Anesthesia and analgesia
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Anesthesia and analgesia · Jul 1985
A retrospective study of the incidence and causes of failed spinal anesthetics in a university hospital.
One hundred sequential spinal anesthetic procedures were reviewed retrospectively to study specifically the incidence and causes of spinal anesthesia. Variables examined included the patient population, the technical aspects of performing subarachnoid tap and subsequent blockade, and the level of training of the anesthetists. We found a 17% incidence of spinal failure, defined as the need to use general anesthesia during the surgical procedure. ⋯ We attribute the high incidence of failed spinal anesthesia mainly to technical reasons, most of them avoidable. The use of local and regional anesthesia requires considerable technical skills and demands a precise and total understanding of regional anatomic relationships. With the decreasing use of regional anesthesia in our operating rooms, only those regional anesthesia techniques that require minimum dexterity, such as spinal and epidural anesthesia, continue to be utilized widely; and even these techniques, safe as they are, are being poorly taught.
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Anesthesia and analgesia · Jul 1985
Vecuronium and d-tubocurarine combination: potentiation of effect.
To evaluate possible potentiation of neuromuscular blocking effect of a combination of vecuronium and d-tubocurarine, cumulative dose-response curves were constructed to compare the potency of this combination with vecuronium and d-tubocurarine given alone. Ten patients each were given incremental injections of 80 micrograms/kg d-tubocurarine or 5 micrograms/kg vecuronium plus 40 micrograms/kg d-tubocurarine, the data for incremental administration of 10 micrograms/kg vecuronium being used from our previously published study (7). The results showed the combination of vecuronium plus d-tubocurarine to be significantly more potent (P less than 0.05) than would be expected from a simple additive effect of the individual drugs given alone. The ED95 doses of d-tubocurarine and vecuronium were 530 micrograms/kg and 57 micrograms/kg, respectively, when administered alone, but when administered together, the ED95 doses were 160 and 20 micrograms/kg, respectively.
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Anesthesia and analgesia · Jun 1985
Safety and efficacy of epinephrine added to bupivacaine for lumbar epidural analgesia in obstetrics.
The effects of epidural bupivacaine with and without 1:300,000 epinephrine on uterine activity, progress of labor, fetal heart rate, maternal blood pressure and heart rate, newborn Apgar scores, neonatal acid-base status, and Neurologic and Adaptive Capacity Scoring System (NACS) were compared in 32 parturients during labor and delivery. Patients in group I (n = 16) received 0.5% bupivacaine with 1:300,000 epinephrine and those in group II (n = 16) received 0.5% bupivacaine alone. Addition of epinephrine to bupivacaine had no significant effects on uterine activity, duration of first or second stages of labor, fetal heart rate and variability, or the incidence of abnormal fetal heart rate patterns. ⋯ Apgar scores, neonatal acid-base status, and the NACS were equally good in the two groups. Duration of analgesia was significantly longer in group I than in group II (186.8 +/- 11.6 vs 85.3 +/- 6.1 (mean +/- SEM) min, P less than 0.001). It is concluded that adding epinephrine to bupivacaine during epidural anesthesia in the normal parturient has no adverse effects on either mother, fetus, neonate, or the progress of labor; and that it significantly prolongs the duration of anesthesia and decreases the incidence of maternal hypotension.
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The effects of intravenously administered fentanyl (25 micrograms/kg, n = 9; 50 micrograms/kg, n = 5) and alfentanil (12.5 micrograms/kg, n = 5; 25 micrograms/kg, n = 7) on the noxiously evoked, single-unit activity of cells in the nucleus reticularis gigantocellularis (NRGC) were studied in decerebrate cats. Only cells of the NRGC excited exclusively by supramaximal electrical stimulation of A delta fibers (noxious stimulation) of the superficial radial nerve were studied. ⋯ Fentanyl and alfentanil effects were antagonized by the intravenous administration of naloxone. These results indicate that opioid suppression of noxiously evoked activity is seen in neurons located in the brainstem, and thus suppression of brainstem neurons may be important in the production of fentanyl and alfentanil analgesia.