Regional anesthesia and pain medicine
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Reg Anesth Pain Med · May 2009
Randomized Controlled Trial Comparative StudyThe rectus sheath block: accuracy of local anesthetic placement by trainee anesthesiologists using loss of resistance or ultrasound guidance.
The aim of this study was to compare the accuracy of local anesthetic placement in the rectus sheath block when performed by trainee anesthetists using loss of resistance (LOR) or ultrasound guidance. ⋯ Ultrasound guidance improves the accuracy of local anesthetic placement when undertaking the rectus sheath block. An additional fascial plane above the anterior layer of the rectus sheath may be wrongly perceived as the anterior layer of the rectus sheath when the block is undertaken without the aid of ultrasound.
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Reg Anesth Pain Med · May 2009
Survey of the utilization of regional and general anesthesia in a tertiary teaching hospital.
Although the subspecialty of regional anesthesiology has become an important focus during residency training, there are many factors that might influence a resident's experience in regional anesthesia (RA). There are few data examining the utilization of regional techniques in an anesthesiology residency program. We undertook a prospective observational study to determine the frequency and reasons for not choosing RA in cases for which it was considered an option. ⋯ Our prospective observational study suggests that anesthesiology-related reasons may be an important factor for not undertaking these techniques. Although we did not specifically examine the effect on resident education, our study does provide some evidence to support program directors and department chiefs to set up their regional rotations with faculty most likely to perform RA.
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Reg Anesth Pain Med · May 2009
Clinical TrialMinimum effective volume of local anesthetic for ultrasound-guided supraclavicular brachial plexus block.
The aim of this study was to determine the minimum effective anesthetic volume required to produce an effective supraclavicular block for surgical anesthesia using an ultrasound (US)-guided technique. ⋯ In this study, the minimum volume required for US-guided supraclavicular block in 50% of patients was 23 mL, and in 95% of patients was 42 mL. Under the present study conditions, the calculated volume of LA required for US-guided supraclavicular block does not seem to differ from the conventionally recommended volume required for supraclavicular blocks using non-US-based nerve localization techniques.
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Reg Anesth Pain Med · May 2009
Minimal local anesthetic volume for peripheral nerve block: a new ultrasound-guided, nerve dimension-based method.
Nerve blocks using local anesthetics are widely used. High volumes are usually injected, which may predispose patients to associated adverse events. Introduction of ultrasound guidance facilitates the reduction of volume, but the minimal effective volume is unknown. In this study, we estimated the 50% effective dose (ED50) and 95% effective dose (ED95) volume of 1% mepivacaine relative to the cross-sectional area of the nerve for an adequate sensory block. ⋯ Based on the ultrasound measured cross-sectional area and using ultrasound guidance, a mean volume of 0.7 mL represents the ED95 dose of 1% mepivacaine to block the ulnar nerve at the proximal forearm.
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Reg Anesth Pain Med · May 2009
Vertical infraclavicular brachial plexus block: needle redirection after elicitation of elbow flexion.
In vertical infraclavicular brachial plexus block, success depends on distal flexion or extension response. Initially, elbow flexion (lateral cord) is generally observed. However, specific knowledge about how to reach the medial or posterior cord is lacking. We investigated the mid-infraclavicular area in undisturbed anatomy and tested the findings in a clinical setting. ⋯ In the clinical study, in 98% of cases, the final stimulation response of posterior or medial cord was found as predicted by the findings of the anatomic study. Once elbow flexion is elicited, a further (ie, deeper) advancement of the needle will result in the proper distal motor response.