Regional anesthesia and pain medicine
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Reg Anesth Pain Med · Jul 2011
Multicenter Study Comparative StudySpinal anesthesia failure after local anesthetic injection into cerebrospinal fluid: a multicenter prospective analysis of its incidence and related risk factors in 1214 patients.
Different mechanisms have been proposed to explain spinal anesthesia failure even after LA injection into the subarachnoid space. The aim of this prospective multicenter study was to assess the incidence of spinal anesthesia failure, excluding technical problems, and then to suggest independent factors leading to failure. ⋯ The results of this study showed that the incidence of spinal anesthesia failure was 3.2%. The number of puncture attempts at 3 or more and the absence of adjuvant medication associated with local anesthetic were independent factors associated with the increased risk of failure. The failure of spinal anesthesia was rare in patients older than 70 years.
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Reg Anesth Pain Med · Jul 2011
Randomized Controlled Trial Comparative StudyLateral versus medial needle approach for ultrasound-guided supraclavicular block: a randomized controlled trial.
When performing a supraclavicular brachial plexus block (SCB) under ultrasound (US) guidance, the needle may approach the nerves in-plane with the US beam from 1 of 2 directions relative to the transducer, lateral-to-medial (lateral) or medial-to-lateral (medial). We aimed to compare the rates of sensory and motor block of the 4 major peripheral nerves of the upper extremity following a lateral or medial needle approach for US-guided SCB. ⋯ The rates of sensory and motor block of all 4 major peripheral nerves of the upper extremity did not differ at any time following a lateral compared with medial needle approach for US-guided SCB. Regardless of needle approach, the rate of ulnar nerve sensory block was less compared with the other peripheral nerves following US-guided SCB.
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Reg Anesth Pain Med · Jul 2011
Comparative StudyOptical detection of the brachial plexus for peripheral nerve blocks: an in vivo swine study.
Accurate identification of nerves is critical to ensure safe and effective delivery of regional anesthesia during peripheral nerve blocks. Nerve stimulation is commonly used, but it is not perfect. Even when nerve stimulation is performed in conjunction with ultrasound guidance, determining when the needle tip is at the nerve target region can be challenging. In this in vivo pilot study, we investigated whether close proximity to the brachial plexus and penetration of the axillary artery can be identified with optical reflectance spectroscopy, using a custom needle stylet with integrated optical fibers. ⋯ Spectroscopic information obtained with the optical needle is distinct from nerve stimulation and complementary to ultrasound imaging, and it could potentially allow for reliable identification of the injection site during peripheral nerve blocks.
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Reg Anesth Pain Med · Jul 2011
Randomized Controlled Trial Comparative Study Clinical TrialLow-volume ultrasound-guided nerve block provides inferior postoperative analgesia compared to a higher-volume landmark technique.
Ultrasound guidance reduces the required local anesthetic volume for successful peripheral nerve blockade, but it is unclear whether this impacts postoperative analgesia. This prospective, randomized, observer-blinded study tested the hypothesis that a low-volume ultrasound-guided ankle block would provide similar analgesia after foot surgery compared with a conventional-volume surface landmark technique. ⋯ Low-volume ultrasound-guided ankle block is associated with a high block success rate after foot surgery; however, compared with a conventional volume (surface landmark) technique, the reduced local anesthetic volume marginally compromises postoperative analgesia during the first 24 hours.