Intraoperative fluid balance and cardiac surgery-associated acute kidney injury: a multicenter prospective study

Abstract Background Recent data suggest the regime of fluid therapy intraoperatively in patients undergoing major surgeries may interfere in patient outcomes. The development of postoperative Acute Kidney Injury (AKI) has been associated with both Restrictive Fluid Balance (RFB) and Liberal Fluid Balance (LFB) during non-cardiac surgery. In patients undergoing cardiac surgery, this influence remains unclear. The study objective was to evaluate the relationship between intraoperative RFB vs. LFB and the incidence of Cardiac-Surgery-Associated AKI (CSA-AKI) and major postoperative outcomes in patients undergoing on-pump Coronary Artery Bypass Grafting (CABG). Methods This prospective, multicenter, observational cohort study was set at two high-complexity university hospitals in Brazil. Adult patients who required postoperative intensive care after undergoing elective on-pump CABG were allocated to two groups according to their intraoperative fluid strategy (RFB or LFB) with no intervention. Results The primary endpoint was CSA-AKI. The secondary outcomes were in-hospital mortality, cardiovascular complications, ICU Length of Stay (ICU-LOS), and Hospital LOS (H-LOS). After propensity score matching, 180 patients remained in each group. There was no difference in risk of CSA-AKI between the two groups (RR = 1.15; 95% CI, 0.85-1.56, p= 0.36). The in-hospital mortality, H-LOS and cardiovascular complications were higher in the LFB group. ICU-LOS was not significantly different between the two groups. ROCcurve analysis determined a fluid balance above 2500 mL to accurately predict in-hospital mortality. Conclusion Patients undergoing on-pump CABG with LFB when compared with patients with RFB present similar CSA-AKI rates and ICU-LOS, but higher in-hospital mortality, cardiovascular complications, and H-LOS.

Application of a pharmacokinetics-pharmacodynamics approach to the free propofol plasma levels during coronary artery bypass grafting surgery with hypothermic cardiopulmonary bypass

OBJECTIVES: The objective of this study was to apply a pharmacokinetics-pharmacodynamics approach to investigate the free propofol plasma levels in patients undergoing coronary artery bypass grafting under hypothermic conditions compared with the off-pump procedure. METHODS: Nineteen patients scheduled for on-pump coronary artery bypass grafting under hypothermic conditions (n=10) or the equivalent off-pump surgery (n=9) were anesthetized with sufentanil and propofol target-controlled infusion (2 μg/mL) during surgery. The propofol concentration was then reduced to 1 μg/mL, and a pharmacokinetics-pharmacodynamics analysis using the maximum-effect-sigmoid model obtained by plotting the bispectral index values against the free propofol plasma levels was performed. RESULTS: Significant increases (two- to five-fold) in the free propofol plasma levels were observed in the patients subjected to coronary artery bypass grafting under hypothermic conditions. The pharmacokinetics of propofol varied according to the free drug levels in the hypothermic on-pump group versus the off-pump group. After hypothermic coronary artery bypass was initiated, the distribution volume increased, and the distribution half-life was prolonged. Propofol target-controlled infusion was discontinued when orotracheal extubation was indicated, and the time to patient extubation was significantly higher in the hypothermic on-pump group than in the off-pump group (459 versus 273 min, p=0.0048). CONCLUSIONS: The orotracheal intubation time was significantly longer in the hypothermic on-pump group than in the off-pump group. Additionally, residual hypnosis was identified through the pharmacokinetics-pharmacodynamics approach based on decreases in drug plasma protein binding in the hypothermic on-pump group, which could explain the increased hypnosis observed with this drug in this group of patients.

Independent early predictors of mortality in polytrauma patients: a prospective, observational, longitudinal study

OBJECTIVES: Trauma is an important public health issue and associated with substantial socioeconomic impacts and major adverse clinical outcomes. No single study has previously investigated the predictors of mortality across all stages of care (pre-hospital, emergency room, surgical center and intensive care unit) in a general trauma population. This study was designed to identify early predictors of mortality in severely injured polytrauma patients across all stages of care to provide a better understanding of the physiologic changes and mechanisms by which to improve care in this population. METHODS: A longitudinal, prospective, observational study was conducted between 2010 and 2013 in São Paulo, Brazil. Patients submitted to high-energy trauma were included. Exclusion criteria were as follows: injury severity score <16, <18 years old or insufficient data. Clinical and laboratory data were collected at four time points: pre-hospital, emergency room, and 3 and 24 hours after hospital admission. The primary outcome assessed was mortality within 30 days. Data were analyzed using tests of association as appropriate, nonparametric analysis of variance and generalized estimating equation analysis (p<0.05). ClinicalTrials.gov: NCT01669577. RESULTS: Two hundred patients were included. Independent early predictors of mortality were as follows: arterial hemoglobin oxygen saturation (p<0.001), diastolic blood pressure (p<0.001), lactate level (p<0.001), Glasgow Coma Scale score (p<0.001), infused crystalloid volume (p<0.015) and presence of traumatic brain injury (p<0.001). CONCLUSION: Our results suggest that arterial hemoglobin oxygen saturation, diastolic blood pressure, lactate level, Glasgow Coma Scale, infused crystalloid volume and presence of traumatic brain injury are independent early mortality predictors.

Aplicabilidade do escore fisiológico agudo simplificado (SAPS 3) em hospitais brasileiros / Aplicabilidad de la puntuación fisiológica aguda simplificada (SAPS 3) en hospitales brasileños / Applicability of the simplified acute physiology score (SAPS 3) in brazilian hospitals

Justificativa e objetivos: O sistema prognóstico SAPS 3 (Simplified Acute Physiology Score 3) é composto de 20 variáveis, representadas por escore fisiológico agudo e avaliação do estado prévio, visando estabelecer índice preditivo de mortalidade para pacientes admitidos em unidades de terapia intensiva (UTI). O estudo teve objetivo de validar este sistema e verificar o poder discriminatório deste índice em pacientes cirúrgicos do Brasil. Método: Estudo prospectivo, realizado em duas UTI especializadas em pacientes cirúrgicos de dois diferentes hospitais, no período de um ano, excluiuse pacientes com idade inferior a 16 anos, que permaneceram tempo inferior a 24 horas na UTI, readmitidos e aqueles admitidos para procedimento dialítico. A habilidade preditiva do índice SAPS 3 em diferenciar sobreviventes e não sobreviventes foi verificada utilizando curva ROC e a calibração pelo teste Hosmer-Lemeshow goodness-of-fit. Resultados: Foram incluídos no estudo 1.310 pacientes. Operações gastrintestinais foram predominantes (34,9 por cento). O menor valor do índice SAPS 3 foi 18 e o maior 154, média de 48,5 ± 18,1. A mortalidade hospitalar prevista e real foi de 10,3 por cento e de 10,8 por cento, respectivamente, razão de mortalidade padronizada (SMR) foi 1,04 (IC95 por cento = 1,03-1,07). A calibração pelo método Hosmer e Lemeshow mostrou X² = 10,47 p = 0,234. O valor do escore SAPS 3 que melhor discriminou sobreviventes e não sobreviventes foi 57, com sensibilidade de 75,8 por cento e especificidade de 86 por cento. Dos pacientes com índice SAPS 3 maior que 57, 73,5 por cento não sobreviveram versus 26,5 por cento de sobreviventes (OR = 1,32 IC95 por cento 1,23 - 1,42, p < 0,0001). Conclusões: O sistema SAPS 3 é válido na população brasileira de pacientes cirúrgicos, sendo útil para indicar pacientes graves e determinar maiores cuidados neste grupo.

Background and objectives: The SAPS 3 (Simplified Acute Physiology Score 3) prognostic system is composed of 20 parameters, represented by an acute physiology score and assessment of the previous status, aimed at establishing a predictive mortality index for patients admitted to intensive care units (ICU). The objective of this study was to validate this system and determine its discriminatory power in surgical patients in Brazil. Methods: This is a prospective study undertaken in two surgical ICUs of two different hospitals over a one-year period; patients younger than 16 years, who stay at the ICU for less than 24 hours, readmitted to the unit, and those admitted for dialysis were excluded from the study. The predictive ability of the SAPS 3 index to differentiate survivors and non-survivors was determined by the ROC curve and calibration by the Hosmer-Lemeshow goodness-of-fit test. Results: One thousand three-hundred and ten patients were included in the study. Gastrointestinal surgeries predominated (34.9 percent). Eighteen was the lower SAPS 3 index and the highest was 154, with a mean of 48.5 ± 18.1. The predicted and real hospital mortality was 10.3 percent and 10.8 percent, respectively; the standardized mortality ratio (SMR) was 1.04 (95 percentCI = 1.03-1.07). Calibration by the Hosmer and Lemeshow method showed X² = 10.47 p = 0.234. The SAPS 3 score that better discriminated survivors and non-survivors was 57, with sensitivity of 75.8 percent and specificity 86 percent. Among the patients with SAPS 3 index higher than 57, 73.5 percent did not survive versus 26.5 percent who survived (OR= 1.32, 95 percentCI 1.23-1.42, p < 0.0001). Conclusions: The SAPS 3 system is valid for the Brazilian population of surgical patients, being a useful indicator of critical patients and to determine greater care in this group.

Justificativa y objetivos: El sistema de pronóstico SAPS 3 (Simplified Acute Physiology Score 3), se compone de 20 variables, representadas por una puntuación fisiológica aguda y por una evaluación del estado previo, con el fin de establecer el índice predictivo de mortalidad para los pacientes admitidos en las unidades de cuidados intensivos (UCI). El estudio quiso validar ese sistema y verificar el poder discriminatorio de ese índice en pacientes quirúrgicos de Brasil. Método: Estudio prospectivo, realizado en dos UCIs especializadas en pacientes quirúrgicos de dos hospitales diferentes, en el período de un año, donde quedaron excluidos pacientes con edad inferior a los 16 años, que permanecieron un tiempo inferior a 24 horas en la UCI, los readmitidos y los que fueron admitidos para el procedimiento de diálisis. La habilidad predictiva del índice SAPS 3 para diferenciar a los sobrevivientes y a los no sobrevivientes, se constató utilizando la curva ROC y la calibración a través del test Hosmer-Lemeshow goodness-of-fit. Resultados: Se incluyeron en el estudio 1310 pacientes. Las operaciones gastrointestinales fueron predominantes (34,9 por ciento). El menor valor del índice SAPS 3 fue 18 y el mayor 154, un promedio de 48,5 ± 18,1. La mortalidad hospitalaria prevista y real alcanzó los 10,3 por ciento y 10,8 por ciento respectivamente, la razón de mortalidad estandarizada (SMR) fue 1,04 (IC95 por ciento = 1,03-1,07). La calibración por el método Hosmer y Lemeshow mostró X2 = 10,47 p = 0,234. El valor de la puntuación SAPS 3 que desglosó mejor a los sobrevivientes y a los no sobrevivientes fue 57, con una sensibilidad de un 75,8 por ciento y una especificidad de un 86 por ciento. De los pacientes con el índice SAPS 3 mayor que 57, un 73,5 por ciento no sobrevivieron contra un 26,5 por ciento de sobrevivientes (OR = 1,32 IC95 por ciento 1,23 – 1,42, p < 0,0001). Conclusiones: El sistema SAPS 3 es valido en la población brasileña...

Effects of cardiopulmonary bypass on propofol pharmacokinetics and bispectral index during coronary surgery

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.

Há espaço para o tratamento endovascular nas dissecções crônicas da aorta descendente? / Is the endovascular procedure an option for treatment of cronic type B aortic dissections?

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 por cento dos pacientes e, no abdome, somente em 18,2 por cento, 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 percent of the patients and in the abdomen in 81.8 percent. 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.