Anesthesia and analgesia
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Anesthesia and analgesia · Dec 2004
The volume kinetics of acetated Ringer's solution during laparoscopic cholecystectomy.
We studied the distribution and elimination of an IV infusion of 20 mL/kg of acetated Ringer's solution (approximately 1500 mL) over 60 min in 12 women undergoing laparoscopic cholecystectomy. A plasma dilution of 4.2% developed during the induction of general anesthesia, even though fluid was withheld. The additional plasma dilution induced by the subsequent volume expansion was slightly larger than expected from previous volunteer experiments and averaged 18%. ⋯ These data represent a half-life of the fluid in the patients that is 17 times longer (median, 4.5 h) than the half-life of the plasma dilution (16 min), indicating a strong tendency to the formation of peripheral edema. A nomogram based on the kinetic variables suggests that infusion rates should be relatively rapid early on during surgery but slower later. This strategy creates a constant plasma dilution at any desired level without causing undue peripheral accumulation of fluid.
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Anesthesia and analgesia · Dec 2004
Potent activation of the human tandem pore domain K channel TRESK with clinical concentrations of volatile anesthetics.
The tandem pore domain K channel family mediates background K currents present in excitable cells. Currents passed by certain members of the family are enhanced by volatile anesthetics, thus suggesting a novel mechanism of anesthesia. The newest member of the family, termed TRESK (TWIK [tandem pore domain weak inward rectifying channel]-related spinal cord K channel), has not been studied for anesthetic sensitivity. ⋯ Amide and ester local anesthetics inhibit TRESK in a concentration-dependent manner but at concentrations generally larger than those that inhibit other tandem pore domain K channels. We also determined that TRESK is found not only in spinal cord, but also in human brain RNA. These results identify TRESK as a target of volatile anesthetics and suggest a role for this background K channel in mediating the effects of inhaled anesthetics in the central nervous system.
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Anesthesia and analgesia · Dec 2004
A novel method to assess platelet inhibition by eptifibatide with thrombelastograph.
We examined a novel method to detect platelet inhibition with thrombelastography (TEG). We hypothesized that this method would be suitable for monitoring the antiplatelet effects of eptifibatide (Integrilin). Whole blood from healthy volunteers was anticoagulated with 3.2% citrate or unfractionated heparin (7 IU/mL). ⋯ The kaolin TEG showed a decrease in maximum amplitude (MA) only at the eptifibatide concentration of 24 mug/mL and no change in alpha angle, whereas with the batroxobin-based TEG, the difference in MA and alpha angle was observed at concentrations >/=0.8 microg/mL. Additionally, the time to achieve maximum MA was much shorter for batroxobin TEG than for kaolin TEG. We conclude that the batroxobin-modified TEG is a sensitive method that detects platelet inhibition induced by eptifibatide.