Minerva anestesiologica
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Minerva anestesiologica · May 2010
Randomized Controlled TrialEpidural volume expansion: is there a ceiling effect?
The optimal volume of epidural saline administration on spinal anesthesia is not clear. The aim of this study was therefore to evaluate the block characteristics of 5, 10, 15, and 20 mL epidural saline after spinal anesthesia. ⋯ The present results indicate that a ceiling effect was observed on the duration of spinal analgesia using plain bupivacaine with epidural saline loading (maximum--15 mL).
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Neurally adjusted ventilatory assist (NAVA) is a form of partial ventilatory support wherein the machine applies positive pressure to the airway opening throughout each inspiration. In contrast to all other modes of ventilation, which adopt conventional pneumatic signals (flow, volume, and airway pressure) to drive and control the ventilator operation, NAVA utilizes the electrical activity of the diaphragm, which is the best available signal to estimate the respiratory drive and to trigger on and cycle off the delivery of the mechanical assistance and regulate its amount and intra-breath profile. ⋯ These investigations indicate that this novel mode is efficient in unloading the respiratory muscles and maintaining adequate gas exchange while improving the patient-ventilator interaction. This review article aims to summarize the results of the studies published to date on this topic.
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Minerva anestesiologica · May 2010
Randomized Controlled TrialTime course of endogenous nitric oxide inhibitors in severe sepsis in humans.
Asymmetric and symmetric dimethylarginines (ADMA and SDMA, respectively) are protein breakdown markers; both compete with arginine for cellular transport and both are excreted in urine. Moreover, ADMA is a non-selective inhibitor of nitric oxide (NO) synthase that is metabolized by a specific hydrolase in which the activity during stress remains controversial. While an increase in ADMA is known to be associated with adverse events, little is known about SDMA. We investigated plasma ADMA and SDMA levels during ICU stay to reveal the time course of endogenous NO inhibition in patients with sepsis. ⋯ ADMA catabolism appears to be activated by inflammation; its increase during the advanced septic phase in surviving patients may suggest an endogenous inhibition of NO synthesis during the full-blown septic phase. In severe sepsis, SDMA, but not ADMA, appears to be a marker of alterations in vital functions and mortality.