Efficacy of Single-Bolus Administration of Remimazolam During Induction of Anesthesia in Patients Undergoing Cardiac Surgery: A Prospective, Single-Center, Randomized Controlled Study.

BACKGROUND: Remimazolam is a recently marketed ultrashort-acting benzodiazepine. This drug is considered safe and effective during general anesthesia; however, limited information is available about its effects on patients undergoing cardiac surgery. Therefore, the present study was conducted to evaluate the efficacy and hemodynamic stability of a bolus administration of remimazolam during anesthesia induction in patients undergoing cardiac surgery. METHODS: Patients undergoing elective cardiac surgery were randomly assigned to any 1 of the following 3 groups: anesthesia induction with a continuous infusion of remimazolam 6 mg/kg/h (continuous group), a single-bolus injection of remimazolam 0.1 mg/kg (bolus 0.1 group), or a single-bolus injection of remimazolam 0.2 mg/kg (bolus 0.2 group). Time to loss of responsiveness, defined as modified Observer's Assessment of Alertness/Sedation Scale <3, and changes in hemodynamic status during anesthetic induction were measured. RESULTS: Times to loss of responsiveness were 137 ± 20, 71 ± 35, and 48 ± 9 seconds in the continuous, bolus 0.1, and bolus 0.2 groups, respectively. The greatest mean difference was observed between the continuous and bolus 0.2 groups (89.0, 95% confidence interval [CI], 79.1-98.9), followed by the continuous and bolus 0.1 groups (65.8, 95% CI, 46.9-84.7), and lastly between the bolus 0.2 and bolus 0.1 groups (23.2, 95% CI, 6.6-39.8). No significant differences were found in terms of arterial blood pressures and heart rates of the patients. CONCLUSIONS: A single-bolus injection of remimazolam provided efficient anesthetic induction in patients undergoing cardiac surgery. A 0.2 mg/kg bolus injection of remimazolam resulted in the shortest time to loss of responsiveness among the 3 groups, without significantly altering the hemodynamic parameters. Therefore, this dosing can be considered a favorable anesthetic induction method for patients undergoing cardiac surgery.

Effects of Balanced Versus Saline-based Solutions on Acute Kidney Injury in Off-pump Coronary Artery Bypass Surgery: A Randomized Controlled Trial.

OBJECTIVES: To determine whether balanced solutions can reduce the incidence of acute kidney injury after off-pump coronary artery bypass surgery compared with saline. DESIGN: Randomized controlled trial. SETTING: Single tertiary care center. PARTICIPANTS: Patients who underwent off-pump coronary artery bypass surgery between June 2014 and July 2020. INTERVENTIONS: Balanced solution-based chloride-restrictive intravenous fluid strategy. MEASUREMENTS AND MAIN RESULTS: The primary outcome was acute kidney injury within 7 postoperative days, as defined by the 2012 Kidney Disease: Improving Global Outcomes Clinical Practice Guideline. The incidence of acute kidney injury was 4.4% (8/180) in the balanced group and 7.3% (13/178) in the saline group. The difference was not statistically significant (risk difference, -2.86%; 95% confidence interval [CI], -7.72% to 2.01%; risk ratio, 0.61, 95% CI, 0.26 to 1.43; p = 0.35). Compared with the balanced group, the saline group had higher levels of intraoperative serum chloride and lower base excess, which resulted in a lower pH. CONCLUSIONS: In patients undergoing off-pump bypass surgery with a normal estimated glomerular filtration rate, the intraoperative balanced solution-based chloride-restrictive intravenous fluid administration strategy did not decrease the rate of postoperative acute kidney injury compared with the saline-based chloride-liberal intravenous fluid administration strategy.

Effects of intraoperative inspired oxygen fraction (FiO2 0.3 vs 0.8) on patients undergoing off-pump coronary artery bypass grafting: the CARROT multicenter, cluster-randomized trial.

BACKGROUND: To maintain adequate oxygenation is of utmost importance in intraoperative care. However, clinical evidence supporting specific oxygen levels in distinct surgical settings is lacking. This study aimed to compare the effects of 30% and 80% oxygen in off-pump coronary artery bypass grafting (OPCAB). METHODS: This multicenter trial was conducted in three tertiary hospitals from August 2019 to August 2021. Patients undergoing OPCAB were cluster-randomized to receive either 30% or 80% oxygen intraoperatively, based on the month when the surgery was performed. The primary endpoint was the length of hospital stay. Intraoperative hemodynamic data were also compared. RESULTS: A total of 414 patients were cluster-randomized. Length of hospital stay was not different in the 30% oxygen group compared to the 80% oxygen group (median, 7.0 days vs 7.0 days; the sub-distribution hazard ratio, 0.98; 95% confidence interval [CI] 0.83-1.16; P = 0.808). The incidence of postoperative acute kidney injury was significantly higher in the 30% oxygen group than in the 80% oxygen group (30.7% vs 19.4%; odds ratio, 1.94; 95% CI 1.18-3.17; P = 0.036). Intraoperative time-weighted average mixed venous oxygen saturation was significantly higher in the 80% oxygen group (74% vs 64%; P < 0.001). The 80% oxygen group also had a significantly greater intraoperative time-weighted average cerebral regional oxygen saturation than the 30% oxygen group (56% vs 52%; P = 0.002). CONCLUSIONS: In patients undergoing OPCAB, intraoperative administration of 80% oxygen did not decrease the length of hospital stay, compared to 30% oxygen, but may reduce postoperative acute kidney injury. Moreover, compared to 30% oxygen, intraoperative use of 80% oxygen improved oxygen delivery in patients undergoing OPCAB. Trial registration ClinicalTrials.gov (NCT03945565; April 8, 2019).

Peak systolic myocardial velocity in patients undergoing surgical aortic valve replacement for severe aortic stenosis: prognostic value and natural course.

Myocardial systolic longitudinal function has been known to decrease in patients with severe aortic stenosis (AS). Preoperative peak systolic myocardial velocity at the septal mitral valve annulus (S'), measured using Doppler tissue imaging, was used as an indicator for myocardial systolic longitudinal function. The prognostic value and natural course of S' after surgical aortic valve replacement for severe AS have not been elucidated. This retrospective observational study included patients from January 2006 to December 2018. The patients were divided to 2 groups (pre-S'HIGH vs. pre-S'LOW) with a cut-off 5.4 cm/s of preoperative S' (pre-S') that was identified by restricted cubic spline curve. The primary outcome was postoperative long-term all-cause mortality. Nine hundred and five patients were analyzed. All-cause mortality rate at the median follow-up period of 5.2 years was 12% in pre-S'LOW and 8% in pre-S'HIGH. Multivariate analysis showed that pre-S'LOW was associated with an increased all-cause mortality (hazard ratio, 1.60; 95% confidence interval, 1.04-2.48; P = 0.032). Significantly different trajectories of postoperative S' (post-S') were found between two groups (P < 0.001 for difference): In pre-S'LOW, post-S' increased within 6 months after surgery, and gradually decreased over time, whereas it slowly decreased up to 5 years after surgery and then reached a plateau in pre-S'HIGH. The difference in pre-S' level maintained over time, and remained consistent in the adjusted analysis. Pre-S' < 5.4 cm/s was found to be associated with an increased long-term all-cause mortality. In addition, the trajectories for post-S' were different according to pre-S', which remained after adjustment.

Impact of Body Mass Index and Sarcopenia on Short- and Long-Term Outcomes After Esophageal Cancer Surgery: An Observational Study.

BACKGROUND: The effects of specific body mass index (BMI) category and sarcopenia within each BMI category on outcomes in patients undergoing esophageal surgery with esophageal squamous cell carcinoma have not been thoroughly examined. METHODS: This study included 1141 patients. Sarcopenia was determined with a total psoas muscle cross-sectional area at the level of the third lumbar vertebra in computed tomography. The outcomes were long-term survival, including overall survival (OS) and recurrence-free survival (RFS), and postoperative complications. RESULTS: The overweight and no sarcopenia group was considered as the reference. After adjusting covariates, the underweight and the normal weight and sarcopenia groups both showed worse OS (underweight group: hazard ratio [HR] 2.04, 95% confidence interval [CI] 1.33-3.13, p = 0.001; normal weight and sarcopenia group: HR 1.93, 95% CI 1.39-2.69, p < 0.001) and worse RFS (underweight group: HR 1.78, 95% CI 1.19-2.67, p = 0.005; normal weight and sarcopenia group: HR 1.70, 95% CI 1.25-2.30, p = 0.001). In addition, the underweight group (odds ratio [OR] 4.74, 95% CI 2.05-10.96, p < 0.001), the normal weight and sarcopenia group (OR 3.26, 95% CI 1.60-6.62, p = 0.001), the overweight and sarcopenia group (OR 2.54, 95% CI 1.14-5.68, p = 0.023), and the obese and no sarcopenia group (OR 2.44, 95% CI 1.14-5.22, p = 0.021) were at significantly higher risk of postoperative 30-day composite complications. CONCLUSIONS: Compared with the overweight and no sarcopenia group, the underweight and the normal weight and sarcopenia groups were associated with worse short- and long-term outcomes.

Incremental Prognostic Value of Left Ventricular Longitudinal Strain Over Ejection Fraction in Coronary Artery Bypass Grafting.

OBJECTIVES: To evaluate the incremental prognostic value of longitudinal strain over left ventricular ejection fraction (LVEF) after coronary artery bypass grafting (CABG). DESIGN: Retrospective cohort study. SETTING: Single tertiary-care center. PARTICIPANTS: Patients underwent isolated CABG between January 2014 and December 2019. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: There were 999 patients (median age, 65 years, 23.5% female) categorized into 3 groups according to their left ventricular (LV) systolic function status: pEF/pS (preserved LVEF and preserved longitudinal strain, n = 490), pEF/iS (preserved LVEF and impaired longitudinal strain, n = 186), and rEF (reduced LVEF, n = 323). During a median follow-up of 2.7 years, 86 (8.6%) patients had died. The 5-year survival significantly differed in patients with preserved LVEF according to the strain status (pEF/pS v pEF/iS, 90.0% v 84.6%; p = 0.002). After adjusting for potential confounders, the pEF/iS group (adjusted hazard ratio [HR], 2.17; 95% CI, 1.10-4.28; p = 0.03) and the rEF group (adjusted HR, 2.96; 95% CI, 1.46-6.00; p = 0.003) had significantly higher risks for all-cause death compared with the pEF/pS group. The addition of longitudinal strain to LVEF in the prediction model significantly improved its performance (global chi-squared, 105.2 v 110.2; p = 0.03). CONCLUSIONS: Left ventricular longitudinal strain could differentiate the prognosis after CABG in patients with preserved LVEF and provide significant incremental prognostic value to LVEF.

Postoperative changes in left ventricular systolic function after combined mitral and aortic valve replacement in patients with rheumatic heart disease.

BACKGROUNDS: We sought to identify short- and long-term changes in postoperative left ventricular systolic function in patients with rheumatic heart disease (RHD) who underwent combined aortic and mitral valve replacement. METHODS: We analyzed 146 patients according to their preoperative left ventricular ejection fraction (LVEF) (113 with preoperative LVEF ≥50% and 33 with preoperative LVEF <50%). A restricted cubic spline model was used to assess the effect of time on the postoperative changes in echocardiographic parameters. RESULTS: There were no significant difference in preoperative and immediately postoperative LVEF before discharge in either group. During median follow-up of 3.2 years (interquartile range: 1.3-4.7 years) after surgery, postoperative LVEF increased slightly and then plateaued in patients with preoperative LVEF ≥50%, whereas it increased over 3-4 years after surgery and then gradually decreased in patients with preoperative LVEF <50% (p < .001). CONCLUSION: Long-term postoperative LVEF showed a downward trend in RHD patients with reduced preoperative LVEF, whereas it reached a plateau in RHD patients with normal preoperative LVEF.

Perioperative rupture risk of unruptured intracranial aneurysms in cardiovascular surgery.

Although unruptured intracranial aneurysms are increasingly being diagnosed incidentally, perioperative rupture risk of unruptured intracranial aneurysm in patients undergoing cardiovascular surgery remains unclear. Therefore, we conducted an observational study to assess the prevalence and perioperative rupture risk of unruptured intracranial aneurysm in patients undergoing cardiovascular surgery. Adult patients (n = 4864) who underwent cardiovascular surgery between January 2010 and December 2016 were included. We assessed the prevalence of unruptured intracranial aneurysms in these patients using preoperative neurovascular imaging. The incidence of postoperative 30-day subarachnoid haemorrhage from aneurysmal rupture was investigated in patients undergoing cardiovascular surgery with unruptured intracranial aneurysm. Postoperative outcomes were compared between patients with unruptured intracranial aneurysm and those without unruptured intracranial aneurysm. Of the 4864 patients (39.6% females; mean ± standard deviation age, 62.3 ± 11.3 years), 353 patients had unruptured intracranial aneurysms (prevalence rate, 7.26%; 95% confidence interval, 6.52-8.06%). Of these, eight patients received surgical or endovascular treatment before surgery and 345 patients underwent cardiovascular surgery with unruptured intracranial aneurysms. Within 30 days postoperatively, subarachnoid haemorrhage occurred only in one patient, and the cumulative postoperative 30-day subarachnoid haemorrhage incidence was 0.29% (95% confidence interval, 0.01% to 1.61%). The Kaplan-Meier estimated subarachnoid haemorrhage probabilities according to the unruptured intracranial aneurysm rupture risk scores were not higher than the previously reported risk in the general population. There were no significant differences in postoperative subarachnoid haemorrhage-free survival, haemorrhagic stroke-free survival, in-hospital mortality, and hospital length of stay between patients with unruptured intracranial aneurysm and those without unruptured intracranial aneurysm. In conclusion, the prevalence of unruptured intracranial aneurysm in patients undergoing cardiovascular surgery is higher than in the general population. However, incidentally detected unruptured intracranial aneurysms are not linked to an increased risk of subarachnoid haemorrhage or adverse postoperative outcomes. These findings may help determine the optimal management of unruptured intracranial aneurysms before cardiovascular surgery.

Association between red blood cell transfusion and long-term mortality in patients with cancer of the esophagus after esophagectomy.

The impact of red blood cell transfusion on long-term mortality has not been well characterized in patients with cancer of the esophagus after esophagectomy. Our retrospective observational study investigated 611 patients with cancer of the esophagus after esophagectomy from January 2005 to December 2012. Perioperative red blood cell transfusion was defined as red blood cell transfusion during intraoperative and postoperative period. One hundred ninety-six (32.1%) patients received red blood cell transfusion. During follow-up period, 153 (36.9%) patients without red blood cell transfusion and 120 (61.2%) patients with red blood cell transfusion died. Multivariable analysis identified that there was an incremental association between the amount of red blood cell transfusion and long-term mortality (hazard ratio 1.06, 95% confidence interval 1.04-1.08, P < 0.001). The association between red blood cell transfusion and worse long-term mortality was also demonstrated in propensity-matched patients (hazard ratio 1.62, 95% confidence interval 1.15-2.28, P = 0.006). Therefore, there might be an independent association between perioperative red blood cell transfusion and worse long-term mortality in patients with cancer of the esophagus after esophagectomy. Furthermore, there was an incremental increase in long-term mortality in patients who was transfused with red blood cell during perioperative period.

Prognostic Impacts of Increases in Amino Transaminases Following Coronary Artery Bypass Grafting on Mortality.

OBJECTIVE: To evaluate the prognostic impacts of postoperative increases in serum amino transaminases on 1-year mortality in patients who underwent coronary artery bypass graft. DESIGN: A retrospective analysis. SETTING: A tertiary care university hospital. PARTICIPANTS: A total of 1,950 patients who underwent coronary artery bypass graft. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Aspartate amino transaminase and alanine amino transaminase ratios were calculated as the ratio between the peak aspartate amino transaminase and alanine amino transaminase within the first 5 post-operative days and their respective upper limit of normal values. A ratio of 2.0 was seen to be the minimum for which a difference in 1-year mortality could be detected in univariate analysis, when considering simultaneously both aspartate amino transaminase and alanine amino transaminase ratios. Multivariable analysis showed an association between an aspartate amino transaminase ratio > 2.0 and increased 1-year mortality (hazard ratio [HR] 2.68, 95% confidence interval [CI] 1.42-5.05, P = 0.002), and also between both an aspartate amino transaminase and alanine amino transaminase ratio > 2.0 and increased 1-year mortality (HR 3.90, 95% CI 1.87-8.14, P < 0.001). However, increases in alanine amino transaminase only above the upper limit of normal were not associated with increased 1-year mortality. CONCLUSIONS: Postoperative increases in aspartate amino transaminase only and increases in both aspartate amino transaminase and alanine amino transaminase greater than twice the upper limit of normal were associated with increased 1-year mortality in patients undergoing coronary artery bypass graft.

Prediction of the optimal depth for superior vena cava cannulae with cardiac computed tomography during minimally invasive cardiac surgery: a prospective observational cohort study.

BACKGROUND: The determination of the adequate depth of superior vena cava cannulae during minimally invasive cardiac surgery is important for warranting venous drainage and preventing complications during cardiopulmonary bypass. We investigated whether preoperative cardiac computed tomography might be useful for predicting the optimal depth of superior vena cava cannulae. METHODS: The patients who required superior vena cava cannulation and had cardiac tomographic image among those scheduled to undergo a minimally invasive cardiac surgery were evaluated. The distance between the upper border of the clavicular sternal head and the superior vena cava-right atrium junction was measured on cardiac computed tomography. Equivalence test for the difference between the distance measured on cardiac computed tomography and the distance verified by surgeon's direct inspection in the surgical field was performed. The range -1 cm to 1 cm was predefined as an equivalence region. In addition, the distances between the upper border of the clavicular sternal head and the carina level on chest radiography were measured to compare the relative position of carina with regard to the superior vena cava-right atrium junction. RESULTS: A total of 46 patients were evaluated. The distance from the upper border of the clavicular sternal head to the superior vena cava-right atrium junction measured on cardiac computed tomography and the distance verified by surgeon's inspection was equivalent, with the 95% confidence interval for the mean difference within the equivalence region (0.05-0.52, P < 0.0001). The carina level on chest radiography was found at least 2 cm above the superior vena cava-right atrium junction in all patients. CONCLUSIONS: Preoperative cardiac computed tomography might be valuable for predicting the adequate depth of superior vena cava cannulae. Additionally, the carina on chest radiography might indicate a useful landmark for proper position of central venous catheter. TRIAL REGISTRATION: This study has been registered at Clinical Research Information Service on 6 July 2012 (KCT0000477) .

Development of a scoring system to predict massive postpartum transfusion in placenta previa totalis.

PURPOSE: It is important to predict massive postpartum hemorrhage in patients with placenta previa totalis (PPT) and a method that accurately predicts this event is needed. The present study developed a scoring system that predicts massive transfusion in patients with PPT. METHODS: This single-center retrospective cohort study comprised 238 patients with PPT who underwent caesarean section between January 2004 and December 2010. Massive transfusion was defined as the transfusion of ≥8 units of packed red blood cells within 24 h after delivery. Multivariate regression analysis was used to estimate the risks of massive transfusion. A probability score model was then constructed and tested for performance. Subsequently, the model was validated in other patients with PPT (n = 117). RESULTS: Thirty-one patients (13.0%) underwent massive transfusion. Ultrasound suspicion of placental adhesion, previous caesarean section, gestational age <37 weeks, sponge-like appearance of the cervix, and anterior placenta were all independent predictors of massive transfusion. The performance for the score model revealed good calibration (Hosmer-Lemeshow chi-squared 1.64; P = 0.44), and its discrimination (the area under the receiver operating characteristic for this model was 0.84) was better than when suspicion of placental adhesion was used alone (0.67; P < 0.001). In the validation set, the performance was 0.88. CONCLUSION: The scoring system developed using the five independent risk factors had better performance to predict massive transfusion in patients with PPT than when suspicion of placental adhesion was used alone. However, further large-scale studies are warranted to clarify the usefulness and accuracy of this model.

Effect of Exogenous Albumin on the Incidence of Postoperative Acute Kidney Injury in Patients Undergoing Off-pump Coronary Artery Bypass Surgery with a Preoperative Albumin Level of Less Than 4.0 g/dl.

BACKGROUND: Hypoalbuminemia may increase the risk of acute kidney injury (AKI). The authors investigated whether the immediate preoperative administration of 20% albumin solution affects the incidence of AKI after off-pump coronary artery bypass surgery. METHODS: In this prospective, single-center, randomized, parallel-arm double-blind trial, 220 patients with preoperative serum albumin levels less than 4.0 g/dl were administered 100, 200, or 300 ml of 20% human albumin according to the preoperative serum albumin level (3.5 to 3.9, 3.0 to 3.4, or less than 3.0 g/dl, respectively) or with an equal volume of saline before surgery. The primary outcome measure was AKI incidence after surgery. Postoperative AKI was defined by maximal AKI Network criteria based on creatinine changes. RESULTS: Patient characteristics and perioperative data except urine output during surgery were similar between the two groups studied, the albumin group and the control group. Urine output (median [interquartile range]) during surgery was higher in the albumin group (550 ml [315 to 980]) than in the control group (370 ml [230 to 670]; P = 0.006). The incidence of postoperative AKI in the albumin group was lower than that in the control group (14 [13.7%] vs. 26 [25.7%]; P = 0.048). There were no significant between-group differences in severe AKI, including renal replacement therapy, 30-day mortality, and other clinical outcomes. There were no significant adverse events. CONCLUSION: Administration of 20% exogenous albumin immediately before surgery increases urine output during surgery and reduces the risk of AKI after off-pump coronary artery bypass surgery in patients with a preoperative serum albumin level of less than 4.0 g/dl.

Preoperative hypoalbuminemia and anemia as predictors of transfusion in radical nephrectomy for renal cell carcinoma: a retrospective study.

BACKGROUND: The only curative therapy for renal cell carcinoma is the complete removal of malignant tissue. Surgical bleeding during radical nephrectomy may require blood transfusion. Blood transfusion, however, is associated with postoperative morbidity and mortality. This study investigated predictive factors of transfusion requirement in patients undergoing radical nephrectomy, as well as the effects of transfusion on postoperative outcomes. METHODS: This study retrospectively enrolled 526 patients who underwent open radical nephrectomy for renal cell carcinoma between 2010 and 2012. Univariate and multivariate logistic regression analyses were used to determine independent predictive factors of a requirement for packed red blood cell (PRBC) transfusion. Postoperative outcomes included an admission to the intensive care unit (ICU) and lengths of ICU and hospital stay. RESULTS: Of the 526 patients, 93 (17.7 %) required PRBC transfusion, with these patients requiring a mean 5.5 units. Preoperative hypoalbuminemia (serum albumin <3.5 g/dL) was observed in 75 (14.3 %) patients, and preoperative anemia (hemoglobin <12.0 g/dL) in 121 (23.0 %). Multivariate logistic regression analysis showed that preoperative hypoalbuminemia, preoperative anemia, and a high cancer stage were independent factors significantly associated with PRBC transfusion in open radical nephrectomy. The transfused group had higher incidence of ICU admission and longer lengths of ICU and hospital stay than the non-transfused group. CONCLUSIONS: Preoperative hypoalbuminemia and anemia are important predictors of PRBC transfusion during radical nephrectomy for renal cell carcinoma. Furthermore, transfusion is associated with poor postoperative outcomes.

Sonographic optic nerve sheath diameter as a surrogate measure for intracranial pressure in anesthetized patients in the Trendelenburg position.

BACKGROUND: It remains to be elucidated whether the Trendelenburg position increases intracranial pressure (ICP). ICP can be evaluated by measuring the sonographic optic nerve sheath diameter (ONSD). We investigated the effect of the isolated Trendelenburg position on ONSD in patients undergoing robot-assisted laparoscopic radical prostatectomy. Additionally, we evaluated the effect of the Trendelenburg position combined with pneumoperitoneum on ONSD. METHODS: Twenty-one patients scheduled for robot-assisted laparoscopic radical prostatectomy were enrolled. Sonographic ONSDs and hemodynamic parameters were measured at specific time points: in the supine position after induction of anesthesia, 3 min after the steep Trendelenburg position (35° incline), 3 min after the steep Trendelenburg position combined with pneumoperitoneum, and in the supine position after desufflation of the pneumoperitoneum. RESULTS: The ONSD 3 min after the steep Trendelenburg position was significantly higher than that of the supine position after induction of anesthesia (5.1 ± 0.3 mm vs. 4.5 ± 0.4 mm). In addition, the ONSD 3 min after the steep Trendelenburg position combined with pneumoperitoneum was higher than that of the supine position after induction of anesthesia (4.9 ± 0.4 mm vs. 4.5 ± 0.4 mm). The ONSD in the supine position after desufflation of the pneumoperitoneum was similar to that in the supine position after induction of anesthesia. CONCLUSIONS: Use of the isolated steep Trendelenburg position, for even a short duration, increased the sonographic ONSD, providing a better understanding of the effect of only a transient steep Trendelenburg position on ONSD as a surrogate measure for ICP.

Relationship between Serum Uric Acid Concentration and Acute Kidney Injury after Coronary Artery Bypass Surgery.

An elevated serum concentration of uric acid may be associated with an increased risk of acute kidney injury (AKI). The aim of this study was to investigate the impact of preoperative uric acid concentration on the risk of AKI after coronary artery bypass surgery (CABG). Perioperative data were evaluated from patients who underwent CABG. AKI was defined by the AKI Network criteria based on serum creatinine changes within the first 48 hr after CABG. Multivariate logistic regression was utilized to evaluate the association between preoperative uric acid and postoperative AKI. We evaluated changes in C statistic, the net reclassification improvement, and the integrated discrimination improvement to determine whether the addition of preoperative uric acid improved prediction of AKI. Of the 2,185 patients, 787 (36.0%) developed AKI. Preoperative uric acid was significantly associated with postoperative AKI (odds ratio, 1.18; 95% confidence interval, 1.10-1.26; P<0.001). Adding uric acid levels improved the C statistic and had significant impact on risk reclassification and integrated discrimination for AKI. Preoperative uric acid is related to postoperative AKI and improves the predictive ability of AKI. This finding suggests that preoperative measurement of uric acid may help stratify risks for AKI in in patients undergoing CABG.

Does remote ischaemic preconditioning with postconditioning improve clinical outcomes of patients undergoing cardiac surgery? Remote Ischaemic Preconditioning with Postconditioning Outcome Trial.

AIMS: The aim of this study was to evaluate whether remote ischaemic preconditioning (RIPC) combined with remote ischaemic postconditioning (RIPostC) improves the clinical outcomes of patients undergoing cardiac surgery. METHODS AND RESULTS: From June 2009 to November 2010, 1280 patients who underwent elective cardiac surgery were randomized into the RIPC with RIPostC group or the control group in the morning of the surgery. In the RIPC with RIPostC group, four cycles of 5-min ischaemia and 5-min reperfusion were administered twice to the upper limb-before cardiopulmonary bypass (CPB) or coronary anastomoses for RIPC and after CPB or coronary anastomoses for RIPostC. The primary endpoint was the composite of major adverse outcomes, including death, myocardial infarction, arrhythmia, stroke, coma, renal failure or dysfunction, respiratory failure, cardiogenic shock, gastrointestinal complication, and multiorgan failure. Remote ischaemic preconditioning with RIPostC did not reduce the composite outcome compared with the control group (38.0 vs. 38.1%, respectively; P = 0.998) and there was no difference in each major adverse outcome. The intensive care unit and hospital stays were not different between the two groups. However, in the off-pump coronary artery bypass surgery subgroup, multivariate logistic regression analysis revealed that RIPC with RIPostC was related to increased composite outcome (odds ratio: 1.54; 95% confidence interval: 1.02-2.30; P = 0.038). CONCLUSION: Remote ischaemic preconditioning with RIPostC by transient upper limb ischaemia did not improve clinical outcome in patients who underwent cardiac surgery.

Intraoperative renal regional oxygen desaturation can be a predictor for acute kidney injury after cardiac surgery.

OBJECTIVE: To evaluate the usefulness of renal regional oxygen saturation (renal rSO2) in predicting the risk of acute kidney injury (AKI) after cardiac surgery. DESIGN: A prospective observational study. SETTING: Tertiary care university hospital. PARTICIPANTS: One hundred patients undergoing cardiac surgery. INTERVENTIONS: Renal rSO2 was monitored continuously by near-infrared spectroscopy (NIRS) throughout the anesthetic period. MEASUREMENTS AND MAIN RESULTS: Postoperative AKI was defined using the Risk, Injury, Failure, Loss, and End-stage (RIFLE) criteria. Of 95 patients who were included in the final analysis, 34 patients developed AKI after surgery. Recorded renal rSO2 data were used to calculate the total duration of the time when renal rSO2 was below the threshold values of 70%, 65%, 60%, 55%, and 50%. The total periods when the renal rSO2 level was below each of the threshold values were significantly longer in patients with AKI than in those without AKI (p = 0.001 or p<0.001). Receiver operating characteristic (ROC) curve analysis was used to evaluate the predictive power of renal rSO2 for AKI. The ROC curve analysis showed that renal rSO2 could predict the risk of AKI with statistical significance and that a renal rSO2<55% had the best performance (area under the curve-ROC, 0.777; 95% CI, 0.669-0.885; p<0.001). Multivariate logistic regression analysis revealed that AKI significantly correlated with the duration of renal rSO2<55% (p = 0.002) and logistic EuroSCORE (p = 0.007). CONCLUSIONS: Intraoperative renal regional oxygen desaturation can be a good predictor of AKI in adult patients undergoing cardiac surgery.