Anesthesia and analgesia
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Anesthesia and analgesia · Mar 1992
Randomized Controlled Trial Comparative Study Clinical TrialUse of patient-controlled analgesia to compare the efficacy of epidural to intravenous fentanyl administration.
Fentanyl, unlike morphine, is highly lipophilic and rapidly diffuses out of the epidural space. Respiratory depression is, therefore, unlikely when fentanyl is given epidurally. However, much of fentanyl's analgesic effect is mediated by systemic rather than spinal receptor binding. ⋯ There were also no significant differences in the cumulative dosage of fentanyl within each group (epidural vs IV) or between the groups. Thus, the analgesic effects of epidural fentanyl appear largely mediated by systemic absorption. Intravenous fentanyl achieves a similar degree of analgesia and a more rapid onset of effect without the need for epidural catheterization.
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Anesthesia and analgesia · Mar 1992
Randomized Controlled Trial Comparative Study Clinical TrialMivacurium: dose-response relationship and administration by repeated injection or infusion.
The dose-response relationship and neuromuscular blockade after infusion or repeated injection of mivacurium were studied in 65 patients in nitrous oxide-narcotic anesthesia. The ED95 (twitch tension) was determined in 45 patients by intravenous injection of a single bolus of 30, 39, 47, 54, or 60 micrograms/kg (9 patients per dose). Another 20 patients received an initial bolus of 2 x ED95 followed either by an infusion started at 5% twitch recovery (i.e., 95% depression) and adjusted to sustain 95% twitch depression (n = 10) or by repeated injection of 0.6 x ED95 whenever twitch tension had recovered to 25% of control (n = 10). ⋯ A 6 +/- 2 min recovery index was found after up to 10 repeat injections given every 9 +/- 3 min. There was no significant effect of neostigmine in both groups. In conclusion, the recovery indices after the infusion or repeat injection of near-equal doses of mivacurium were identical.
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Anesthesia and analgesia · Mar 1992
Randomized Controlled Trial Clinical TrialSystemic piroxicam as an adjunct to combined epidural bupivacaine and morphine for postoperative pain relief--a double-blind study.
In a randomized, double-blind, placebo-controlled trial, we assessed the value of adding rectal piroxicam to a low-dose epidural regimen for postoperative pain relief. Forty-four patients scheduled for major upper abdominal surgery during combined thoracic epidural (bupivacaine + morphine) and general anesthesia were studied. Postoperative analgesia was achieved by using epidural bupivacaine (10 mg/h) plus morphine (0.2 mg/h) for 72 h. ⋯ The sensory level of analgesia was evaluated by pinprick. We found no significant difference between piroxicam and placebo with regard to postoperative pain scores or need for supplementary analgesics. Thus, we were unable to demonstrate enhanced analgesia by adding piroxicam to an otherwise very effective low-dose epidural bupivacaine and morphine treatment after upper abdominal surgery.
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Anesthesia and analgesia · Mar 1992
Randomized Controlled Trial Clinical TrialAlkalinization of mepivacaine for axillary block.
We examined the onset and distribution of sensory blockade, the onset of motor blockade, and venous mepivacaine concentrations after axillary block with 1.25% mepivacaine with and without bicarbonate. There were no statistically significant differences between the alkalinized and placebo groups with respect to distribution of analgesia or anesthesia, time to onset of analgesia, or time to onset of paresis. ⋯ Concentrations of mepivacaine in venous blood did not differ significantly. We conclude that alkalinized mepivacaine offers the advantage of quicker onset of more profound blockade in several terminal nerve distributions.
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Anesthesia and analgesia · Mar 1992
Comparative StudyHemidiaphragmatic paresis during interscalene brachial plexus block: effects on pulmonary function and chest wall mechanics.
We studied the effects of unilateral hemidiaphragmatic paresis caused by interscalene brachial plexus block on routine pulmonary function in eight patients. In an additional four patients, we studied changes in chest wall motion during interscalene block anesthesia by chest wall magnetometry. Ipsilateral hemidiaphragmatic paresis, as diagnosed by ultrasonography, developed in all patients within 5 min of interscalene injection of 45 mL of 1.5% mepivacaine with added epinephrine and bicarbonate. ⋯ Peak expiratory and maximum midexpiratory flow rates were also significantly reduced. Interscalene block caused changes in pulmonary function and chest wall mechanical motion that were similar to those published in previous studies on patients with hemidiaphragmatic paresis of pathological or surgical etiology. Interscalene block probably should not be performed in patients who are dependent on intact diaphragmatic function and in those patients unable to tolerate a 25% reduction in pulmonary function.