0 to 10 points), mobility and discharge times, opioid usage, subjective adverse side effects, and forty-eight-hour anesthesia recovery surveys. Short-term measures included one-week and twelve-week Lysholm knee scores.

RESULTS

No adverse effects or increased quadriceps weakness were observed following use of the nerve block. Improvement in early NRS scores and subjective nausea (p = 0.03) were detected. Patients for whom the block was successful also had improved twelve-week Lysholm knee scores (p = 0.04). No differences in opioid usage, mobility time, forty-eight-hour anesthesia recovery scores, or one-week Lysholm knee scores were found.

CONCLUSIONS

No significant adverse effect or disadvantage was identified for blocks of the infrapatellar branch of the saphenous nerve used in simple knee arthroscopy. In addition to decreased early NRS scores and nausea, blocks of the infrapatellar branch of the saphenous nerve demonstrated potential benefit at twelve weeks after simple knee arthroscopy.

Prevention of accidental exposure in radiotherapy: the risk matrix approach

Knowledge and lessons from past accidental exposures in radiotherapy are very helpful in finding safety provisions to prevent recurrence. Disseminating lessons is necessary but not sufficient. There may be additional latent risks for other accidental exposures, which have not been reported or have not occurred, but are possible and may occur in the future if not identified, analyzed, and prevented by safety provisions. Proactive methods are available for anticipating and quantifying risk from potential event sequences. In this work, proactive methods, successfully used in industry, have been adapted and used in radiotherapy. Risk matrix is a tool that can be used in individual hospitals to classify event sequences in levels of risk. As with any anticipative method, the risk matrix involves a systematic search for potential risks; that is, any situation that can cause an accidental exposure. The method contributes new insights: The application of the risk matrix approach has identified that another group of less catastrophic but still severe single-patient events may have a higher probability, resulting in higher risk. The use of the risk matrix approach for safety assessment in individual hospitals would provide an opportunity for self-evaluation and managing the safety measures that are most suitable to the hospital's own conditions.

[Quality of conventional PAP smears. Quality assessment and motivation for improvement]

The success of cytology in screening programs for cervical cancer is highly dependent on the smear quality. Interdisciplinary projects which evaluate the smear quality and the results of collection devices could be helpful for an improvement and a successful example for quality improvement is presented here. An average of 83% technically adequate and representative smears was documented for 12 million conventional PAP smears; however only an average of 68% technically adequate and representative smears was found for the group of least successful smear takers of all laboratories. This indicates a potential for improvement. Following an interdisciplinary project on smear quality improvement the average rate of representative smears increased from 69 to 83% and in another project this rate remained stable at 86%. Based on 158,411 conventional smears, representative smears were achieved in 92% using Cervex-Brush®, 86% using Szalay Spatula and 82% Cytobrush methods. The combinations of Cytobrush with the Ayre wooden spatula, cotton wool swab or Szalay Spatula achieved 97%, 94% and 92% representative smears, respectively.

The threshold elicited motor response via an in situ femoral nerve catheter predicts analgesia following total knee replacement

Background

Continuous femoral nerve blocks are a part of the multimodal perioperative anesthetic regimen following total knee replacement. Elicitation of a quadriceps muscle contraction (QC) at placement is desirable. We prospectively evaluated the relationship between elicited motor response and threshold current with block success in situ femoral nerve catheters after total knee replacement.

Methods

After Institutional Review Board approval and written informed consent, 100 adults aged ≥18 years, undergoing total knee replacement were studied. The threshold current for an elicited motor response (QC or sartorius muscle contraction [SC]) was recorded during needle insertion, after femoral nerve catheter advancement, and prior to local anesthetic administration on the first postoperative day. Patients were assessed for pinprick sensory anesthesia of the femoral nerve distribution by an observer unaware of the current threshold or evoked motor response at 5-minute intervals for 30 minutes. A successful block was considered a lack of pinprick sensation within 30 minutes.

Results

Ninety patients completed the study. A QC was obtained at needle insertion in 89 and maintained following catheter advancement in 77 subjects. Prior to drug administration a QC was obtained in 66 patients, 13 demonstrated an SC, and 11 had no motor response. QC prior to drug administration had a sensitivity of 0.85 (95% confidence intervals [CI]: 0.75 to 0.92) and a specificity of 0.55 (95% CI: 0.37 to 0.72) for complete femoral nerve block. The specificity of a QC prior to drug administration was greater than at catheter placement (P = 0.006). Compared to the threshold current at catheter placement, 27 patients had a decrease, 60 had an increase, and 3 exhibited no change in the threshold current prior to drug administration (P < 0.01). The median interquartile range (IQR) threshold current in patients that achieved a complete block was 0.56 (0.29 to 0.80) mA compared with 1.1 mA (0.41 to 2.75) mA for incomplete blocks (P < 0.01). The area under the receiver operator characteristics curve for current threshold prior to local anesthetic administration (0.74) was greater than at catheter placement (0.45) (P < 0.001). The intersection of sensitivity and specificity for the minimal threshold current prior to local anesthetic injection was 0.84 mA.

Conclusion

The elicited motor response and current threshold from a stimulating femoral catheter measured prior to local anesthetic injection is an important determinant of the success of femoral nerve block following bolus administration.

Removal of a knotted stimulating femoral nerve catheter using a saline bolus injection

Objective

Stimulating peripheral nerve catheters have become increasingly popular as part of postoperative multimodal analgesia for total knee arthroplasty. We describe a case of a successful nonsurgical removal of a knotted stimulating femoral nerve catheter after saline expansion of the catheter pocket at the bedside.

Case report

A 65-year-old female underwent total knee arthroplasty under combined spinal epidural anesthesia. Postoperatively, a stimulating femoral nerve catheter was placed without complication. The catheter was threaded 12 cm past the needle tip with minimal resistance. Function of the catheter was verified by loss of pinprick sensation in the femoral nerve distribution and excellent analgesic efficacy was achieved. The first attempt at catheter removal was unsuccessful. Thigh flexion and rotation also failed to facilitate catheter removal. The catheter was then left to continuous tension for 6 hours, but further attempts at removal remained unsuccessful. Under ultrasound visualization, 10 mL of saline was injected through the catheter with moderate resistance and without patient discomfort, after which the catheter was removed using minimal tension. The catheter was intact but had a single knot at the distal end of the catheter.

Conclusions

We present a rare case of a knotted stimulating catheter in which the use of a saline bolus to dilate the catheter pocket proved to be successful after other simple methods of catheter removal had failed. Given the simple nature of this technique, it can be attempted at the bedside before more invasive procedures are planned.

Effects of tumor-induced osteomalacia on the bone mineralization process

Fibroblast growth factor 23 (FGF23) overexpression has been identified as a causative factor for tumor-induced osteomalacia (TIO) characterized by hypophosphatemia due to increased renal phosphate wasting, low 1,25(OH)(2)D(3) serum levels, and low bone density. The effects of long-lasting disturbed phosphate homeostasis on bone mineralization are still not well understood. We report on a patient with a 12-year history of TIO, treated with 1,25(OH)(2)D(3) and phosphate, who finally developed hyperparathyroidism with gland hyperplasia before the tumor could be localized in the scapula and removed. During surgery a transiliac bone biopsy was obtained. FGF23 expression in the tumor cells was confirmed by in situ hybridization. Serum FGF23 levels as measured by ELISA were found to be extremely elevated before and decreased after removal of the tumor. Bone histology/histomorphometry and measurement of bone mineralization density distribution using quantitative backscattered electron imaging were performed on the bone biopsy. The data showed important surface osteoidosis and a slightly increased osteoblast but markedly decreased osteoclast number. The mineralized bone volume (-11%) and mineralized trabecular thickness (-18%) were low. The mean degree of mineralization of the bone matrix (-7%), the most frequent calcium concentration (-4.1%), and the amounts of fully mineralized bone (-40.3%) were distinctly decreased, while the heterogeneity of mineralization (+44.5%) and the areas of primary mineralization (+131.6%) were dramatically increased. We suggest that the elevated levels of FGF23 and/or low phosphate concentrations disturb the mineralization kinetics in vivo without affecting matrix mineralization of pre-existing bone packets.

Relationship between ultrasound imaging and eliciting motor response during femoral nerve stimulation

OBJECTIVE

Nerve stimulator-assisted localization of the femoral nerve is well described; however, direct ultrasound imaging of the femoral nerve branches may be challenging. The purpose of this study was to correlate the evoked motor responses obtained by femoral nerve stimulation and the topographic orientation of the femoral nerve branches during ultrasound examinations of the infrainguinal region.

METHODS

Eighty-two patients undergoing total knee replacement were enrolled in this study. A 25-mm, 5- to 10-MHz broadband linear array transducer was used to identify the femoral nerve at the inguinal crease. The medial and lateral aspects of the femoral nerve were stimulated under ultrasound imaging. Twenty cadavers were dissected to support our clinical findings.

RESULTS

A quadriceps contraction was elicited in 1.2% and 96% of the patients when stimulating the medial and lateral aspects of the femoral nerve, respectively. In contrast, a sartorius muscle contraction was elicited in 94% and 0% when stimulating the medial and lateral aspects of the femoral nerve. Our findings during anatomic dissection revealed that the femoral nerve branch to the quadriceps muscle, when compared with the branch to the sartorius muscle, originated laterally in 95% and medially in 5% of the specimens.

CONCLUSIONS

When using out-of-plane ultrasound imaging at the inguinal crease, directing the stimulating needle to the lateral half of the femoral nerve may be associated with a higher probability of encountering the motor branch to the quadriceps muscle.

Evaluation of a Proximal Block Site and the Use of Nerve-Stimulator-Guided Needle Placement for Posterior Tibial Nerve Block

BACKGROUND

Posterior tibial nerve (PTN) block has traditionally been performed in the para-medial malleolar area without nerve stimulator (NS) guidance. The PTN can also be blocked proximally (7 cm) above the medial malleolus in the subfascial plane between the flexor hallucis longus and flexor digitorum longus tendons. In this study we compared the frequency of successful PTN block at the traditional distal (D) site (2 cm above the medial malleolus) with and without NS guidance. We also compared block success and latency at the D site versus the proximal (P) block site.

METHODS

Subjects were randomized to P-NS (n = 45), D-NS (n = 45), or D without NS (n = 45). Levobupivacaine 0.625%, 0.15 mL/kg was used for all blocks. Pinprick sensory anesthesia was evaluated in the distribution of the medial plantar, lateral plantar, and medial calcaneal nerves. PTN block was considered successful if surgical anesthesia was achieved in all PTN distributions.

RESULTS

The frequency of successful PTN block was greater for D-NS (100%) and P-NS (93.5%), compared with D (73.3%) (P = 0.02). Median latency to complete block was less for D-NS (8 min, 95% CI 7-9 min) than D (20 min, 95% CI 13-26 min) (P < 0.01) and P-NS (15 min, 95% CI 12-18 min) (P = 0.04).

CONCLUSIONS

NS-guided needle placement improves the success and decreases the latency to onset of complete PTN block at the D site. The P approach to PTN block may be a useful alternative to the traditional D site approach, particularly in patients with restricted access to the D site.

Neurologic Sequelae After Interscalene Brachial Plexus Block for Shoulder/Upper Arm Surgery: The Association of Patient, Anesthetic, and Surgical Factors to the Incidence and Clinical Course

We determined the incidence, distribution, and resolution of neurologic sequelae and the association with anesthetic, surgical, and patient factors after single-injection interscalene block (ISB) using levobupivacaine 0.625% with epinephrine 1:200,000 in subjects undergoing shoulder or upper arm surgery, or both, in 693 consecutive adult patients. After a standardized ISB, assessments were made at 24 and 48 h and at 2 and 4 wk for anesthesia, hypesthesia, paresthesias, pain/dysesthesias, and motor weakness. Symptomatic patients were monitored until resolution. Subjects reporting pain or discomfort >3 of 10 and those with motor or extending sensory symptoms received diagnostic assessment. Six-hundred-sixty subjects completed 4 wk of follow-up. Fifty-eight neurologic sequelae were reported by 56 subjects. Symptoms were sensory except for two cases of motor weakness (lesions identified distant from the ISB site). Thirty-one sequelae with likely ISB association were reported by 29 subjects, including 14 at the ISB site, 9 at the distal phalanx of thumb/index finger, 7 involving the posterior auricular nerve, and 1 clinical brachial plexopathy. Sequelae not likely associated with the ISB were reported by 27 subjects with symptoms reported in the median (n = 9) and ulnar (n = 4) nerves, surgical neuropraxias (n = 12), and motor weakness (n = 2). Symptoms resolved spontaneously (median 4 wk; range, 2-16 wk) except in the two patients with motor weaknesses and the patient with clinical brachial plexopathy, who received therapeutic interventions. Variables identified as independent predictors of neurologic sequelae likely related to ISB were paresthesia at needle insertion and ISB site pain or bruising at 24 h. In contrast, surgery preformed in the sitting position, as well as ISB site bruising, was identified as a predictor of neurologic sequelae not likely related to ISB. In conclusion, neurologic sequelae after single-injection ISB using epinephrine mainly involve transient minor sensory symptoms.

Nerve Stimulator-Assisted Evoked Motor Response Predicts the Latency and Success of a Single-Injection Sciatic Block

Variable onset latency of single-injection sciatic nerve block (SNB) may result from drug deposition insufficiently close to all components of the nerve. We hypothesized that this variability is caused by the needle tip position relative to neural components, which is objectified by the type of evoked motor response (EMR) elicited before local anesthetic injection. One-hundred ASA I-II patients undergoing reconstructive ankle surgery received infragluteal-parabiceps SNB using 0.4 mL/kg (maximum 35 mL) of levobupivacaine 0.625%. The end-point for injection was the first elicited EMR: inversion (I), plantar flexion (PF), dorsiflexion (DF), or eversion (E) at 0.2-0.4 mA. The frequencies of the EMRs were: I 40%, PF 43%, E 14%, and DF 3%. SNB was considered complete if both tibial and common peroneal nerves were blocked and failed if either analgesia to pinprick was not observed at 30 min or anesthesia at 60 min. Patients with an EMR of I demonstrated shorter mean times (+/-95% confidence interval [CI]) to complete the block with 8.5 (95% CI, 6.2-10.8) min compared to 27.0 (95% CI, 20.6-33.4) min after PF (P < 0.001) and 30.4 (95% CI, 24.9-35.8) min after E (P < 0.001). No rescue blocks were required in group I compared with 24% (P = 0.001) and 71% (P < 0.001) of patients in groups PF and E, respectively. We conclude that EMR type during nerve stimulator-assisted single-injection SNB predicts latency and success of complete SNB because the observed EMR is related to the positioning of the needle tip relative to the tibial and common peroneal nerves.

[Minimally invasive, safe treatment of the neurogenic bladder with botulinum-A-toxin in children with myelomeningocele]

PURPOSE

The efficacy and durability of botulinum-A toxin in the treatment of detrusor hyperreflexia in myelomeningocele (MMC) children was evaluated prospectively.

MATERIALS AND METHODS

A total of 15 children (10 male and 5 female, mean age 5.8 years), all on clean intermittent catheterisation (CIC) due to MMC, were "non responders" to orally and intravesically administered anticholinergic medication. Pretreatment assessment included a videourodynamic evaluation, incontinence scoring and a mercaptoacetyltriglycine-3 renal scan. We injected from 10 U/kg up to a maximum of 360 U botulinum-A toxin at 25-40 sites of the detrusor, sparing the trigone. Follow-up was 24 months. All children had a urodynamic reevaluation with assessment of bladder capacity and incontinence score at 3, 9 and 12 months.

RESULTS

Mean bladder reflex volume increased from 72.00 +/- 28.12 ml to 298 +/- 32.45 ml (p < 0.001). The maximal detrusor pressure decreased from 78.76 +/- 23.14 cm H(2)O to 42.76 +/- 24.34 cm H(2)O (p < 0.001). Maximal bladder capacity increased from 136.34 +/- 45.71 ml to 297.02 +/- 87.17 ml (p < 0.001). Detrusor compliance increased from 18.29 +/- 27.19 ml/cm H(2)O to 51.17 +/- 38.17 ml/mmH(2)O (p < 0.001). While 10 patients became completely dry between CIC, the remaining 2 patients improved from score 3 to 1. Results at 9 months were similar to the ones at 3 months. The mean efficacy and durability of the toxin was 10.5 months after the first intravesical injection.

CONCLUSIONS

Botulinum-A toxin is a safe alternative in the management of detrusor hyperreflexia in MMC children. Preliminary results are promising concerning urodynamic parameters and continence.

Mineralized microstructure of calcified avian tendons: a scanning small angle X-ray scattering study

The micrometer level spatial distribution of the size, shape, and orientation of mineral crystallites in the calcifying matrix of tendons near the edge of the mineralizing front was investigated by scanning small angle X-ray scattering using synchrotron X-ray radiation. Using a special microbeam arrangement enabling 20 microm beam resolution and short measurement times, linear diffraction scans were made on sections from the normally calcifying tendons (tibialis cranialis) from the domestic turkey, which calcify in the distal to proximal direction. A change in shape and arrangement of mineral crystals was observed within the first 200 microm of the mineralization front, and the mineral crystal distribution was highly anisotropic with crystals aligned parallel to the fiber axis. In a cross-section of the tendon cut at right angles to the fiber axis, the orientation distribution of crystals was not azimuthally symmetric, and showed a small but nonzero anisotropy and a continuous change in mean orientation angle across the width of the tendon cross-section.

2 Years' experience with inspiratory muscle training in patients with neuromuscular disorders

PURPOSE

The aim of our study was to assess the long-term effects of specific inspiratory muscle training (IMT) in patients with neuromuscular disorders (NMDs) who have various degrees of respiratory impairment.

PATIENTS AND METHODS

Twenty-seven patients with NMDs (Duchenne's muscular dystrophy, 18 patients; spinal muscular atrophy, 9 patients) underwent 24 months of IMT. Patients were divided into three groups according to their vital capacity (VC) values. VC was measured as the parameter for the respiratory system involvement of the disease. Maximal inspiratory pressure (PImax) was assessed as the parameter for respiratory muscle strength, and the results of the 12-s maximum voluntary ventilation test (12sMVV) were assessed as the parameter for respiratory muscle endurance. Pulmonary and inspiratory muscle function parameters were assessed 6 months before training, at the beginning of training, and then every 3 months.

RESULTS

The PImax values improved in group A (VC, 27 to 50% predicted) from 51.45 to 87.00 cm H(2)O, in group B (VC, 51 to 70% predicted) from 59.38 to 94.4 cm H(2)O, and in group C (VC, 71 to 96% predicted) from 71.25 to 99.00 cm H(2)O. The 12sMVV values improved in group A from 52.69 to 69.50 L/min, in group B from 53.18 to 62.40 L/min, and in group C from 59.48 to 70.5 L/min. For all three groups, there was a significant improvement of PImax (p < 0.007) and 12sMVV (p < 0.015) until the 10th month when a plateau phase was reached with no decline in the following month until the end of training.

CONCLUSION

With IMT, respiratory muscle function can be improved in the long term of up to 2 years.

Dose-dependent effects of inspiratory muscle training in neuromuscular disorders

The goal of this study was to show whether a correlation exists between the intensity of specific respiratory muscle training and the improvement of strength and endurance in inspiratory musculature in patients with neuromuscular disorders (NMD). Sixteen patients with NMD (13 with Duchenne muscular dystrophy and 3 with spinal muscular atrophy) performed inspiratory muscle training (IMT) at home with a special training apparatus for 9 months. Maximal inspiratory mouth pressure (PI(MAX)) and 12s-maximum voluntary ventilation (12s-MVV) test served as parameters for inspiratory muscle strength and endurance, respectively. In patients whose inspiratory vital capacity (VC(in)) declined by less than 10% during the year before training began (n = 10), a significant positive correlation was found between the number of successfully completed strength and endurance exercises and the improvement of PI(MAX) (P < 0.05) and 12s-MVV (P < 0.05). In patients whose VC(in)-decline exceeded 10% (n = 6), indicating more progressive respiratory system involvement of the disease, no significant correlation between the improvement of PI(MAX) and 12s-MVV and the intensity of training was found. In patients with NMD, the effects of IMT-runs are dose-dependent, provided that the respiratory system involvement of the disease is only slowly progressive.

[Osteoporosis and metabolic bone diseases; clinical relationship]

Metabolic bone diseases with disturbed bone remodeling lead to loss of biomechanical quality and atraumatic fractures. Differential diagnosis, prevention and adequate treatment should already start early in the course of these disorders to prevent fractures. Thus, clinical osteology is more than the simplified connection "low bone mineral density--fractures--osteoporosis". This review summarizes physiological relations between bone tissue and calcium homoeostasis as well as the relation between structure and function. In addition, the main metabolic osteopathies "osteoporosis, primary hyperparathyroidism and osteomalacia" are presented from a clinical point of view. The importance and the diagnostic values of biochemical parameters and of the transiliacal biopsy are discussed. In this respect the quantitative measurement of the mineralization density (bone mineral density distribution = BMDD) seems to be of high value and extends the well established bone histomorphometry. This recently introduced method has the power to distinguish between small differences in the degree of mineralization of the matrix with high precision and reproducibility. The results of quantitative backscattered electron imaging in the scanning electron microscope improve the differential diagnosis of bone diseases with alterations in mineralization density, helps to detect mixed etiology (e.g. osteoporosis plus osteomalacia) and facilitate decision making for treatments. The value of biochemical, radiological, osteodensitometric and histopathological tests for diagnosis and treatment depends on the knowledge of the clinical relations and the complex interactions between calcium-, phosphate- and bone metabolism.

Clinicopathogenetic significance of chromosomal abnormalities in patients with blastic peripheral B-cell lymphoma. Kiel-Wien-Lymphoma Study Group

So far, reproducible histomorphologic and immunological criteria to distinguish clinicopathologic subtypes of blastic peripheral B-cell non-Hodgkin's lymphoma (BBCL), especially centroblastic (cb) and immunoblastic (ib) lymphomas, for daily diagnostic use are still lacking. Therefore, we correlated the cytogenetic findings in 126 patients with BBCL with histopathologic diagnoses. Subclassification of cb and ib lymphomas relied on the criteria defined in the updated Kiel classification; these subtypes are also listed in the Revised European-American Lymphoma (REAL) classification and in a preliminary report on the newly established World Health Organization classification, to investigate their clinical significance. Moreover, we performed a multivariate analysis to compare the prognostic significance of cytogenetic findings with the International Index. There were significant differences in the frequency of chromosome aberrations between different BBCL subtypes: t(8;14) was predominantly present in Burkitt's lymphomas, t(14;18) in centroblastic lymphomas, deletions in 8q and 14q, changes of 4q and losses of chromosome 10 in immunoblastic lymphomas; t(11;14) was restricted to blastoid mantle cell lymphomas and associated with a poor prognosis. In cb lymphomas, deletions in 1q42-qter, duplications in 1q23-32, trisomy 5, and changes of 15q were identified as independent prognostic factors. In ib lymphomas, changes of 7q and 8q had stronger impact on survival than the International Index. These findings underline that Burkitt's, cb, ib, and blastoid mantle-cell lymphoma are biologically distinct and clinically relevant entities and that cytogenetic findings can be helpful to subtype BBCL.