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S R Weitz

Publications and source records attributed to S R Weitz.

6 recordsLinked to original sources
PubMed1995

Local anesthetic test dose as a predictor of effective epidural opioid analgesia.

BACKGROUND: When local anesthetic is used to produce epidural anesthesia intraoperatively, epidural catheter placement is confirmed. However, when epidural catheters are placed intraoperatively only to provide postoperative opioid analgesia, correct catheter placement may not be confirmed by administration of a local anesthetic. The current study tests the hypothesis that the extent of sensory blockade produced by a 10-ml dose of 1.5% lidocaine can be used to predict the adequacy of epidural opioid analgesia. METHODS: Forty-nine patients undergoing major abdominal surgery in whom a lumbar epidural catheter was placed intraoperatively were studied, but no more than 3 ml 1% lidocaine had been injected. Placement of the epidural catheter was assessed in the postanesthesia care unit by administration of a 10-ml dose of 1.5% lidocaine. The extent of sensory blockade was determined using the pinprick technique: All dermatomes, T2 and below, were assessed and scored using 1 point per dermatome per side from L1 to T2 to a maximum of 24 points. Scores were arbitrarily divided into three groups, where group 1, 0-7 points; group 2, 8-15 points; and group 3, 16-24 points. Epidural morphine infusion was initiated independently of the extent of the sensory blockade and adjusted using predetermined guidelines. Adequacy of opioid-induced analgesia was determined using the visual analog scale. RESULTS: Significantly lower visual analog scale scores for pain at rest and with movement from epidural morphine infusion were associated with sensory blockade score of 16-24 points. Seven patients failed to obtain a detectable sensory block. No patient requested alternative analgesia. None of the epidural catheters was removed because of inadequate pain relief, even in patients who failed to obtain a detectable sensory block. CONCLUSIONS: Extensive sensory block from 10 ml 1.5% lidocaine was associated with excellent epidural opioid analgesia. Extent of analgesia after a 10-ml test dose of 1.5% lidocaine can be used to predict the adequacy of analgesia resulting from an epidural opioid infusion. The failure of a local anesthetic dose to produce sensory blockade does not necessarily predict a failure to produce analgesia from an epidural opioid infusion, as indicated by the presence of analgesia in several patients without detectable sensory block.

Analgesia, Epidural↗
PubMed1995

Neurologic complications of lumbar epidural anesthesia and analgesia.

We reviewed the clinical features of 12 patients with neurologic complications following lumbar epidural anesthesia or analgesia. Eleven patients experienced lumbosacral radiculopathy or polyradiculopathy and, of these, 10 received epidural anesthesia or analgesia and one received subarachnoid injection of medication after intended epidural anesthesia. One patient suffered a moderately severe thoracic myelopathy in the setting of unintended spinal anesthesia. The two patients with more severe polyradiculopathy had severe lumbar spinal stenosis on MRI. The other patients experienced mild to moderate neurologic deficits most often involving the L-2 root, and MRIs, when performed, were unremarkable. EMG on three patients helped to localize the lesions to the lumbosacral roots and to quantify the extent of axonal loss. Ten patients were ambulatory upon discharge from the hospital and had good neurologic outcome. One patient with severe polyradiculopathy did not improve after 4 years and had severe motor axonal loss based upon electrodiagnostic studies. The patient with a thoracic myelopathy was ambulatory 4 months after onset. Although generally a safe procedure with low frequency of complications, lumbar epidural anesthesia or analgesia occasionally causes neurologic sequelae such as radiculopathy or myelopathy. Neurologic complications may be more severe in the presence of spinal stenosis or after inadvertent subarachnoid injection of anesthetic or analgesic agent.

Adult↗