Der Anaesthesist
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Randomized Controlled Trial Comparative Study Clinical Trial
[Postoperative warming therapy in the recovery room. A comparison of radiative and convective warmers].
Hypothermia (Tcore < 36 degrees C) can be observed in 60%-80% of all admissions to the post-anaesthetic recovery unit. Effective warming devices may accelerate rewarming, improve patient comfort, and suppress shivering thermogenesis. This study was designed to compare the efficiency of warming devices in extubated postoperative patients and their effect on postoperative oxygen uptake (VO2). ⋯ External rewarming did not reduce the average load (mean VO2). Thus, concerning the goal of accelerating rewarming, it appears more rational to prevent intraoperative heat loss. For a comparison of efficiency of different warming devices, postoperative extubated patients do not appear to be an ideal model for study.
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Knowledge of normal and impaired pulmonary gas exchange is essential to the anaesthesiologist. Analysis of an arterial blood sample allows evaluation of whether or not pulmonary gas exchange is normal. For this purpose comparison with the oxygenation index or the alveolar-arterial PO2 difference is helpful. ⋯ In daily practice, venous admixture or intrapulmonary shunt can be calculated using arterial and mixed-venous blood. By analysing arterial and expired PCO2, dead-space ventilation can be determined, but extended analyses of VA/Q distribution are not possible in daily practice. However, knowledge of the principles of typical disturbances of pulmonary gas exchange in acute and chronic lung disease allows the use of therapeutic strategies based on the pathophysiological changes.
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Comparative Study Clinical Trial
[Inverse fick's principle in comparison to measurements of oxygen consumption in respiratory gases. Does intrapulmonary oxygen uptake account for differences shown by different system methods?].
Automated measurements of respiratory gas exchange recently became available for the determination of oxygen uptake (VO2) in critically ill patients. Whereas these metabolic gas monitoring systems (MBM) are assumed to measure total body VO2, the reversed Fick method in principle excludes intrapulmonary VO2. Previous clinical reports comparing VO2 measured by the reversed Fick principle (VO2Fick) with VO2 measured by MBM (VO2MBM) found that VO2MBM was significantly greater than VO2Fick. ⋯ RESULTS. Neither in the study group nor in the control group could a significant difference between methods be demonstrated. In patients with pneumonia the mean difference between methods (VO2Fick-VO2MBM) was 15.2 ml/min (4.2%); the double standard deviation of differences (2 SD) was 59.2 ml/min (19.2%).
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Clinical Trial
[Continuous intravascular blood gas analysis. Clinical evaluation of a new fiber optic monitor].
Continuous monitoring of blood gases and pH could add substantially to patient safety. During the last decade, efforts have been made to develop continuous optochemical blood gas sensors. The initial evaluation of such fibreoptic-based systems showed major patient-interface problems [11]. ⋯ The continuous blood gas monitor is sufficiently accurate and precise for clinical use. Bias and precision are better than those known from former studies evaluating fibreoptic blood gas monitors under experimental conditions [7]. Cost-effectiveness was not an issue of this study.
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Clinical Trial
[Perioperative endothelin, ACTH and cortisol plasma concentrations in coronary bypass patients].
To follow up endothelin (ET), adrenocorticotropic hormone (ACTH), and cortisol levels in patients undergoing aortocoronary bypass grafting (CABG) and to determine whether these are extracted from plasma by the pulmonary circulation. ⋯ No interrelation between ET and the hypothalamic-pituitary-adrenal axis could be established by the ET, ACTH, and cortisol plasma levels. However, the significant correlation between perioperative ET and cortisol lends further support to the hypothesis of ET release by cortisol from vascular smooth-muscle cells. There is a net pulmonary clearance of ET in patients prior to CABG that is lost intra- and early postoperatively, but tends to be restored on the 1st day thereafter at an increased level.