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CONTEXT Myocardial oxidative stress plays an essential role in the pathogenesis of ischaemia-reperfusion injury associated with coronary artery bypass grafting (CABG). Both propofol and volatile anaesthetics have been shown to reduce reactive oxygen species in experimental and clinical studies. MAIN OBJECTIVE To compare the influence of sevoflurane and propofol on myocardial oxidative stress markers (F2-isoprostanes and nitrates/nitrites) in coronary sinus blood samples from patients undergoing off-pump CABG. DESIGN AND SETTING Randomised controlled clinical study of patients scheduled for off-pump CABG in a tertiary academic university hospital from June 2007 to August 2009. Forty patients consented to enrolment and were assigned to receive either propofol or sevoflurane. INTERVENTIONS Upon completion of the proximal anastomosis, a retroplegia cannula was inserted in the coronary sinus to obtain blood samples, according to the study protocol. MAIN OUTCOME MEASURES Markers of lipoperoxidation (F2-isoprostanes) and nitrosative stress (nitrates/nitrites) were measured in coronary sinus blood samples at three time points: after the end of the proximal anastomosis (T1), after completion of all grafts (T2) and 15 min after revascularisation (T3). RESULTS Of the 40 recruited patients, 38 fully completed the study. In the sevoflurane group (n = 20), concentrations of oxidative stress markers in the coronary sinus remained almost constant and were significantly lower than those in the propofol group (n = 18) at all time points. F2-isoprostanes concentrations were as follows at T1: sevoflurane group 37.2 ± 27.5 pg ml vs. propofol group 170.7 ± 30.9 pg ml [95% confidence interval (CI) 112.16-155.08, P

Resumen Objetivos Evaluar los factores de riesgo de la insuficiencia renal postoperatoria (IRP) en pacientes adultos con funcion renal normal sometidos a cirugia mayor con ingreso hospitalario, y analizar la mortalidad y la estancia hospitalaria de los pacientes que desarrollan IRP. Pacientes y metodos Se analizan los datos del estudio multicentrico de cohortes prospectivo ARISCAT realizado en 2006. La variable dependiente fue la IRP definida como un deterioro de la funcion renal demostrada por un aumento del doble de la creatinina plasmatica basal, o descenso del 50% del filtrado glomerular estimado. Se realizo un analisis bivariable y multivariable para identificar los factores de riesgo pre e intraoperatorios. Resultados Participaron 59 hospitales y fueron incluidos 2.378 pacientes, de los que 25 (1,1%) desarrollaron IRP. Se identificaron 5 factores de riesgo de IRP: edad, arteriopatia periferica, incision quirurgica, perdidas hematicas y la administracion de coloides. El area bajo la curva ROC fue de 0,88 (IC 95%: 0,79-0,96). La estancia hospitalaria fue mayor en los pacientes que desarrollaron una IRP (21,8 frente 5,5 dias, P = 0,007). La mortalidad fue mayor a los 30 dias (36% frente 0,9%) y a los tres meses (48 % frente 1,7%). Conclusiones La tasa de la IRP fue ligeramente superior al 1%. La identificacion de los factores de riesgo de la IRP puede ser util para adecuar la planificacion anestesica y quirurgica, con el objeto de reducir la morbimortalidad postoperatoria y la estancia hospitalaria.

The aim of the present study was to test the efficacy of adaptive support ventilation (ASV) to automatically adapt the ventilatory settings to the changes in the respiratory mechanics that occur during pneumoperitoneum and Trendelenburg position in gynaecological surgeries.We prospectively studied 22 ASA I women scheduled for gynaecological laparoscopic surgery in the Trendelenburg position. After intravenous induction of general anaesthesia, patients were ventilated with ASV, a closed-loop mode of mechanical ventilation based on the Otis formula, designed to automatically adapt the ventilatory settings to changes in the patient's respiratory system mechanics, while maintaining preset minute ventilation. Respiratory mechanics variables, ventilatory setting parameters and analysis of blood gases were recorded at three time points: 5 min after induction (baseline), 15 min after pneumoperitoneum and Trendelenburg positioning (Pneumo-Trend) and 15 min after pneumoperitoneum withdrawal (final).A reduction of 44.4% in respiratory compliance and an increase of 29.1% in airway resistance were observed during the Pneumo-Trend period. Despite these changes in respiratory mechanics, minute ventilation was kept constant. ASV adapted the ventilatory settings by automatically increasing inspiratory pressure by 3.2 +/- 0.9 cmH(2)O (+19%), P0.01, respiratory rate by 1.3 +/- 0.5 breaths per minute (+9%) and the inspiratory to total time ratio (T(i)/T(tot)) by 43.3%. At final time, these parameters returned towards their baseline values. Adequate gas exchange was maintained throughout all periods. PaCO(2) increased moderately (+13%) from 4.4 +/- 0.6 (baseline) to 5.0 +/- 0.9 kPa (Pneumo-Trend), P0.01; and decreased slightly at final time (4.7 +/- 0.8 kPa), P0.05. Clinician's intervention was needed in only one patient who showed a moderate hypercapnia (PaCO(2) 6.9 kPa) during pneumoperitoneum.In healthy women undergoing gynaecologic laparoscopy, ASV automatically adapted the ventilatory settings to the changes in the respiratory mechanics, keeping constant the preset minute ventilation, providing an adequate exchange of respiratory gases and obviating clinician's interventions.

BACKGROUND: Postoperative respiratory failure (PRF) is the most frequent respiratory complication following surgery. OBJECTIVE:/nThe objective of this study was to build a clinically useful predictive model for the development of PRF. DESIGN: A prospective observational study of a multicentre cohort. SETTING: Sixty-three hospitals across Europe. PATIENTS: Patients undergoing any surgical procedure under general or regional anaesthesia during 7-day recruitment periods. MAIN OUTCOME MEASURES: Development of PRF within 5 days of surgery. PRF was defined by a partial pressure of oxygen in arterial blood (PaO2) less than 8 kPa or new onset oxyhaemoglobin saturation measured by pulse oximetry (SpO2) less than 90% whilst breathing room air that required conventional oxygen therapy, noninvasive or invasive mechanical ventilation./nRESULTS: PRF developed in 224 patients (4.2% of the 5384 patients studied). In-hospital mortality [95% confidence interval (95% CI)] was higher in patients who developed PRF [10.3% (6.3 to 14.3) vs. 0.4% (0.2 to 0.6)]. Regression modelling identified a predictive PRF score that includes seven independent risk factors: low preoperative SpO2; at least one preoperative respiratory symptom; preoperative chronic liver disease; history of congestive heart failure; open intrathoracic or upper abdominal surgery; surgical procedure lasting at least 2 h; and emergency surgery. The area under the receiver operating characteristic curve (c-statistic) was 0.82 (95% CI 0.79 to 0.85) and the Hosmer-Lemeshow goodness-of-fit statistic was 7.08 (P = 0.253). CONCLUSION: A risk score based on seven objective, easily assessed factors was able to predict which patients would develop PRF. The score could potentially facilitate preoperative risk assessment and management and provide a basis for testing interventions to improve outcomes.The study was registered at ClinicalTrials.gov (identifier NCT01346709). The PERISCOPE study was funded and supported through the European Society of Anaesthesiology’s Clinical Trials Network.

Morbidly obese patients show an increased risk of postoperative hypoxemia and pulmonary complications when compared with normal weight subjects. The purpose of this study was to determine the effects of preoperative inspiratory muscular training (IMT) on postoperative arterial oxygenation in morbidly obese patients submitted to laparoscopic bariatric surgery.Forty-four morbidly obese patients were randomly assigned to receive either preoperative usual care (control group, n = 21) or preoperative IMT (trained group, n = 23) for a month prior to the date of surgery. Data on oxygenation (PaO2/FiO2 ratio) were obtained at 1 h and at 12 h after surgery (PACU 1 h and PACU 12 h, respectively). Data on maximum static inspiratory pressure (MIP) were obtained before and after the training period, and at postanesthesia care unit (PACU) 12-h time point.PaO2/FiO2 was significantly higher in the trained group than in the control group, both at PACU 1 h (305.2 ± 77.6 vs. 248.8 ± 53.8, P = 0.008) and at PACU 12 h (333.5 ± 59.6 vs. 289.7 ± 79.6, P = 0.044). As a consequence, the percentage of patients with relative hypoxemia (PaO2/FiO2 lower than 300 mmHg) at the time of PACU discharge was higher in the control group (57 vs. 17 %, P: 0.006). MIP was significantly higher in the trained group compared with the control group at the preoperative time point (89.87 ± 19.00 vs. 77.00 ± 21.20 cm H2O, P = 0.04).Preoperative IMT improved postoperative oxygenation and increased inspiratory muscular strength in morbidly obese patients submitted to laparoscopic bariatric surgery.