Anesthesia and analgesia
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Anesthesia and analgesia · Feb 1996
Randomized Controlled Trial Comparative Study Clinical TrialHemodynamic effects of spinal anesthesia in the elderly: single dose versus titration through a catheter.
Sixty elderly patients (> 70 yr old) undergoing surgery for hip fracture were prospectively studied in order to compare hemodynamic tolerance of titrated doses of hyperbaric bupivacaine using continuous spinal anesthesia (CSA) versus single-dose spinal anesthesia (SDSA). Patients were randomized into two groups (CSA group: n = 30; SDSA group: n = 30). The SDSA patients received 10-15 mg of 0.5% hyperbaric bupivacaine (based on age and height), and the CSA patients received a starting dose of 5 mg of 0.5% hyperbaric bupivacaine, followed after 15 min by optional reinjection of 2.5 mg every 5 min until a T10 level sensory block was reached. ⋯ The mean dose of ephedrine was significantly less in the CSA group (1.8 +/- 0.7 mg, administered to only 37% of patients) than in the SDSA group (19.4 +/- 3.3 mg administered to all patients, P < 0.0001). No late complications related to the spinal anesthesia technique were observed in either group. We concluded that CSA, using small titrated doses of 0.5% hyperbaric bupivacaine, is safe, efficient, and provides better hemodynamic stability than SDSA in elderly patients.
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Anesthesia and analgesia · Feb 1996
Randomized Controlled Trial Comparative Study Clinical TrialCompound motor action potential recording distinguishes differential onset of motor block of the obturator nerve in response to etidocaine or bupivacaine.
The purpose of this investigation was to establish an objective (quantitative) method for determining onset time of motor block induced by different local anesthetics. Twenty-four consenting patients undergoing transurethral surgery during spinal anesthesia were randomized to receive direct obturator nerve block with 10 mL of plain bupivacaine 0.5% (n = 12) or 10 mL of plain etidocaine 1% (n = 12). Another 14 patients (control group) received obturator nerve "block" with saline. ⋯ While CMAP amplitudes in the control group returned to their initial (baseline) values after 3-6 min, the patients receiving etidocaine or bupivacaine achieved > or = 90% motor blockade after 6 and 13 min, respectively. In the present report, the time to > or = 90% block was significantly faster in patients given etidocaine compared with those given bupivacaine. We conclude that electromyographic recording of CMAPs can be used to compare the ability of different local anesthetics to induce motor block.
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Anesthesia and analgesia · Feb 1996
Bupivacaine plasma concentrations during continuous epidural anesthesia in infants and children.
Venous bupivacaine plasma concentrations were measured in six neonates and infants aged 4 days to 3.9 mo (mean, 2.1 mo) and 10 infants and children aged 9 mo to 6 yr (mean, 3.1 yr) after administration of an initial bolus of 0.5 mL/kg bupivacaine 0.25%, followed by a continuous infusion of local anesthetic (0.25 mL.kg-1.h-1) over a period of 4 h (first hour: bupivacaine 0.25%, then reduced to 0.125%). Plasma concentrations of local anesthetic measured at 180 min and 300 min after beginning of bupivacaine administration were significantly higher in younger infants when compared to older infants and children (180 min: 0.67 +/- 0.24 micrograms/mL [0.25-0.97] vs 0.27 +/- 0.11 micrograms/mL [0.19-0.55], P < 0.01; 300 min: 0.86 +/- 0.36 micrograms/mL [0.35-1.25] vs 0.34 +/- 0.12 micrograms/mL [0.18-0.57], P < 0.01). The results of our study show that despite applying the same dosage of epidural bupivacaine significantly higher plasma concentrations were seen after short periods of continuous infusion in infants up to 4 mo than in children older than 9 mo.
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Anesthesia and analgesia · Feb 1996
Randomized Controlled Trial Clinical TrialIntravenous lidocaine does not attenuate the cardiovascular and catecholamine response to a rapid increase in desflurane concentration.
This study was designed to investigate the effect of intravenous lidocaine on the sympathetic activity after a rapid increase in desflurane concentration. Twenty ASA grade I and II patients, were allocated randomly to a control group (C) and a lidocaine group (L). After induction of anesthesia with intravenous propofol 2 mg/kg and muscle relaxation with intravenous vecuronium 0.1 mg/kg, desflurane was given to achieve an end-tidal minimum alveolar anesthetic concentration (MAC) of 0.7 Group L received 1.5 mg/kg lidocaine intravenously, while Group C received an equal volume of 0.9% sodium chloride solution intravenously. ⋯ Plasma catecholamines were not significantly different between the groups. Intravenous lidocaine did not attenuate the sympathetic response to a rapid increase in desflurane concentration. It is unlikely that airway irritation is the cause of this phenomenon.
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Anesthesia and analgesia · Feb 1996
Repeated dural punctures increase the incidence of postdural puncture headache.
Previous studies have failed to find a significant correlation between the number of dural punctures and the incidence of postdural puncture headache (PDPH), questioning the hypothesis that leakage of cerebrospinal fluid (CSF) through the dural tear is the cause of PDPH. We hypothesized that insufficient statistical power of these studies was the cause for this unexpected finding, and re-examined whether repeated dural punctures increase the incidence of PDPH by analyzing prospectively collected data on 8034 spinal anesthetics. Uneventful spinal anesthetics, including a single subarachnoid injection of local anesthetics, occurred in 7865 (97.9%) cases, whereas failed spinal anesthetics requiring repeated dural puncture for a second subarachnoid injection of local anesthetics occurred in 165 (2.1%) cases. ⋯ We found that repeated dural punctures significantly increased the incidence of PDPH. We conclude that increased risk of PDPH is a disadvantage of performing a second subarachnoid injection of local anesthetics after a failed spinal anesthetic. Moreover, this result suggests that leakage of CSF through the dural tear is the most plausible cause of PDPH.