Articles: analgesia.
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Several pathophysiological mechanisms may be responsible for initiation and maintenance of chronic postherpetic pain. (1) Peripheral nociceptive fibers can develop abnormal sensitization. Secondary to this, central nociceptive "second-order" neurons in the spinal cord dorsal horn can also be sensitized, i.e. they become hyperexcitable and start responding to non-noxious stimuli. (2) Degeneration of nociceptive neurons may trigger anatomical sprouting of low-threshold mechanosensitive terminals to form connections with central nociceptive neurons and may subsequently induce functional synaptic reorganization in the dorsal horn. According to these mechanisms theoretical possibilities of therapeutical interventions to prevent postherpetic neuralgia are (1) adequate analgesia in the acute phase (analgesics, antidepressants, sympathetic blocks) and (2) prevention of C-fiber degeneration by reducing the inflammatory reaction (antiviral drugs, corticosteroids, neurotrophins). ⋯ Although there is no clear evidence in favor of a prevention of postherpetic neuralgia for any of the interventions, it is definitely reasonable to perform the best analgesia possible during the acute phase of herpes zoster.
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Randomized Controlled Trial Comparative Study Clinical Trial
Epidural analgesia compared with combined spinal-epidural analgesia during labor in nulliparous women.
Among nulliparous women, there appears to be an association between the use of epidural analgesia during labor and an increased risk of dystocia. We tested the hypothesis that combined spinal-epidural analgesia, which permits ambulation during labor, is associated with a lower incidence of dystocia than continuous lumbar epidural analgesia. ⋯ As compared with continuous lumbar epidural analgesia, the combination of spinal and epidural analgesia is not associated with an overall decrease in the incidence of cesarean delivery.
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Randomized Controlled Trial Comparative Study Clinical Trial
Patient-controlled analgesia after major shoulder surgery: patient-controlled interscalene analgesia versus patient-controlled analgesia.
The authors compared patient-controlled interscalene analgesia (PCIA) with local anesthetics with intravenous patient-controlled analgesia (PCA) with opioids to manage postoperative pain after major shoulder surgery. ⋯ The use of the PCIA technique was uncomplicated and provided better pain relief than PCA during the first 18 h after operation. The incidence of side effects such as vomiting and pruritus was significantly decreased with the use of PCIA, and patient satisfaction was superior in the PCIA group.
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Anesthesia and analgesia · Dec 1997
Pharmacokinetics and efficacy of long-term epidural ropivacaine infusion for postoperative analgesia.
The aim of this study was to evaluate the pharmacokinetics and efficacy of the new local anesthetic ropivacaine when used for epidural infusion for up to 72 h after major orthopedic surgery. Immediately after surgery, an epidural infusion of ropivacaine 2 mg/mL was begun at a rate of 6 mL/h in 11 patients. The infusion rate was then adjusted according to patient analgesic needs or side effects. Blood samples were taken during and after the infusion to determine total and unbound ropivacaine and alpha1-acid glycoprotein (AAG) concentrations. Patients were assessed regularly for sensory and motor block and pain using a visual analog scale (VAS) score (0-100 mm). Ten patients received 63-72 h of infusion. Total plasma concentrations of ropivacaine and binding protein (AAG) increased during the infusion such that free concentrations plateaued or began to fall over time. VAS values during mobilization were less than 40 mm in 93% of patients. The majority of patients had no measurable motor block once the surgical block had regressed. When epidural ropivacaine was titrated to achieve a stable sensory block, there was a low incidence of motor block, and free plasma ropivacaine levels were well below the toxic range. ⋯ The pharmacokinetics of continuous epidural infusions of ropivacaine are described in patients for up to 72 h postoperatively. Clinical efficacy and side effects are also reported. An understanding of the plasma concentrations obtained and modes of elimination during prolonged epidural infusion is important for safe, routine clinical use in postoperative analgesia.