Anesthesia and analgesia
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Anesthesia and analgesia · Mar 1990
Randomized Controlled Trial Comparative Study Clinical TrialComparison of patient-controlled epidural analgesia and conventional intermittent "top-up" injections during labor.
In a prospective, randomized manner, bolus injection patient-controlled epidural analgesia (PCEA; n = 30) and conventional intermittent "top-up" injections (CIT; n = 28) of bupivacaine in nulliparous parturients during first stage of labor were compared. Group A (PCEA) patients self-administered, using a patient-controlled analgesia device, 4-mL increments of 0.125% bupivacaine with 1: 400,000 epinephrine, to a maximum 12 mL/h as required. Group B (CIT) patients received 12 mL of the same solution, on request, from the anesthesiologist. ⋯ The groups were demographically comparable and equally low hourly bupivacaine requirements were seen (group A, 6.36 +/- 0.43 mg; group B, 6.23 +/- 0.39 mg) producing similar mean sensory levels. Pain relief obtained in both groups was similar but was associated with greater satisfaction in patients using PCEA (P less than 0.05). This study shows that PCEA is a viable alternative for providing pain relief in the first stage of labor.
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Anesthesia and analgesia · Mar 1990
Rate of change of somatosensory evoked potentials during isoflurane anesthesia in newborn piglets.
Most studies of the effects of inhalation anesthetics on somatosensory evoked potentials (SSEPs) have examined SSEP at single times after initiation of an anesthetic. This study describes SSEP changes as functions of time of exposure to isoflurane. Both transient and sustained SSEP changes were observed. ⋯ The long time constants ranged from 7 to 33 min. At 0.5% isoflurane, SSEP changes were often small or not sustained, and the changes could not always be well described by an exponential curve. These data suggest that the time-course of anesthetic effects on SSEPs may be prolonged and complex, and the possibility of changes over time should be considered both in experimental studies and during intra-operative monitoring.
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Anesthesia and analgesia · Mar 1990
Comparative StudyPharmacokinetics of ropivacaine in nonpregnant and pregnant ewes.
The pharmacokinetics of ropivacaine were studied in chronically instrumented nonpregnant and pregnant ewes. On the day of study, the urinary bladder was catheterized. Ropivacaine (2.5 or 3.0 mg/kg) was administered by intravenous infusion over 2 or 4 min. ⋯ It is concluded that ovine pregnancy is accompanied by changes in the pharmacokinetics of ropivacaine. Inadvertent intravenous injections of similar drug doses to pregnant and nonpregnant women might result in higher plasma concentrations of ropivacaine in the former. However, the rate of decline in plasma levels of the drug would be similar in both.
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Anesthesia and analgesia · Mar 1990
Letter Historical ArticleOne hundred thirty-six years of ether anesthesia.