Acta anaesthesiologica Scandinavica
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Acta Anaesthesiol Scand · Jan 1980
Calculation of the fresh gas flow requirements of the Hafnia A and D anaesthetic circuits.
Semi-closed anaesthetic circuits are converted into the corresponding Hafnia circuits by replacing the expiratory valve by a side tube connected to an ejector flowmeter. Theoretical analysis of the Hafnia A and D circuits revealed by the fresh gas flow requirements are dependent on the inspiration/expiration time ratio. Using a ratio of 1/1.2 and a sine-wave respiratory waveform, the minimal fresh gas requirements were calculated as 2.1 (Hafnia A) and 2.5 (Hafnia D) times the respiratory minute volume. The fresh gas requirements are identical with spontaneous or controlled ventilation.
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Acta Anaesthesiol Scand · Jan 1980
Comparative StudySister chromatid exchanges in lymphocytes in operating room personnel.
Sister chromatid exchanges (SCE) and sister chromatid exchange points (SCE-points) were counted in lymphocytes in peripheral blood drawn from hospital personnel exposed to anesthetics as well as from persons not exposed. A total of 38 healthy persons were investigated, representing female nurse anaesthetists, male physicians practising anaesthesia, female nurses from the intensive care unit, and female secretaries. ⋯ Correlation of cigarette smoking and number of SCE could not be demonstrated (r=0.255, n=38). It was concluded that by this method there was no indication of a mutagen effect of long-term exposure to waste anaesthetic gases such as halothane and nitrous oxide.
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Acta Anaesthesiol Scand · Jan 1980
Comparative StudyInfluence of the Taurus radiowave blood warmer on human red cells. Hemolysis and erythrocyte ATP and 2,3 DPG concentrations following warming by radiowaves, microwaves and water bath.
The warming properties of the Taurus radiowave blood warmer were studied. The safety limits were the same as for microwave warming (Haemotherm). Hemolysis was noted in units with a hematocrit over 0.75 or containing less than 300 g of blood. ⋯ Warming of blood in a +35 degrees C water bath for 3 min had no effect on these parameters. There was, however, a tendency for ATP and 2,3 DPG levels to decrease after 60 min water bath incubation (+37 and +45 degrees C), but to increase levels following electromagnetic warming depending on the age of the warmed erythrocytes. Thus, electromagnetic radiation appeared to influence the red cell metabolism, which cannot be explained by the effect of temperature alone.
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Acta Anaesthesiol Scand · Jan 1980
Comparative StudyThe role of thiopental and fentanyl in the production of balanced anaesthesia.
In order to clarify the interactions between various doses of thiopental and fentanyl in producing "balanced anaesthesia", their effects on consciousness, superficial nociception, and respiration and circulation were studied during N2O+O2 inhalation in connection with the induction of anaesthesia. Altogether 60 patients were studied; the drug combinations used were thiopental 5 mg/kg (TP5), thipental 3 mg/kg (TP3), thiopental 3 mg/kg and fentanyl 0.5 micrograms/kg (TP3F0.5), thiopental 2 mg/kg and fentanyl 1 micrograms/kg (TP2F1), thiopental 1 mg/kg and fentanyl 2 micrograms/kg (TP1F2), and fentanyl 3 micrograms/kg (F3). Five minutes after the i.v. supplementation of N2O+O2 anaesthesia, the depth of anaesthesia and analgesia (antinociception) were evaluated from the eyelid reflex and by pinching an inguinal skin fold. ⋯ The respiratory depression was most pronounced in groups receiving 3, 2 and 1 micrograms/kg fentanyl and weakest in groups where only thiopental was used. Blood pressure decreased in all groups but no statistically significant differences were noted. On the basis of the results it seems obvious that attempts to achieve what is called "balanced anaesthesia" by the supplementation of an N2O+O2 mixture with fentanyl only leads to an unnecessarily prnounced respiratory depression, whereas supplementation with thiopental alone does not offer adequate antinociception.