Anesthesia and analgesia
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Anesthesia and analgesia · Jul 1986
Intrathecal morphine and heroin in humans: six-hour drug levels in spinal fluid and plasma.
Lumbar spinal fluid and plasma concentrations of morphine were measured by radioimmunoassay after intrathecal administration of 1 mg of morphine (n = 13) or heroin (n = 10). Plasma levels of morphine were measured regardless of 'whether heroin or morphine was injected intrathecally, because of the rapid biotransformation of heroin to morphine in plasma. Significant drug concentrations appeared in plasma after intrathecal heroin (peak concentration 47.8 +/- 9.0 nmol/L, time to peak concentration 10 +/- 2.4 min); after intrathecal morphine plasma drug concentrations were significantly lower (8.1 +/- 1.0 nmol/L; P less than 0.002) and significantly later (216 +/- 39 min; P less than 0.002). Elimination half-life of heroin from spinal fluid (43 +/- 5 min) was significantly shorter than for morphine (73 +/- 5 min; P less than 0.02).
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Anesthesia and analgesia · Jul 1986
The dorsomedian connective tissue band in the lumbar epidural space of humans: an anatomical study using epiduroscopy in autopsy cases.
An anatomical study of the lumbar epidural space in 48 autopsy subjects was made using a method of endoscopy developed by the author called epiduroscopy. In every case there was a dorsal connective tissue band in the midline of the epidural space between the dura mater and the flaval ligaments. The appearance of the band varied from strands of connective tissue to a complete membrane. This connection fixed the dura mater to the flaval ligaments and also narrowed the epidural space in the midline.
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Anesthesia and analgesia · Jul 1986
Electrical and mechanical train-of-four responses during depolarizing and nondepolarizing neuromuscular blockade.
Simultaneous measurements of train-of-four (TOF) responses by integrated electromyography (IEMG) and twitch force were compared for atracurium, vecuronium, and succinylcholine in 30 subjects during nitrous oxide-fentanyl anesthesia. Determinations of TOF were made during neuromuscular blockade (NMB) onset and recovery. Scattergrams and least squares regression lines were plotted, and z-tests for parallel slope and common intercept were used to compare lines. ⋯ This finding is important for interpretation of IEMG when used for clinical monitoring. Comparison of data for depolarizing NMB shows more complex relationships. Integrated electromyography is found to be convenient and reliable for monitoring nondepolarizing NMB.
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Anesthesia and analgesia · Jul 1986
Wakefulness during cesarean section after anesthetic induction with ketamine, thiopental, or ketamine and thiopental combined.
Thirty-six pregnant women (ASA class I or II) at term who underwent general anesthesia and cesarean section received either ketamine, 1 mg/kg (n = 12); thiopental, 4 mg/kg (n = 13); or a combination of ketamine, 0.5 mg/kg, and thiopental, 2 mg/kg (n = 11). A blood pressure cuff inflated to 250 mm Hg isolated one arm from the effects of succinylcholine so that awareness during anesthesia could be assessed by asking the patient to move her hand. Although only one patient receiving ketamine responded to commands during anesthesia, 46% of patients receiving either thiopental or the combination responded to commands intraoperatively. ⋯ Three patients (8%) had postoperative recall of intraoperative awareness; one had received thiopental and two the combination. Maternal intraoperative cardiovascular responses among the groups were similar, as were umbilical blood gas values, newborn Apgar scores, and neonatal neurobehavioral test scores at 4 and 24 hr. Ketamine more effectively blocked maternal responsiveness to commands and strong stimuli during the first few minutes after anesthetic induction for cesarean section than did thiopental or a combination of thiopental and ketamine, each at a lower dose.