Journal of anesthesia
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CO2 absorbents acting on sevoflurane produce compound A [CF2=C(CF3)OCH2F]. Rats breathing 25-50 ppm of compound A for 3-12 h demonstrate corticomedullary renal injury. Several halogenated alkenes also produce a well described corticomedullary lesion by conversion of glutathione conjugates of these alkenes to cysteine s-conjugates and subsequent metabolism by renal cysteine conjugate β-lyase to nephrotoxic halothionoacetyl halides. ⋯ In rats exposed to 800 ppm compound A, pretreatment with AOAA increased necrosis from 63.8±30.1% to 81.2±27.7% (P<0.1). Unlike many other halogenated alkenes, compound A does not appear to produce renal injury by conversion of a cysteine S-conjugate to a toxic thiol, nor does injury require metabolism mediaited by cytochrome P-450. Injury may result from direct toxicity of compound A or by an undetermined metabolic pathway.
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Journal of anesthesia · Mar 1997
Predictors of inotropic support during weaning from cardiopulmonary bypass in coronary artery bypass grafting surgery.
Early or prophylactic inotropic drug administration is occasionally required to facilitate separation from cardiopulmonary bypass (CPB) in cardiac surgery. However, it is not without untoward effects and should be conducted on the basis of rational criteria. The purpose of our study was to clarify variables associated with the requirement for inotropic support during separation from CPB and to testify whether pre-CPB left ventricular (LV) function, as evaluated by transesophageal echocardiography (TEE), is one of the significant variables. ⋯ Stepwise multiple logistic regression analysis identified pre-CPB LV regional wall motion abnormalities (RWMA), NYHA class, age, and duration of CPB (in order of significance) as factors associated with inotropic support for discontinuing CPB. Pre-CPB LV enddiastolic area or fractional area change was not a significant variable in the multivariate model. Our result suggests that evaluation of pre-CPB LV RWMA is useful in predicting the need of inotropic intervention during separation from CPB in patients undergoing CABG surgery.
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Journal of anesthesia · Mar 1997
Continuous measurement of oxygen consumption using the reversed fick method.
We developed a continuous oxygen consumption (Vo2) measurement system employed the reversed Fick method, in which Vo2 in computed from continuously measured sured arterial and mixed venous oxygen saturation assed by pulse oximetry and mixed venous oximetry, respectively, and cardiac output by the heat deprivation technique. This system was compared with the conventional intermittent reversed fick method in 7 patients during surgery and with indirect calorimetry in 4 intensive care unit (ICU) patients. ⋯ The 95% confidence limits (bias±2 SD) of the continuous reversed Fick method were -0.6±45 ml·min-1 with the intermittent Fick method and -31±56 ml·min-1 with indirect calorimetry. The continuous Fick method is in satisfactory agreement with the conventional methods for the measured of Vo2 and potentially allows for convenient assessment of Vo2 in critically ill patients.
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Journal of anesthesia · Mar 1997
Effects of estazolam as a premedication in mentally retarded patients.
In anesthesia for mentally retarded patients, adequate preoperative sedation is important. We have investigated the sedative effects of estazolam in 16 mentally retarded patients who were given 0.1 mg·kg-1 orally; its sedative effects were compared with those of hydroxyzine (50 mg intramuscularly, 6 patients). Estazolam was observed to be significantly more effective as a sedative than hydroxyzine throughout the period under study. ⋯ The sedative effects of estazolam lasted on average 9h and patients were still well sedated after the operation. There was no serious complication due to estazolam. Thus, it was found to be an effective drug for premedication in mentally retarded patients.