Regional anesthesia and pain medicine
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Reg Anesth Pain Med · May 2009
Randomized Controlled Trial Comparative StudyUltrasound improves the success rate of a tibial nerve block at the ankle.
The tibial nerve provides the majority of sensation to the foot. Although multiple techniques have been described, there exists little evidence-based medicine evaluating different techniques for blocking the tibial nerve at the ankle. We hypothesized that an ultrasound (US)-guided tibial nerve block at the ankle would prove more successful than a conventional approach based on surface landmarks. ⋯ In healthy volunteers, US guidance results in a more successful tibial nerve block at the ankle than does a traditional approach using surface landmarks.
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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
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
Comparative StudyAdverse outcomes associated with stimulator-based peripheral nerve blocks with versus without ultrasound visualization.
In this retrospective study, we queried our Quality Improvement database of anesthetic-related complications to evaluate the frequency of noncatheter peripheral nerve block-related adverse occurrences. We hypothesized that adverse complications of nerve blockade are less common when ultrasonography is used in conjunction with peripheral nerve stimulation to guide needle placement, when compared with the sole use of physical landmarks and nerve stimulation. ⋯ High-definition ultrasonography offers potential advantages in the administration of peripheral nerve blockade. The significant difference in major central nervous system local anesthetic toxicity observed in this study supports the use of ultrasound guidance in conjunction with peripheral nerve stimulation to provide brachial plexus peripheral nerve blockade in an academic, ambulatory anesthesia practice.