Improving the performance of the Cleveland Clinic Score for predicting acute kidney injury after cardiac surgery: a prospective multicenter cohort study.

BACKGROUND: Cardiac surgery-associated acute kidney injury (CSA-AKI) is associated with high short- and long-term mortality rates. The prediction of CSA-AKI is crucial for early detection and treatment. Current predictive models may be improved by potentially useful preoperative and intraoperative information. METHODS: This multicenter prospective cohort study recruited 261 consecutive patients at high risk for developing CSA-AKI, based on a Cleveland Clinical Score (CCS) of ≥4 points from July to December 2017 in 14 hospitals in Spain and the UK. Postoperative AKI occurred in 145 (55.5%) patients. The receiver operating characteristics curve (AUC) of a base model including only the CCS was compared with models including additional preoperative and intraoperative variables such as the estimated glomerular filtration rate (eGFR) instead of plasmatic creatinine, intraoperative urine output, baseline hemoglobin, nadir hemoglobin, and glycosylated hemoglobin (HbA1c) instead of diabetes mellitus. The performance of each model for AKI was compared. RESULTS: The CCS alone gave an AUC of 0.67 (95% CI, 0.56-0.78) for postoperative AKI. None of the single variables added to the base model CCS improve discrimination. The AUC for postoperative AKI was improved when baseline hemoglobin, eGFR instead of plasmatic creatinine, HbA1c, and nadir hemoglobin were added to the CCS (AUC=0.77; 95% CI, 0.67-0.87; P=0.02). CONCLUSIONS: The addition of baseline hemoglobin, eGFR, HbA1c, and nadir intraoperative hemoglobin may be useful for improving the discrimination of the clinical predictive risk scores for AKI.

Hydroxyethyl starch and acute kidney injury in high-risk patients undergoing cardiac surgery: A prospective multicenter study.

BACKGROUND: Hydroxyethyl starch (HES) solutions increase the risk of acute kidney injury (AKI) in critically ill patients admitted to intensive care unit (ICU) for medical indications. We conducted a cohort study to evaluate the renal safety of modern 6% HES solutions in high-risk patients having cardiac surgery. METHOD: In this multicentre prospective cohort study, we recruited 261 consecutive patients at high-risk for developing cardiac surgery-associated AKI, based on a Cleveland score ≥ 4 points, from July to December 2017th in 14 hospitals in Spain and the United Kingdom. Multivariable logistic regression modeling and propensity-score matched-pairs analysis were used to determine the adjusted association between administration of HES and AKI. RESULTS: Of the cohort, 95 patients (36.4%) received 6% HES 130/0.4 either intraoperatively or postoperatively. Postoperative AKI occurred in 145 patients (55.5%). The unadjusted odds of AKI was significantly higher in the HES group, when compared to those not receiving HES (OR 2.22, 95% CI 1.30-3.80, p = 0.003). In multivariable logistic regression models, modern HES was not associated with significantly increased risk of AKI (adjusted OR 0.84, 95% CI 0.41-1.71, p = 0.63). In propensity score match-pairs analysis of 188 patients, the HES group experienced similar adjusted odds of AKI (OR 1.05, CI 95% 0.87-1.27, p = 0.57) and RRT (OR 1.06, CI 95% 0.92-1.22, p = 0.36). CONCLUSIONS: The use of modern hydroxyethyl starch 6% HES 130/0.4 was not associated with an increased risk of AKI nor dialysis in this cohort of patients at elevated risk for developing AKI after cardiac surgery.

Effects of oxygen on post-surgical infections during an individualised perioperative open-lung ventilatory strategy: a randomised controlled trial.

BACKGROUND: We aimed to examine whether using a high fraction of inspired oxygen (FIO2) in the context of an individualised intra- and postoperative open-lung ventilation approach could decrease surgical site infection (SSI) in patients scheduled for abdominal surgery. METHODS: We performed a multicentre, randomised controlled clinical trial in a network of 21 university hospitals from June 6, 2017 to July 19, 2018. Patients undergoing abdominal surgery were randomly assigned to receive a high (0.80) or conventional (0.3) FIO2 during the intraoperative period and during the first 3 postoperative hours. All patients were mechanically ventilated with an open-lung strategy, which included recruitment manoeuvres and individualised positive end-expiratory pressure for the best respiratory-system compliance, and individualised continuous postoperative airway pressure for adequate peripheral oxyhaemoglobin saturation. The primary outcome was the prevalence of SSI within the first 7 postoperative days. The secondary outcomes were composites of systemic complications, length of intensive care and hospital stay, and 6-month mortality. RESULTS: We enrolled 740 subjects: 371 in the high FIO2 group and 369 in the low FIO2 group. Data from 717 subjects were available for final analysis. The rate of SSI during the first postoperative week did not differ between high (8.9%) and low (9.4%) FIO2 groups (relative risk [RR]: 0.94; 95% confidence interval [CI]: 0.59-1.50; P=0.90]). Secondary outcomes, such as atelectasis (7.7% vs 9.8%; RR: 0.77; 95% CI: 0.48-1.25; P=0.38) and myocardial ischaemia (0.6% [n=2] vs 0% [n=0]; P=0.47) did not differ between groups. CONCLUSIONS: An oxygenation strategy using high FIO2 compared with conventional FIO2 did not reduce postoperative SSIs in abdominal surgery. No differences in secondary outcomes or adverse events were found. CLINICAL TRIAL REGISTRATION: NCT02776046.

Influence of Chemotherapy Within 30 Days Before ICU Admission on Mortality in Critically Ill Medical Patients With Cancer.

BACKGROUND: The main objective was to determine whether the administration of chemotherapy (CT) during the month before intensive care unit (ICU) admission of medical patients with cancer influences the survival rate. The design was a single-institution observational cohort study in an ICU of a tertiary university hospital. METHODS: Our cohort included 248 oncology patients admitted to the ICU from 2005 to 2014 due to nonsurgical problems. Seventy-six (30.6%) patients had received CT in the month before admission (CT group) and 172 did not receive CT (control group). The main outcome measures were ICU, hospital, 30-day, 90-day, and 1-year mortalities. We performed survival analysis using the Kaplan-Meier estimator, comparing both groups using the log-rank test, and multivariate analysis using Cox regression adjusted for gender, age, maximum Sequential Organ Failure Assessment (SOFA), and delta maximum SOFA to calculate the hazard ratios (HRs) and their respective 95% confidence intervals. This association was also evaluated by a graphic representation of survival. RESULTS: The CT group presented an ICU mortality rate of 27.6% versus 25.5% in the control group. The multivariate analysis adjusted for age, sex, and delta maximum SOFA showed significant differences between the groups (HR: 2.12; P = .009). The hospital mortality rate was 55.3% in the CT group compared to 45.4% in the control group (adjusted HR: 1.81; P = .003). At 30 days, the mortality rate was 56.6% in the CT group compared to 46.5% in the control group (adjusted HR: 1.69; P = .008). Mortality at 90 days was 65.8% in the CT group versus 59.9% in the control group (adjusted HR: 1.47; P = .03). One-year mortality was also higher in the CT group (79% vs 72.7%, adjusted HR: 1.44; P = .02). CONCLUSION: The administration of CT in the month before ICU admission in patients with cancer was associated with higher mortality in the ICU, in the hospital, and 30 and 90 days after admission when adjusted for the increase in organ failure measured by delta maximum SOFA. We provide useful new information for decision-making about ICU management of patients with cancer.

Preoperative predictive model for acute kidney injury after elective cardiac surgery: a prospective multicenter cohort study.

BACKGROUND: Predictive models of acute kidney injury after cardiac surgery (CS-AKI) include emergency surgery and patients with hemodynamic instability. Our objective was to evaluate the performance of validated predictive models (Thakar and Demirjian) in elective cardiac surgery and to propose a better score in the case of poor performance. METHODS: A prospective, multicenter, observational study was designed. Data were collected from 942 patients undergoing cardiac surgery, after excluding emergency surgery and patients with an intra-aortic balloon pump. The main outcome measure was CS-AKI defined by the composite of requiring dialysis or doubling baseline creatinine values. RESULTS: Both models showed poor discrimination in elective surgery (Thakar's model, AUC=0.57, 95% CI: 0.50-0.64 and Demirjian's model, AUC=0.64, 95% CI: 0.58-0.71). We generated a new model whose significant independent predictors were: anemia, age, hypertension, obesity, congestive heart failure, previous cardiac surgery and type of surgery. It classifies patients with scores 0-3 as at low risk (<5%), patients with scores 4-7 as at medium risk (up to 15%), and patients with scores >8 as at high risk (>30%) of developing CS-AKI with a statistically significant correlation (P<0.001). Our model reflects acceptable discriminatory ability (AUC=0.72, 95% CI: 0.66-0.78) which is significantly better than Thakar and Demirjian's models (P<0.01). CONCLUSIONS: We developed a new simple predictive model of CS-AKI in elective surgery based on available preoperative information. Our new model is easy to calculate and can be an effective tool for communicating risk to patients and guiding decision-making in the perioperative period. The study requires external validation.

Rationale and study design for an individualised perioperative open-lung ventilatory strategy with a high versus conventional inspiratory oxygen fraction (iPROVE-O2) and its effects on surgical site infection: study protocol for a randomised controlled trial.

INTRODUCTION: Surgical site infection (SSI) is a serious postoperative complication that increases morbidity and healthcare costs. SSIs tend to increase as the partial pressure of tissue oxygen decreases: previous trials have focused on trying to reduce them by comparing high versus conventional inspiratory oxygen fractions (FIO2) in the perioperative period but did not use a protocolised ventilatory strategy. The open-lung ventilatory approach restores functional lung volume and improves gas exchange, and therefore it may increase the partial pressure of tissue oxygen for a given FIO2. The trial presented here aims to compare the efficacy of high versus conventional FIO2 in reducing the overall incidence of SSIs in patients by implementing a protocolised and individualised global approach to perioperative open-lung ventilation. METHODS AND ANALYSIS: This is a comparative, prospective, multicentre, randomised and controlled two-arm trial that will include 756 patients scheduled for abdominal surgery. The patients will be randomised into two groups: (1) a high FIO2 group (80% oxygen; FIO2 of 0.80) and (2) a conventional FIO2 group (30% oxygen; FIO2 of 0.30). Each group will be assessed intra- and postoperatively. The primary outcome is the appearance of postoperative SSI complications. Secondary outcomes are the appearance of systemic and pulmonary complications. ETHICS AND DISSEMINATION: The iPROVE-O2 trial has been approved by the Ethics Review Board at the reference centre (the Hospital Clínico Universitario in Valencia). Informed consent will be obtained from all patients before their participation. If the approach using high FIO2 during individualised open-lung ventilation decreases SSIs, use of this method will become standard practice for patients scheduled for future abdominal surgery. Publication of the results is anticipated in early 2019. TRIAL REGISTRATION NUMBER: NCT02776046; Pre-results.

Perioperative hemoglobin area under the curve is an independent predictor of renal failure after cardiac surgery. Results from a Spanish multicenter retrospective cohort study.

Perioperative anemia is an important risk factor for cardiac surgery-associated acute kidney injury (CSA-AKI). Nonetheless, the severity of the anemia and the time in the perioperative period in which the hemoglobin level should be considered as a risk factor is conflicting. The present study introduces the concept of perioperative hemoglobin area under the curve (pHb-AUC) as a surrogate marker of the evolution of perioperative hemoglobin concentration. Through a retrospective analysis of prospectively collected data, we assessed this new variable as a risk factor for the development of acute kidney injury after cardiac surgery in 966 adult patients who underwent cardiac surgery with cardiopulmonary bypass, at twenty-three academic hospitals in Spain. Exclusion criteria were patients on renal replacement therapy, who needed a reoperation because of bleeding and/or with missing perioperative hemoglobin or creatinine values. Using a multivariate regression analysis, we found that a pHb-AUC <19 g/dL was an independent risk factor for CSA-AKI even after adjustment for intraoperative red blood cell transfusion (OR 1.41, p <0.05). It was also associated with mortality (OR 2.48, p <0.01) and prolonged hospital length of stay (4.67 ± 0.99 days, p <0.001).

External validation of predictive models for acute kidney injury following cardiac surgery: A prospective multicentre cohort study.

BACKGROUND: Four predictive models for acute kidney injury associated with cardiac surgery were developed by Demirjian in the United States in 2012. However, the usefulness of these models in clinical practice needs to be established in different populations independent of that used to develop the models. OBJECTIVES: Our aim was to evaluate the predictive performance of these models in a Spanish population. DESIGN: A multicentre, prospective observational study. DATA SOURCES: Twenty-three Spanish hospitals in 2012 and 2013. ELIGIBILITY CRITERIA: Of 1067 consecutive cardiac patients recruited for the study, 1014 patients remained suitable for the final analysis. MAIN OUTCOME MEASURES: Dialysis therapy, and a composite outcome of either a doubling of the serum creatinine level or dialysis therapy, in the 2 weeks (or until discharge, if sooner) after cardiac surgery. RESULTS: Of the 1014 patients analysed, 34 (3.4%) required dialysis and 95 (9.4%) had either dialysis or doubled their serum creatinine level. The areas under the receiver operating characteristic curves of the two predictive models for dialysis therapy, which include either presurgical variables only, or combined presurgical and intrasurgical variables, were 0.79 and 0.80, respectively. The model for the composite endpoint that combined presurgical and intrasurgical variables showed better discriminatory ability than the model that included only presurgical variables: the areas under the receiver operating characteristic curves were 0.76 and 0.70, respectively. All four models lacked calibration for their respective outcomes in our Spanish population. CONCLUSION: Overall, the lack of calibration of these models and the difficulty in using the models clinically because of the large number of variables limit their applicability.

Risk prediction model for respiratory complications after lung resection: An observational multicentre study.

BACKGROUND: Patients undergoing lung surgery are at risk of postoperative pulmonary complications (PPCs). Identifying those patients is important to optimise individual perioperative management. The Clinical Prediction Rule for Pulmonary Complications (CPRPCs) after thoracic surgery, developed by the Memorial Sloan-Kettering Cancer Center, might be an ideal predictor. The hypothesis was that CPRPC performs well for the prediction of PPCs. OBJECTIVE: The aim of our study was to provide the external validation of the CPRPC after lung resection for primary tumours, before universal acceptance. In case of poor discrimination, we planned, as a second objective, to derive a new predictive index for PPCs. DESIGN: Retrospective, observational multicentre study. PATIENTS: A total of 559 adult consecutive patients who underwent pulmonary resection. Inclusion criteria were adult patients (aged over 17 years). SETTING: Thirteen Spanish hospitals during the first half of 2011. INTERVENTIONS: A record of the PPCs defined, as in the original publication, as the presence of any of the following events: atelectasis; pneumonia; pulmonary embolism; respiratory failure; and need for supplemental oxygen at hospital discharge. MAIN OUTCOME MEASURES: The performance of the CPRPC was determined in order to examine its ability to discriminate and calibrate the presence of PPCs. RESULTS: The study included 559 patients, of whom 75 (11.6%) suffered PPCs. The CPRPC did not show enough discriminatory power for our cohort area under the receiver operating characteristic (ROC) curve 0.47 (95% confidence interval 0.37 to 0.57)]. After a fitting step by stepwise multivariate logistic regression, we identified three main predictors of PPCs: age; smoking status; and predicted postoperative forced expiratory volume in 1 s. Combining them into a simple risk score, we were able to obtain an area under the ROC curve of 0.74 (95% confidence interval 0.68 to 0.79). CONCLUSION: In this external validation, the CPRPC performed poorly despite its simplicity. The CPRPC was not a useful scale in our cohort. In contrast, we used a more accurate score to predict the occurrence of PPCs in our cohort. It is based on age, smoking status and predicted postoperative forced expiratory volume in 1 s. We propose that our formula should be externally validated.

Cardiac surgery-associated acute kidney injury.

Acute kidney injury develops in up to 30% of patients who undergo cardiac surgery, with up to 3% of patients requiring dialysis. The requirement for dialysis after cardiac surgery is associated with an increased risk of infection, prolonged stay in critical care units and long-term need for dialysis. The development of acute kidney injury is independently associated with substantial short- and long-term morbidity and mortality. Its pathogenesis involves multiple pathways. Haemodynamic, inflammatory, metabolic and nephrotoxic factors are involved and overlap each other leading to kidney injury. Clinical studies have identified predictors for cardiac surgery-associated acute kidney injury that can be used effectively to determine the risk for acute kidney injury in patients undergoing cardiac surgery. High-risk patients can be targeted for renal protective strategies. Nonetheless, there is little compelling evidence from randomized trials supporting specific interventions to protect or prevent acute kidney injury in cardiac surgery patients. Several strategies have shown some promise, including less invasive procedures in those at greatest risk, natriuretic peptide, fenoldopam, preoperative hydration, preoperative optimization of anaemia and postoperative early use of renal replacement therapy. The efficacy of larger-scale trials remains to be confirmed.

External validation and comparison of three scores to predict renal replacement therapy after cardiac surgery: a multicenter cohort.

PURPOSE: Cardiac surgery-associated acute kidney injury requiring renal replacement therapy (RRT) is independently associated with mortality. Several risk scores have been developed to predict the need for RRT after cardiac surgery. We have compared and verified the external validity of the three main available scores for RRT prediction after cardiac surgery: the Thakar score, the Mehta tool, and the Simplified Renal Index. METHODS: The risk scores were calculated in a cohort of 1084 adult patients, 248 of whom required RRT, who underwent open-heart surgery in 24 Spanish hospitals in 2007. The performance of the systems was determined by examining their discrimination (areas under the receiver operating characteristic curves (aROC) and calibration (Lemeshow-Hosmer chi-square goodness-of-fit statistics). RESULTS: The aROCs in the Thakar score, the Mehta tool, and the Simplified Renal Index were 0.82, 0.76 and 0.79, respectively. The three scoring systems were poorly calibrated and tended to underestimate the actual need for RRT. CONCLUSIONS: The Thakar score and the Simplified Renal Index discriminated well between low - and high-risk patients in our cohort, and Thakar outperformed the Mehta tool. These best-performing scores may aid in the selection of optimal therapy, facilitate the planning of hospital resource utilization, improve preoperative counseling, select participants for clinical trials of renal-protective therapies and enable an accurate comparison between different institutions or surgeons.

Timing of renal replacement therapy after cardiac surgery: a retrospective multicenter Spanish cohort study.

BACKGROUND: The optimal time to initiate renal replacement therapy (RRT) in cardiac surgery-associated acute kidney injury (CSA-AKI) is unknown. Evidence suggests that the early use of RRT in critically ill patients is associated with improved outcomes. We studied the effects of time to initiation of RRT on outcome in patients with CSA-AKI. METHODS: This was a retrospective observational multicenter study (24 Spanish hospitals). We analyzed data on 203 patients who required RRT after cardiac surgery in 2007. The cohort was divided into 2 groups based on the time at which RRT was initiated: in the early RRT group, therapy was initiated within the first 3 days after cardiac surgery; in the late group, RRT was begun after the 3rd day. Multivariate nonconditional logistic and linear regression models were used to adjust for potential confounders. RESULTS: In-hospital mortality was significantly higher in the late RRT group compared with early RRT patients (80.4 vs. 53.2%; p < 0.001; adjusted odds ratio of 4.1, 95% CI: 1.6-10.0). Also, patients in the late RRT group had longer adjusted hospital stays by 11.6 days (95% CI: 1.4-21.9) and higher adjusted percentage increases in creatinine at discharge compared with baseline by 67.7% (95% CI: 28.5-106.4). CONCLUSIONS: Patients who undergo early initiation of RRT after CSA-AKI have improved survival rates and renal function at discharge and decreased lengths of hospital stay.

Cardiac-surgery associated acute kidney injury requiring renal replacement therapy. A Spanish retrospective case-cohort study.

BACKGROUND: Acute kidney injury is among the most serious complications after cardiac surgery and is associated with an impaired outcome. Multiple factors may concur in the development of this disease. Moreover, severe renal failure requiring renal replacement therapy (RRT) presents a high mortality rate. Consequently, we studied a Spanish cohort of patients to assess the risk factors for RRT in cardiac surgery-associated acute kidney injury (CSA-AKI). METHODS: A retrospective case-cohort study in 24 Spanish hospitals. All cases of RRT after cardiac surgery in 2007 were matched in a crude ratio of 1:4 consecutive patients based on age, sex, treated in the same year, at the same hospital and by the same group of surgeons. RESULTS: We analyzed the data from 864 patients enrolled in 2007. In multivariate analysis, severe acute kidney injury requiring postoperative RRT was significantly associated with the following variables: lower glomerular filtration rates, less basal haemoglobin, lower left ventricular ejection fraction, diabetes, prior diuretic treatment, urgent surgery, longer aortic cross clamp times, intraoperative administration of aprotinin, and increased number of packed red blood cells (PRBC) transfused. When we conducted a propensity analysis using best-matched of 137 available pairs of patients, prior diuretic treatment, longer aortic cross clamp times and number of PRBC transfused were significantly associated with CSA-AKI.Patients requiring RRT needed longer hospital stays, and suffered higher mortality rates. CONCLUSION: Cardiac-surgery associated acute kidney injury requiring RRT is associated with worse outcomes. For this reason, modifiable risk factors should be optimised and higher risk patients for acute kidney injury should be identified before undertaking cardiac surgery.

Serum C-reactive protein on the prognosis of oncology patients with acute renal failure: an observational cohort study.

BACKGROUND: We undertook this study to evaluate the significance of the C-reactive protein level (CRP) as a prognostic factor in oncology patients with acute renal failure (ARF) during nephrology consultation. METHODS: The study was comprised of a cohort of 375 consecutive oncology patients who had been admitted to a university-affiliated hospital between March 1998 and April 2006 and had been diagnosed with ARF. One hundred and fifty nine patients with ARF who matched at least one of the RIFLE criteria on increased serum creatinine were included for subsequent analysis. We used a Cox proportional hazard model. RESULTS: Clinical pathological variables were compared among patients with serum CRP levels > or =8 mg/dL (exposed group; cut-off point: median) and patients with serum CRP level <8 mg/dL (control group). In-hospital mortality rates associated with CRP levels were 53.8% for > or =8 mg/dL and 21.5% for <8 mg/dL (p <0.001). After adjusted analysis, the presence of a CRP level > or =8 mg/dL was significantly associated with an increased in-hospital mortality (HR 2.10; 95% CI: 1.17-3.78) than in those patients with similar Liano scoring, the same RIFLE classes, and the same treatment for ARF. In addition, each increment of 1 mg/dL of serum CRP was associated with an adjusted 4% increment of in-hospital mortality (HR 1.04, 95% CI: 1.01-1.06). CONCLUSIONS: CRP levels at nephrology consultation were an independent predictor of death in this cohort of oncology patients with ARF. Patients with levels > or =8 mg/dL may be considered at higher risk of death.

A randomized, double-blinded comparison of thoracic epidural ropivacaine, ropivacaine/fentanyl, or bupivacaine/fentanyl for postthoracotomy analgesia.

UNLABELLED: Epidural ropivacaine has not been compared with bupivacaine for postthoracotomy analgesia. Eighty patients undergoing elective lung surgery were randomized in a double-blinded manner to receive one of three solutions for high thoracic epidural analgesia. A continuous epidural infusion of 0.1 mL. kg(-1). h(-1) of either 0.2% ropivacaine, 0.15% ropivacaine/fentanyl 5 micro g/mL, or 0.1% bupivacaine/fentanyl 5 micro g/mL was started at admission to the intensive care unit. We assessed pain scores (rest and spirometry), IV morphine consumption, spirometry, hand grip strength, PaCO(2), heart rate, blood pressure, respiratory rate, and side effects (sedation, nausea, vomiting, and pruritus) for 48 h. Thoracic epidural ropivacaine/fentanyl provided adequate pain relief similar to bupivacaine/fentanyl during the first 2 postoperative days after posterolateral thoracotomy. The use of plain 0.2% ropivacaine was associated with worse pain control during spirometry, larger consumption of IV morphine, and increased incidence of postoperative nausea and vomiting. Morphine requirements were larger in the ropivacaine group, with no differences between bupivacaine/fentanyl and ropivacaine/fentanyl groups. Patients in the ropivacaine group experienced more pain and performed worse in spirometry than patients who received epidural fentanyl. There was no significant difference in motor block. We conclude that epidural ropivacaine/fentanyl offers no clinical advantage compared with bupivacaine/fentanyl for postthoracotomy analgesia. IMPLICATIONS: Thoracic epidural ropivacaine/fentanyl provided adequate pain relief and similar analgesia to bupivacaine/fentanyl during the first 2 postoperative days after posterolateral thoracotomy. Plain 0.2% ropivacaine was associated with worse pain control and an increased incidence of postoperative nausea and vomiting. We conclude that epidural ropivacaine/fentanyl offers no clinical advantage compared with bupivacaine/fentanyl for postthoracotomy analgesia.