Preoperative estimated glomerular filtration rate and the risk of major adverse cardiovascular and cerebrovascular events in non-cardiac surgery

Risk Prediction Models for Renal Function Decline After Cardiac Surgery Within Different Preoperative Glomerular Filtration Rate Strata

BACKGROUND

Our goal was to create a simple risk-prediction model for renal function decline after cardiac surgery to help focus renal follow-up efforts on patients most likely to benefit.

METHODS AND RESULTS

This single-center retrospective cohort study enrolled 24 904 patients who underwent cardiac surgery from 2012 to 2019 at Fuwai Hospital, Beijing, China. An estimated glomerular filtration rate (eGFR) reduction of ≥30% 3 months after surgery was considered evidence of renal function decline. Relative to patients with eGFR 60 to 89 mL/min per 1.73 m2 (4.5% [531/11733]), those with eGFR ≥90 mL/min per 1.73 m2 (10.9% [1200/11042]) had a higher risk of renal function decline, whereas those with eGFR ≤59 mL/min per 1.73 m2 (5.8% [124/2129]) did not. Each eGFR stratum had a different strongest contributor to renal function decline: increased baseline eGFR levels for patients with eGFR ≥90 mL/min per 1.73 m2, transfusion of any blood type for patients with eGFR 60 to 89 mL/min per 1.73 m2, and no recovery of renal function at discharge for patients with eGFR ≤59 mL/min per 1.73 m2. Different nomograms were established for the different eGFR strata, which yielded a corrected C-index value of 0.752 for eGFR ≥90 mL/min per 1.73 m2, 0.725 for eGFR 60-89 mL/min per 1.73 m2 and 0.791 for eGFR ≤59 mL/min per 1.73 m2.

CONCLUSIONS

Predictors of renal function decline over the follow-up showed marked differences across the eGFR strata. The nomograms incorporated a small number of variables that are readily available in the routine cardiac surgical setting and can be used to predict renal function decline in patients stratified by baseline eGFR.

Prediction of Acute Myocardial Injury in Noncardiac Surgery in Patients at Risk for Major Adverse Cardiovascular and Cerebrovascular Events: A Multivariable Risk Model

BACKGROUND

The best use of perioperative cardiac biomarkers assessment is still under discussion. Massive postoperative troponin surveillance can result in untenably high workloads and costs for health care systems and potentially harmful interventions for patients. In a cohort of patients at risk for major adverse cardiovascular and cerebrovascular events (MACCEs), we aimed to (1) determine whether preoperative biomarkers can identify patients at major risk for acute myocardial injury in noncardiac surgery, (2) develop a risk model for acute myocardial injury prediction, and (3) propose an algorithm to optimize postoperative troponin surveillance.

METHODS

Prospective, single-center cohort study enrolling consecutive adult patients (≥45 years) at risk for MACCE scheduled for intermediate-to-high-risk noncardiac surgery. Baseline high-sensitivity troponin T (hsTnT) and N-terminal fragment of pro-B-type natriuretic peptide (NT-proBNP), as well as hsTnT on the first 3 postoperative days were obtained. The main outcome was the occurrence of acute myocardial injury. Candidate predictors of acute myocardial injury were baseline concentrations of hsTnT ≥14 ng/L and NT-proBNP ≥300 pg/mL and preoperative and intraoperative variables. A multivariable risk model and a decision curve were constructed.

RESULTS

Of 732 patients, 42.1% had elevated hsTnT and 37.3% had elevated NT-proBNP levels at baseline. Acute myocardial injury occurred in 161 patients (22%). Elevated baseline hsTnT, found in 84% of patients with acute myocardial injury, was strongly associated with this outcome: odds ratio (OR), 12.08 (95% confidence interval [CI], 7.78-19.42). Logistic regression identified 6 other independent predictors for acute myocardial injury: age, sex, estimated glomerular filtration rate (eGFR) <45 mL·min -1 ·1.73 m -2 , functional capacity <4 METs or unknown, NT-proBNP ≥300 pg/mL, and estimated intraoperative blood loss. The c -statistic for the risk model was 77% (95% CI, 0.73-0.81). The net benefit of the model began at a risk threshold of 7%.

CONCLUSIONS

Baseline determination of cardiac biomarkers in patients at risk for MACCE shortly before intermediate- or high-risk noncardiac surgery helps identify those with the highest risk for acute myocardial injury. A baseline hsTnT ≥14 ng/L indicates the need for postoperative troponin surveillance. In patients with baseline hsTnT <14 ng/L, our 6-predictor model will identify additional patients at risk for acute myocardial injury who may also benefit from postoperative surveillance.

Patient selection in ambulatory surgery

Patient selection is important for ambulatory surgical practices. Proper patient selection for ambulatory practices will optimize resources and lead to increased patient and provider satisfaction. As the number and complexity of procedures in ambulatory surgical centers increase, it is important to ensure that patients are best cared for in facilities that can provide appropriate levels of care. This review addresses the multiple variables and resources that should be considered when selecting patients for anesthesia in ambulatory centers and offices.

Prevalence and trends of perioperative major adverse cardiovascular and cerebrovascular events during cancer surgeries

Major adverse cardiovascular and cerebrovascular events (MACCE) is an important cause of morbidity and mortality during perioperative period. In this study, we looked for national trends in perioperative MACCE and its components as well as cancer types associated with high rates of perioperative MACCE during major cancer surgeries. This study was a retrospective analysis of the National Inpatient Sample, 2005-2014. Hospitalizations for surgeries of prostate, bladder, esophagus, pancreas, lung, liver, colorectal, and breast among patients 40 years and greater were included in the analysis. MACCE was defined as a composite measure that included in-hospital all-cause mortality, acute myocardial infarction (AMI), and ischemic stroke. A total of 2,854,810 hospitalizations for major surgeries were included in this study. Of these, 67,316 (2.4%) had perioperative MACCE. Trends of perioperative MACCE showed that it decreased significantly for AMI, death and any MACCE, while stroke did not significantly change during the study period. Logistic regression analysis for perioperative MACCE by cancer types showed that surgeries for esophagus, pancreas, lung, liver, and colorectal cancers had significantly greater odds for perioperative MACCE. The surgeries identified to have greater risks for MACCE in this study could be risk stratified for better informed decision-making and management.

Association of Kidney Function With Major Postoperative Events After Noncardiac Ambulatory Surgeries: A Population-Based Cohort Study

OBJECTIVE

The aim of this study was to estimate the association between estimated glomerular filtration rate (eGFR) and acute myocardial infarction (AMI) or death after ambulatory noncardiac surgery.

SUMMARY BACKGROUND DATA

People with chronic kidney disease (CKD) commonly undergo surgical procedures. Although most are performed in an ambulatory setting, the risk of major perioperative outcomes after ambulatory surgery for people with CKD is unknown.

METHODS

In this retrospective population-based cohort study using administrative health data from Alberta, Canada, we included adults with measured preoperative kidney function undergoing ambulatory noncardiac surgery between April 1, 2005 and February 28, 2017. Participants were categorized into 6 eGFR categories (in mL/min/1.73m 2 )of ≥60 (G1-2), 45 to 59 (G3a), 30 to 44 (G3b), 15 to 29 (G4), <15 not receiving dialysis (G5ND), and those receiving chronic dialysis (G5D). The odds of AMI or death within 30 days of surgery were estimated using multivariable generalized estimating equation models.

RESULTS

We identified 543,160 procedures in 323,521 people with a median age of 66 years (IQR 56-76); 52% were female. Overall, 2338 people (0.7%) died or had an AMI within 30 days of surgery. Compared with the G1-2 category, the adjusted odds ratio of death or AMI increased from 1.1 (95% confidence interval: 1.0-1.3) for G3a to 3.1 (2.6-3.6) for G5D. Emergency Department and Urgent Care Center visits within 30 days were frequent (17%), though similar across eGFR categories.

CONCLUSIONS

Ambulatory surgery was associated with a low risk of major postoperative events. This risk was higher for people with CKD, which may inform their perioperative shared decision-making and management.

Perioperative management for people with kidney failure receiving dialysis: A scoping review

BACKGROUND

People with kidney failure receiving dialysis (CKD-G5D) are more likely to undergo surgery and experience poorer postoperative outcomes than those without kidney failure. In this scoping review, we aimed to systematically identify and summarize perioperative strategies, protocols, pathways, and interventions that have been studied or implemented for people with CKD-G5D.

METHODS

We searched MEDLINE, EMBASE, CINAHL Plus, Cochrane Database of Systematic Reviews, and Cochrane Controlled Trials registry (inception to February 2020), in addition to an extensive grey literature search, for sources that reported on a perioperative strategy to guide management for people with CKD-G5D. We summarized the overall study characteristics and perioperative management strategies and identified evidence gaps based on surgery type and perioperative domain. Publication trends over time were assessed, stratified by surgery type and study design.

RESULTS

We included 183 studies; the most common study design was a randomized controlled trial (27%), with 67% of publications focused on either kidney transplantation or dialysis vascular access. Transplant-related studies often focused on fluid and volume management strategies and risk stratification, whereas dialysis vascular access studies focused most often on imaging. The number of publications increased over time, across all surgery types, though driven by non-randomized study designs.

CONCLUSIONS

Despite many current gaps in perioperative research for patients with CKD-G5D, evidence generation supporting perioperative management is increasing, with recent growth driven primarily by non-randomized studies. Our review may inform organization of evidence-based strategies into perioperative care pathways where evidence is available while also highlighting gaps that future perioperative research can address.

Does Preoperative Estimated Glomerular Filtration Rate (eGFR) Predict Short-Term Surgical Outcomes in Patients Undergoing Pancreatic Resections?

INTRODUCTION

Preoperative eGFR has been found to be a reliable predictor of post-operative outcomes in patients with normal creatinine levels who undergo surgery. The aim of our study was to evaluate the impact of preoperative eGFR levels on short-term post-operative outcomes in patients undergoing pancreatectomy.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) pancreatectomy file (2014-2017) was queried for all adult patients (age ≥ 18) who underwent pancreatic resection. Patients were stratified into two groups based on their preoperative eGFR (eGFR < 60 mL/min/1.73m² and eGFR ≥ 60 mL/min/1.73m²). Outcome measures included post-operative pancreatic fistula, discharge disposition, hospital length of stay, 30-day readmission rate, and 30-day morbidity and mortality. Multivariate logistic regression analysis was performed.

RESULTS

A total of 21,148 were included in the study of which 12% (n = 2256) had preoperative eGFR < 60 mL/min/1.73m². Patients in the eGFR < 60 group had prolonged length of stay, were less likely to be discharged home, had higher minor and major complication rates, and higher rates of mortality. On logistic regression analysis, lower preoperative eGFR (< 60 mL/min/1.73m²) was associated with higher odds of prolonged length of stay [aOR: 1.294 (1.166-1.436)], adverse discharge disposition [aOR: 1.860 (1.644-2.103)], minor [aOR: 1.460 (1.321-1.613)] and major complications [aOR: 1.214 (1.086-1.358)], bleeding requiring transfusion [aOR: 1.861 (1.656-2.091)], and mortality [aOR: 2.064 (1.523-2.797)].

CONCLUSION

Preoperative decreased renal function measured by eGFR is associated with adverse outcomes in patients undergoing pancreatic resection. The results of this study may be valuable in improving preoperative risk stratification and post-operative expectations.

Predictors of peri-operative cardiac events and development of a scoring tool for patients with chronic kidney disease undergoing non-cardiac surgeries: A prospective observational multicentre study

Background and Aims:

Cardiovascular diseases are the leading causes of morbidity and mortality in chronic kidney disease (CKD) patients. Our aim was to derive predictors of cardiac morbidity, mortality, cardiac complications and to develop/validate a scoring tool in patients with CKD undergoing non-cardiac surgery.

Methods:

A prospective observational multicentre study was done on 770 patients with CKD. The primary outcome (“Event”) was one or more than one of sudden cardiac death, pulmonary oedema, acute coronary syndrome, arrhythmia and 30-day mortality. Secondary outcome was hypertension and hypotension. Predictors of cardiac risk were identified. A scoring tool was developed on the 2018 dataset and was validated on the 2019 dataset.

Results:

The overall incidence of cardiac events was 290 (37.66%) whereas the incidence of major adverse cardiac and cerebrovascular events was 15.04%. Mortality due to cardiac cause was 13 (1.68%). On multivariate regression analysis, seven perioperative variables had significant association with increased risk of events: age > 65 years (P = 0.004), metabolic equivalents (METS) ≤4 (P≤0.032), emergency surgery (P =0.032), mean arterial pressure >119 (P = 0.001), echocardiographic scoring (P = 0.054), type of anaesthesia (P ≤ 0.0001) and type of surgery (P = 0.056). Using these variables, a risk stratification tool was developed. C statistics showed favourable predictive accuracy (0.714) and the model showed good calibration.

Conclusion:

This risk scoring tool based on preoperative variables will help to predict the risk of events in high-risk CKD patients undergoing non-cardiac surgery. This will help in better counselling and optimisation.

The comparative and added prognostic value of biomarkers to the Revised Cardiac Risk Index for preoperative prediction of major adverse cardiac events and all-cause mortality in patients who undergo noncardiac surgery

BACKGROUND

The Revised Cardiac Risk Index (RCRI) is a widely acknowledged prognostic model to estimate preoperatively the probability of developing in-hospital major adverse cardiac events (MACE) in patients undergoing noncardiac surgery. However, the RCRI does not always make accurate predictions, so various studies have investigated whether biomarkers added to or compared with the RCRI could improve this.

OBJECTIVES

Primary: To investigate the added predictive value of biomarkers to the RCRI to preoperatively predict in-hospital MACE and other adverse outcomes in patients undergoing noncardiac surgery. Secondary: To investigate the prognostic value of biomarkers compared to the RCRI to preoperatively predict in-hospital MACE and other adverse outcomes in patients undergoing noncardiac surgery. Tertiary: To investigate the prognostic value of other prediction models compared to the RCRI to preoperatively predict in-hospital MACE and other adverse outcomes in patients undergoing noncardiac surgery.

SEARCH METHODS

We searched MEDLINE and Embase from 1 January 1999 (the year that the RCRI was published) until 25 June 2020. We also searched ISI Web of Science and SCOPUS for articles referring to the original RCRI development study in that period.

SELECTION CRITERIA

We included studies among adults who underwent noncardiac surgery, reporting on (external) validation of the RCRI and: - the addition of biomarker(s) to the RCRI; or - the comparison of the predictive accuracy of biomarker(s) to the RCRI; or - the comparison of the predictive accuracy of the RCRI to other models. Besides MACE, all other adverse outcomes were considered for inclusion.

DATA COLLECTION AND ANALYSIS

We developed a data extraction form based on the CHARMS checklist. Independent pairs of authors screened references, extracted data and assessed risk of bias and concerns regarding applicability according to PROBAST. For biomarkers and prediction models that were added or compared to the RCRI in ≥ 3 different articles, we described study characteristics and findings in further detail. We did not apply GRADE as no guidance is available for prognostic model reviews.

MAIN RESULTS

We screened 3960 records and included 107 articles.   Over all objectives we rated risk of bias as high in ≥ 1 domain in 90% of included studies, particularly in the analysis domain. Statistical pooling or meta-analysis of reported results was impossible due to heterogeneity in various aspects: outcomes used, scale by which the biomarker was added/compared to the RCRI, prediction horizons and studied populations.  Added predictive value of biomarkers to the RCRI Fifty-one studies reported on the added value of biomarkers to the RCRI. Sixty-nine different predictors were identified derived from blood (29%), imaging (33%) or other sources (38%). Addition of NT-proBNP, troponin or their combination improved the RCRI for predicting MACE (median delta c-statistics: 0.08, 0.14 and 0.12 for NT-proBNP, troponin and their combination, respectively). The median total net reclassification index (NRI) was 0.16 and 0.74 after addition of troponin and NT-proBNP to the RCRI, respectively. Calibration was not reported. To predict myocardial infarction, the median delta c-statistic when NT-proBNP was added to the RCRI was 0.09, and 0.06 for prediction of all-cause mortality and MACE combined. For BNP and copeptin, data were not sufficient to provide results on their added predictive performance, for any of the outcomes. Comparison of the predictive value of biomarkers to the RCRI  Fifty-one studies assessed the predictive performance of biomarkers alone compared to the RCRI. We identified 60 unique predictors derived from blood (38%), imaging (30%) or other sources, such as the American Society of Anesthesiologists (ASA) classification (32%). Predictions were similar between the ASA classification and the RCRI for all studied outcomes. In studies different from those identified in objective 1, the median delta c-statistic was 0.15 and 0.12 in favour of  BNP and NT-proBNP alone, respectively, when compared to the RCRI, for the prediction of MACE. For C-reactive protein, the predictive performance was similar to the RCRI. For other biomarkers and outcomes, data were insufficient to provide summary results. One study reported on calibration and none on reclassification. Comparison of the predictive value of other prognostic models to the RCRI   Fifty-two articles compared the predictive ability of the RCRI to other prognostic models. Of these, 42% developed a new prediction model, 22% updated the RCRI, or another prediction model, and 37% validated an existing prediction model. None of the other prediction models showed better performance in predicting MACE than the RCRI. To predict myocardial infarction and cardiac arrest, ACS-NSQIP-MICA had a higher median delta c-statistic of 0.11 compared to the RCRI. To predict all-cause mortality, the median delta c-statistic was 0.15 higher in favour of ACS-NSQIP-SRS compared to the RCRI. Predictive performance was not better for CHADS₂, CHA₂DS₂-VASc, R₂CHADS₂, Goldman index, Detsky index or VSG-CRI compared to the RCRI for any of the outcomes. Calibration and reclassification were reported in only one and three studies, respectively.

AUTHORS' CONCLUSIONS

Studies included in this review suggest that the predictive performance of the RCRI in predicting MACE is improved when NT-proBNP, troponin or their combination are added. Other studies indicate that BNP and NT-proBNP, when used in isolation, may even have a higher discriminative performance than the RCRI. There was insufficient evidence of a difference between the predictive accuracy of the RCRI and other prediction models in predicting MACE. However, ACS-NSQIP-MICA and ACS-NSQIP-SRS outperformed the RCRI in predicting myocardial infarction and cardiac arrest combined, and all-cause mortality, respectively. Nevertheless, the results cannot be interpreted as conclusive due to high risks of bias in a majority of papers, and pooling was impossible due to heterogeneity in outcomes, prediction horizons, biomarkers and studied populations. Future research on the added prognostic value of biomarkers to existing prediction models should focus on biomarkers with good predictive accuracy in other settings (e.g. diagnosis of myocardial infarction) and identification of biomarkers from omics data. They should be compared to novel biomarkers with so far insufficient evidence compared to established ones, including NT-proBNP or troponins. Adherence to recent guidance for prediction model studies (e.g. TRIPOD; PROBAST) and use of standardised outcome definitions in primary studies is highly recommended to facilitate systematic review and meta-analyses in the future.

Impact of postoperative acute kidney injury in patients undergoing major gastrointestinal surgery on 1-year survival and renal outcomes: a national multicentre cohort study

Background

The intermediate-term impact of acute kidney injury (AKI) in patients after major gastrointestinal and liver surgery has not been well characterized. This study aimed to evaluate the 1-year mortality rate and renal outcomes associated with postoperative AKI in a national prospective cohort.

Methods

This prospective multicentre, observational cohort with 1-year postoperative follow-up included adults undergoing major gastrointestinal and liver surgery across the UK and Ireland between 23 September and 18 November 2015. AKI was defined according to Kidney Disease Improving Global Outcomes (KDIGO) criteria. The primary outcome was death at 1-year after surgery, and the secondary outcome was Major Adverse Kidney Events (MAKE-365). Cox proportionate and multilevel logistic regression were used to account for case mix.

Results

Of 5745 patients across 173 centres, 1-year follow-up data was completed for 3504 patients (62.2 per cent, 126 centres), with attrition largely explained by centre non-participation (63.1 per cent). Some 13.6 per cent (475 of 3504) patients developed AKI by 7 days after surgery (stage 1: 9.2 per cent; stage 2/3: 4.3 per cent). At 1 year, 10.8 per cent (378 patients) experienced a MAKE-365 endpoint (303 patients had died, 61 had renal replacement therapy and 78 had renal dysfunction). Patients who experienced AKI by 7 days after surgery had a higher hazard of death at 1 year for KDIGO stage 1 (hazard ratio 1.50 (95 per cent c.i. 1.08 to 2.08), P = 0.016) and KDIGO stage 2/3 (hazard ratio 2.96 (95 per cent c.i. 2.02 to 4.33), P < 0.001). Both KDIGO stage 1 (odds ratio 2.09 (95 per cent c.i. 1.50 to 2.92), P < 0.001) and stage 2/3 (odds ratio 9.26 (95 per cent c.i. 6.31 to 13.59), P < 0.001) AKI were independently associated with MAKE-365.

Conclusion

AKI events within 7 days after gastrointestinal or liver surgery are associated with significantly worse survival and renal outcomes at 1 year.

The association of estimated glomerular filtration rate with outcomes following infrainguinal bypass for peripheral arterial disease

OBJECTIVE

Chronic kidney disease (CKD) is a recognized predictor of long-term survival, frequently coexisting with peripheral arterial disease (PAD). Estimated glomerular filtration rate (eGFR) is a more accurate marker of renal function than creatinine. This study sought to determine the graded impact of CKD, defined by eGFR, on infrainguinal lower extremity bypass (LEB) outcomes.

METHODS

This retrospective study examined 44,332 patients from the Vascular Quality Initiative database who underwent LEB between January 2003 and November 2019. The GFR was estimated using the Modification of Diet in Renal Disease equation. Multivariable logistic regression was used to study perioperative mortality and Kaplan-Meier survival estimation and multivariable Cox regression were used to evaluate 5-year mortality, 1-year major amputation, and major amputation/death.

RESULTS

The 30-day mortality odds was increased for CKD 3 (odds ratio [OR], 1.58; 95% confidence interval [CI], 1.32-1.91; P < .001) and CKD 5 (OR, 3.08; 95% CI, 2.45-3.87; P < .001) relative to CKD 1 to 2. Comparing CKD stages 3, 4, and 5 with CKD 1 and 2, there was a stepwise increase in the adjusted hazard of 5-year mortality (hazard ratio [HR], 1.18; 95% CI, 1.09-1.27; P < .001), (HR, 1.73; 95% CI; 1.47-2.03; P < .001) and (HR, 2.58; 95% CI, 2.33-3.84; P < .001), respectively. Although the risk of 1-year death or major amputation did not differ for CKD 3 compared with CKD 1, this was 50% higher for CKD 4 (HR, 1.50; 95% CI, 1.26-1.78; P < .001) and doubled for CKD 5 (HR, 2.07; 95% CI, 1.87-2.29; P < .001) compared with CKD 1 and 2. The adjusted HR for major amputation in 1 year was 0.81 (95% CI, 0.71-0.92; P = .002), 1.14 (95% CI, 0.84-1.54; P = .396) and 1.56 (95% CI,1.31-1.84; P < .001) for CKD 3, 4, and 5, respectively, compared with CKD 1 and 2.

CONCLUSIONS

The estimated GFR is a useful predictor of postoperative mortality, overall survival, and/or amputation after LEB in patients with PAD. It should be considered in the preoperative risk-benefit analysis process to guide patient selection in the population with concomitant PAD and CKD being considered for LEB.

Hepatocellular carcinoma in patients with chronic renal disease: Challenges of interventional treatment

Hepatocellular carcinoma (HCC) is a common malignancy worldwide, recognized as the fourth most common cause of cancer related death. Many risk factors, leading to liver cirrhosis and associated HCC, have been recognized, among them viral hepatitis infections play an important role worldwide. Patients suffering from chronic kidney disease (CKD), especially those on maintenance dialysis, show a higher prevalence of viral hepatitis than the general population what increases the risk of HCC onset. In addition, renal dysfunction may have a negative prognostic impact on both immediate and long-term outcomes after malignancy treatment. Several interventional procedures for the treatment of HCC are currently available: thermal ablation, transcatheter arterial chemoembolization, liver surgery or even liver transplantation. The Barcelona Clinic Liver Cancer system provides an evidence-based treatment algorithm to address different categories of patients to the most-effective treatment in consideration of the extension of disease, liver function and performance status. Liver resection and transplantation are usually reserved to patients with early stage HCC and acceptable performance status, while the other treatments are more indicated in case of impaired liver function or locally advanced or unresectable tumors. However, there is no validated treatment algorithm for HCC in CKD patients, mainly due to the rarity of reports in this cohort of patients. Hereby we discuss the available evidences on interventional HCC treatments in CKD patients, and briefly report up-to-date pharmacological therapy for HCC patients affected by viral hepatitis.

Estimated GFR and Incidence of Major Surgery: A Population-Based Cohort Study

RATIONALE & OBJECTIVE

Kidney disease is associated with an increased risk for postoperative morbidity and mortality. However, the incidence of major surgery on a population level is unknown. We aimed to determine the incidence of major surgery by level of kidney function.

STUDY DESIGN

Retrospective cohort study with entry from January 1, 2008, through December 31, 2009, and outcome surveillance from January 1, 2010, through December 31, 2016.

SETTING & PARTICIPANTS

Population-based study using administrative health data from Alberta, Canada; adults with an outpatient serum creatinine measurement or receiving maintenance dialysis formed the study cohort.

EXPOSURE

Participants were categorized into 6 estimated glomerular filtration rate (eGFR) categories: ≥60 (G1-G2), 45 to 59 (G3a), 30 to 44 (G3b), 15 to 29 (G4), and<15mL/min/1.73m² with (G5D) and without (G5) dialysis. eGFR was examined as a time-varying exposure based on means of measurements within 3-month ascertainment periods throughout the study period.

OUTCOME

Major surgery defined as surgery requiring admission to the hospital for at least 24 hours.

ANALYTICAL APPROACH

Incidence rates (IRs) for overall major surgery were estimated using quasi-Poisson regression and adjusted for age, sex, income, location of residence, albuminuria, and Charlson comorbid conditions. Age- and sex-stratified IRs of 13 surgery subtypes were also estimated.

RESULTS

1,455,512 cohort participants were followed up for a median of 7.0 (IQR, 5.3) years, during which time 241,989 (16.6%) underwent a major surgery. Age and sex modified the relationship between eGFR and incidence of surgery. Men younger than 65 years receiving maintenance dialysis experienced the highest rates of major surgery, with an adjusted IR of 243.8 (95% CI, 179.8-330.6) per 1,000 person-years. There was a consistent trend of increasing surgery rates at lower eGFRs for most subtypes of surgery.

LIMITATIONS

Outpatient preoperative serum creatinine measurement was necessary for inclusion and outpatient surgical procedures were not included.

CONCLUSIONS

People with reduced eGFR have a significantly higher incidence of major surgery compared with those with normal eGFR, and age and sex modify this increased risk. This study informs our understanding of how surgical burden changes with differing levels of kidney function.

Reassessment of kidney function equations in predicting long-term survival in cardiac surgery

BACKGROUND/OBJECTIVES

Chronic kidney disease (CKD) is a risk factor for long-term survival in cardiac surgery. The Cockcroft-Gault, Modification of Diet in Renal Disease (MDRD) study, CKD Epidemiology Collaboration (CKD-EPI), revised Lund-Malmö (LM), and full age spectrum equations are used to estimate glomerular filtration rates (eGFR), but each have advantages and disadvantages. Our objective was to determine which equation better predicts long-term survival.

METHODS

Data on 1492 consecutive patients who underwent isolated off-pump coronary artery bypass surgery between September 1996 and December 2008 were prospectively collected. Preoperative and postoperative eGFR were calculated using the five equations and compared using Cox regression analyses and time-dependent receiver operating characteristic (ROC) curves at 10 years.

RESULTS

In a Cox regression model after correction for significant predictors of long-term mortality, adjusted hazard ratios (HR) for one standard deviation increase in preoperative eGFR were 0.661 (P < .0001), 0.844 (P = .0166), 0.787 (P = .0002), 0.746 (P < .0001), and 0.717 (P < .0001) for the CG, MDRD, CKD-EPI, LM, and FAS equations, respectively. The areas under the time-dependent ROC curve at 10 years also showed that the CG formula has a better predictive value. Postoperative eGFR at discharge were also significant predictors of long-term mortality (HR = 0.603, P < .0001; HR = 0.725, P < .0001; HR = 0.688, P < .0001; HR = 0.673, P < .0001; HR = 0.632, P < .0001 for the CG, MDRD, CKD-EPI, LM, and FAS equations, respectively).

CONCLUSIONS

The CG formula was shown to better predict survival in cardiac surgery, though the FAS equation has a comparable prognostic value. Additionally, postoperative eGFR at discharge also predicted long-term survival.

Adverse Cardiovascular Events Associated With Female Pelvic Reconstructive Surgery

OBJECTIVE

To evaluate national trends in major adverse cardiovascular and cerebrovascular events (MACCE) in female pelvic reconstructive surgery (FPRS).

METHODS

Data from the National Inpatient Sample was used to identify women undergoing FPRS between 2012 and 2016. Demographic, procedural, and comorbidity data were collected. Patients were stratified into those with and without MACCE (defined as all-cause mortality, cardiac arrest, myocardial infarction (MI) and acute ischemic stroke). Descriptive statistics are expressed as medians and interquartile ranges. Pairwise analysis was performed using Wilcoxon rank-sum or Fisher exact test as appropriate. Multivariable logistic regression was used to identify independent risk factors for MACCE.

RESULTS

During the study period, 53,540 patients underwent FPRS. The rate of MACCE was 4.8 per 1000 surgeries; MI, 3.7; acute ischemic stroke, 0.6; cardiac arrest, 0.4; and all-cause mortality, 0.3. Patients experiencing MACCE were more likely to have major preexisting cardiovascular comorbidities, coagulopathy, neurologic disease (ND), and diabetes and were more likely to undergo robotic colpopexy (20.7% vs 9.6%, P < 0.001), vaginal colpopexy (32.0% vs 28.5%, P = 0.04), and to receive a blood transfusion (8.2% vs 2.5%, P < 0.001).On logistic regression, preexisting coagulopathy was the strongest predictor of MACCE (adjusted odds ratio [aOR], 5.53; 95% confidence interval [CI], 2.39-12.78), followed by blood transfusion (aOR, 4.84; 95% CI, 1.89-12.45), congestive heart failure (aOR, 3.61; 95% CI, 1.56-8.37), ND (aOR, 3.14; 95% CI, 1.23-8.06), and electrolyte abnormalities (aOR, 1.99; 95% CI, 1.05-3.99).

CONCLUSION

Major adverse cardiovascular and cerebrovascular events after FPRS is a rare event, with MI being the most common manifestation. Preexisting ND, congestive heart failure, coagulopathy, electrolyte disturbances, and perioperative transfusions are strongly associated with MACCE.

Acute Kidney Injury and Risk of Death After Elective Surgery: Prospective Analysis of Data From an International Cohort Study

BACKGROUND

Postoperative acute kidney injury (AKI) is associated with a high mortality rate. However, the relationship among AKI, its associations, and mortality is not well understood.

METHODS

Planned analysis of data was collected during an international 7-day cohort study of adults undergoing elective in-patient surgery. AKI was defined using Kidney Disease Improving Global Outcomes criteria. Patients missing preoperative creatinine data were excluded. We used multivariable logistic regression to examine the relationships among preoperative creatinine-based estimated glomerular filtration rate (eGFR), postoperative AKI, and hospital mortality, accounting for the effects of age, major comorbid diseases, and nature and severity of surgical intervention on outcomes. We similarly modeled preoperative associations of AKI. Data are presented as n (%) or odds ratios (ORs) with 95% confidence intervals.

RESULTS

A total of 36,357 patients were included, 743 (2.0%) of whom developed AKI with 73 (9.8%) deaths in hospital. AKI affected 73 of 196 (37.2%) of all patients who died. Mortality was strongly associated with the severity of AKI (stage 1: OR, 2.57 [1.3-5.0]; stage 2: OR, 8.6 [5.0-15.1]; stage 3: OR, 30.1 [18.5-49.0]). Low preoperative eGFR was strongly associated with AKI. However, in our model, lower eGFR was not associated with increasing mortality in patients who did not develop AKI. Conversely, in older patients, high preoperative eGFR (>90 mL·minute·1.73 m) was associated with an increasing risk of death, potentially reflecting poor muscle mass.

CONCLUSIONS

The occurrence and severity of AKI are strongly associated with risk of death after surgery. However, the relationship between preoperative renal function as assessed by serum creatinine-based eGFR and risk of death dependent on patient age and whether AKI develops postoperatively.

Adverse outcomes after non urological surgeries in patients with chronic kidney disease: a propensity-score-matched study

Objective

To evaluate the complications, mortality, and medical expenditures after nonurological surgical procedures in patients with chronic kidney disease (CKD).

Methods

Using claims data of Taiwan’s National Health Insurance, we conducted a matched cohort study of 35,643 patients with CKD who underwent nonurological surgeries in 2008–2013. By using a propensity-score matching procedure, 35,643 non-CKD patients were selected for comparison. Logistic regression was used to calculate the odds ratios (ORs) and the 95% confidence intervals (CIs) of postoperative complications and in-hospital mortality associated with CKD.

Results

The results showed that patients with CKD had higher risks of postoperative septicemia (OR: 1.78, 95% CI: 1.68–1.89), pneumonia (OR: 1.60, 95% CI: 1.48–1.73), stroke (OR: 1.34, 95% CI: 1.24–1.44), and in-hospital mortality (OR: 2.17, 95% CI: 1.90–2.47) compared with non-CKD patients. Longer hospital stays and higher medical expenditures after nonurological surgical procedures were noted in CKD patients. The association between CKD and postoperative adverse events was significant in both sexes, all of the age groups, and the other subgroups. Histories of myocardial infarction, epilepsy, and ages greater than 70 years were factors that were significantly associated with postoperative adverse events.

Conclusion

Compared with non-CKD patients, surgical patients with CKD exhibited more adverse events, with risks of in-hospital mortality that were approximately 2-fold higher after nonurinary surgery. These findings suggest an urgent need to revise the protocols for postoperative care in this population.

The Relationship Between Age and Chronic Kidney Disease in Patients Undergoing Pancreatic Resection

BACKGROUND

Severe chronic kidney disease (CKD) predicts adverse outcomes in patients undergoing pancreatectomy, but the impact of milder CKD is unknown. Additionally, some authors have suggested that, due to physiologic changes of aging, CKD is over-diagnosed in patients above age 65.

METHODS

Patients undergoing pancreatectomy for malignancy from 2005 to 2014 were identified from the National Surgical Quality Improvement Program. Primary outcomes were all-cause mortality and major complication, defined as myocardial infarction, cardiac arrest, stroke, venous thromboembolism, respiratory failure, deep surgical site infection, pneumonia, acute kidney injury, coma > 24 h, or re-operation occurring within 30 days of surgery.

RESULTS

The mean age of 16,173 participants was 66 (range 18-90). Median preoperative creatinine was 0.80 mg/dL (0.10-11.0), and median preoperative eGFR was 86.36 mL/min/1.73m² (2.98-182.2). Mortality and major complication occurred in 3 and 23% of patients, respectively. In adjusted analyses, CKD stages 2 (adjusted odds ratio (aOR) 1.24, 95% confidence interval (CI) 1.10-1.40), 3a (aOR 1.50, 95% CI 1.24-1.82), 3b (aOR 1.56, 95% CI 1.19-2.06), and 4 (aOR 2.17, 95% CI 1.25-3.76) were associated with increased major complication, and CKD stage 4 was associated with increased mortality (aOR 2.68, 95% CI 1.10-6.56). Age did not influence the relationship between CKD and either outcome.

CONCLUSION

CKD of any stage was associated with an increased risk of postoperative major complication, and severe CKD was associated with increased mortality among patients undergoing pancreatectomy for malignancy. These associations were not diminished in elderly patients. Our findings could inform preoperative counseling and decision-making.

Absence of Association between Preoperative Estimated Glomerular Filtration Rates and Postoperative Outcomes following Elective Gastrointestinal Surgeries: A Prospective Cohort Study

Background

Preoperative risk stratification and optimising care of patients undergoing elective surgery are important to reduce the risk of postoperative outcomes. Renal dysfunction is becoming increasingly prevalent, but its impact on patients undergoing elective gastrointestinal surgery is unknown although much evidence is available for cardiac surgery. This study aimed to investigate the impact of preoperative estimated glomerular filtration rate (eGFR) and postoperative outcomes in patients undergoing elective gastrointestinal surgeries.

Methods

This prospective study included consecutive adult patients undergoing elective gastrointestinal surgeries attending preassessment screening (PAS) clinics at the Queen Elizabeth Hospital Birmingham (QEHB) between July and August 2016. Primary outcome measure was 30-day overall complication rates and secondary outcomes were grade of complications, 30-day readmission rates, and postoperative care setting.

Results

This study included 370 patients, of which 11% (41/370) had eGFR of <60 ml/min/1.73 m². Patients with eGFR < 60 ml/min/1.73 m² were more likely to have ASA grade 3/4 (p < 0.001) and >2 comorbidities (p < 0.001). Overall complication rates were 15% (54/370), with no significant difference in overall (p=0.644) and major complication rates (p=0.831) between both groups. In adjusted models, only surgery grade was predictive of overall complications. Preoperative eGFR did not impact on overall complications (HR: 0.89, 95% CI: 0.45–1.54; p=0.2).

Conclusions

Preoperative eGFR does not appear to impact on postoperative complications in patients undergoing elective gastrointestinal surgeries, even when stratified by surgery grade. These findings will help preassessment clinics in risk stratification and optimisation of perioperative care of patients.

Management of antiplatelet therapy in patients with coronary stents undergoing noncardiac surgery: association with adverse events

BACKGROUND

Perioperative discontinuation of antiplatelet therapy (APT) in patients with coronary stents has been associated with major adverse cardiac events. Our aim was to analyse the perioperative management of APT in such patients and its relationship to the incidence of major adverse cardiac and cerebrovascular events (MACCE) and major bleeding events (MBE) in noncardiac surgery.

METHODS

We completed a prospective multicentre observational study of patients with coronary stents undergoing noncardiac surgery in 11 hospitals in Spain. The main objectives were to record perioperative events and prospectively analyse the management of APT, and to assess whether the different preoperative APT regimens were associated with MACCE and MBE.

RESULTS

Of 432 surgical procedures studied, 15% experienced a perioperative MACCE and 37% a MBE. Overall mortality was 3.0%. Presurgical APT was prescribed in 95% of procedures, and was preoperatively discontinued in 15%. Surgery was urgent or emergent in 22% of patients, 31% were ASA IV, and 38% had a Revised Cardiac Risk Index of IV. MACCE were related to recent myocardial infarction (P=0.038), chronic kidney disease (P<0.001), insulin-dependent diabetes (P=0.006) and no preoperative APT (P=0.018). MBE also increased MACCE risk (P<0.001). We found statin therapy (P=0.049) and obesity (P=0.016) to be protective factors for MACCE.

CONCLUSIONS

Patients with coronary stents undergoing noncardiac surgery suffer a high incidence of perioperative adverse events, even with perioperative APT. Major adverse cardiac and cerebrovascular events are mainly related to previous medical conditions and perioperative major bleeingn events. Our findings should be treated with caution when applied to an elective surgery population.

CLINICAL TRIAL REGISTRATION

NCT01171612.

Prediction of Major Adverse Cardiovascular and Cerebrovascular Events (MACCE) after Thoracic Surgery- The Role of Estimated GFR

Introducton

Little is known about the prognostic utility of preoperative estimated GFR (eGFR) on perioperative Major Adverse Cardiovascular and Cerebrovascular Events (MACCE) in apparently lower risk patients undergoing moderate risk surgeries like thoracotomy.

Aim

The current study sought to identify a clinically relevant cut-off value of eGFR for identifying thoracotomy patients at higher risk for MACCE.

Materials and Methods

Between July 2012 and July 2016, 436 consecutive patients were retrospectively studied after elective thoracotomy in a single institution. Patients were classified into six groups according to the calculated Chronic Kidney Disease Epidemiology Collaboration equations (CKD-EPI) eGFR (ml min ^-11.73 m ^-2): Stage 1, eGFR >90; Stage 2, eGFR=60-89.9; Stage 3a, eGFR=45-59.9; Stage 3b, eGFR=30-44.9; Stage 4, eGFR=15-29.9; Stage 5, eGFR <15. All the eGFR groups were analysed for perioperative MACCE, length of hospital stay, and mortality.

Results

The incidence of perioperative MACCE in our study was 4.24%. The mean eGFR in our study as calculated by the CKD-EPI equation was 83 ml min^-11.73 m^-2. With the exception of nonfatal cardiac arrest which was not seen in any patient, the incidence of all MACCE increased with progressively worsening preoperative eGFR.It was seen by logistic regression analysis that the occurrence of any perioperative MACCE increased significantly with worsening eGFR (p<0.001). The increase in MACCE was particularly marked from Stage 3b onwards to the later stages (OR 1.9 in 3a vs. 3.6 in 3b). The two mortalities observed in the study were in Stages 4 and 5 with no deaths seen in the better eGFR subgroups. There was also an increased length of hospital stay with declining eGFR.

Conclusion

Preoperative eGFR is a predictor of perioperative MACCE in homogenous moderate risk elective surgical population like thoracic surgeries. There is an inverse relationship between eGFR and MACCE, particularly manifested at eGFR values <45 ml/min/1.73. Routine use of preoperative eGFR for cardiovascular and cerebrovascular risk assessment in patients undergoing moderate risk surgeries like thoracotomy would be beneficial.

Preoperative Renal Insufficiency: Underreporting and Association With Readmission and Major Postoperative Morbidity in an Academic Medical Center

BACKGROUND

Making a formal diagnosis of chronic kidney disease (CKD) in the preoperative setting may be challenging because of lack of longitudinal data. We explored the predictive value of a single reduced preoperative estimated glomerular filtration rate (eGFR) value on adverse patient outcomes in the first 30 days after elective surgery. We compared the rate of major postoperative adverse events, including 30-day readmission rate, hospital length of stay, infection, acute kidney injury (AKI), and myocardial infarction across patients with declining preoperative eGFR values. We hypothesized that there is an association between decreasing preoperative eGFR values and major postoperative morbidity including readmission within 30 days of discharge and that the reasons for unplanned readmissions may be associated with poor preoperative renal function.

METHODS

This was a retrospective analysis of the electronic health record of 39 989 adult patients who underwent elective surgery between June 2011 and July 2013 at our institution. Patients with reduced eGFR (<60 mL/min/1.73 m) were identified and categorized by the stages of CKD that correlated with the preoperative eGFR value. Odds of readmission to our hospital within 30 days, as well as new diagnosis of AKI, myocardial infarction, and infection, were determined with multivariate logistic regression. The subset of patients who were readmitted within 30 days also were subdivided further into patients who had an eGFR <60 mL/min/1.73 m and those with an eGFR ≥60 mL/min/1.73 m, as well as whether the readmission was planned or unplanned.

RESULTS

Of the 4053 patients with eGFR <60 mL/min/1.73 m, 3290 (81.2%) did not carry a preoperative diagnosis of CKD. Adjusted odds ratios of being readmitted were 1.48 (99% confidence interval [CI], 1.18-1.87; P < .001) for eGFR 30 to 44 mL/min/1.73 m to 2.06 (99% CI, 1.32-3.23; P < .001) for eGFR <15 mL/min/1.73 m compared with patients with a preoperative eGFR value ≥60 mL/min/1.73 m. Patients with a lower eGFR also demonstrated increasing odds of AKI from 2.78 (99% CI, 1.86-4.17; P < .001) for eGFR 45 to 59 mL/min/1.73 m to 3.81 (99% CI, 1.68-8.16; P < .001) for eGFR <15 mL/min/1.73 m.

CONCLUSIONS

This study highlights that preoperative renal insufficiency may be underreported and appears to be significantly associated with postoperative complications. It extends the association between a single low preoperative eGFR and postoperative morbidity to a broader range of surgical populations than previously described. Our results suggest that preoperative calculation of eGFR may be a relatively low-cost, readily available tool to identify patients who are at an increased risk of readmission within 30 days of surgery and postoperative morbidity in patients presenting for elective surgery.

Planning, Execution, and Follow-up for Endovascular Aortic Aneurysm Repair Using a Highly Restrictive Iodinated Contrast Protocol in Patients with Severe Renal Disease

BACKGROUND

The cumulative amount of iodinated contrast medium necessary for endovascular repair (EVAR) planning, operative procedure, and subsequent follow-up is a threat for the onset of end-stage renal disease in patients with preoperative impaired kidney function. The purpose of this study was to describe a mini-invasive approach aimed to minimize the exposure of these patients to iodinated contrast medium and the subsequent risk of renal function worsening.

METHODS

From 2012 to 2015, all patients with abdominal aortic aneurysm (AAA) at high surgical risk and fit for standard EVAR (simple aortic-iliac anatomy: proximal and distal neck length ≥15 mm, no severe angulation), underwent EVAR through the following "near-zero contrast" approach, if their glomerular filtration rate (GFR) was <30 mL/min: preoperative planning was performed by noncontrast-enhanced computed tomography and duplex ultrasound (DU); the origin of renal/hypogastric arteries and aortic bifurcation was evaluated and matched with vertebral bone landmarks and the endograft deployed accordingly, using <20 cc of isotonic iodinate contrast medium and contrast-enhancement DU (CEUS). Follow-up was by DU/CEUS at 1, 6, and 12 months. Primary end points were technical success (TS: renal/hypogastric artery patency, absence of type I/III endoleaks, iliac stenosis/kinking, intraoperative mortality, and conversion), 30-day mortality, and new onset of permanent dialysis with renal function evaluation at 1, 6, and 12 months. Secondary end points were type II endoleaks, reinterventions, AAA, and renal-related mortality during the follow-up.

RESULTS

Eighteen patients (median age: 74 years, interquartile range [IQR]: 6, male: 78%, American Society of Anaesthesiologists [ASA] IV: 100%) were enrolled. The median AAA diameter and preoperative GFR were 66 mm (IQR: 13) and 22 mL/min (IQR: 4), respectively. Infrarenal (n = 10) and suprarenal fixation (n = 8) endografts were implanted, with a mean dose of iodinate contrast medium injection of 18 mL (IQR) and 100% TS rate. Two type II endoleaks were detected at the completion CEUS. The median postoperative GFR was 22 mL/min (IQR: 5). No patients had GFR worsening ≥30% at 1 day and 30 days. The 30-day mortality was 11% (2 deaths for heart failure). At a median follow-up of 16 months (IQR: 8), no patients needed hemodialytic treatment and no endoleaks were detected. One patient died at 6 months for cancer and one at 13 months for myocardial infarction. No reinterventions or AAA and renal-related mortality occurred during the follow-up.

CONCLUSIONS

A "near-zero contrast" approach is feasible in EVAR for patients with simple aorto-iliac anatomy. Patients with very poor renal function may still undergo to successful procedures, avoiding renal function impairment.

Acute kidney injury and mortality 1 year after major non-cardiac surgery

Background

Even mild and transient acute kidney injury (AKI), defined by increases in serum creatinine level, has been associated with adverse outcomes after major surgery. However, characteristic decreases in creatinine concentration during major illness could confound accurate assessment of postoperative AKI.

Methods

In a single-hospital, retrospective cohort study of non-cardiac surgery, the association between postoperative AKI, defined using the Kidney Disease: Improving Global Outcomes criteria, and 1-year survival was modelled using a multivariable Cox proportional hazards analysis. Factors associated with development of AKI were examined by means of multivariable logistic regression. Temporal changes in serum creatinine during and after the surgical admission in patients with and without AKI were compared.

Results

Some 1869 patients were included in the study, of whom 128 (6·8 per cent) sustained AKI (101 stage 1, 27 stage 2–3). Seventeen of the 128 patients with AKI (13·3 per cent) died in hospital compared with 16 of 1741 (0·9 per cent) without AKI (P &lt; 0·001). By 1 year, 34 patients with AKI (26·6 per cent) had died compared with 106 (6·1 per cent) without AKI (P &lt; 0·001). Over the 8–365 days after surgery, AKI was associated with an adjusted hazard ratio for death of 2·96 (95 per cent c.i. 1·86 to 4·71; P &lt; 0·001). Among hospital survivors without AKI, the creatinine level fell consistently (median difference at discharge versus baseline –7 (i.q.r. –15 to 0) µmol/l), but not in those with AKI (0 (–16 to 26) µmol/l) (P &lt; 0·001).

Conclusion

Although the majority of postoperative AKI was mild, there was a strong association with risk of death in the year after surgery. Underlying decreases in serum creatinine concentration after major surgery could lead to underestimation of AKI severity and overestimation of recovery.

[The role of renal anemia and cardiovascular disease in the progression of chronic glomerulonephritis]

AIM

To study the rate of chronic glomerulonephritis progression when added by anemia and cardiovascular disease (CVD).

SUBJECTS AND METHODS

231 patients (133 men and 98 women) with predialysis chronic glomerulonephritis (CGN) were examined. The patients' mean age of was 35.8±11.8 years; the disease duration was 1 to 17 years. The disease onset was the date when urinalysis showed evidence of persistent proteinuria and (or) hematuria. Besides, the time when anemia developed and the clinical and instrumental signs of CVD appeared was taken as the initial reference point; the time when end-stage renal failure was diagnosed was taken to be the endpoint. Red blood cell counts with the inclusion of its indices, hemoglobin concentration, hematocrit values, daily proteinuria values, and glomerular filtration rate were analyzed. The biochemical parameters included the concentrations of electrolytes, creatinine, fibrinogen, iron, cholesterol, total protein and C-reactive protein (CRP). Electrocardiography and echocardiography, bicycle ergometry and 24-hour ECG monitoring were used to detect CVD.

RESULTS

The presence of anemia and CVD in patients with predialysis CGN versus those without anemia and CVD was associated with an increase in the concentrations of CRP [36.2 and 12.6%; respectively; (p<0.05)], creatinine [123.0 (83.2-217.0) and 86.5 (72.0-128.5) µmol/L; (p<0.05)] and a decrease in GFR [65.4 (30.8-95.5) and 92.7 (64.5-122.3) ml/min; (p<0.05)]. The 8-year survival of patients with CGN concurrent with CVD was noted to be 58% whereas the renal survival in patients with CGN + CVD + anemia was shorter and the 6-year survival in this case was as high as 52%.

CONCLUSION

Anemia and CVD in patients with CGN serve as additional independent factors for the progression of the underlying disease. The concurrence of CGN, anemia, and CVD substantially reduces the predialysis period.

Preoperative renal dysfunction and mortality after non-cardiac surgery

BACKGROUND

Chronic kidney disease is an important preoperative risk factor. However, the association between renal dysfunction and risk of death has not been well explored in non-cardiac surgery.

METHODS

Two prospective observational studies in non-cardiac surgery were analysed: the European Surgical Outcomes Study (EuSOS) and the UK National Confidential Enquiry into Patient Outcome and Death (NCEPOD). The relationship between preoperative estimated glomerular filtration rate (eGFR) and postoperative mortality was examined using multivariable Cox proportional hazards models.

RESULTS

In EuSOS, 1580 (4·3 per cent) of 36 779 patients died in hospital; in NCEPOD, 298 (2·8 per cent) of 10 466 patients had died by 60 days after surgery. Chronic kidney disease (eGFR below 60·0 ml per min per 1·73 m(2) ) was present in 6415 patients (17·4 per cent) in EuSOS and 2262 (21·6 per cent) in NCEPOD. Preoperative chronic kidney disease was associated with older age, men, diagnosis of diabetes, cardiovascular or respiratory disease, and non-elective surgery. Preoperative eGFR categories below 60·0 ml per min per 1·73 m(2) were associated with increasing adjusted hazard ratios (HRs) for death compared with a value of 90·0 ml per min per 1·73 m(2) and above. In EuSOS, the risk of death increased with lower eGFR category, to a maximum with eGFR 15·0-29·9 ml per min per 1·73 m(2) (HR 3·37, 95 per cent c.i. 2·70 to 4·22). In NCEPOD, the risk of death also increased with declining eGFR and was maximal for eGFR below 15·0 ml per min per 1·73 m(2) (HR 3·40, 1·78 to 6·50).

CONCLUSION

Renal dysfunction is an important risk factor for death after non-cardiac surgery and the risk increases steeply for patients with moderate to severe kidney dysfunction.

Hyperglycemia and Acute Kidney Injury During the Perioperative Period

Hyperglycemia and acute kidney injury (AKI) are frequently observed during the perioperative period. Substantial evidence indicates that hyperglycemia increases the prevalence of AKI as a surgical complication. Patients who develop hyperglycemia and AKI during the perioperative period are at significantly elevated risk for poor outcomes such as major adverse cardiac events and all-cause mortality. Early observational and interventional trials demonstrated that the use of intensive insulin therapy to achieve strict glycemic control resulted in remarkable reductions of AKI in surgical populations. However, more recent interventional trials and meta-analyses have produced contradictory evidence questioning the renal benefits of strict glycemic control. Although the exact mechanisms through which hyperglycemia increases the risk of AKI have not been elucidated, multiple pathophysiologic pathways have been proposed. Hypoglycemia and glycemic variability may also play a significant role in the development of AKI. In this literature review, the complex relationship between hyperglycemia and AKI as well as its impact on clinical outcomes during the perioperative period is explored.

Nephrectomy and inferior vena cava thrombectomy for renal cell carcinoma among patients with impaired renal function: defining predictors of outcomes

BACKGROUND

Management of renal cell carcinoma (RCC) with inferior vena cava thrombus (IVCT) is associated with high morbidity. Chronic kidney disease (CKD) is a known risk factor for perioperative complications in many surgical procedures. The objective of this study was to review the association between preoperative CKD (eGFR < 60 mL/min) and post-operative outcomes in patients with RCC and IVCT undergoing radical nephrectomy (RN) and tumour thrombectomy (TT).

METHODS

A retrospective review of patients with RCC and IVCT treated with RN and TT was carried out. Complications were recorded according to the Clavien-Dindo classification. Multivariable models were fitted using logistic regression analyses for high-grade complications and salvage therapies and linear-regression for intraoperative blood loss (IBL).

RESULTS

One hundred and one patients with RCC and IVCT, treated with RN and TT, were identified. Forty per cent of patients had preoperative CKD. Median IBL was higher in CKD arm (2.5 versus 1.6 L, P = 0.04). In a multivariate linear regression analysis, CKD (beta 1.34, P = 0.01) remained an independent predictor of IBL. High-grade complications were more frequent in the CKD group (34% versus 16%, P = 0.09) and in logistic regression analysis, CKD was an independent predictor of high-grade complications (OR 3.33, 95% CI 1.01-10.9). Furthermore, CKD patients were less likely to be considered for salvage therapies (62% versus 38%, P = 0.02).

CONCLUSIONS

In patients treated with RN and TT, CKD is an independent predictor of perioperative morbidity. This clinical variable should be considered when selecting patients and subsequent efforts should be made to optimize other competing risk factors in order to reduce the incidence of perioperative adverse events in this patient population.