British journal of anaesthesia
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Failed epidural anaesthesia or analgesia is more frequent than generally recognized. We review the factors known to influence the success rate of epidural anaesthesia. Reasons for an inadequate epidural block include incorrect primary placement, secondary migration of a catheter after correct placement, and suboptimal dosing of local anaesthetic drugs. ⋯ Addition of adjuvants, especially opioids and epinephrine, may substantially increase the success rate of epidural analgesia. Adjuvant opioids may have a spinal or supraspinal action. The use of patient-controlled epidural analgesia with background infusion appears to be the best method for postoperative analgesia.
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Randomized Controlled Trial Comparative Study
Effects of an intraoperative infusion of 4% succinylated gelatine (Gelofusine(R)) and 6% hydroxyethyl starch (Voluven(R)) on blood volume.
This study aims to study changes in blood volume after 1 litre infusions of Gelofusine(®) [4% succinylated gelatine in 0.7% saline, weight-average molecular weight (MWw) 30 kDa] and Voluven(®) (6% hydroxyethyl starch in 0.9% saline, MWw 130 kDa) in the presence of increased capillary permeability. ⋯ The blood volume-expanding effects of the two colloids were not significantly different, despite the increase in postoperative urinary ACR and the 100 kDa difference in MWw.
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Randomized Controlled Trial
Changes in cerebrospinal fluid magnesium levels in patients undergoing spinal anaesthesia for hip arthroplasty: does intravenous infusion of magnesium sulphate make any difference? A prospective, randomized, controlled study.
Most investigators have attributed the reduced postoperative pain or anaesthetic drug requirements in patients receiving i.v. magnesium sulphate (MgSO(4)) infusion during spinal or general anaesthesia to central N-methyl-d-aspartate (NMDA) receptor magnesium (Mg) activity. In this study, we investigated how cerebrospinal fluid (CSF) Mg concentrations change after spinal anaesthesia, and whether peripherally infusing MgSO(4) influences central Mg levels. ⋯ Spinal anaesthesia unexpectedly reduced CSF total and ionized Mg concentrations in patients undergoing hip arthroplasty, although the mechanism is unclear. The dose used for peripheral MgSO(4) infusion in this study had no influence on central Mg concentrations in neurologically healthy patients undergoing spinal anaesthesia. If CSF Mg concentration is a reliable marker of Mg brain bioavailability, peripherally infused MgSO(4) during spinal anaesthesia is unlikely to influence central NMDA receptor activity.