RESUMO
Cardiopulmonary bypass (CPB) is widely used for cardiac surgery by virtue of its proven safety over the course of its use during the past half century. Even though perfusion is safer, incidents still occur. During the repair of a ventricular-septal defect in an 11-month-old infant, we experienced a critical incident related to the potential hazardous effect of volatile anesthetics on the polycarbonate connector of extra-corporeal circuit. The damage to the polycarbonate connector had occurred after spillage of isoflurane during the filling of the vaporizer, causing it to crack and leak. The incident was managed by replacement of the cracked connector during a temporary circulatory arrest. The patient was hypothermic and the time off bypass was less than 1.5 min. There were no neurologic sequelae, the patient made an uneventful recovery. In conclusion, the spillage of volatile anesthetics can cause cracks in the polycarbonate connector of the extra-corporeal circuit, leading to potentially interruption of CPB.
RESUMO
BACKGROUND: In the Korean National Health Insurance Corporation (KNHIC), payment for inhaled anesthetics are made according to the simulated dose and not the consumed dose. We compare the consumption of inhaled anesthetics according to fresh gas flow (FGF) and anesthetic circuits to compare the consumption of anesthetics and the guidelines for KNHIC payments. METHODS: 161 patients were randomized into six groups who received isoflurane using a closed circuit (group I-C), a semi-closed circuit with FGF 3 L/min (group I-3), or 4 L/min (group I-4), as for the sevoflurane group (group S-C, S-3, and S-4). Mean arterial pressure (MAP) and heart rate (HR) were maintained within +/- 20% of baseline. Minimum alveolar concentration (MAC) and consumption of inhaled anesthetics were recorded by a new anesthetic machine. RESULTS: There were no significant differences among the groups for MAP, HR, and MAC. During anesthesia maintenance, the mean consumption per 15 minutes of inhaled anesthetics was significantly lower in group I-C (1.0 +/- 0.3 ml) than in group I-3 (3.5 +/- 0.7 ml) and than group I-4 (4.9 +/- 0.9 ml) and similar to the sevoflurane groups (group S-C [1.3 +/- 0.4 ml] vs group S-3 [5.3 +/- 1.0 ml] vs group S-4 [6.9 +/- 1.3 ml], respectively; P < 0.05). CONCLUSIONS: In sevoflurane groups, inhaled anesthetics were consumed more than in isoflurane groups. The KNHIC payment guidelines were close to the actual consumption of inhaled anesthetics under using a semi-closed circuit with FGF 3 L/min in sevoflurane and FGF 4 L/min in isoflurane.
RESUMO
A practical approach has been implemented to calculate the ionization balance and electrical conductivity of warm dense aluminum plasma with the Coulomb coupling effect taken into account. The correction term for ionization potential is formulated with a number of basic dimensionless parameters that characterize nonideal plasma and incorporated with the fitted formulas of excess free energy given by Tanaka, Mitake, and Ichimaru [Phys. Rev. A 32, 1896 (1985)] and Chabrier and Potekhin [Phys. Rev. E 58, 4941 (1998)] to determine the ionization balance in an equilibrium state. The calculated degree of ionization of aluminum plasma exhibits a sudden increase near the solid density approximately 1 g/cm(3) at temperatures of a few eV, which effectively demonstrates the pressure-induced ionization. The electrical conductivity is evaluated in a partially ionized plasma regime based on a linear mixture rule that takes into account both the electron-ion and electron-neutral collisions and then the computed results are compared with available data from recent experiments. It is shown that the calculation well reproduces the overall trend of measured electrical conductivity of nonideal aluminum plasma accounting for the metal-insulator transition.
