Der Anaesthesist
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Randomized Controlled Trial Comparative Study Clinical Trial
[Intravenous anesthesia with propofol versus thiopental-/enflurane anesthesia. A consumption and cost analysis].
It may be possible to reduce costs in anaesthesia when there is a choice of drugs and methods. Two of the most widespread techniques are inhalation anaesthesia with enflurane following induction with thiopentone, and intravenous anaesthesia (IVA) with propofol. The aims of our study were to compare the costs, effectiveness and side effects of the anaesthetics involved in these two techniques, and to measure significant clinical parameters. ⋯ Minute ventilation, oxygen consumption, heart rate and CO2 production indicated a less pronounced stress response and sympathetic activity during and after propofol. Quicker recovery of cognitive and psychomotor abilities, less postoperative pain and less impairment of respiratory function after IVA may lead to an earlier release from the postoperative recovery unit. This might be a cost-reducing factor that should be taken into account when these two anaesthetic regimens are concerned.
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Randomized Controlled Trial Clinical Trial
[CO2 stores in laparoscopic cholecystectomy with CO2 pneumoperitoneum].
Two groups of 22 patients each were studied in a prospective, randomised fashion during laparoscopic cholecystectomy (LCh) and CO2 pneumoperitoneum (PP) with regard to end-tidal and arterial PCO2 and pulmonary elimination of CO2 (ECO2, Servoventilator with integrated CO2-analyser 930, Siemens). In group 1 minute ventilation was kept constant, resulting in moderate hypercapnia during PP. paCO2 increased by about 10 mmHg during up to 50 min PP. In group 2 paCO2 was kept constant by a stepwise increase in minute ventilation (Fig. 1, Table 2). ⋯ Assuming a stable metabolic CO2 production rate during the observation period and no differences in CO2 absorption from the PP between the two study groups, differences in ECO2 between groups would be a measure of CO2 stored in group 1 patients during the increase in paCO2 with PP (Fig. 3, Table 3). CO2 storage rapidly increased between 0 and 15 min PP, more or less reached a plateau between 15 and 35 min PP, and ceased at 45 min PP. Storing capacity for CO2 during the first 45 min PP amounted to a mean value of 1.20 ml CO2/kg body weight and mmHg paCO2, which agrees favourably with data from the literature and a computer model from Fahri and Rahn published in 1960 (Fig. 4, Table 4). If during LCh with CO2-PP patients are ventilated with a constant minute ventilation, a moderate increase in paCO2 of about 10 mm Hg can be expected. In this case, during the first 45 min PP a 70-kg patient will retain about 1000 ml CO2 in blood and tissues, which must be eliminated after cessation of PP. If the paCO2 is to be held constant during PP, minute ventilation has to be progressively increased by about 40%.
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Propofol is commercially available as Disoprivan. It is formulated as an aqueous emulsion with 1% 2,6-diisopropylphenol, 10% soya bean oil, 2,5% glycerol and 1.2% egg phosphatide. Since 1986, propofol has been used as a sedative drug in the ICU and is highly valued for its numerous positive qualities. ⋯ First, cardiovascular depression, especially if potentiated by drugs such as beta- and Ca-entry blockers, may lead to hypotensive episodes. Potential problems (drug tolerance, hypertriglyceridaemia) may be revealed in long-term studies. As long as no such studies have been presented, the authors believe that it is too early to consider propofol the ideal drug for long-term sedation.
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The safety of blood and blood components is an important aspect of transfusion medicine. Even if absolute safety of blood products cannot be achieved, this goal has come closer due to significant improvements. These include: (1) exact donor registration; (2) component preparation according to legal requirements and GMP guidelines; (3) determination of all relevant diagnostic parameters according to GMP/GLP guidelines; (4) adequate storage of products; and (5) and often underestimated parameter ensuring safety, strict guidelines for the use of blood products in the treatment of patients. Some of the results of the first Graz Consensus Conference on Transfusion Medicine are presented.
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After rapid changes in transfusion practice over the past few years, blood conservation techniques have become standard in modern perioperative management. As a result, the amount of homologous blood products transfused has been markedly reduced in some types of surgical procedures. Provided that skillful surgical technique is applied and the use of blood products is restricted, autologous transfusion techniques (predonation of autologous blood, preoperative plasmapheresis, acute normovolaemic haemodilution, and intra- and postoperative blood salvage) can be performed with an acceptable risk for patients. ⋯ If storage is necessary, autologous blood products should be preparated like homologous products. The feasibility of predonation and retransfusion of autologous blood in patients with infectious diseases like hepatitis or acquired immune deficiency syndrome and the amount of labaratomy testing are still under discussion. Although blood conservation programs are time-consuming and more expensive, they reduce the various risks of using homologous blood products.