Regional anesthesia and pain medicine
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Reg Anesth Pain Med · Jul 2009
Ultrasound-guided cervical selective nerve root block: a fluoroscopy-controlled feasibility study.
Reports of intravascular injection during cervical transforaminal injections, even after confirmation by contrast fluoroscopy, have led some to question the procedure's safety. As ultrasound allows for visualization of soft tissues, nerves, and vessels, thus potentially improving precision and safety, we evaluated its feasibility in cervical nerve root injections. ⋯ Our case series shows the feasibility of using ultrasound imaging to guide selective cervical nerve root injections. It may facilitate identifying critical vessels at unexpected locations relative to the intervertebral foramen and avoiding injury to such vessels, which is the leading cause of the reported complications from cervical nerve root injections. A randomized controlled trial to compare the effectiveness and safety of ultrasound imaging against other imaging techniques seems warranted.
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Reg Anesth Pain Med · Jul 2009
Ultrasound-guided lumbar medial branch block in obese patients: a fluoroscopically confirmed clinical feasibility study.
Obesity is a major risk factor for lower back pain. Fluoroscope-guided medial branch block is a common diagnostic tool in these patients. Although approach to the facet joint guided by ultrasound has been demonstrated successfully in lean patients, its success in obese patients is unknown.We therefore evaluated the success rate of real-time ultrasound approach in obese patients in a clinical feasibility study. ⋯ Medial branch blocks in obese patients cannot be performed by ultrasound guidance exclusively.
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Reg Anesth Pain Med · Jul 2009
Prevalence and risk factors predisposing to coagulopathy in patients receiving epidural analgesia for hepatic surgery.
Patients undergoing liver resection may have marginal preoperative liver function, extensive intraoperative blood loss, and perioperative hepatic dysfunction. We evaluated the prevalence and types of coagulopathic conditions that occur in patients with epidural catheters undergoing hepatic resection. ⋯ A high prevalence of hemostatic abnormalities in patients undergoing major hepatic resection while receiving epidural analgesia occurred. Important considerations may include discussion with the surgical team, measuring coagulation, and heightened clinical monitoring in the postoperative period.
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Reg Anesth Pain Med · Jul 2009
Calcium chloride prolongs the effects of lidocaine and bupivacaine in rat sciatic nerve.
Elevated extracellular calcium ion has been shown to shift the voltage dependence of Na+- and K+-ion channels rightward, making the nerve less excitable. We hypothesized that calcium chloride (CaCl2) when used as an adjuvant prolongs and intensifies the block by local anesthetics (LAs). We investigated the effects of LAs combined with calcium in rat sciatic nerve blockade and in cultured rat GH3 cells expressing Na+ channels. Furthermore, we tested for histologic changes due to CaCl2. ⋯ The mechanism of prolonged nerve block of CaCl2 coadministered with LAs seems to be a raised threshold for nerve excitation. Major histopathologic changes at higher concentrations of CaCl2 are evident, and therefore, clinical application as an adjuvant to LAs seems unlikely.
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Reg Anesth Pain Med · Jul 2009
Measurement of shift of the cauda equina in the subarachnoid space by changing position.
To perform spinal anesthesia, patients are usually placed in the lateral decubitus position with the knees drawn up to the stomach, the legs fully flexed, and the neck flexed to curve the back outward. Because the nerve roots of the cauda equina have considerable mobility in the subarachnoid space, the position of the cauda equina in the lateral decubitus position may be different from that in the supine position. However, the anatomic position of the cauda equina in the lateral decubitus position with fully flexed legs has not been carefully studied. In the present study, we geometrically measured the movement of the cauda equina in the subarachnoid space by changing positions, using magnetic resonance imaging (MRI). ⋯ The present study using MRI showed dynamical movement of the spinal cord and cauda equina due to changing position. The most obvious movements by changing from supine to lateral decubitus position and fully flexed legs were observed at the L2/3 and L1/2 levels, respectively.