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
Bactericidal activity of skin disinfectants on methicillin-resistant Staphylococcus aureus.
We studied bactericidal activity of 10% povidone-iodine, 0.5% chlorhexidine gluconate, and 0.5% chlorhexidine in 80% ethanol on four strains of methicillin-resistant and two strains of methicillin-susceptible Staphylococcus aureus. The pathogen was exposed to each of the disinfectants for 15, 30, 60, 120, and 240 s at room temperature. The inocula from these suspensions were cultured 72 h at 37 degrees C after the antimicrobial activity of the disinfectants in the suspensions was inactivated by 1:1000 dilution with neutralizer. ⋯ The 15-, 30-, and 60-s exposure to 10% povidone-iodine reduced the mean colony count by 55.2%, 91.2%, and 96.7%, respectively, and the exposures to 0.5% chlorhexidine gluconate reduced the mean colony count by 37.2%, 77.1%, and 93.3%, respectively. The difference in colony count between disinfectants was significant at 15- and 30-s exposures (P < 0.01 and 0.05, respectively). The results suggest that bactericidal activity of 0.5% chlorhexidine in 80% ethanol is more potent and more rapid against methicillin-susceptible and methicillin-resistant strains of S. aureus.
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Anesthesia and analgesia · Sep 1995
Comparative StudyIntrathecal administration of liposomal morphine in a mouse model.
The authors determined the duration of analgesia, toxicity, and neuraxial distribution of liposomal morphine after intrathecal administration in the mouse. Analgesic duration was determined using the tail-flick test after intrathecal injection of 12.5, 25, or 50 micrograms of plain or liposomal morphine (n = 6 mice/dose/formulation). Toxicity of the formulations was compared by estimating LD50. ⋯ For plain morphine, the drug was not confined to a specific neuraxial segment, and segmental levels declined rapidly. After liposomal morphine, the most morphine was concentrated and persisted in the low spinal cord segment at each time interval. These results show that a single dose of liposomal morphine produces prolonged analgesia with decreased toxicity compared to the plain formulation.
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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).