Regional anesthesia and pain medicine
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Reg Anesth Pain Med · Jan 2017
Anatomic and Ultrasonographic Evaluation of the Knee Sensory Innervation: A Cadaveric Study to Determine Anatomic Targets in the Treatment of Chronic Knee Pain.
Osteoarthrosis is a main cause of knee pain in the elderly. Pain associated with this condition is often refractory to conservative treatment. Total knee replacement may be the best option for severe pathologies; however, the occurrence of a chronic pain state after knee replacement has been well documented in the literature. The previous descriptions of the genicular nerves have been considered somewhat inaccurate. This innervation is complex and exhibits significant interindividual variability. A precise description of these nerves will increase our knowledge on different patterns and targets, to guide treatment and improve outcomes. The objective of this study was to determine sensory innervation patterns of the knee joint and correlate them with dynamic visualization via ultrasound imaging. ⋯ We conclude that reproducible correlations showing the sensory innervations for the knee are linked to muscular structures. However, high variability among individuals makes it difficult to predict their paths. Our systematic approach, using direct visualization via ultrasound, allows a more accurate placement of the needle for therapeutic purposes.
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Reg Anesth Pain Med · Jan 2017
Randomized Controlled TrialEffect of Nerve Stimulation Use on the Success Rate of Ultrasound-Guided Subsartorial Saphenous Nerve Block: A Randomized Controlled Trial.
Ultrasound-guided subsartorial saphenous nerve block is commonly used to provide complete surgical anesthesia of the foot and ankle in combination with a popliteal sciatic nerve block. However, in part owing to its small caliber and absence of a prominent vascular landmark in the subsartorial plane distal to the adductor canal, the saphenous nerve is more difficult to reliably block than the sciatic nerve in the popliteal fossa. Although the saphenous nerve is a sensory nerve only, neurostimulation can be used to elicit a "tapping" sensation on the anteromedial aspect of the lower leg extending toward the medial malleolus. Our objective was to test the hypothesis that the addition of nerve stimulation use to an ultrasound (US)-guided technique will increase the success rate of subsartorial saphenous nerve block. ⋯ The addition of the use of nerve stimulation did not improve the success rate of US-guided subsartorial saphenous nerve block. However, in the NS group, an inability to elicit a "tapping" sensation in the saphenous nerve distribution was associated with block failure.
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Reg Anesth Pain Med · Jan 2017
Randomized Controlled TrialFluoroscopic Guidance Increases the Incidence of Thoracic Epidural Catheter Placement Within the Epidural Space: A Randomized Trial.
Thoracic epidural analgesia can reduce postoperative pain and cardiopulmonary morbidity, but it is associated with a high rate of clinical failure. Up to 50% of clinical failure is thought to be related to technical insertion. In this study, patients undergoing thoracic surgery were randomized to one of two catheter insertion techniques: fluoroscopically guided or conventional loss of resistance with saline/air. Our primary aim was to examine whether fluoroscopic guidance could increase the incidence of correct catheter placement and improve postoperative analgesia. Our secondary aim was to assess the potential impact of correct epidural catheter positioning on length of stay in the postanesthesia care unit and total hospital length of stay. ⋯ Fluoroscopic guidance increases the incidence of epidural catheter positioning within the epidural space and may reduce postanesthesia care unit and hospital lengths of stay. Future work should validate the effectiveness of this approach.This clinical trial is registered with ClinicalTrials.gov (NCT02678039).
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Reg Anesth Pain Med · Jan 2017
Clinical Efficacy of an Ultrasound-Guided Greater Occipital Nerve Block at the Level of C2.
The purpose of this prospective open-label study was to investigate the analgesic effects of an ultrasound-guided greater occipital nerve (GON) block at the level of C2, as the nerve courses superficially to the obliquus capitis inferior muscle. ⋯ This prospective open-label study demonstrated successful blockade of the GON at the level of C2 using a novel ultrasound-guided technique. Significant reductions in pain scores were observed over the 4-week study period, and no adverse events were reported. The observations from this study provide important preliminary data for future randomized trials involving patients with occipital neuralgia and cervicogenic headache.
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Reg Anesth Pain Med · Jan 2017
A Cadaveric Study Evaluating the Feasibility of an Ultrasound-Guided Diagnostic Block and Radiofrequency Ablation Technique for Sacroiliac Joint Pain.
Ultrasound (US)-guided diagnostic block/radiofrequency ablation (RFA) along the lateral sacral crest (LSC) has been proposed for managing sacroiliac joint (SIJ) pain. We sought to investigate (1) ease of visualization of bony landmarks using US; (2) consistency of US-guided needle placement along the LSC; and (3) percentage of the posterior sacral network (PSN) innervating the SIJ complex that would be captured if an RFA strip lesion were created between the needles. ⋯ The findings suggest that US-guided needle placement along the LSC is consistent and could capture most or all of the PSN. A clinical study evaluating the outcomes of this technique is in progress.