Articles: nerve-block.
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Anesthesia and analgesia · Dec 1996
Randomized Controlled Trial Clinical TrialThe effect of bupivacaine skull block on the hemodynamic response to craniotomy.
The placement of pointed cranial pins into the periosteum is a recognized acute noxious stimulation during intracranial surgery which can result in sudden increases in blood pressure and heart rate, causing increases in intracranial pressure. A skull block (blockade of the nerves that innervate the scalp, including the greater and lesser occipital nerves, the supraorbital and supratrochlear nerves, the auriculotemporal nerves, and the greater auricular nerves) may be effective in reducing hypertension and tachycardia. Twenty-one patients were allocated in a prospective, double-blind fashion to a control group or a bupivacaine group. ⋯ Systolic (SAP), diastolic (DAP), mean arterial pressure (MAP), heart rate (HR), and end-tidal isoflurane were recorded at the following times: 5 min after the induction of anesthesia, during performance of the skull block, during head pinning, and 5 min after head pinning. Significant increases in SAP of 40 +/- 6 mm Hg, DAP of 30 +/- 5 mm Hg, MAP of 32 +/- 6 mm Hg, and HR of 22 +/- 5 bpm occurred during head pinning in the control group, while remaining unchanged in the bupivacaine group. These results demonstrate that a skull block using 0.5% bupivacaine successfully blunts the hemodynamic response to head pinning.
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Randomized Controlled Trial Clinical Trial
Propofol and alfentanil for sedation during placement of retrobulbar block for cataract surgery.
To determine if the addition of alfentanil to propofol is more effective than propofol alone to provide adequate conditions for placement of a retrobulbar block prior to cataract surgery. ⋯ The combination of alfentanil and propofol may be used to sedate patients in order to limit movement and provide a cooperative, alert patient with stable hemodynamics and limited respiratory depression during placement of retrobulbar block prior to ophthalmic surgery. However, excessive dosage of these drugs may result in hazardous respiratory depression in this patient population.
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Anesthesia and analgesia · Dec 1996
Randomized Controlled Trial Clinical TrialMaternal posture influences the extent of sensory block produced by intrathecal dextrose-free bupivacaine with fentanyl for labor analgesia.
The cephalad extent of sensory block produced by intrathecal (IT) dextrose-free local anesthetics and opioids has been reported to be quite variable. Most reports describing the effects of IT analgesics do not control for patients posture. Because these medications are hypobaric relative to cerebrospinal fluid (CSF), parturients in a sitting position may develop greater cephalad extents of sensory block than those in a lateral position during IT injection. ⋯ Mean cephalad extent of block was greater in the sitting group at 20 and 30 min. When sensory block asymmetry was observed, the extent of block was greater on the nondependent side. Posture during IT injection of this dextrose-free analgesic combination affects extent of sensory block in laboring parturients.
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Neurolytic agents such as phenol (5% to 10%) and absolute alcohol have long been used clinically to destroy the pathogenic nerve regions that manifest pain. Both phenol and alcohol are highly destructive to nerve fibers. However, these agents exert only weak local anesthetic effects and therefore are difficult to administer to alert patients without pain. This report describes a tetracaine derivative that displays both local anesthetic and neurolytic properties. Studies with such a compound may lead to the design of neurolytic agents that are more effective and more easily administered than phenol and alcohol. ⋯ A single injection of N-butyl tetracaine produces ultralong sciatic nerve block in rats. This compound possesses both local anesthetic and neurolytic properties and may prove useful as a neurolytic agent in pain management.
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Regional anesthesia · Nov 1996
Randomized Controlled Trial Clinical TrialLidocaine-clonidine retrobulbar block for cataract surgery in the elderly.
Clonidine, an alpha-2-adrenoreceptor agonist, has been shown to decrease intraocular pressure (IOP) and to have some analgesic and sedative effects when it is used in premedication for ophthalmic surgery. This study was designed to investigate the efficacy of lidocaine-clonidine retrobulbar block for cataract surgery with respect to its effect on IOP, analgesic action, and sedative effects. ⋯ Addition of clonidine to lidocaine for retrobulbar block causes a decrease in intraocular pressure, a sedative effect, and an increased duration of analgesia and akinesia, with relatively stable hemodynamic parameters.