Anesthesia and analgesia
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Anesthesia and analgesia · Mar 2013
Volume-independent elastance: a useful parameter for open-lung positive end-expiratory pressure adjustment.
A decremental positive end-expiratory pressure (PEEP) trial after full lung recruitment allows for the adjustment of the lowest PEEP that prevents end-expiratory collapse (open-lung PEEP). For a tidal volume (Vt) approaching zero, the PEEP of minimum respiratory system elastance (PEEP(minErs)) is theoretically equal to the pressure at the mathematical inflection point (MIP) of the pressure-volume curve, and seems to correspond to the open-lung PEEP in a decremental PEEP trial. Nevertheless, the PEEP(minErs) is dependent on Vt and decreases as Vt increases. To circumvent this dependency, we proposed the use of a second-order model in which the volume-independent elastance (E1) is used to set open-lung PEEP. ⋯ PEEPminE1 better identifies the open-lung PEEP independently of the adjusted Vt, and may be a practical, more individualized approach for PEEP titration.
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Anesthesia and analgesia · Mar 2013
Single-dose application of antithrombin as a potential alternative anticoagulant during continuous renal replacement therapy in critically ill patients with advanced liver cirrhosis: a retrospective data analysis.
Adequate anticoagulation is essential to achieve efficient and cost-effective continuous renal replacement therapy (CRRT). However, in critically ill patients with advanced liver cirrhosis, this goal is challenging because of the concomitant bleeding disorder. Therefore, the evaluation of alternative anticoagulants is necessary. ⋯ Our data suggest that anticoagulation with single doses of AT may be an alternative to continuously administered low-dose heparin in critically ill patients with advanced liver cirrhosis during CRRT. However, additional controlled trials are necessary to confirm our findings.
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Anesthesia and analgesia · Mar 2013
Microarray analyses of genes regulated by isoflurane anesthesia in vivo: a novel approach to identifying potential preconditioning mechanisms.
Although general anesthetics are recognized for their potential to render patients unconscious during surgery, exposure can also lead to long-term outcomes of both cellular damage and protection. As regards the latter, delayed anesthetic preconditioning is an evolutionarily conserved physiological response that has the potential for protecting against ischemic injury in a number of tissues. Although it is known that delayed preconditioning requires de novo protein synthesis, knowledge of anesthetic-regulated genes is incomplete. In this study, we used the conserved nature of preconditioning to analyze differentially regulated genes in 3 different rat tissues. We hypothesized that by selecting those genes regulated in multiple tissues, we could develop a focused list of gene candidates potentially involved in delayed anesthetic preconditioning. ⋯ Through using an analysis approach focusing on coordinately regulated genes, we were able to generate a focused list of interesting gene candidates with potential to enable future preconditioning studies.
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Anesthesia and analgesia · Mar 2013
Kinetics of uptake and washout of lidocaine in rat sciatic nerve in vitro.
The potency and efficacy of local anesthetics injected clinically for peripheral nerve block depends strongly on the rate of neural drug uptake. However, because diffusion into surrounding tissues and removal by the vascular system are major factors in the overall distribution of lidocaine in vivo, true kinetics of drug/neural tissue interactions must be studied in the absence of those confounding factors. ⋯ Lidocaine enters a nerve by a process other than free diffusion, through an epineurial sheath that is a slight obstacle. Given the rapid entry in vitro compared with the much smaller and transient content measured in vivo, it seems highly unlikely that lidocaine equilibrates with the nerve during a peripheral blockade.