Articles: nerve-block.
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Reg Anesth Pain Med · Nov 2009
Randomized Controlled Trial Multicenter Study Comparative StudyHemidiaphragmatic paresis can be avoided in ultrasound-guided supraclavicular brachial plexus block.
Supraclavicular brachial plexus block is associated with 50% to 67% incidence of hemidiaphragmatic paresis as a result of phrenic nerve block. We examined whether ultrasound-guided compared with nerve stimulation supraclavicular brachial plexus block using 0.75% ropivacaine results in a lower incidence of hemidiaphragmatic paresis. ⋯ Ultrasound-guided supraclavicular brachial plexus block, using 20 mL of 0.75% ropivacaine with the described technique, is not associated with hemidiaphragmatic paresis.
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Reg Anesth Pain Med · Sep 2009
Randomized Controlled Trial Multicenter Study Comparative StudyEffect on neurostimulation of injectates used for perineural space expansion before placement of a stimulating catheter: normal saline versus dextrose 5% in water.
We clinically assessed the electrophysiologic effect of dextrose 5% in water (D5W) and of normal saline (NS) used for expansion of the perineural space before placing a stimulating catheter. We questioned if higher current was required with NS but not with D5W, as has been observed experimentally. ⋯ The current needed to electrostimulate the femoral or sciatic nerve was higher after injection of NS than after D5W.
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Reg Anesth Pain Med · Jul 2009
Multicenter StudyVarious possible positions of conventional catheters around the femoral nerve revealed by neurostimulation.
In continuous femoral nerve blocks, the various perineural positions of the tip of a conventional catheter and their clinical implication are not completely known.We used stimulating catheters to explore the relationship of catheter tip to nerve. ⋯ The effectiveness of a continuous femoral block depends on neurostimulation characteristics, which likely correspond to various possible catheter tip positions. Conventional catheters provide no information on this issue. These results suggest that better VAS scores are attainable by placing catheters with neurostimulation guidance.
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Comment Letter Multicenter Study
Survey of combined regional blocks and general anaesthesia.
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Anesthesia and analgesia · Jan 2009
Randomized Controlled Trial Multicenter StudyThe effects of local anesthetic concentration and dose on continuous infraclavicular nerve blocks: a multicenter, randomized, observer-masked, controlled study.
It remains unclear whether local anesthetic concentration or total drug dose is the primary determinant of continuous peripheral nerve block effects. The only previous investigation, involving continuous popliteal-sciatic nerve blocks, specifically addressing this issue reported that insensate limbs were far more common with higher volumes of relatively dilute ropivacaine compared with lower volumes of relatively concentrated ropivacaine. However, it remains unknown if this relationship is specific to the sciatic nerve in the popliteal fossa or whether it varies depending on anatomic location. We therefore tested the null hypothesis that providing ropivacaine at different concentrations and rates, but at an equal total basal dose, produces comparable effects when used in a continuous infraclavicular brachial plexus block. ⋯ For continuous infraclavicular nerve blocks, local anesthetic concentration and volume influence perineural infusion effects in addition to the total mass of local anesthetic administered. Insensate limbs were far more common with smaller volumes of relatively concentrated ropivacaine. This is the opposite of the relationship previously reported for continuous popliteal-sciatic nerve blocks. The interaction between local anesthetic concentration and volume is thus complex and varies among catheter locations.