Regional anesthesia and pain medicine
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Reg Anesth Pain Med · May 2004
Review Case ReportsSpinal cord compression from intrathecal catheter-tip inflammatory mass: case report and a review of etiology.
The majority of intrathecal pumps are implanted by anesthesiologists. Despite a recent increase in case reports involving intrathecal catheter-tip inflammatory masses, this complication is rarely reported in the anesthesiology literature. The present case report describes a patient with spinal cord compression as a result of an inflammatory mass and reviews the current literature as to the etiology of inflammatory mass formation. ⋯ Delivery of high-dose intrathecal opioids can result in the formation of an inflammatory mass, leading to poor pain control and neurologic complications. Anesthesiologists should be vigilant as to these complications when managing patients receiving intrathecal pump therapy.
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Reg Anesth Pain Med · May 2004
ReviewSelective nerve root blocks for low back pain and radiculopathy.
In the management of patients with low back pain and radiculopathy, selective nerve root blocks (SNRBs) are now a common procedure for both diagnostic and therapeutic purposes. This article reviews the available studies as well as the relevant anatomy, pathology, technical considerations, and complications.
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Reg Anesth Pain Med · May 2004
Case ReportsElectrical nerve stimulation using a stimulating catheter: what is the lower limit?
To minimize the risk of intraneural injection when performing nerve blocks, some authors caution against injecting through a needle placed with motor responses observed at nerve stimulator output settings of 0.3 mA or less. We present a case of placing a continuous cervical paravertebral catheter with brisk motor response while stimulating the catheter at 0.05 mA, with no adverse sequelae. ⋯ We present a single case of successful placement of a stimulating catheter with no neurological injury even when motor response occurred at very low nerve stimulator output settings.
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Reg Anesth Pain Med · May 2004
Comparative StudyInjection pressures by anesthesiologists during simulated peripheral nerve block.
Anesthesiologists typically rely on a subjective evaluation ("syringe feel") of possible abnormal resistance to injection while performing a peripheral nerve block (PNB). A greater force required to perform the injection is believed to be associated with intraneural injection. The hypothesis of this study is that anesthesiologists vary in their perception of "normal" injection force, that the syringe feel method is inconsistent in estimating resistance, and that needle design may affect the injection force. ⋯ Anesthesiologists vary widely in their perception of appropriate force and rate of injection during PNB. The syringe-feel method of assessing injection force is inconsistent and may be further affected by variability in needle design.
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Reg Anesth Pain Med · May 2004
Comparative StudyElectrophysiologic effect of injectates on peripheral nerve stimulation.
A small volume of local anesthetic or normal saline abolishes the muscle twitch induced by a 1ow current (0.5 mA) during electrolocation. This study examines the hypothesis that the mechanism of this phenomenon is primarily the electrophysiologic effect of the injectate on the electrical current density at the needle tip. ⋯ The injection of a conducting solution (i.e., NS) rendered the current that was previously sufficient to elicit a motor response (0.5 mA) ineffective. The most likely reason for this change is that the conductive area surrounding the stimulating needle expanded after the injection and dispersion of the conducting solution (i.e., NS), thereby reducing the current density at the target nerve. This effect can be reversed by injecting a nonconducting solution (i.e., D5W) via the stimulating needle.