Der Anaesthesist
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Intraoperative autotransfusion is contraindicated in cancer surgery because of the possible risk of systemic tumor spread. The aim of the present study was to investigate whether a cell saver in combination with a white blood cell depletion filter can remove osteosarcoma cells. ⋯ The sole use of the autotransfuser DIDECO BT 795/P during osteosarcoma surgery is not recommended because of the potential danger of retransfusion of malignant cells. In combination with the leukocyte depletion filter PALL BPF 4, no osteosarcoma cells were identified in the red cell concentrate. Since the adhesiveness of tumor cells from established cell lines may be different from that of tumor cells in the intraoperative salvaged blood, further studies with blood from the surgical field are necessary to determine the efficacy of white cell depletion filters to eliminate osteosarcoma cells.
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Randomized Controlled Trial Clinical Trial
[The effect of a heat and moisture exchanger (HME) on bronchial mucus transport in a closed inhalation anesthesia system].
The administration of dry anaesthetic gases for ventilation leads to morphological changes of the tracheobronchial epithelium that may cause postoperative pulmonary complications. Therefore, additional humidification with a heat and moisture exchanger (HME) is suggested for ventilation during anaesthesia, particularly when using semi-open breathing systems. Recommendations concerning the use of a HME in the semi-closed system are controversial. There are no data in the literature as to whether a HME improves mucociliary transport under these conditions. We therefore studied bronchial mucus transport velocity (BTV) with and without the use of a HME in the semi-closed circle system in humans. ⋯ BTV does not improve with the use of a HME in the semi-closed circle system with a fresh gas flow of 31. With modern anaesthesia machines lower fresh gas flows should be administered, whereby the humidity and temperature of the inspired gases are further increased.
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Impaired pulmonary gas exchange can result from lung parenchymal failure inducing oxygenation deficiency and fatigue of the respiratory muscles, which is characterized by hypercapnia or a combination of both mechanisms. Contractility of and coordination between the diaphragm and the thoracoabdominal respiratory muscles predominantly determine the efficiency of spontaneous breathing. Sepsis, cardiac failure, malnutrition or acute changes of the load conditions may induce fatigue of the respiratory muscles. ⋯ As with APRV, alveolar ventilation is maintained even if the spontaneous breathing efforts of the patient cease, which improves the safety of both modes of respiratory therapy. The contribution of spontaneous breathing to total minute ventilation may be important, since a decreased shunt and improved VA/Q relationship have been observed in experimental non-cardiogenic lung oedema. These data give support to the concept that spontaneous breathing should be maintained and augmented in the setting of acute respiratory failure.
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In the presence of completely dry soda lime volatile anaesthetics will decompose to carbon monoxide (CO). In an in vitro study, the absorbent (soda lime, ICI) was dried with a constant gas flow of 11/min oxygen for 120 h. The weight loss during the drying was 17.1%. ⋯ The temperature inside the absorbent rose from the ambient temperature (19.8 degrees C) to a maximum of 52.1 degrees C during CO production and decreased when the CO production lowered after approximately 1 h (all anaesthetics). During CO production no measurable concentration of halothane left the absorber. After passing through the absorbent the concentrations of isoflurane and enflurane were slightly lower than the corresponding concentrations in the fresh gas measured before absorption.
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Comparative Study
[Comparative study of the efficiency of bacterial filters in long-term mechanical ventilation].
Two commercially available bacterial filters to be used as part of the mechanical ventilation unit during anaesthesia were tested for hygienic criteria. Manufacturers claim that bacterial breathing filters have a filtration capacity of about 99.995%, so that there would be no need for thermal disinfection of tubing and ventilation circuits after each use. One filter is designed for a single use only, the other can be used up to 24 times after sterilisation. Both filters consist of hydrophobic glass fibres. ⋯ The use of bacterial filters during mechanical ventilation reduces the probability of bacterial contamination, but does not make sterilisation of the tubes and ventilation circuit unnecessary.