Journal of anesthesia
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Journal of anesthesia · Dec 2020
Evaluation of a new face mask concept for oxygen administration: a crossover study in healthy volunteers.
We developed a new face mask concept for oxygen administration using non-woven textiles. The aim of this study was to evaluate whether the new mask improves acceptability without compromising O2 delivery and CO2 elimination. 10 healthy adult volunteers were randomized to either the conventional plastic face mask-first group or the new face mask-first group. Participants were asked to wear the assigned mask with O2 at 3 L/min for 10 min while seated. ⋯ Median et-O2 with the new mask was 33%, compared with 30% with the conventional mask (P = 0.008). There were no significant differences in et-CO2 by mask type (new, 32 mmHg; conventional, 30 mmHg). In conclusion, the new mask was more comfortable and provided higher et-O2 than the conventional mask.
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Journal of anesthesia · Dec 2020
Postoperative renal morbidity and mortality after volume replacement with hydroxyethyl starch 130/0.4 or albumin during surgery: a propensity score-matched study.
We aimed to compare retrospectively the rates of renal morbidity and mortality in surgical patients receiving 6% HES 130/0.4 to those receiving albumin. ⋯ Postoperative renal morbidity and mortality did not differ between patients receiving HES 130/0.4 and those receiving albumin. HES 130/0.4 was associated with shorter hospital stay and less fluid requirement compared to albumin. These findings support the use of 6% HES 130/0.4 for perioperative volume replacement as an alternative to albumin.
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Journal of anesthesia · Dec 2020
Why the natural frequency and the damping coefficient do not evaluate the dynamic response of clinically used pressure monitoring circuits correctly.
The dynamic response of pressure monitoring circuits must be evaluated to obtain true invasive blood pressure values. Since Gardner's recommendations in 1981, the natural frequency and the damping coefficient have become standard parameters for anesthesiologists. In 2006, we published a new dynamic response evaluation method (step response analysis) that can plot frequency spectrum curves instantly in clinical situations. We also described the possibility of the defect of the standard parameters. However, the natural frequency and the damping coefficient are considered the gold standard and are even included in a major anesthesiology textbook. Therefore, we attempted to clarify the issues of these parameters with easy-to-understand pressure waves and basic numerical formulae. ⋯ The natural frequency and the damping coefficient are inadequate for the dynamic response evaluation. These parameters are primarily obtained from the phase spectrum curve and not from the amplitude spectrum curve. We strongly recommend an evaluation using the amplitude spectrum curve with our step response analysis method. It is crucial to maintain an amplitude gain of 1 (input amplitude = output amplitude) in the pressure wave frequency range of 0-20 Hz.