Journal of anesthesia
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Journal of anesthesia · Mar 1995
Compound A concentration and the temperature of CO2 absorbents during low-flow sevoflurane anesthesia in surgical patients.
Sevoflurane, a new inhalational anesthetic, is metabolically broken down into several decomposition products in the presence of CO2 absorbents. One of the products, CF2=C (CF3) OCH2F (compound A), which appears to be the most toxic, was quantitated in 20 surgical patients subjected to more than 3 h of anesthesia using a low-flow anesthesia circuit. To minimize the variables in the reaction velocity between sevoflurane and the CO2 absorbents, we maintained the sevoflurane concentration at 2%. ⋯ We also measured the temperature in CO2 absorbents, which had been reported to influence compound A production. The elevation in the temperature was 27.9±1.3°C in Wakolime-A, 29.4±8.4°C in Baralyme, and 31.0±5.0°C in Sodasorb II. Further studies are needed to assess the safety and efficacy of sevoflurane.
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Journal of anesthesia · Mar 1995
Ischemia may be less detrimental than anemia for O2 transport because of CO 2 transport: A model analysis.
We analyzed the relationship between oxygen delivery (Do2) and Pto2 (tissue Po2). We found an important factor which has not been specified before. In the previous O2 transport model, Do2 was a dependent variable, calculated from hemoglobin, blood flow, Pao2, and the oxygen dissociation curve (ODC). ⋯ In ischemia the CO2 transport is disturbed, leading a higher draining venous Pco2, which in turn maintains a higher Po2 the capillary, resulting in a higher gradient for Po2 between capillary and the tissue. Between ischemia and anemia, ischemia is less detrimental than anemia. In ischemia, the CO2 transport is disturbed, which in turn maintains a higher Po2 at the capillary.
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Journal of anesthesia · Mar 1995
Auditory brainstem responses after out-of-hospital cardiac arrest: Are they useful for outcome prediction?
We evaluated whether we could predict the neurologic outcome in 55 out-of-hospital cardiac arrest patients using auditory brainstem responses (ABR). ABR patterns were classified into one of 3 types by evaluation of 5 components: type 1, with all 5 components; type 2, lack of at least one response between the 2nd and 5th components; type 3, with only the first component or no response. The relation between the ABR patterns on the 3rd day following resuscitation and the neurologic outcome on hospital discharge was evaluated. ⋯ In the type-1 ABR patients, the negative predictive value that the patients were awake was 100%. In the type-3 ABR patients, the negative predictive value that the patients became brain dead was 90.9%. These results suggest that ABR on the 3rd post-resuscitation day may not be useful for predicting if patients are awake or become brain dead, although the loss of components may be a sign of morbidity, and the presence of the 2nd or later components indicates possible future prevention of brain death.