Perioperative hyperoxia and myocardial injury after surgery: a randomized controlled trial.

BACKGROUND: The World Health Organization recommends hyperoxia (80% fraction of inspired oxygen, FiO2) during and for 2-6 hours following surgery to reduce surgical site infection (SSI). However, some studies suggest increased cardiovascular complications with such a high perioperative FiO2. The goal of our study was to compare the appearance of cardiovascular complications in elective adult colorectal surgery comparing the use of FiO2>0.8 versus conventional therapy (FiO2<0.4). METHODS: We performed a randomized controlled trial in intubated patients undergoing elective major colorectal surgery. Patients were randomly assigned to receive perioperative FiO2>0.8 or FiO2<0.4. The primary outcome, expressed as Odds Ratio (OR) ±95% Confidence Interval (95%CI), was the incidence of MINS (myocardial injury after noncardiac surgery evaluated for the first 4 postoperative days). Secondary outcomes included MACCE (major adverse cardiovascular and cerebral events) up to 30 postoperative days, SSI, other postoperative complications (according to Clavien-Dindo classification) and length of stay. RESULTS: We included in the final analyses 403 patients. Comparing the FiO2>0.8 and FiO2<0.4 groups, there was no difference in the appearance of MINS (6.0% vs. 10.4%; OR 0.55; 95% CI: 0.26-1.14; P=0.945). There were no differences between the groups for important secondary outcomes including MACCE to 30 days, SSI, postoperative complications or length of stay. CONCLUSIONS: Perioperative hyperoxia therapy (FiO2>0.8) with the aim of decreasing SSI did not increase cardiovascular complications after elective colorectal surgery in a general population.

Disfunción cognitiva después de cirugía cardiaca: Saturación cerebral e índice biespectral: estudio longitudinal / Neuropsychological dysfunction after cardiac surgery: Cerebral saturation and bispectral index: A longitudinal study

Background: Neuropsychological dysfunction is a major cause of morbidity and mortality after cardiac surgery. Aim: To evaluate if intraoperative cerebral desatu-ration and depth of anesthesia measured by bispectral index are related to postoperative cognitive dysfunction in cardiac surgery. Material and Methods: Prospective study in patients undergoing elective cardiac surgery with cardiopulmonary bypass. A comprehensive neuropsychological assessment was applied preoperatively and 3 months after surgery. Postoperative dysfunction was defined as a decrease of at least one standard deviation in two or more neuropsychological tests. Cerebral oxygenation and bispectral index were continuously recorded and corrected throughout surgery. Cerebral oxygenation data were analyzed by the mean value and at three thresholds: 50%, 40% and < 25% of the basal value. Bispectral index was analyzed at threshold of 45. Results: Fifty-six patients were initially enrolled and 48 completed the study. Nine of these (18.8 %) presented postoperative cognitive dysfunction. Mean cerebral saturation and bispectral index data were not different among the patients with or without cognitive dysfunction. There was no association between cerebral desaturation and bispectral index with changes in neurocognitive tests or with length of stay in the intensive care unit. A significant but weak correlation was found between baseline Ray-neurocognitive score and intensive care unit stay (rho = -0.46; P = 0.001). Conclusions: We did not find a significant association between cerebral desaturation and depth of anesthesia with postoperative cognitive decline in this population of patients.

[Neuropsychological dysfunction after cardiac surgery: Cerebral saturation and bispectral index: A longitudinal study]. / Disfunción cognitiva después de cirugía cardiaca: Saturación cerebral e índice biespectral: estudio longitudinal.

BACKGROUND: Neuropsychological dysfunction is a major cause of morbidity and mortality after cardiac surgery. AIM: To evaluate if intraoperative cerebral desaturation and depth of anesthesia measured by bispectral index are related to postoperative cognitive dysfunction in cardiac surgery. MATERIAL AND METHODS: Prospective study in patients undergoing elective cardiac surgery with cardiopulmonary bypass. A comprehensive neuropsychological assessment was applied preoperatively and 3 months after surgery. Postoperative dysfunction was defined as a decrease of at least one standard deviation in two or more neuropsychological tests. Cerebral oxygenation and bispectral index were continuously recorded and corrected throughout surgery. Cerebral oxygenation data were analyzed by the mean value and at three thresholds: 50%, 40% and < 25% of the basal value. Bispectral index was analyzed at threshold of 45. RESULTS: Fifty-six patients were initially enrolled and 48 completed the study. Nine of these (18.8 %) presented postoperative cognitive dysfunction. Mean cerebral saturation and bispectral index data were not different among the patients with or without cognitive dysfunction. There was no association between cerebral desaturation and bispectral index with changes in neurocognitive tests or with length of stay in the intensive care unit. A significant but weak correlation was found between baseline Ray-neurocognitive score and intensive care unit stay (rho = -0.46; P = 0.001). CONCLUSIONS: We did not find a significant association between cerebral desaturation and depth of anesthesia with postoperative cognitive decline in this population of patients.