Articles: nerve-block.
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Regional anesthesia · Sep 1996
Case ReportsPeripheral nerve catheterization in the management of terminal cancer pain.
Peripheral nerve catheterization techniques were used in two patients with severe pain associated with the terminal stages of metastatic cancer. The first patient had severe upper limb pain and lymphedema secondary to breast carcinoma, and the second patient had an acutely ischemic leg secondary to pelvic obstruction from an ovarian tumor. The goal of treatment was to relieve the pain, which was resistant to opioid drugs, and to optimize the quality of life that remained, estimated to be only a few weeks. ⋯ Peripheral nerve catheterization proved beneficial in two patients who presented with difficult pain management problems and should be more widely considered for the relief of severe cancer-related pain in both the upper and lower limbs.
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The enantiomerically pure (S-enantiomer) amide local anaesthetic drug ropivacaine blocked nerve fibres responsible for transmission of pain (Aδ and fibres) more completely than those that control motor function (Aβ fibres) in in vitro studies. The drug shares the biphasic vascular effects common to the amide local anaesthetic drug class. In vitro studies indicate that ropivacaine is less cardiotoxic than equimolar concentrations of bupivacaine. Apart from one trial in women undergoing hysterectomy, clinical studies that compared the efficacy of different doses of epidurally administered ropivacaine in patients undergoing various surgical procedures did not reveal any consistent dose-related differences with respect to sensory blockade. However, motor blockade did become more intense as the dose of ropivacaine increased. Overall, direct comparisons show that epidural ropivacaine is less potent than epidural bupivacaine when the 2 drugs are administered at the same concentration. However, this difference is less marked in terms of sensory blockade than motor blockade. The greater degree of separation between motor and sensory blockade seen with ropivacaine relative to bupivacaine is more apparent at the lower end of the dosage scale. Nevertheless, higher doses of ropivacaine than bupivacaine are generally required to elicit equivalent anaesthetic effects. Ropivacaine has been shown to induce successful brachial plexus anaesthesia when given at a concentration of 5 mg/ml, but not 2.5 mg/ml, and was as effective as bupivacaine in comparative studies in this indication. Limited data indicate that continuous epidural infusion of ropivacaine post-operatively reduces postsurgical pain in a dose-related manner. Morphine consumption was also reduced. Higher doses of ropivacaine were significantly more effective than placebo. Similarly, ropivacaine controlled postsurgical pain when infiltrated directly into surgical wound sites (i.e. wound infiltration) and was as effective as bupivacaine, and more effective than placebo, in this regard. Adverse events associated with epidurally administered ropivacaine include hypotension, nausea, bradycardia, transient paraesthesia, back pain, urinary retention and fever. The drug appears to have an adverse event profile similar to that of bupivacaine. In animal studies, overdoses of ropivacaine were better tolerated than overdoses of bupivacaine but not lidocaine (lignocaine). Human volunteers tolerated a higher intravenous dosage of ropivacaine than bupivacaine before developing initial signs of toxicity. Thus, ropivacaine, according to animal data, is less cardiotoxic than bupivacaine. Based on available clinical data, ropivacaine appears to be as effective and well tolerated as bupivacaine when equianalgesic doses are compared. The greater degree of separation between motor and sensory blockade seen with ropivacaine relative to bupivacaine at lower concentrations (≈5 mg/ml) will be advantageous in certain applications. ⋯ Recommended epidural doses of ropivacaine for surgical anaesthesia range between 113 and 200mg. Different doses can be achieved by varying either the concentration or volume of solution injected. Epidural ropivacaine administered to control postsurgical pain can be given as a 20 to 40mg bolus with 20 to 30mg top-up doses at ≥30-minute intervals or as a 2 mg/ml continuous epidural infusion at a rate of 6 to 14 ml/h (lumbar) or 4 to 8 ml/h (thoracic).
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Randomized Controlled Trial Clinical Trial
Alkalinisation of lignocaine to reduce the pain of digital nerve blockade.
To see if the alkalinisation of lignocaine caused a reduction in the pain of injection for digital nerve blockade. ⋯ Alkalinisation of lignocaine reduces the pain of injection for digital nerve blockade.
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Randomized Controlled Trial Clinical Trial
Dorsal penile nerve block in children undergoing circumcision in a day-care surgery.
Circumcision is performed under general anaesthesia (GA) with dorsal penile nerve block (DPNB) as an analgesic technique for postoperative pain. The purpose of this study was to compare DPNB as the sole anaesthetic procedure vs GA and DPNB for circumcision in children as an outpatient procedure. ⋯ These data confirm that DPNB has advantages over GA + DPNB for paediatric circumcision in day-care surgery.
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There is a clinical requirement for longer-acting local anesthetics, particularly for the management of post-operative and chronic pain. In this regard, liposomes have been suggested to represent a potentially useful vehicle for sustained drug release after local administration. In the current study, the authors used a transmembrane pH gradient to efficiently encapsulate bupivacaine within large unilamellar vesicles. They report on the kinetics of drug uptake and release and the duration of nerve blockade. ⋯ Large unilamellar vesicles that exhibit a pH gradient can efficiently encapsulate bupivacaine and subsequently provide a sustained-release system that greatly increases the duration of neural blockade.