Anesthesia and analgesia
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Anesthesia and analgesia · Sep 1995
Factors affecting the concentration of compound A resulting from the degradation of sevoflurane by soda lime and Baralyme in a standard anesthetic circuit.
Carbon dioxide absorbents, such as soda lime and Baralyme brand absorbent, convert sevoflurane to CF2 = C(CF3)OCH2F, a vinyl ether called "Compound A," whose toxicity raises concerns regarding the safety of sevoflurane in rebreathing circuits. Because an increased inflow rate to an anesthetic circuit decreases rebreathing, we assumed that an increased rate would proportionately decrease the concentration of Compound A. In the present report, we measured the Compound A concentration resulting from the action of wet (standard) soda lime and wet (standard) Baralyme on 2% sevoflurane in a model anesthetic circuit, using inflow rates (0.5, 1.0, 2.0, 4.0, and 6.0 L/min), ventilations (5 and 10 L/min), and carbon dioxide production/removal (200 and 400 mL/min) found in clinical practice. ⋯ An increase in ventilation increased the concentration of Compound A, having a much greater effect at high rather than low inflow rates. An increase in amount of carbon dioxide absorbed also increased the concentration of Compound A. We conclude that inflow rate, ventilation, and carbon dioxide production are major determinants of the concentration of Compound A.
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Anesthesia and analgesia · Sep 1995
Comparative StudyAnesthesiology critical care medicine fellowship training.
Anesthesiology critical care medicine (ACCM) fellowship training was accredited in 1989, and a small number of graduating anesthesiology residents pursue this additional training. Considering the flexible program guidelines of the American Board of Anesthesiology (ABA), we hypothesized that ACCM fellowship training programs varied significantly among the 42 institutions accredited to offer this program. This study of ACCM fellowship programs used a six-part, 57-item questionnaire completed by 36 program directors to describe six aspects of the program: institution size, program director, attending staff, fellowship applicants, curriculum, and the role of the American Society of Critical Care Anesthesiologists (ASCCA). ⋯ Fellowship curricula had varied requirements for research, intraoperative anesthesia, and ICU procedures performed by the fellow. In general, program directors believe that salary and on-call responsibility are not important issues for applicants. Nineteen percent of program directors train ACCM fellows longer than the 12 mo required by the ABA and believe that ACCM training should be lengthened.
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Anesthesia and analgesia · Sep 1995
Sciatic cryoneurolysis in rats: a model of sympathetically independent pain. Part 1: Effects of sympathectomy.
The purpose of this study was to evaluate the effects of preemptive and postlesion sympathectomy in the sciatic cryoneurolysis (SCN) model of neuropathic pain in rats. SCN in rats produces a prolonged significant mechanical allodynia (hypersensitivity to previously non-noxious mechanical stimuli) with no thermal hyperalgesia. In at least two other models, sympathectomy is effective in attenuating existing mechanical allodynia and thermal hyperalgesia or deterring their development after nerve injury. ⋯ To investigate these concepts in the SCN model, sympathectomy was performed prior to SCN in animals with established SCN-induced allodynia. Sympathectomy did not alter the pattern of existing allodynia or its development in this model. The results suggest that SCN is a useful and easily reproducible model of sympathetically independent pain (SIP).
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Anesthesia and analgesia · Sep 1995
Randomized Controlled Trial Comparative Study Clinical TrialComparison of ondansetron and droperidol in the prevention of nausea and vomiting after inpatient minor gynecologic surgery.
Ondansetron and droperidol are both effective in the prevention of postoperative nausea and vomiting (PONV). In this randomized, double-blind study, 80 inpatients scheduled for minor gynecologic surgery received either ondansetron 8 mg intravenously (i.v.) or droperidol 2.5 mg i.v. 5 min prior to induction of isoflurane-narcotic anesthesia. PONV was absent in 68% of the patients after ondansetron and in 88% after droperidol (P < 0.05). ⋯ After ondansetron and droperidol, the incidence of severe drowsiness, restlessness, anxiety, or dizziness was 5% and 28%, respectively (P < 0.01). Thus after minor gynecologic surgery, droperidol 2.5 mg i.v. was superior to ondansetron 8 mg i.v. in the prevention of PONV. However, relative to ondansetron, droperidol entailed an average 1-h delay in recovery from anesthesia.
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Anesthesia and analgesia · Sep 1995
Temperature corrected thrombelastography in hypothermic patients.
Thrombelastograms and other coagulation studies are performed at 37 degrees C, regardless of the patient's body temperature. This prospective study of 45 patients undergoing orthotopic liver transplantation was conducted to evaluate the effect on the thrombelastogram performed at the patient's actual body temperature compared with a control thrombelastogram heated in the standard fashion to 37 degrees C. Thrombelastograms were obtained after the induction of anesthesia and at various times throughout the operation when clinically indicated. ⋯ The variables of the thrombelastogram measured were: r (reaction time in minutes), r + K (coagulation time in minutes), alpha (coagulation rate in degrees), and MA (maximum amplitude in millimeters). Whenever the patient's body temperature was less than 37 degrees C, statistically significant prolongation of the reaction time, coagulation time, and decrease in the clot formation rate occurred compared with control variables at 37 degrees C. Overall means were as follows: r for control, 8.24 +/- 0.28 min; r for temperature corrected, 9.32 +/- 0.27 min; r + K for control, 15.4 +/- 0.65 min; r + K for temperature corrected, 17.5 +/- 0.81 min; and alpha for control, 39.8 +/- 1.22 degrees; alpha for temperature corrected, 37.7 +/- 1.23 degrees.(ABSTRACT TRUNCATED AT 250 WORDS)