Anesthesiology
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Randomized Controlled Trial Clinical Trial
The dose-response of caudal ropivacaine in children.
Ropivacaine, a new local anesthetic, is less cardiotoxic in adults and is less likely to cause motor blockade than is bupivacaine. The authors evaluated the clinical effectiveness and hemodynamic effects of ropivacaine compared with bupivacaine and the pharmacokinetics of ropivacaine when given for caudal blocks in 56 children 4.1 +/- 1.2 yr old (mean +/- SD). ⋯ Ropivacaine is well tolerated and provides effective analgesia when given for caudal blockade in small children for inguinal hernia repair.
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Randomized Controlled Trial Clinical Trial
The dynamic relationship between end-tidal sevoflurane and isoflurane concentrations and bispectral index and spectral edge frequency of the electroencephalogram.
Inhalational anesthetics produce dose-dependent effects on electroencephalogram-derived parameters, such as 95% spectral edge frequency (SEF) and bispectral index (BIS). The authors analyzed the relationship between end-tidal sevoflurane and isoflurane concentrations (FET) and BIS and SEF and determined the speed of onset and offset of effect (t1/2k(e0)). ⋯ The speed of onset and offset of anesthetic effect did not differ between isoflurane and sevoflurane; isoflurane was approximately twice as potent as sevoflurane. The greater values of t1/2k(e0) derived from the BIS data compared with those derived from the SEF data may be related to computational and physiologic delays.
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Physicians and their patients are greatly concerned about perioperative blood administration. Although isovolemic hemodilution is utilized to decrease the incidence of transfusion, it is unclear at what degree of hemodilution hepatoenteric ischemia and injury occurs. The authors hypothesized that hepatic ischemia, systemic ischemia, and tissue injury would occur during hemodilution in rabbits, and that the severity of ischemia and injury may be dependent on the fluid administered. ⋯ Isovolemic hemodilution (approximately 5% hematocrit) with albumin, pentastarch, or hetastarch solutions does not result in significant hepatic ischemia or injury assessed by histology.