PURPOSE: Cardiopulmonary bypass is known to alter propofol pharmacokinetics in patients undergoing cardiac surgery. However, few studies have evaluated the impact of these alterations on postoperative pharmacodynamics. This study was designed to test the hypothesis that changes in propofol pharmacokinetics increase hypnotic effects after cardiopulmonary bypass. METHODS: Twenty patients scheduled for on-pump coronary artery bypass graft (group, n=10) or off-pump coronary artery bypass graft (group, n=10) coronary artery bypass grafts were anesthetized with sufentanil and a propofol target controlled infusion (2.0 µg/mL). Depth of hypnosis was monitored using the bispectral index. Blood samples were collected from the induction of anesthesia up to 12 hours after the end of propofol infusion, at predetermined intervals. Plasma propofol concentrations were measured using high-performance liquid chromatography, followed by a non-compartmental propofol pharmacokinetic analysis. Data were analyzed using ANOVA, considering p<0.05 as significant. RESULTS: After cardiopulmonary bypass, despite similar plasma propofol concentrations in both groups, bispectral index values were lower in the on-pump coronary artery bypass graft group. Time to extubation after the end of propofol infusion was greater in the on-pump coronary artery bypass graft group (334 ± 117 vs. 216 ± 85 min, p = 0.04). Patients undergoing cardiopulmonary bypass had shorter biological (1.82 ± 0.5 vs. 3.67 ± 1.15h, p < 0.01) and terminal elimination (6.27 ± 1.29 vs. 10.5h ± 2.18, p < 0.01) half-life values, as well as higher total plasma clearance (28.36 ± 11.40 vs.18.29 ± 7.67 mL/kg/min, p = 0.03), compared to patients in the off-pump coronary artery bypass graft group. CONCLUSION: Aside from the increased sensitivity of the brain to anesthetics after cardiopulmonary bypass, changes in propofol pharmacokinetics may contribute to its central nervous system effects.

OBJETIVO: Questões relativas a quais pacientes/doenças que efetivamente deveriam ser submetidos ao tratamento endovascular ainda geram controvérsias. O objetivo deste trabalho visa a questionar o tratamento endovascular nas dissecções crônicas tipo B de Stanford. MÉTODOS: No período de 2003 a 2006, 11 pacientes portadores de dissecção crônica da aorta tipo B de Stanford com dilatação somente no tórax (diâmetro > 5,5cm), foram submetidos à colocação de prótese endovascular autoexpansível pela artéria femoral. Todos os pacientes foram submetidos à angiotomografia de controle com 6 meses, 1 ano e após, anualmente, com o intuito de avaliar a presença de fluxo na falsa luz e estudar a evolução dos diâmetros da aorta torácica descendente e abdominal no decorrer do tempo. Para esta análise foram utilizados os testes Anova de duas vias para medidas repetidas e o qui-quadrado com o programa SPSS 13. RESULTADOS: Não houve mortalidade hospitalar. Nenhum paciente apresentou endoleak imediatamente após a operação. Durante o período de seguimento médio de 28 meses/paciente, não houve óbitos, um paciente foi submetido à substituição da aorta tóraco-abdominal e dois aguardam esta mesma intervenção. A endoprótese interrompeu o fluxo na falsa luz no tórax em 72,7% dos pacientes e, no abdome, somente em 18,2%, porém isto não implicou na redução dos diâmetros da aorta torácica nem abdominal. CONCLUSÃO: O tratamento endovascular nas dissecções crônicas tipo B de Stanford parece não ser suficiente para tratar esses pacientes no curto/médio prazo, apesar do tamanho reduzido da amostra estudada.

OBJECTIVE: Questions regarding the specific patient/disease that should be submitted to the endovascular procedure still remain unclear. The purpose of this report is to evaluate the endovascular treatment in chronic type B aortic dissections. METHODS: Between 2003 and 2006, 11 patients with chronic type B aortic dissection were submitted to endovascular procedure through femoral artery. All of them were monitored with CT within 6 months, 1 year and afterwars anually. We prospectively evaluated false lumen patency and thoracic and abdominal aortic diameters in each time point. The data comparisons were made using Anova and chi-square tests with SPSS 13. RESULTS: The endovascular stent-graft deployment was technically successful for all patients, with no hospital mortality. During the follow-up period the false lumen flows remained persistent in the thorax in 27.3% of the patients and in the abdomen in 81.8%. However, in all patients, in both segments, the aorta diameter was not significantly changed in size and shape. CONCLUSION: Despite the small number of studied patients, the endovascular procedure for chronic type B aortic dissections does not appear to be an option for the treatment of these patients.