Anesthesia and analgesia
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Anesthesia and analgesia · Mar 2013
A transesophageal echocardiography technique to locate the kidney and monitor renal perfusion.
Monitoring the renal arterial Doppler flow velocity indices, the resistive index and pulsatility index, with ultrasound may help predict renal dysfunction. However, such monitoring has been done intermittently by transcutaneous ultrasound in the postoperative intensive care setting. In the operating room, transesophageal echocardiography (TEE) is an alternative to transcutaneous ultrasound for obtaining indices of renal perfusion. ⋯ We propose a new technique to locate the left kidney that, in our experience, is simple and easy to perform. We believe, starting from a transgastric left ventricular short-axis view, turning left to locate the abdominal aorta, and following it to the origin of the left renal artery may help locate the left kidney faster than previously described techniques. We also propose a new technique to monitor these Doppler indices using TEE during the intraoperative period.
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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
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.
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Anesthesia and analgesia · Mar 2013
Expression of calcium/calmodulin-dependent protein kinase II and pain-related behavior in rat models of type 1 and type 2 diabetes.
Abnormalities in peripheral nerves and dorsal root ganglia are noticed in the early stage of experimentally provoked diabetic neuropathy. Enzyme calcium/calmodulin-dependent protein kinase II (CaMKII) may have a modulating role in diabetic neuropathy because of its role in calcium homeostasis. ⋯ Our findings may indicate involvement of CaMKII in transmission of nociceptive input early in DM1, but not in DM2. CaMKII may be a suitable pharmacological target for diabetic neuropathy.
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Anesthesia and analgesia · Mar 2013
Association of denervation severity in the dermis with the development of mechanical allodynia and hyperalgesia in a murine model of postherpetic neuralgia.
Postherpetic neuralgia (PHN) is a common complication of herpes zoster and remains a challenging condition of neuropathic pain. Allodynia, a prominent feature of PHN, extends beyond the margins of the initial rash area. In the present study, we investigated the association between cutaneous denervation and the development of postherpetic allodynia and hyperalgesia by using a murine model of PHN. ⋯ The present results suggest that the severity of dermal denervation in the scarred skin is associated with the development of postherpetic allodynia and hyperalgesia that extend beyond the margins of the initial rash area. The decrease of epidermal nerve density in the scarred and stimulation skins may not be associated with postherpetic allodynia and hyperalgesia.