Regional anesthesia
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Regional anesthesia · Jan 1996
A trigonometric analysis of needle redirection and needle position during neural block.
Successful regional anesthesia involves a three-dimensional visualization of anatomy and an informed approach to needle placement and repositioning. This study trigonometrically examines the relationship between needle insertion angle and resultant needle position. ⋯ Incremental needle redirection of 5 degrees allows a precise survey of neural and adjacent anatomy and results in approximately one half the change in needle position occurring with a 10 degree angle of redirection. However, a 10 degree angle of redirection may result in walking over the desired neural structure.
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Regional anesthesia · Jan 1996
Randomized Controlled Trial Clinical TrialThe effect of continuous lumbar epidural infusion of ropivacaine (0.1%, 0.2%, and 0.3%) and 0.25% bupivacaine on sensory and motor block in volunteers: a double-blind study.
In animal studies, ropivacaine has shown more pronounced sensory block than motor block, which makes it an interesting drug for postoperative pain relief. The aim of this study was to investigate the dose response of sensory and motor block during continuous epidural infusion of 0.1, 0.2, or 0.3% ropivacaine in volunteers in a double-blind manner. Bupivacaine 0.25% and isotonic saline were used as reference and control, respectively. ⋯ Ropivacaine 0.1% produced limited analgesia and minimal motor block, so that ambulation was possible throughout the investigation. With 0.2 and 0.3% ropivacaine, analgesia was more extensive, and motor block was considered moderate. Ropivacaine 0.2% should be evaluated for future postoperative pain treatment.
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Regional anesthesia · Jan 1996
Case ReportsEpidurograms in the management of patients with long-term epidural catheters.
Standardized test doses have been established in the practice of anesthesiology to determine the location of the epidural catheter tip. The resulting data obtained after test dosing is open to interpretation, and comparison is difficult. A more objective method of catheter verification and epidural space measurement is indicated in long-term epidural catheterization. The goal of this review is to define a standard procedure for epidurography, explore the use of an epidurogram algorithm in differential diagnosis, and review the temporal relationship of a series of epidurograms. ⋯ The review of repeated epidurograms and presented case reports support the use of epidurograms as a diagnostic tool for clinical practice. Abnormal epidurograms helped determine epidural space infection, tumor obstruction, space compression from vertebral compression fractures, and epidural fibrosis. The addition of a contrast computed tomographic scan after epidurography allows for more accurate diagnostic interpretation of epidural space pathology. The use of a standard epidurogram technique allows this procedure to be used in the differential diagnosis of suspected problems in the epidural space.
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Regional anesthesia · Jan 1996
Microscopic analysis of the tips of thin spinal needles after subarachnoid puncture.
Foreign material may pass unrecognized with the spinal needle into the subarachnoid space. Therefore the tips of three clinically used types of spinal needles--Quincke (27-gauge), two-zone bevel (26-gauge), and Sprotte or pencil point (27-gauge)--were prepared for microscopic analysis after subarachnoid puncture in human cadavers. ⋯ Of the three needle types studied, the pencil point type has a tip that best withstands distortion and adherence of foreign material during experimental subarachnoid puncture.
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An epidural anesthetic was planned for a 24-year-old woman for analgesia during labor and for a 28-year-old woman for an elective cesarean delivery. ⋯ To prevent the knotting of an epidural catheter, it should not be inserted more than 3-4 cm into the epidural space. General anesthesia may be one of the options to remove the catheter.