Long-term risk of mortality and acute kidney injury during hospitalization after major surgery. Ann Surg. 2009;249:851-858. [PMID: 19387314 DOI: 10.1097/sla.0b013e3181a40a0b]

Association between preoperative proton pump inhibitor use and postoperative acute kidney injury in patients undergoing major surgery

BACKGROUND

Acute kidney injury (AKI) is a severe postoperative complication in patients undergoing major surgery. Proton pump inhibitors (PPIs) are used preoperatively as prophylaxis for postoperative gastrointestinal bleeding. Whether preoperative PPI use is associated with an increased risk of postoperative AKI remains uncertain.

METHODS

This retrospective cohort study used electronic medical records from the clinical data warehouse of Peking University First Hospital to screen all adult hospitalizations undergoing major surgery between 1 January 2018 and 31 December 2020. Exposure was preoperative PPI use, defined as PPI use within 7 days before major surgery. The primary outcome was postoperative AKI, defined as AKI occurring within 7 days after major surgery; secondary outcomes included in-hospital AKI and in-hospital mortality.

RESULTS

A total of 21,533 patients were included in the study (mean [SD] age, 57.8 [15.0] years; 51.2% male), of which 944 (4.4%) were prescribed PPI within 7 days before major surgery (PPI users). Overall, 72 PPI users (7.6%) and 356 non-users (1.7%) developed postoperative AKI. After adjustment, preoperative PPI use was associated with an increased risk of postoperative AKI (adjusted OR, 1.47; 95% CI, 1.04-2.07) and in-hospital AKI (adjusted OR, 1.41; 95% CI, 1.03-1.94). Moreover, subgroup analyses showed that the risk of PPI on postoperative AKI was amplified by the concomitant use of non-steroidal anti-inflammatory drugs or diuretics. No significant difference was observed between preoperative PPI use and in-hospital mortality in the fully adjusted model (adjusted OR 1.63; 95% CI, 0.55-4.85).

CONCLUSIONS

Preoperative PPI use was associated with an increased risk of AKI in patients undergoing major surgery. This risk may be enhanced by the concomitant use of other nephrotoxic drugs. Clinicians should weigh the pros and cons before initiating PPI prophylaxis.

Utilizing Raman spectroscopy for urinalysis to diagnose acute kidney injury stages in cardiac surgery patients

BACKGROUND

The successful treatment and improvement of acute kidney injury (AKI) depend on early-stage diagnosis. However, no study has differentiated between the three stages of AKI and non-AKI patients following heart surgery. This study will fill this gap in the literature and help to improve kidney disease management in the future.

METHODS

In this study, we applied Raman spectroscopy (RS) to uncover unique urine biomarkers distinguishing heart surgery patients with and without AKI. Given the amplified risk of renal complications post-cardiac surgery, this approach is of paramount importance. Further, we employed the partial least squares-support vector machine (PLS-SVM) model to distinguish between all three stages of AKI and non-AKI patients.

RESULTS

We noted significant metabolic disparities among the groups. Each AKI stage presented a distinct metabolic profile: stage 1 had elevated uric acid and reduced creatinine levels; stage 2 demonstrated increased tryptophan and nitrogenous compounds with diminished uric acid; stage 3 displayed the highest neopterin and the lowest creatinine levels. We utilized the PLS-SVM model for discriminant analysis, achieving over 90% identification rate in distinguishing AKI patients, encompassing all stages, from non-AKI subjects.

CONCLUSIONS

This study characterizes the incidence and risk factors for AKI after cardiac surgery. The unique spectral information garnered from this study can also pave the way for developing an in vivo RS method to detect and monitor AKI effectively.

Acute kidney injury in the acute care surgery patient: What you need to know

ABSTRACT

Acute kidney injury is associated with poor outcomes in the trauma and emergency general surgery population, and recent consensus definitions have allowed for significant advances in defining the burden of disease. The current definitions rely on overall functional measures (i.e., serum creatinine and urine output), which can be confounded by a variety of clinical factors. Biomarkers are increasingly being investigated as more direct diagnostic assays for the diagnosis of acute kidney injury and may allow earlier detection and more timely therapeutic intervention. Etiologies fall into two general categories: disorders of renal perfusion and exposure to nephrotoxic agents. Therapy is largely supportive, and prevention offers the best chance to decrease clinical impact.

Renal dysfunction in surgical patients

PURPOSE OF REVIEW

To provide an overview of the current diagnostic criteria for acute kidney injury (AKI) including their limitations and to discuss prevention and treatment approaches in the perioperative setting.

RECENT FINDINGS

AKI is common in the perioperative period and is associated with worse short- and long-term outcomes. Current definitions of AKI have several limitations and lead to delayed recognition of kidney dysfunction which is why novel diagnostic approaches by using renal biomarkers may be helpful. In general, prevention of the development and progression of AKI is vital as a causal treatment for AKI is currently not available. Optimization of kidney perfusion and avoidance of nephrotoxic drugs reduce the occurrence of AKI in surgical patients. Angiotensin II as a new vasopressor, the use of remote ischemic preconditioning, and amino acids may be approaches with a positive effect on the kidneys.

SUMMARY

Evidence suggests that the implementation of supportive measures in patients at high risk for AKI might reduce the occurrence of AKI. Novel biomarkers can help allocating resources by detecting patients at high risk for AKI.

Recognition patterns of acute kidney injury in hospitalized patients

Background

Acute kidney injury (AKI) during hospitalization is associated with increased complications and mortality. Despite efforts to standardize AKI management, its recognition in clinical practice is limited.

Methods

To assess and characterize different patterns of AKI diagnosis, we collected clinical data, serum creatinine (sCr) levels, comorbidities and outcomes from adult patients using the Hospital Discharge Form (HDF). AKI diagnosis was based on administrative data and according to Kidney Disease: Improving Global Outcomes (KDIGO) criteria by evaluating sCr variations during hospitalization. Additionally, patients were categorized based on the timing of AKI onset.

Results

Among 56 820 patients, 42 900 (75.5%) had no AKI, 1893 (3.3%) had AKI diagnosed by sCr changes and coded in the HDF (full-AKI), 2529 (4.4%) had AKI reported on the HDF but not meeting sCr-based criteria (HDF-AKI) and 9498 (16.7%) had undetected AKI diagnosed by sCr changes but not coded in the HDF (KDIGO-AKI). Overall, AKI incidence was 24.5%, with a 68% undetection rate. Patients with KDIGO-AKI were younger and had a higher proportion of females, lower comorbidity burden, milder AKI stages, more frequent admissions to surgical wards and lower mortality compared with full-AKI patients. All AKI groups had worse outcomes than those without AKI, and AKI, even if undetected, was independently associated with mortality risk. Patients with AKI at admission had different profiles and better outcomes than those developing AKI later.

Conclusions

AKI recognition in hospitalized patients is highly heterogeneous, with a significant prevalence of undetection. This variability may be affected by patients' characteristics, AKI-related factors, diagnostic approaches and in-hospital patient management. AKI remains a major risk factor, emphasizing the importance of ensuring proper diagnosis for all patients.

Impact of spinal or epidural anaesthesia on perioperative outcomes in adult noncardiac surgery: a narrative review of recent evidence

Spinal and epidural anaesthesia and analgesia are important anaesthetic techniques, familiar to all anaesthetists and applied to patients undergoing a range of surgical procedures. Although the immediate effects of a well-conducted neuraxial technique on nociceptive and sympathetic pathways are readily observable in clinical practice, the impact of such techniques on patient-centred perioperative outcomes remains an area of uncertainty and active research. The aim of this review is to present a narrative synthesis of contemporary clinical science on this topic from the most recent 5-year period and summarise the foundational scholarship upon which this research was based. We searched electronic databases for primary research, secondary research, opinion pieces, and guidelines reporting the relationship between neuraxial procedures and standardised perioperative outcomes over the period 2018-2023. Returned citation lists were examined seeking additional studies to contextualise our narrative synthesis of results. Articles were retrieved encompassing the following outcome domains: patient comfort, renal, sepsis and infection, postoperative cancer, cardiovascular, and pulmonary and mortality outcomes. Convincing evidence of the beneficial effect of epidural analgesia on patient comfort after major open thoracoabdominal surgery outcomes was identified. Recent evidence of benefit in the prevention of pulmonary complications and mortality was identified. Despite mechanistic plausibility and supportive observational evidence, there is less certain experimental evidence to support a role for neuraxial techniques impacting on other outcome domains. Evidence of positive impact of neuraxial techniques is best established for the domains of patient comfort, pulmonary complications, and mortality, particularly in the setting of major open thoracoabdominal surgery. Recent evidence does not strongly support a significant impact of neuraxial techniques on cancer, renal, infection, or cardiovascular outcomes after noncardiac surgery in most patient groups.

Effects of early recovery of renal function on adverse renal outcomes and mortality in patients with acute kidney injury: a systematic review and meta-analysis

AIM

This study intended to scrutinize the effect of RFR time on adverse renal outcomes and mortality and try to define the cutoff of early RFR.

METHODS

We conducted a literature search from database inception to February 2023. Outcome measures incorporated the progression of CKD, delivery of RRT, incidence of composite renal outcomes, and mortality. And pooled results were depicted as odds ratio (OR) and 95% confidence interval (CI).

RESULTS

A total of 11 studies were finally selected (507,989 patients, mean follow-up, 3.89 years). The results exhibited that the crude mortality was lower in patients with early RFR (OR = 0.39, 95% CI: 0.16-0.95, P = 0.037). In addition, patients with early RFR had a lower incidence of progression to CKD (OR = 0.38, 95% CI: 0.17-0.85, P < 0.018), RRT (OR = 0.37, 95% CI: 0.20-0.71, P = 0.03), and composite renal outcomes (OR = 0.18, 95% CI: 0.15-0.20, P < 0.001). CKD progression-related events were significantly higher in patients whose renal function recovered after 7 days (OR = 0.69, 95% CI: 0.47-1.09, P = 0.112) than in those whose renal function recovered within 7 days (OR = 0.23, 95% CI: 0.06-0.92, P = 0.038), and the risk of RRT was lower in patients who recovered within 7 days (OR = 0.32, 95% CI: 0.15-0.66, P = 0.002) than in those who recovered after 7 days (OR = 0.72, 95% CI: 0.17-3.09, P = 0.654) or longer.

CONCLUSION

Patients with early RFR had a lower risk of CKD progression, RRT, and composite renal outcomes, as well as lower crude mortality than those without early recovery, despite no marked difference in 30-day, 90-day, and 1-year mortality. We speculated that 7 days may be used as a cutoff for early RFR.

A simple machine learning model for the prediction of acute kidney injury following noncardiac surgery in geriatric patients: a prospective cohort study

BACKGROUND

Surgery in geriatric patients often poses risk of major postoperative complications. Acute kidney injury (AKI) is a common complication following noncardiac surgery and is associated with increased mortality. Early identification of geriatric patients at high risk of AKI could facilitate preventive measures and improve patient prognosis. This study used machine learning methods to identify important features and predict AKI following noncardiac surgery in geriatric patients.

METHODS

The data for this study were obtained from a prospective cohort. Patients aged ≥ 65 years who received noncardiac surgery from June 2019 to December 2021 were enrolled. Data were split into training set (from June 2019 to March 2021) and internal validation set (from April 2021 to December 2021) by time. The least absolute shrinkage and selection operator (LASSO) regularization algorithm and the random forest recursive feature elimination algorithm (RF-RFE) were used to screen important predictors. Models were trained through extreme gradient boosting (XGBoost), random forest, and LASSO. The SHapley Additive exPlanations (SHAP) package was used to interpret the machine learning model.

RESULTS

The training set included 6753 geriatric patients. Of these, 250 (3.70%) patients developed AKI. The XGBoost model with RF-RFE selected features outperformed other models with an area under the precision-recall curve (AUPRC) of 0.505 (95% confidence interval [CI]: 0.369-0.626) and an area under the receiver operating characteristic curve (AUROC) of 0.806 (95%CI: 0.733-0.875). The model incorporated ten predictors, including operation site and hypertension. The internal validation set included 3808 geriatric patients, and 96 (2.52%) patients developed AKI. The model maintained good predictive performance with an AUPRC of 0.431 (95%CI: 0.331-0.524) and an AUROC of 0.845 (95%CI: 0.796-0.888) in the internal validation.

CONCLUSIONS

This study developed a simple machine learning model and a web calculator for predicting AKI following noncardiac surgery in geriatric patients. This model may be a valuable tool for guiding preventive measures and improving patient prognosis.

TRIAL REGISTRATION

The protocol of this study was approved by the Committee of Ethics from West China Hospital of Sichuan University (2019-473) with a waiver of informed consent and registered at www.chictr.org.cn (ChiCTR1900025160, 15/08/2019).

Intraoperative hypotension and postoperative acute kidney injury: A systematic review

BACKGROUND

There is no consensus regarding safe intraoperative blood pressure thresholds that protect against postoperative acute kidney injury (AKI). This review aims to examine the existing literature to delineate safe intraoperative hypotension (IOH) parameters to prevent postoperative AKI.

METHODS

PubMed, Cochrane Central, and Web of Science were systematically searched for articles published between 2015 and 2022 relating the effects of IOH on postoperative AKI.

RESULTS

Our search yielded 19 articles. IOH risk thresholds ranged from <50 to <75 ​mmHg for mean arterial pressure (MAP) and from <70 to <100 ​mmHg for systolic blood pressure (SBP). MAP below 65 ​mmHg for over 5 ​min was the most cited threshold (N ​= ​13) consistently associated with increased postoperative AKI. Greater magnitude and duration of MAP and SBP below the thresholds were generally associated with a dose-dependent increase in postoperative AKI incidence.

CONCLUSIONS

While a consistent definition for IOH remains elusive, the evidence suggests that MAP below 65 ​mmHg for over 5 ​min is strongly associated with postoperative AKI, with the risk increasing with the magnitude and duration of IOH.

Comparison of incidence of acute kidney injury after robot-assisted radical prostatectomy with that after open retropubic and extraperitoneal laparoscopic radical prostatectomies in patients with prostate cancer

Background

We retrospectively evaluated the postoperative renal function in patients who had undergone radical prostatectomy to compare the incidences of postoperative acute kidney injury (AKI) among the patients who had undergone robot-assisted radical prostatectomy (RARP), retropubic radical prostatectomy (RRP), and extraperitoneal laparoscopic radical prostatectomy (exLRP).

Materials and methods

Patients with prostate cancer who had undergone radical prostatectomy at our institution between 2008 and 2014 were included. Robot-assisted radical prostatectomy was performed using an intraperitoneal approach in a 25-degree Trendelenburg position, whereas other procedures were performed with the patient in the supine position. We evaluated the serum creatinine levels and estimated glomerular filtration rates immediately after surgery and on postoperative day 1. We evaluated the incidence of AKI after prostatectomy using the Acute Kidney Injury Network criteria of the Kidney Disease: Improving Global Outcomes guidelines.

Results

A total of 150 consecutive patients were included, with each of the 3 groups (RARP, RRP, and exLRP) comprising 50 patients. Postoperative AKI was observed in 15 (30.0%), 1 (2.0%), and 3 (6.0%) patients in the RARP, RRP, and exLRP groups, respectively. Stage 1 AKI was observed in all the patients except one. The incidence of AKI in RARP group was significantly higher than that in the other groups (p < 0.001). In the RARP group, the serum creatinine level was significantly elevated immediately after the surgery; however, it returned to baseline on postoperative day 1. Surgical procedures were the only independent factor associated with AKI incidence.

Conclusions

This study suggest that compared with RRP and exLRP, RARP is associated with a higher incidence of postoperative AKI, although most patients recover rapidly. Intra-abdominal pneumoperitoneum may contribute to AKI onset.

Sensing Dying Cells in Health and Disease: The Importance of Kidney Injury Molecule-1

Kidney injury molecule-1 (KIM-1), also known as T-cell Ig and mucin domain-1 (TIM-1), is a widely recognized biomarker for AKI, but its biological function is less appreciated. KIM-1/TIM-1 belongs to the T-cell Ig and mucin domain family of conserved transmembrane proteins, which bear the characteristic six-cysteine Ig-like variable domain. The latter enables binding of KIM-1/TIM-1 to its natural ligand, phosphatidylserine, expressed on the surface of apoptotic cells and necrotic cells. KIM-1/TIM-1 is expressed in a variety of tissues and plays fundamental roles in regulating sterile inflammation and adaptive immune responses. In the kidney, KIM-1 is upregulated on injured renal proximal tubule cells, which transforms them into phagocytes for clearance of dying cells and helps to dampen sterile inflammation. TIM-1, expressed in T cells, B cells, and natural killer T cells, is essential for cell activation and immune regulatory functions in the host. Functional polymorphisms in the gene for KIM-1/TIM-1, HAVCR1 , have been associated with susceptibility to immunoinflammatory conditions and hepatitis A virus-induced liver failure, which is thought to be due to a differential ability of KIM-1/TIM-1 variants to bind phosphatidylserine. This review will summarize the role of KIM-1/TIM-1 in health and disease and its potential clinical applications as a biomarker and therapeutic target in humans.

MondoA and AKI and AKI-to-CKD Transition

Key Points

Background

Elderly individuals and patients with CKD are at a higher risk of AKI. The transcription factor MondoA is downregulated in the kidneys of aged individuals or patients with AKI; however, its roles in AKI development and the AKI-to-CKD transition remain unknown.

Methods

We investigated the expression of MondoA in human kidney biopsy samples, ischemia-reperfusion–injured (IRI) mouse kidneys, and cultured proximal tubular epithelial cells under hypoxia/reoxygenation. The role of MondoA during the initial and recovery phases after IRI was evaluated using proximal tubule–specific MondoA knockout mice and MondoA-deficient proximal tubular epithelial cells. Furthermore, we explored the involvement of Rubicon and transcription factor EB (TFEB), both of which are downstream factors of MondoA.

Results

MONDOA expression was decreased in the renal tubules of patients with CKD. In mouse kidneys, MondoA expression was decreased under ischemia, whereas its expression was increased during reperfusion. Genetic ablation of MondoA in proximal tubular epithelial cells inhibited autophagy and increased vulnerability to AKI through increased expression of Rubicon. Ablation of Rubicon in MondoA-deficient IRI kidneys activated autophagy and protected mitochondrial function. MondoA ablation during the recovery phase after ischemia-reperfusion aggravated kidney injury through downregulation of the TFEB-peroxisome proliferator-activated receptor-γ coactivator-1α axis. Pharmacological upregulation of TFEB contributed to maintaining mitochondrial biogenesis and increased peroxisome proliferator-activated receptor-γ coactivator-1α transcription.

Conclusions

Our findings demonstrate that MondoA protected against vulnerability to AKI by maintaining autophagy and subsequently supporting mitochondrial function to prevent progression to CKD.

Internal and External Validation of Machine Learning Models for Predicting Acute Kidney Injury Following Non-Cardiac Surgery Using Open Datasets

This study developed and validated a machine learning model to accurately predict acute kidney injury (AKI) after non-cardiac surgery, aiming to improve patient outcomes by assessing its clinical feasibility and generalizability. We conducted a retrospective cohort study using data from 76,032 adults who underwent non-cardiac surgery at a single tertiary medical center between March 2019 and February 2021, and used data from 5512 patients from the VitalDB open dataset for external model validation. The predictive variables for model training consisted of demographic, preoperative laboratory, and intraoperative data, including calculated statistical values such as the minimum, maximum, and mean intraoperative blood pressure. When predicting postoperative AKI, our gradient boosting machine model incorporating all the variables achieved the best results, with AUROC values of 0.868 and 0.757 for the internal and external validations using the VitalDB dataset, respectively. The model using intraoperative data performed best in internal validation, while the model with preoperative data excelled in external validation. In this study, we developed a predictive model for postoperative AKI in adult patients undergoing non-cardiac surgery using preoperative and intraoperative data, and external validation demonstrated the efficacy of open datasets for generalization in medical artificial modeling research.

Development and validation of a race-agnostic computable phenotype for kidney health in adult hospitalized patients

Standard race adjustments for estimating glomerular filtration rate (GFR) and reference creatinine can yield a lower acute kidney injury (AKI) and chronic kidney disease (CKD) prevalence among African American patients than non-race adjusted estimates. We developed two race-agnostic computable phenotypes that assess kidney health among 139,152 subjects admitted to the University of Florida Health between 1/2012-8/2019 by removing the race modifier from the estimated GFR and estimated creatinine formula used by the race-adjusted algorithm (race-agnostic algorithm 1) and by utilizing 2021 CKD-EPI refit without race formula (race-agnostic algorithm 2) for calculations of the estimated GFR and estimated creatinine. We compared results using these algorithms to the race-adjusted algorithm in African American patients. Using clinical adjudication, we validated race-agnostic computable phenotypes developed for preadmission CKD and AKI presence on 300 cases. Race adjustment reclassified 2,113 (8%) to no CKD and 7,901 (29%) to a less severe CKD stage compared to race-agnostic algorithm 1 and reclassified 1,208 (5%) to no CKD and 4,606 (18%) to a less severe CKD stage compared to race-agnostic algorithm 2. Of 12,451 AKI encounters based on race-agnostic algorithm 1, race adjustment reclassified 591 to No AKI and 305 to a less severe AKI stage. Of 12,251 AKI encounters based on race-agnostic algorithm 2, race adjustment reclassified 382 to No AKI and 196 (1.6%) to a less severe AKI stage. The phenotyping algorithm based on refit without race formula performed well in identifying patients with CKD and AKI with a sensitivity of 100% (95% confidence interval [CI] 97%-100%) and 99% (95% CI 97%-100%) and a specificity of 88% (95% CI 82%-93%) and 98% (95% CI 93%-100%), respectively. Race-agnostic algorithms identified substantial proportions of additional patients with CKD and AKI compared to race-adjusted algorithm in African American patients. The phenotyping algorithm is promising in identifying patients with kidney disease and improving clinical decision-making.

Incidence and predictors of acute kidney injury after elective surgery for lumbar degenerative disease: A 13-year analysis of the US Nationwide Inpatient Sample

BACKGROUND

Acute kidney injury (AKI) is a severe postoperative complication associated with poor clinical outcomes, including the development of chronic kidney disease (CKD) and death. This study aimed to investigate the incidence and determinants of AKI following elective surgeries for degenerative lumbar spine disease.

METHODS

All patient data were extracted from the US Nationwide Inpatient Sample database. After surgery, AKI's incidence and risk factors were identified for lumbar degenerative disease. ICD-9 and ICD-10 codes defined lumbar spine degenerative disease, fusion, decompression, and AKI. The study cohort was categorized by type of surgery, that is, decompression alone or spinal fusion. Regression analysis was used to identify associations between AKI and risk factors organized by surgery type.

RESULTS

The incidence of AKI after decompression or fusion was 1.1% and 1.8%, respectively. However, the incidence of AKI in the United States is rising. The strongest predictor of AKI was underlying CKD, which was associated with an 9.0- to 12.9-fold more significant risk of AKI than in subjects without comorbid CKD. In this setting, older age, congestive heart failure, anemia, obesity, coagulopathy and hospital-acquired infections were also strong predictors of AKI. In contrast, long-term aspirin/anticoagulant usage was associated with lowered AKI risk.

CONCLUSION

Findings of this study inform risk stratification for AKI and may help to optimize treatment decisions and care planning after elective surgery for lumbar degenerative disease.

National clinical and financial outcomes associated with acute kidney injury following esophagectomy for cancer

BACKGROUND

Esophagectomy is a complex oncologic operation associated with high rates of postoperative complications. While respiratory and septic complications have been well-defined, the implications of acute kidney injury (AKI) remain unclear. Using a nationally representative database, we aimed to characterize the association of AKI with mortality, resource use, and 30-day readmission.

METHODS

All adults undergoing elective esophagectomy with a diagnosis of esophageal or gastric cancer were identified in the 2010-2019 Nationwide Readmissions Database. Study cohorts were stratified based on presence of AKI. Multivariable regressions and Royston-Parmar survival analysis were used to evaluate the independent association between AKI and outcomes of interest.

RESULTS

Of an estimated 40,438 patients, 3,210 (7.9%) developed AKI. Over the 10-year study period, the incidence of AKI increased from 6.4% to 9.7%. Prior radiation/chemotherapy and minimally invasive operations were associated with reduced odds of AKI, whereas public insurance coverage and concurrent infectious and respiratory complications had greater risk of AKI. After risk adjustment, AKI remained independently associated with greater odds of in-hospital mortality (AOR: 4.59, 95% CI: 3.62-5.83) and had significantly increased attributable costs ($112,000 vs $54,000) and length of stay (25.7 vs 13.3 days) compared to patients without AKI. Furthermore, AKI demonstrated significantly increased hazard of 30-day readmission (hazard ratio: 1.16, 95% CI: 1.01-1.32).

CONCLUSIONS

AKI after esophagectomy is associated with greater risk of mortality, hospitalization costs, and 30-day readmission. Given the significant adverse consequences of AKI, careful perioperative management to mitigate this complication may improve quality of esophageal surgical care at the national level.

Prognostic Biomarkers and AKI: Potential to Enhance the Identification of Post-Operative Patients at Risk of Loss of Renal Function

Acute kidney injury (AKI) is a common complication after surgery and the more complex the surgery, the greater the risk. During surgery, patients are exposed to a combination of factors all of which are associated with the development of AKI. These include hypotension and hypovolaemia, sepsis, systemic inflammation, the use of nephrotoxic agents, tissue injury, the infusion of blood or blood products, ischaemia, oxidative stress and reperfusion injury. Given the risks of AKI, it would seem logical to conclude that early identification of patients at risk of AKI would translate into benefit. The conventional markers of AKI, namely serum creatinine and urine output are the mainstay of defining chronic kidney disease but are less suited to the acute phase. Such concerns are compounded in surgical patients given they often have significantly reduced mobility, suboptimal levels of nutrition and reduced muscle bulk. Many patients may also have misleadingly low serum creatinine and high urine output due to aggressive fluid resuscitation, particularly in intensive care units. Over the last two decades, considerable information has accrued with regard to the performance of what was termed "novel" biomarkers of AKI, and here, we discuss the most examined molecules and performance in surgical settings. We also discuss the application of biomarkers to guide patients' postoperative care.

Acute kidney disease beyond day 7 after major surgery: a secondary analysis of the EPIS-AKI trial

PURPOSE

Acute kidney disease (AKD) is a significant health care burden worldwide. However, little is known about this complication after major surgery.

METHODS

We conducted an international prospective, observational, multi-center study among patients undergoing major surgery. The primary study endpoint was the incidence of AKD (defined as new onset of estimated glomerular filtration rate (eCFR) < 60 ml/min/1.73 m2 present on day 7 or later) among survivors. Secondary endpoints included the relationship between early postoperative acute kidney injury (AKI) (within 72 h after major surgery) and subsequent AKD, the identification of risk factors for AKD, and the rate of chronic kidney disease (CKD) progression in patients with pre-existing CKD.

RESULTS

We studied 9510 patients without pre-existing CKD. Of these, 940 (9.9%) developed AKD after 7 days of whom 34.1% experiencing an episode of early postoperative-AKI. Rates of AKD after 7 days significantly increased with the severity (19.1% Kidney Disease Improving Global Outcomes [KDIGO] 1, 24.5% KDIGO2, 34.3% KDIGO3; P < 0.001) and duration (15.5% transient vs 38.3% persistent AKI; P < 0.001) of early postoperative-AKI. Independent risk factors for AKD included early postoperative-AKI, exposure to perioperative nephrotoxic agents, and postoperative pneumonia. Early postoperative-AKI carried an independent odds ratio for AKD of 2.64 (95% confidence interval [CI] 2.21-3.15). Of 663 patients with pre-existing CKD, 42 (6.3%) had worsening CKD at day 90. In patients with CKD and an episode of early AKI, CKD progression occurred in 11.6%.

CONCLUSION

One in ten major surgery patients developed AKD beyond 7 days after surgery, in most cases without an episode of early postoperative-AKI. However, early postoperative-AKI severity and duration were associated with an increased rate of AKD and early postoperative-AKI was strongly associated with AKD independent of all other potential risk factors.

Theaflavin pretreatment ameliorates renal ischemia/reperfusion injury by attenuating apoptosis and oxidative stress in vivo and in vitro

Oxidative stress-induced apoptosis is an important pathological process in renal ischemia/reperfusion injury (RIRI). Theaflavin (TF) is the main active pigment and polyphenol in black tea. It has been widely reported because of its biological activity that can reduce oxidative stress and protect against many diseases. Here, we explored the role of theaflavin in the pathological process of RIRI. In the present study, the RIRI model of 45 min ischemia and 24 h reperfusion was established in C57BL/6 J male mice, and theaflavin was used as an intervention. Compared with the RIRI group, the renal filtration function, renal tissue damage and antioxidant capacity of the theaflavin intervention group were significantly improved, while the level of apoptosis was reduced. TCMK-1 cells were incubated under hypoxia for 48 h and then reoxygenated for 6 h to simulate RIRI in vitro. The application of theaflavin significantly promoted the translocation of p53 from cytoplasm to nucleus, upregulated the expression of glutathione peroxidase 1 (GPx-1) in cells, and inhibited oxidative stress damage and apoptosis. Transfection with p53 siRNA can partially inhibit the effect of theaflavin. Thus, theaflavin exerted a protective effect against RIRI by inhibiting apoptosis and oxidative stress via regulating the p53/GPx-1 pathway. We conclude that theaflavin has the potential to become a candidate drug for the prevention and treatment of RIRI.

Impact of Acute Kidney Injury After Transcatheter Aortic Valve Replacement: A Nationwide Study

BACKGROUND

In patients undergoing transcatheter aortic valve replacement (TAVR), the impact of acute kidney injury (AKI) on the prognosis and especially on future kidney function has been sparsely examined, and data from large cohorts are warranted.

METHODS AND RESULTS

With Danish nationwide registries, we identified all patients undergoing TAVR from 2014 to 2021 with no previous dialysis treatment. According to 2 plasma creatinine samples, we identified those suffering a postprocedural AKI within 21 days after TAVR. With 1 year of follow-up, we compared the associated rates of dialysis treatment and death between patients with and without an AKI using multivariable Cox analysis. Finally, according to the lowest recorded creatinine sample, we assessed the kidney function among AKI survivors between 90 and 180 days after the index date. We identified 4091 TAVRs: 193 (4.7%) with AKI (55.4% men; median age, 82 years) and 3898 (95.3%) without AKI (57.0% men; median age, 81 years). Compared with those without AKI, patients with AKI showed increased associated 1-year rates of dialysis treatment (hazard ratio [HR], 7.20 [95% CI, 4.10-12.66]) and death (HR, 2.39 [95% CI, 1.59-3.58]). After 6 months, 74% of AKI survivors had complete kidney recovery, 14.7% had incomplete kidney recovery, 6.3% failed to recover, and 5.1% were on dialysis treatment.

CONCLUSIONS

We identified that AKI after TAVR was associated with an increased rate of future dialysis treatment and all-cause death. Among survivors, 74% had complete kidney recovery within 6 months.

Cystatin C or creatinine for pre-operative assessment of kidney function and risk of post-operative acute kidney injury: a secondary analysis of the METS cohort study

Background

Post-operative acute kidney injury (PO-AKI) is a common surgical complication consistently associated with subsequent morbidity and mortality. Prior kidney dysfunction is a major risk factor for PO-AKI, however it is unclear whether serum creatinine, the conventional kidney function marker, is optimal in this population. Serum cystatin C is a kidney function marker less affected by body composition and might provide better prognostic information in surgical patients.

Methods

This was a pre-defined, secondary analysis of a multi-centre prospective cohort study of pre-operative functional capacity. Participants were aged ≥40 years, undergoing non-cardiac surgery. We assessed the association of pre-operative estimated glomerular filtration rate (eGFR) calculated using both serum creatinine and serum cystatin C with PO-AKI within 3 days after surgery, defined by KDIGO creatinine changes. The adjusted analysis accounted for established AKI risk factors.

Results

A total of 1347 participants were included (median age 65 years, interquartile range 56-71), of whom 775 (58%) were male. A total of 82/1347 (6%) patients developed PO-AKI. These patients were older, had higher prevalence of cardiovascular disease and related medication, were more likely to have intra-abdominal procedures, had more intraoperative transfusion, and were more likely to be dead at 1 year after surgery 6/82 (7.3%) vs 33/1265 (2.7%) (P = .038). Pre-operative eGFR was lower in AKI than non-AKI patients using both creatinine and cystatin C. When both measurements were considered in a single age- and sex-adjusted model, eGFR-Cysc was strongly associated with PO-AKI, with increasing risk of AKI as eGFR-Cysc decreased below 90, while eGFR-Cr was no longer significantly associated.

Conclusions

Data from over 1000 prospectively recruited surgical patients confirms pre-operative kidney function as major risk factor for PO-AKI. Of the kidney function markers available, compared with creatinine, cystatin C had greater strength of association with PO-AKI and merits further assessment in pre-operative assessment of surgical risk.

Persistent Acute Kidney Injury is Associated with Poor Outcomes and Increased Hospital Cost in Vascular Surgery

BACKGROUND

Postoperative acute kidney injury (AKI) is common after major surgery and is associated with increased morbidity, mortality, and cost. Additionally, there are recent studies demonstrating that time to renal recovery may have a substantial impact on clinical outcomes. We hypothesized that patients with delayed renal recovery after major vascular surgery will have increased complications, mortality, and hospital cost.

METHODS

A single-center retrospective cohort of patients undergoing nonemergent major vascular surgery between 6/1/2014 and 10/1/2020 was analyzed. Development of postoperative AKI (defined using Kidney Disease Improving Global Outcomes (KDIGO) criteria: >50% or > 0.3 mg/dl absolute increase in serum creatinine relative to reference after surgery and before discharge) was evaluated. Patients were divided into 3 groups: no AKI, rapidly reversed AKI (<48 hours), and persistent AKI (≥48 hours). Multivariable generalized linear models were used to evaluate the association between AKI groups and postoperative complications, 90-day mortality, and hospital cost.

RESULTS

A total of 1,881 patients undergoing 1,980 vascular procedures were included. Thirty five percent of patients developed postoperative AKI. Patients with persistent AKI had longer intensive care unit and hospital stays, as well as more mechanical ventilation days. In multivariable logistic regression analysis, persistent AKI was a major predictor of 90-day mortality (odds ratio 4.1, 95% confidence interval 2.4-7.1). Adjusted average cost was higher for patients with any type of AKI. The incremental cost of having any AKI ranged from $3,700 to $9,100, even after adjustment for comorbidities and other postoperative complications. The adjusted average cost for patients stratified by type of AKI was higher among patients with persistent AKI compared to those with no or rapidly reversed AKI.

CONCLUSIONS

Persistent AKI after vascular surgery is associated with increased complications, mortality, and cost. Strategies to prevent and aggressively treat AKI, specifically persistent AKI, in the perioperative setting are imperative to optimize care for this population.

Predictors of acute kidney injury after lung resection surgery: a retrospective case-control study

PURPOSE

Patients undergoing lung resection are at increased risk for acute kidney injury (AKI) in the immediate postoperative period, with important consequences for longer term morbidity and mortality. Lung resection surgery has unique considerations that could increase the risk of AKI, including lung resection volume, duration of one-lung ventilation (OLV), and intraoperative fluid restriction. Yet, specific risk factor data are lacking. The objective of this study was to identify independent risk factors for early AKI after lung resection surgery.

METHODS

We conducted a retrospective case-control study of all patients presenting for elective lung resection surgery at an academic medical centre over a four-year period. Cases were patients who experienced an AKI and control patients were those who did not experience an AKI, based on KDIGO criteria. Baseline demographics and comorbidities along with duration of OLV and amount of lung resected were collected by retrospective chart review. The data were analyzed using multivariable logistic regression to identify independent predictors of AKI.

RESULTS

Acute kidney injury occurred within 48 hr in 57/1,045 (5.5%; 95% confidence interval, 4.2 to 7.0) of patients. On multivariable analysis, our model of best fit included preoperative serum creatinine, male sex, use of angiotensin II receptor blockers, and duration of OLV. The rate of complications, intensive care unit admission, and risk of death were all higher in the group of patients who experienced AKI.

CONCLUSIONS

Acute kidney injury occurs frequently after lung resection surgery and is associated with increased risk of postoperative complications. Increased duration of OLV may be a risk factor for AKI in this population.

Development and external validation of multimodal postoperative acute kidney injury risk machine learning models

Objectives

To develop and externally validate machine learning models using structured and unstructured electronic health record data to predict postoperative acute kidney injury (AKI) across inpatient settings.

Materials and Methods

Data for adult postoperative admissions to the Loyola University Medical Center (2009-2017) were used for model development and admissions to the University of Wisconsin-Madison (2009-2020) were used for validation. Structured features included demographics, vital signs, laboratory results, and nurse-documented scores. Unstructured text from clinical notes were converted into concept unique identifiers (CUIs) using the clinical Text Analysis and Knowledge Extraction System. The primary outcome was the development of Kidney Disease Improvement Global Outcomes stage 2 AKI within 7 days after leaving the operating room. We derived unimodal extreme gradient boosting machines (XGBoost) and elastic net logistic regression (GLMNET) models using structured-only data and multimodal models combining structured data with CUI features. Model comparison was performed using the receiver operating characteristic curve (AUROC), with Delong's test for statistical differences.

Results

The study cohort included 138 389 adult patient admissions (mean [SD] age 58 [16] years; 11 506 [8%] African-American; and 70 826 [51%] female) across the 2 sites. Of those, 2959 (2.1%) developed stage 2 AKI or higher. Across all data types, XGBoost outperformed GLMNET (mean AUROC 0.81 [95% confidence interval (CI), 0.80-0.82] vs 0.78 [95% CI, 0.77-0.79]). The multimodal XGBoost model incorporating CUIs parameterized as term frequency-inverse document frequency (TF-IDF) showed the highest discrimination performance (AUROC 0.82 [95% CI, 0.81-0.83]) over unimodal models (AUROC 0.79 [95% CI, 0.78-0.80]).

Discussion

A multimodality approach with structured data and TF-IDF weighting of CUIs increased model performance over structured data-only models.

Conclusion

These findings highlight the predictive power of CUIs when merged with structured data for clinical prediction models, which may improve the detection of postoperative AKI.

Perioperative Acute Kidney Injury: Implications, Approach, Prevention

Acute kidney injury remains a common and significant contributor to perioperative morbidity. Acute kidney injury worsens patient outcomes, and anesthesiologists should make significant efforts to prevent, assess, and treat perioperative renal injury. The authors discuss the impact of renal injury on patient outcomes and putative underlying mechanisms, evidence underlying treatments for acute kidney injury, and practices that may prevent the development of perioperative renal injury.

Perioperative acute kidney injury: Current knowledge and the role of anaesthesiologists

Background

Among the different types of perioperative organ injury, acute kidney injury (AKI) occurs frequently and is consistently associated with increased rates of mortality and mortality. Despite development of many clinical trials to assess perioperative interventions, reliable means to prevent or reverse AKI are still lacking.

Objectives

This narrative review discusses recent literature on modifiable risk factors, current approaches to prevention and potential directions for future research.

Methods

A Pubmed search with the relevant keywords was done for articles published in the last 10 years.

Results

New insights into preoperative identification and optimisation, intraoperative strategies, including the choice of anaesthetic, haemodynamic and fluid management, have been made, with the aim of preventing perioperative AKI.

Conclusion

A patient-centric multidisciplinary approach is essential to protect kidney function of patients going for surgery. Much can be done by anaesthesiologists perioperatively, to reduce the risk of development of AKI, especially in susceptible patients. There is a need for further multicentred trials to enhance the currently generic perioperative recommendations.

Epidemiology of surgery associated acute kidney injury (EPIS-AKI): a prospective international observational multi-center clinical study

PURPOSE

The incidence, patient features, risk factors and outcomes of surgery-associated postoperative acute kidney injury (PO-AKI) across different countries and health care systems is unclear.

METHODS

We conducted an international prospective, observational, multi-center study in 30 countries in patients undergoing major surgery (> 2-h duration and postoperative intensive care unit (ICU) or high dependency unit admission). The primary endpoint was the occurrence of PO-AKI within 72 h of surgery defined by the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Secondary endpoints included PO-AKI severity and duration, use of renal replacement therapy (RRT), mortality, and ICU and hospital length of stay.

RESULTS

We studied 10,568 patients and 1945 (18.4%) developed PO-AKI (1236 (63.5%) KDIGO stage 1500 (25.7%) KDIGO stage 2209 (10.7%) KDIGO stage 3). In 33.8% PO-AKI was persistent, and 170/1945 (8.7%) of patients with PO-AKI received RRT in the ICU. Patients with PO-AKI had greater ICU (6.3% vs. 0.7%) and hospital (8.6% vs. 1.4%) mortality, and longer ICU (median 2 (Q1-Q3, 1-3) days vs. 3 (Q1-Q3, 1-6) days) and hospital length of stay (median 14 (Q1-Q3, 9-24) days vs. 10 (Q1-Q3, 7-17) days). Risk factors for PO-AKI included older age, comorbidities (hypertension, diabetes, chronic kidney disease), type, duration and urgency of surgery as well as intraoperative vasopressors, and aminoglycosides administration.

CONCLUSION

In a comprehensive multinational study, approximately one in five patients develop PO-AKI after major surgery. Increasing severity of PO-AKI is associated with a progressive increase in adverse outcomes. Our findings indicate that PO-AKI represents a significant burden for health care worldwide.

Altered gut microbiome plays an important role in AKI to CKD transition in aged mice

Introduction

This study investigated the role of renal-intestinal crosstalk in the transition from acute kidney injury (AKI) to chronic kidney disease (CKD) in elderly individuals.

Methods

Using young and aged mice, we induced bilateral ischemia-reperfusion injury (IRI) and compared intestinal and kidney inflammation over 28 days. To determine the role of the microbiome in gut-kidney crosstalk, we analyzed the microbiome of fecal samples of the young vs. aged mice and examined the effects of probiotic supplementation.

Results

In the post-IRI recovery phase, prolonged intestinal and renal inflammation along with dysbiosis were evident in aged vs. younger mice that was associated with severe renal dysfunction and fibrosis progression in aged mice. Probiotic supplementation with Bifidobacterium bifidum BGN4 and Bifidobacterium longum BORI alleviated intestinal inflammation but not intestinal leakage, characterized by decreased inflammatory cytokine levels and decreased infiltration of macrophages, neutrophils, and Th17 cells. This was associated with improved M1-dominant renal inflammation and ultimately improved renal function and fibrosis, suggesting that renal-intestinal crosstalk in aged mice contributes to the transition from AKI to CKD.

Discussion

Our study findings suggest that exacerbation of chronic inflammation through the gut-kidney axis might be an important mechanism in the transition from AKI to CKD in the elderly.

Recovery after AKI: Effects on outcomes over 15 years

PURPOSE

To examine the effect of kidney recovery on mortality, dialysis and kidney transplantation up to 15 years after AKI.

MATERIALS AND METHODS

We studied 29,726 survivors of critical illness and compared these outcomes stratified by AKI and recovery status at hospital discharge. Kidney recovery was defined as a return of serum creatinine to ≤150% of baseline without dialysis prior to hospital discharge.

RESULTS

Overall AKI occurred in 59.2% in which two thirds developed stage 2-3 AKI. Recovery rate of AKI at hospital discharge was 80.8%. Patients who did not recover experienced the worst 15-year mortality compared to those who recovered and those without AKI (57.8% vs 45.2% vs 30.3%, p < 0.001). This pattern was also found in subgroups of patients with suspected sepsis-associated (57.1% vs 47.9% vs 36.5%, p < 0.001) and cardiac surgery-associated AKI (60.1% vs 41.8% vs 25.9%, p < 0.001). The rates of dialysis and transplantation at 15 years were low and not associated with recovery status.

CONCLUSIONS

Recovery of AKI in critically ill patients at hospital discharge had an effect on long-term mortality for up to 15 years. These results have implications for acute care, follow-up and choice of endpoints for clinical trials.

Clinical Considerations for Patients Experiencing Acute Kidney Injury Following Percutaneous Nephrolithotomy

Acute kidney injury (AKI) is a common postoperative outcome in urology patients undergoing surgery for nephrolithiasis. The objective of this study was to determine the prevalence of postoperative AKI and its degrees of severity, identify risk factors, and understand the resultant outcomes of AKI in patients with nephrolithiasis undergoing percutaneous nephrolithotomy (PCNL). A cohort of patients admitted between 2012 and 2019 to a single tertiary-care institution who had undergone PCNL was retrospectively analyzed. Among 417 (n = 326 patients) encounters, 24.9% (n = 104) had AKI. Approximately one-quarter of AKI patients (n = 18) progressed to Stage 2 or higher AKI. Hypertension, peripheral vascular disease, chronic kidney disease, and chronic anemia were significant risk factors of post-PCNL AKI. Corticosteroids and antifungals were associated with increased odds of AKI. Cardiovascular, neurologic complications, sepsis, and prolonged intensive care unit (ICU) stay percentages were higher in AKI patients. Hospital and ICU length of stay was greater in the AKI group. Provided the limited literature regarding postoperative AKI following PCNL, and the detriment that AKI can have on clinical outcomes, it is important to continue studying this topic to better understand how to optimize patient care to address patient- and procedure-specific risk factors.

Prognosis and mortality within 90 days in community-acquired acute kidney injury in the Southwest of Sweden

BACKGROUND

Community-acquired acute kidney injury (CA-AKI) is common among hospitalized patients and has a poor prognosis. Research is scarce on the impact of a CA-AKI episode among patients without preexisting kidney disease and has not previously been investigated in Sweden. The aim was to describe the outcomes of patients with normal pre-hospitalization kidney function, admitted with community-acquired AKI and to investigate the association between AKI severity with outcomes.

METHODS

A retrospective population-based study was applied including patients with CA-AKI according to KDIGO classification, admitted via emergency department (ED) 2017-2019 and with a 90-day follow-up period from the ED-admission, collecting data from the Regional Healthcare Informative Platform. Age, gender and AKI stages, mortality and follow-up regarding recovery and readmission was registered. Hazard ratio (HR) and 95% confidence Interval (CI) for mortality was analyzed using Cox regression adjusted for age, comorbidities, and medication.

RESULTS

There were 1646 patients included, mean age was 77.5 years. CA-AKI stage 3 occurred in 51% of patients < 65 years of age and 34% among those > 65 years. In this study, 578 (35%) patients died and 233 (22%) recovered their kidney function. Mortality rate peaked within the first two weeks and among those at AKI stage 3. Nephrology referral post discharge occurred in 3% and 29% were readmitted. HRs for mortality was 1.9 (CI 1.38-2.62) for those who are > 65 years, 1.56 (CI 1.30-1.88) for atherosclerotic-cardiovascular disease. Medication with RAASi related to a decreased HR 0.27 (95% CI 0.22-0.33).

CONCLUSIONS

CA-AKI is associated with high mortality within 90 days, increased risk for developing chronic kidney disease (CKD) and only one fifth recover their kidney function after hospitalization with an AKI. Nephrology referral was sparse. Patient follow-up after a hospitalization with AKI should be carefully planned during the first 90 days and focused on identifying those with a higher risk of developing CKD.

Incidence, risk factors and outcomes of acute kidney injury in surgical intensive care unit octogenarians at the Jordan University Hospital

BACKGROUND

Acute kidney damage (AKI) is among the most severe consequences observed in surgical intensive care units (SICUs). We aim to observe the incidence, risk factors, and outcomes of acute kidney injury in SICU octogenarians.

METHODS

A cross-sectional retrospective study was conducted at the SICU of Jordan University Hospital (JUH), a tertiary teaching hospital in a developing country, between January 2018 and December 2019. Patients who were 80 years or older at the time of data collection were included. The definition of AKI was based on Kidney Disease Improving Global Outcomes (KDIGO) criteria. Demographic, clinical, and laboratory data were reviewed.

RESULTS

A total number of 168 patients were included. The mean age was 84.0 ± 3.8 years, and 54.8% of the participants were women. Of those, 115 (68.5%) had surgery before or during ICU stay, and 28.7% of the patients' surgeries were an emergency surgery. Also, 47.8% of surgeries were considered by anesthesia to be high-risk surgeries. A total of 55 patients (32.7%) developed AKI during their SICU stay. The factors that were significantly associated with AKI in the ICU patients included use of beta blocker [AOR: 3.7; 95% CI: 1.2-11.8; p = 0.025], and inotropes [AOR:4.0; 95% CI: 1.2-13.3; p = 0.03]. The factors that were significantly associated with mortality in the ICU included using mechanical ventilation [AOR:18.7; 95% CI: 2.4-141.9; p = 0.005] and inotropes use [AOR: 12.3; 95% CI: 1.2-120.7; p = 0.031].

CONCLUSIONS

The incidence of AKI during SICU stay in this study was 32.7% and it was significantly associated with the use of beta blockers, mechanical ventilation, and inotropes. The mortality rate among octogenarians who developed AKI during SICU stay was 36.4%. Further studies are needed globally to assess the incidence of AKI in octogenarian surgical patients and identify risk factors to provide preventative measurements and strategies.

Risk factors for acute kidney injury after pancreatoduodenectomy, and association with postoperative complications and death

BACKGROUND

Acute kidney injury (AKI) is associated with increased morbidity and mortality after general surgery, although little is known among patients undergoing pancreatoduodenectomy. The objective was to investigate the association between AKI and postoperative complications and death after pancreatoduodenectomy.

METHODS

All patients ≥18 years who underwent a pancreatoduodenectomy 2008-2019 at the Karolinska University Hospital, Stockholm, Sweden, were included. Standardized criteria for AKI, including estimated glomerular filtration rate (eGFR) and urine volume measurements, were used to grade postoperative AKI.

RESULTS

In total, 970 patients were included with a median age of 68 years (IQR 61-74) of whom 517 (53.3%) were men. There were 137 (14.1%) patients who developed postoperative AKI. Risk factors for AKI included lower preoperative eGFR, cardiovascular disease and treatment with renin-angiotensin system inhibitors or diuretics. Those who developed AKI had a higher risk of severe postoperative complications, including Clavien-Dindo score ≥ IIIa (adjusted OR 3.35, 95% CI 2.24-5.01) and ICU admission (adjusted OR 7.83, 95% CI 4.39-13.99). In time-to-event analysis, AKI was associated with an increased risk for both 30-day mortality (adjusted HR 4.51, 95% CI 1.54-13.27) and 90-day mortality (adjusted HR 4.93, 95% CI 2.37-10.26). Patients with benign histology and AKI also had an increased 1-year mortality (HR 4.89, 95% CI 1.88-12.71).

CONCLUSIONS

Postoperative AKI was associated with major postoperative complications and an increased risk of postoperative mortality. Monitoring changes in serum creatinine levels and urine volume output could be important in the immediate perioperative period to improve outcomes after pancreatoduodenectomy.

Defining a postoperative mean arterial pressure threshold in association with acute kidney injury after cardiac surgery: a prospective observational study

Acute kidney injury (AKI) is a common but fatal complication after cardiac surgery. In the absence of effective treatments, the identification and modification of risk factors has been a major component of disease management. However, the optimal blood pressure target for preventing cardiac surgery-associated acute kidney injury (CSA-AKI) remains unclear. We sought to determine the effect of postoperative mean arterial pressure (MAP) in CSA-AKI. It is hypothesized that longer periods of hypotension after cardiac surgery are associated with an increased risk of AKI. This prospective cohort study was conducted on adult patients who underwent cardiac surgery requiring cardiopulmonary bypass at a tertiary center between October 2018 and May 2020. The primary outcome is the occurrence of CSA-AKI. MAP and its duration in the ranges of less than 65, 65 to 74, and 75 to 84 mmHg within 24 h after surgery were recorded. The association between postoperative MAP and CSA-AKI was examined by using logistic regression. Among the 353 patients enrolled, 217 (61.5%) had a confirmed diagnosis of CSA-AKI. Each 1 h epoch of postoperative MAP less than 65 mmHg was associated with an adjusted odds ratio of 1.208 (95% CI, 1.007 to 1.449; P = 0.042), and each 1 h epoch of postoperative MAP between 65 and 74 mmHg was associated with an adjusted odds ratio of 1.144 (95% CI, 1.026 to 1.275; P = 0.016) for CSA-AKI. A potentially modifiable risk factor, postoperative MAP less than 75 mmHg for 1 h or more is associated with an increased risk of CSA-AKI.

Postoperative Antibiotics Confer No Protective Association After Fat Grafting for Breast Reconstruction

INTRODUCTION

Autologous fat grafting after breast reconstruction is a commonly used technique to address asymmetry and irregularities in breast contour. While many studies have attempted to optimize patient outcomes after fat grafting, a key postoperative protocol that lacks consensus is the optimal use of perioperative and postoperative antibiotics. Reports suggest that complication rates for fat grafting are low relative to rates after reconstruction and have been shown to not be correlated to antibiotic protocol. Studies have additionally demonstrated that the use of prolonged prophylactic antibiotics do not lower the complication rates, stressing the need for a more conservative, standardized antibiotic protocol. This study aims to identify the optimal use of perioperative and postoperative antibiotics that optimizes patient outcomes.

METHODS

Patients in the Optum Clinformatics Data Mart who underwent all billable forms of breast reconstruction followed by fat grafting were identified via Current Procedural Terminology codes. Patients meeting inclusion criteria had an index reconstructive procedure at least 90 days before fat grafting. Data concerning these patient's demographics, comorbidities, breast reconstructions, perioperative and postoperative antibiotics, and outcomes were collected via querying relevant reports of Current Procedural Terminology; International Classification of Diseases, Ninth Revision; International Classification of Diseases, Tenth Revision; National Drug Code Directory, and Healthcare Common Procedure Coding System codes. Antibiotics were classified by type and temporal delivery: perioperatively or postoperatively. If a patient received postoperative antibiotics, the duration of antibiotic exposure was recorded. Outcomes analysis was limited to the 90-day postoperative period. Multivariable logistic regression was performed to ascertain the effects of age, coexisting conditions, reconstruction type (autologous or implant-based), perioperative antibiotic class, postoperative antibiotic class, and postoperative antibiotic duration on the likelihood of any common postoperative complication occurring. All statistical assumptions made by logistic regression were met successfully. Odds ratios and corresponding 95% confidence intervals were calculated.

RESULTS

From more than 86 million longitudinal patient records between March 2004 and June 2019, our study population included 7456 unique records of reconstruction-fat grafting pairs, with 4661 of those pairs receiving some form of prophylactic antibiotics. Age, prior radiation, and perioperative antibiotic administration were consistent independent predictors of increased all-cause complication likelihood. However, administration of perioperative antibiotics approached a statistically significant protective association against infection likelihood. No postoperative antibiotics of any duration or class conferred a protective association against infections or all-cause complications.

CONCLUSIONS

This study provides national, claims-level support for antibiotic stewardship during and after fat grafting procedures. Postoperative antibiotics did not confer a protective benefit association against infection or all-cause complication likelihood, while administering perioperative antibiotics conferred a statistically significant increase in the likelihood that a patient experienced postoperative complication. However, perioperative antibiotics approach a significant protective association against postoperative infection likelihood, in line with current guidelines for infection prevention. These findings may encourage the adoption of more conservative postoperative prescription practices for clinicians who perform breast reconstruction, followed by fat grafting, reducing the nonindicated use of antibiotics.

AKI3-Risk Predictors and Scores in Radical Nephrectomy with High Thrombectomy under Extracorporeal Circulation for Renal Cell Carcinoma with Supradiaphragmatic Inferior Vena Cava/Right Atrial Thrombus: A Single-Centre Retrospective Study

Background and Objectives: The recommended therapeutic management in renal cell carcinoma (RCC) with supradiaphragmatic inferior vena cava/right atrial thrombus (IVC/RA) is surgery. Extracorporeal circulation is required. Acute kidney injury (AKI), a frequent complication after nephrectomy and cardiac surgery is associated with long-term kidney disease. This study aims to identify the risk factors involved in the occurrence of the severe postoperative AKI (AKI3) and to analyse various preoperative validated risk scores from cardiac and noncardiac surgery in predicting this endpoint. Materials and Methods: The medical data of all patients with RCC with supradiaphragmatic IVC/RA thrombus who underwent radical nephrectomy with high thrombectomy, using extracorporeal circulation, between 2004-2018 in the Prof. C. C. Iliescu Emergency Institute for Cardiovascular Diseases, Bucharest, were retrospectively analysed. The patients who died intraoperatively were excluded from the study. The predefined study endpoint was the postoperative AKI3. Preoperative, intraoperative and postoperative data were collected according to the stratification of study population in two subgroups: AKI3-present and AKI3- absent patients. EuroSCORE, EuroSCORE II, Logistic EuroSCORE, NSQIP any-complications and NSQIP serious-complications were analysed. Results: We reviewed 30 patients who underwent this complex surgery between 2004-2018 in our institute. Two patients died intraoperatively. Nine patients (32.14%) presented postoperative AKI3. Age (OR 1.151, CI 95%: 1.009-1.312), preoperative creatinine clearance (OR 1.066, CI 95%: 1.010-1.123) and intraoperative arterial hypotension (OR 13.125, CI 95%: 1.924-89.515) were risk factors for AKI3 (univariable analysis). Intraoperative arterial hypotension emerged as the only independent risk factor in multivariable analysis (OR 11.66, CI 95%: 1.400-97.190). Logistic EuroSCORE (ROC analysis: AUC = 0.813, p = 0.008, CI 95%: 0.633-0.993) best predicted the endpoint. Conclusions: An integrated team effort is essential to avoid intraoperative arterial hypotension, the only independent risk factor of AKI3 in this highly complex surgery. Some risk scores can predict this complication. Further studies are needed.

Association of serum N-terminal pro-brain natriuretic peptide levels with survival and renal outcomes among elderly patients with acute kidney injury in chronic heart failure

Background

Elderly patients exhibit a higher incidence of chronic heart failure (CHF). Patients with CHF can develop acute kidney injury (AKI) during follow-up, which can result in poor prognosis. This relationship between kidney dysfunction and levels of N-terminal pro-brain natriuretic peptides (NT-proBNP), with regard to prognosis, is complicated and has rarely been analyzed in elderly patients with CHF.

Method

We conducted a retrospective cohort study involving patients with a CHF history aged ≥ 65 years, who experienced an episode of AKI. Kaplan-Meier curves and Cox or logistic proportional hazards regression models were used to evaluate the association between serum NT-proBNP concentrations and mortality or renal recovery by day 90.

Results

A total of 1,160 eligible patients with AKI were available for the study. Of this sample, 41.5% of patients died within 90 days of the onset of AKI. Patients with a decreased change in NT-proBNP accompanying the episode of AKI had a lower risk (adjusted OR = 0.56, 95% CI = 0.34-0.91) of more severe AKI (stage 2 and 3 vs. stage 1). The more severe AKI were associated with higher mortality and non-recovery of renal function in elderly patients with CHF, independent of NT-proBNP levels. Elevated levels of baseline lnNT-proBNP (adjusted HR = 1.27, 95% CI = 1.17-1.38) predicted mortality in elderly patients with CHF within 90 days of AKI onset. Patients with a decrease in NT-proBNP accompanying AKI had a lower risk of mortality (adjusted HR = 0.62, 95% CI = 0.48-0.79). However, a decrease in NT-proBNP is a risk factor (adjusted OR = 1.59, 95% CI = 1.02-2.48) for the non-recovery of renal function following AKI-especially in elderly survivors with low baseline NT-proBNP levels.

Conclusion

A decreased change in NT-proBNP maybe protective for elderly patients with CHF by improving survival outcomes and preventing severe AKI. However, an excessive decrease in NT-proBNP is a risk factor for the non-recovery of renal function following AKI. Avoiding excessive changes in NT-proBNP may be protective for survival and renal injury prognosis.

Beneficial Impacts of Fenoldopam on Patients With or at Risk for Acute Renal Failure and Undergoing Surgery: A Meta-Analysis of Randomized Clinical Trials

This meta-analysis aims to determine the beneficial impacts of fenoldopam on patients with or at high risk of acute kidney injury (AKI) and undergoing surgery. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed while performing the present meta-analysis. Two investigators searched electronic databases including PubMed, EMBASE, and the Cochrane library, from inception until January 10, 2023, for relevant studies. The key terms used to search for relevant articles included "fenoldopam", "acute kidney injury" and "surgery". The primary outcome was the incidence of new AKI. Secondary outcomes included change in serum creatine from baseline (mg/dl), length of stay in ICU (days), renal replacement therapy (RRT), and all-cause mortality that included mortality before or at 30 days. A total of 10 studies involving 1484 patients were included in the present meta-analysis. The risk of AKI was lower in the fenoldopam group compared to the control group [risk ratio (RR): 0.73, 95% CI: 0.57-0.95]. The length of ICU stay was also shorter in the fenoldopam group [mean difference (MD): -0.35 days, 95% confidence interval (CI): -0.68, -0.03]. No significant differences were reported in terms of all-cause mortality, change in serum creatinine, and RRT. In conclusion, our meta-analysis of studies on the use of fenoldopam in adult patients undergoing major surgery showed that fenoldopam significantly reduces the risk of AKI and shortens ICU stays. However, there was no significant impact on all-cause mortality or RRT.

Risk of Acute Kidney Injury and Fracture-Related Infection After Antibiotic Prophylaxis With Piperacillin-Tazobactam in Open Fractures

OBJECTIVES

To evaluate the effects of prophylactic piperacillin-tazobactam (PT) on inpatient acute kidney injury (AKI) and fracture-related infection (FRI) in patients with open fractures.

SETTING

The study was conducted at a Level 1 trauma center.

PATIENTS

We reviewed 358 Gustilo-Anderson type II and III open fractures at our institution from January 2013 to December 2017.

INTERVENTION

Administration of PT (the PT group) or antibiotics other than PT (the historical control group) during the first 48 hours of arrival for open fracture antibiotic prophylaxis.

MAIN OUTCOME MEASUREMENTS

The main outcome measurements were rates of inpatient AKI and FRI within six months after definitive fixation.

RESULTS

There were 176 patients in the PT group and 182 patients in the historical control group. The PT group had worse American Society of Anesthesiologists class ( P = 0.004) and injury severity scores ( P < 0.001), a higher average number of debridements before closure/coverage ( P = 0.043), and higher rates of gross soil contamination ( P = 0.049) and staged procedures ( P = 0.008) compared with the historical control group.There was no difference in the rate of AKI between the PT and historical control groups (5.7% vs. 2.7%, P = 0.166) nor when stratified by Gustilo-Anderson fracture classification (type II: 5.8% vs. 3.6%, P = 0.702; type III: 5.6% vs. 2.0%, P = 0.283). There was no significant difference in the rate of FRI between the PT and historical control groups (23.6% vs. 19.6%, P = 0.469).

CONCLUSION

The use of PT in prophylactic antimicrobial treatment in patients with Gustilo-Anderson type II and III open fractures does not increase the rate of AKI or FRI. We believe PT can be used as an effective monotherapy in these patients without an increased risk of renal injury, but future investigations are necessary.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Laboratory Diagnostic of Acute Kidney Injury and Its Progression: Risk of Underdiagnosis in Female and Elderly Patients

Acute kidney injury (AKI) is a common disease, with high morbidity and mortality rates. In this study, we investigated the potential influence of sex and age on laboratory diagnostics and outcomes. It is known that serum creatinine (SCr) has limitations as a laboratory diagnostic parameter for AKI due to its dependence on muscle mass, which may lead to an incorrect or delayed diagnosis for certain patient groups, such as women and the elderly. Overall, 7592 cases with AKI, hospitalized at the University of Leipzig Medical Center (ULMC) between 1st January 2017 and 31st December 2019, were retrospectively analyzed. The diagnosis and staging of AKI were performed according to the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines, based on the level and dynamics of SCr. The impact of sex and age was analyzed by the recalculation of a female to male and an old to young SCr using the CKD-EPI equation. In our study cohort progressive AKI occurred in 19.2% of all cases (n = 1458). Female cases with AKI were underrepresented (40.4%), with a significantly lower first (-3.5 mL/min) and last eGFR (-2.7 mL/min) (p < 0.001). The highest incidence proportion of AKI was found in the [61-81) age group in female (49.5%) and male (52.7%) cases. Females with progressive AKI were underrepresented (p = 0.04). By defining and staging AKI on the basis of relative and absolute changes in the SCr level, it is more difficult for patients with low muscle mass and, thus, a lower baseline SCr to be diagnosed by an absolute SCr increase. AKIN1 and AKIN3 can be diagnosed by a relative or absolute change in SCr. In females, both stages were less frequently detected by an absolute criterion alone (AKIN1 ♀ 20.2%, ♂ 29.5%, p < 0.001; AKIN3 ♀ 13.4%, ♂ 15.2%, p < 0.001). A recalculated SCr for females (as males) and males (as young males) displayed the expected increase in AKI occurrence and severity with age and, in general, in females. Our study illustrates how SCr, as the sole parameter for the diagnosis and staging of AKI, bears the risk of underdiagnosis of patient groups with low muscle mass, such as women and the elderly. A sex- and age-adapted approach might offer advantages.

Implementation of a new definition for acute kidney injury in the National Surgical Quality Improvement Project: What is the impact?

BACKGROUND

The National Surgical Quality Improvement Project is the preeminent surgical quality database, but it undercaptures acute kidney injury. Recently, the National Surgical Quality Improvement Project lowered the thresholds for acute kidney injury for the first time, so we assessed the impact of implementing the definition change on the rate of acute kidney injuries.

METHODS

For this interrupted time series analysis, we assembled 2 institutional National Surgical Quality Improvement Project files to identify adults undergoing inpatient noncardiac nonvascular surgery. The acute kidney injury definition changed on July 1, 2021, so patients were stratified by their operative date into 12-month pre and post groups. Weighted covariate propensity score matching and logistic regression were used to balance the periods and compare outcomes.

RESULTS

In total, 4,784 adults were eligible (55% pre and 45% post change). The overall rate of postoperative outcomes was similar, aside for acute kidney injury (pre 0.3%, post 5.6%, P < .0001). Regardless of the period, patients with acute kidney injuries had significantly longer lengths of stay and morbidity and mortality rates compared to those without an acute kidney injury. After the definition change, 81% of acute kidney injuries were stage I, and none were identified by urine output alone. After matching, surgery after the definition change was associated with an increased weighted odds of an acute kidney injury compared to surgery before the change (odds ratio 26.2; 95% confidence interval, 12.1-56.8).

CONCLUSION

In the year after the definition change, there was a 1,700% relative increase in the rate of reported acute kidney injuries. Newly identified acute kidney injuries are associated with high complication rates, and this definition change has implications for patient counseling, research, and quality reporting.

Prion Protein Overexpression in Adipose-Derived Mesenchymal Stem Cells (ADMSCs) Effectively Protected Rodent Kidney Against Ischemia-Reperfusion Injury Via Enhancing ATP/Mitochondrial Biogenesis-Role of ADMSC Rejuvenation and Proliferation

BACKGROUND

We tested the hypothesis that overexpression of cellular-prion-protein in adipose-derived mesenchymal stem cells (PrPCOE-ADMSCs) effectively protected the kidney against ischemia-reperfusion (IR) injury in rat.

METHODS

Part I of cell culture was categorized into A1(ADMSCs)/A2(ADMSCs+p-Cresol)/A3(PrPCOE in ADMSCs)/A4 (PrPCOE in ADMSCs+p-Cresol). Part II of cell culture was divided into B1(ADMSCs)/B2[ADMSCs+lipopolysaccharide (LPS)]/B3(PrPCOE in ADMSCs)/B4(PrPCOE in ADMSCs+LPS). Sprague-Dawley (SD) rats (n = 50) were equally categorized into groups 1 (sham-operated-control)/2 (IR)/3 (IR+ADMSCs/6.0 × 105 equally divided into bilateral-renal arteries and 6.0 × 105 intravenous administration by 1 h after IR)/4 [IR+PrPCOE-ADMSCs (identical dosage administered as group 3)]/5 [IR+silencing PRNP -ADMSCs (identical dosage administered as group 3)], and kidneys were harvested post-day 3 IR injury.

RESULTS

Part I results demonstrated that the cell viability at 24/48/72 h, BrdU uptake/number of mitDNA/APT concentration/mitochondrial-cytochrome-C+ cells and the protein expressions of ki67/PrPC at 72 h-cell culturing were significantly higher in PrPCOE-ADMSCs than in ADMSCs (all P < 0.001). The protein expressions of oxidative-stress (NOX-1/NOX2/NOX4/oxidized protein)/mitochondrial-damaged (p22-phox/cytosolic-cytochrome-C)/inflammatory (p-NF-κB/IL-1ß/TNF-α/IL-6)/apoptotic (cleaved caspase-3/cleaved-PARP) biomarkers were lowest in A1/A3 and significantly higher in A2 than in A4 (all P < 0.001). Part II result showed that the protein expressions of inflammatory (p-NF-κB/IL-1ß/TNF-α/IL-6)/apoptotic (cleaved caspase-3/cleaved-PARP) biomarkers exhibited an identical pattern of part I among the groups (all P < 0.001). The protein expressions of inflammatory (p-NF-κB/IL-1ß/TNF-α/MMP-9)/oxidative-stress (NOX-1/NOX-2/oxidized-protein)/mitochondrial-damaged (cytosolic-cytochrome-C/p22-phox)/apoptotic (cleaved caspase-3/cleaved-PARP/mitochondrial-Bx)/autophagic (beclin-1/ratio of LC3B-II/LC3B-I)/fibrotic (Smad3/TGF-ß) biomarkers and kidney-injury-score/creatinine level were lowest in group 1, highest in group 2, significantly higher in group 5 than in groups 3/4 (all P < 0.0001).

CONCLUSION

PrPCOE in ADMSCs rejuvenated these cells and played a cardinal role on protecting the kidney against IR injury.

Artificial intelligence for the prediction of acute kidney injury during the perioperative period: systematic review and Meta-analysis of diagnostic test accuracy

BACKGROUND

Acute kidney injury (AKI) is independently associated with morbidity and mortality in a wide range of surgical settings. Nowadays, with the increasing use of electronic health records (EHR), advances in patient information retrieval, and cost reduction in clinical informatics, artificial intelligence is increasingly being used to improve early recognition and management for perioperative AKI. However, there is no quantitative synthesis of the performance of these methods. We conducted this systematic review and meta-analysis to estimate the sensitivity and specificity of artificial intelligence for the prediction of acute kidney injury during the perioperative period.

METHODS

Pubmed, Embase, and Cochrane Library were searched to 2nd October 2021. Studies presenting diagnostic performance of artificial intelligence in the early detection of perioperative acute kidney injury were included. True positives, false positives, true negatives and false negatives were pooled to collate specificity and sensitivity with 95% CIs and results were portrayed in forest plots. The risk of bias of eligible studies was assessed using the PROBAST tool.

RESULTS

Nineteen studies involving 304,076 patients were included. Quantitative random-effects meta-analysis using the Rutter and Gatsonis hierarchical summary receiver operating characteristics (HSROC) model revealed pooled sensitivity, specificity, and diagnostic odds ratio of 0.77 (95% CI: 0.73 to 0.81),0.75 (95% CI: 0.71 to 0.80), and 10.7 (95% CI 8.5 to 13.5), respectively. Threshold effect was found to be the only source of heterogeneity, and there was no evidence of publication bias.

CONCLUSIONS

Our review demonstrates the promising performance of artificial intelligence for early prediction of perioperative AKI. The limitations of lacking external validation performance and being conducted only at a single center should be overcome.

TRIAL REGISTRATION

This study was not registered with PROSPERO.

The Predictive Role of Systemic Inflammatory Markers in the Development of Acute Kidney Failure and Mortality in Patients with Abdominal Trauma

Background: Abdominal trauma is defined as a variety of injuries to the abdominal wall, solid or hollow intra-abdominal organs, and various intra-abdominal vessels. Recently, there has been a significant amount of interest in the establishment of a reliable biomarker that can predict the outcome in patients with an abdominal injury. The purpose of this study is to confirm the predictive role of inflammatory biomarkers and underlying risk factors and the risk of acute kidney insufficiency (AKI) developing and mortality in abdominal trauma patients; Materials and methods: The current study was intended as an observational, analytical, retrospective cohort study and included all patients over 18 years of age with a diagnosis of abdominal trauma confirmed through a CT scan admitted to the County Emergency Clinical Hospital of Targu-Mureș, Romania between January 2017, and December 2021; Results: Non-survivor patients had a greater age (p = 0.02), as well as a higher prevalence of ischemic heart disease (IHD) (p = 0.007), history of myocardial infarction (MI) (p = 0.002), peripheral arterial disease (PAD) (p = 0.01), chronic kidney disease (CKD) (p = 0.01), and all risk factors (p = 0.0004 and p < 0.0001). In terms of injured organs, we have in the second group a higher incidence of kidney injury (p = 0.003) and hemoperitoneum (p = 0.008). Multivariate analysis showed a high baseline value for all inflammatory biomarkers that are independent predictors of adverse outcomes for all recruited patients. Furthermore, for all hospitalized patients, the history of MI (p = 0.03; p = 0.001; and p = 0.003), PAD (p = 0.01; p = 0.01; and p = 0.002), obesity (for all p < 0.0001), CKD (p < 0.001; p = 0.01; and p = 0.001), and kidney injury (p = 0.02; p = 0.004; and p = 0.01) were independent predictors of all outcomes. Moreover, IHD (p = 0.008 and p = 0.02), tobacco (p < 0.0001 and p = 0.02), and hemoperitoneum (p = 0.009 and p = 0.01) were predictors of mortality and composite endpoint, but not for AKI risk, as well as atrial fibrillation [AF] (p = 0.04) as predictors of the composite endpoint Conclusions: Higher monocyte to lymphocyte ratio (MLR), platelets to lymphocyte ratio (PLR), systemic inflammatory index (SII), neutrophil to lymphocyte ratios (NLR), aggregate inflammatory systemic index (AISI), and systemic inflammatory response index (SIRI) levels at admission, according to our data, highly predict AKI risk and death.

Use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers increases the risk of postoperative acute kidney injury after elective endovascular abdominal aortic aneurysm repair

BACKGROUND

Endovascular abdominal aortic aneurysm repair (EVAR) is the major treatment for abdominal aortic aneurysm (AAA); however, EVAR still carries a considerable risk of acute kidney injury (AKI). The present study aimed to investigate the risk factors for AKI after elective EVAR procedures.

METHODS

This was a retrospective observational study. Eligible patients who underwent EVAR from September 2011 to March 2019 in West China Hospital were included. The primary outcome was the occurrence of AKI within two days after EVAR, which was defined by the Kidney Disease Improving Global Outcomes Clinical Practice Guideline. Demographics, comorbidities, medications, laboratory tests, anatomical parameters of AAA, and relative operative details were collected as variables. Univariable and multivariable logistic regression analyses were applied to identify the risk factors among variables, and covariate interactions were further assessed.

RESULTS

A total of 679 eligible patients were included. The incidence of postoperative AKI was 8.2% (56/679) in the whole cohort, and it was associated with a lower 5-year survival rate (63.5% vs . 80.9%; χ 2  = 4.10; P  = 0.043). The multivariable logistic regression showed that chronic kidney disease (OR, 5.06; 95% CI: 1.43-17.95; P  = 0.012), angiotensin-converting enzyme inhibitors (ACEIs)/angiotensin receptor blockers (ARBs) (OR, 2.60; 95% CI: 1.17-5.76; P  = 0.019), and short neck (OR, 2.85; 95% CI: 1.08-7.52; P  = 0.035) were independent risk factors for postoperative AKI. In the covariate interaction analysis, the effect of ACEIs/ARBs use on postoperative AKI was similar across all subgroups ( P  > 0.05), thereby suggesting a robust effect of ACEIs/ARBs use in all patients undergoing elective endovascular abdominal aortic aneurysm repair.

CONCLUSIONS

Postoperative AKI was associated with lower survival rate, and the use of ACEIs/ARBs was the only adjustable independent risk factor. Clinicians should consider withdrawing ACEIs/ARBs in high-risk patients undergoing elective endovascular abdominal aortic aneurysm repair to prevent postoperative AKI.

Association between postoperative acute kidney injury and mortality after plastic and reconstructive surgery

Acute kidney injury (AKI) is a common postoperative disorder that is associated with considerable morbidity and mortality. Although the role of AKI as an independent risk factor for mortality has been well characterized in major surgeries, its effect on postoperative outcomes in plastic and reconstructive surgery has not been evaluated. This study explored the association between postoperative AKI and mortality in patients undergoing plastic and reconstructive surgery. Consecutive adult patients who underwent plastic and reconstructive surgery without end-stage renal disease (n = 7059) at our institution from January 2011 to July 2019 were identified. The patients were divided into two groups according to occurrence of postoperative AKI: 7000 patients (99.2%) in the no AKI group and 59 patients (0.8%) in the AKI group. The primary outcome was mortality during the first year, and overall mortality and 30-days mortality were also compared. After inverse probability weighting, mortality during the first year after plastic and reconstructive surgery was significantly increased in the AKI group (1.9% vs. 18.6%; hazard ratio, 6.69; 95% confidence interval, 2.65-16.85; p < 0.001). In this study, overall and 30-day mortalities were shown to be higher in the AKI group, and further studies are needed on postoperative AKI in plastic and reconstructive surgery.

Changes in Serum Creatinine May Cause Hypoglycemia among Non-Critically Ill Patients Admitted to Internal Medicine Units

Background: The association between changes in serum creatinine levels and hypoglycemia during hospitalization was investigated. Methods: This was a retrospective analysis of medical charts. Patients were categorized as having significant change in creatinine (SCIC) when serum creatinine levels rose or dropped ≥ 0.3 mg/dL from admission values at any time during their hospitalization. Patients were considered hypoglycemic if they had at least one documented glucose level ≤ 70 mg/dL during the hospitalization. Multiple logistic, linear and Cox regression analyses were used to ascertain the association between incident SCIC, severity and timing with incident hypoglycemia. Results: Included were 25,400 (mean age 69.9 ± 18.0, 49.3% were males). The rate of SCIC was 22.2%, and 62.2% of them were diagnosed upon admission. Patients with SCIC had a higher incidence of hypoglycemia compared to patients without (13.1% vs. 4.1%, respectively, p < 0.001). Patients with SCIC had an increased risk of hypoglycemia (OR 1.853, 95% CI 1.586−2.166, p < 0.001). The magnitude of SCIC was associated with the incidence (OR 1.316, 95% CI 1.197−1.447, p < 0.001) and the number of events (HR 0.054, 95% CI 0.021−0.087, p = 0.001). More than 60% of patients with hypoglycemia had their first event documented during days 0−6 after SCIC occurrence. Of those, the majority of events occurred on day 0−1, and the rate showed a gradual decrease throughout the first 5 days from SCIC occurrence. The results were similar for patients with and without DM. Conclusions: Changes in creatinine during hospitalization may cause hypoglycemia among patients admitted to internal medicine departments, regardless of DM status.

Limited clinical utility for GWAS or polygenic risk score for postoperative acute kidney injury in non-cardiac surgery in European-ancestry patients

BACKGROUND

Prior studies support a genetic basis for postoperative acute kidney injury (AKI). We conducted a genome-wide association study (GWAS), assessed the clinical utility of a polygenic risk score (PRS), and estimated the heritable component of AKI in patients who underwent noncardiac surgery.

METHODS

We performed a retrospective large-scale genome-wide association study followed by a meta-analysis of patients who underwent noncardiac surgery at the Vanderbilt University Medical Center ("Vanderbilt" cohort) or Michigan Medicine, the academic medical center of the University of Michigan ("Michigan" cohort). In the Vanderbilt cohort, the relationship between polygenic risk score for estimated glomerular filtration rate and postoperative AKI was also tested to explore the predictive power of aggregating multiple common genetic variants associated with AKI risk. Similarly, in the Vanderbilt cohort genome-wide complex trait analysis was used to estimate the heritable component of AKI due to common genetic variants.

RESULTS

The study population included 8248 adults in the Vanderbilt cohort (mean [SD] 58.05 [15.23] years, 50.2% men) and 5998 adults in Michigan cohort (56.24 [14.76] years, 49% men). Incident postoperative AKI events occurred in 959 patients (11.6%) and in 277 patients (4.6%), respectively. No loci met genome-wide significance in the GWAS and meta-analysis. PRS for estimated glomerular filtration rate explained a very small percentage of variance in rates of postoperative AKI and was not significantly associated with AKI (odds ratio 1.050 per 1 SD increase in polygenic risk score [95% CI, 0.971-1.134]). The estimated heritability among common variants for AKI was 4.5% (SE = 4.5%) suggesting low heritability.

CONCLUSION

The findings of this study indicate that common genetic variation minimally contributes to postoperative AKI after noncardiac surgery, and likely has little clinical utility for identifying high-risk patients.

Intravenous amino acid therapy for kidney protection in cardiac surgery a protocol for a multi-centre randomized blinded placebo controlled clinical trial. The PROTECTION trial

BACKGROUND

Postoperative acute kidney injury (AKI) is frequent in cardiac surgery patients. Its pathophysiology is complex and involves decreased renal perfusion. Preliminary clinical evidence in critically ill patients shows that amino acids infusion increases renal blood flow and may decrease the incidence and severity of AKI. We designed a study to evaluate the effectiveness of perioperative continuous infusion of amino acids in decreasing AKI.

METHODS

This is a phase III, multi-center, randomized, double-blind, placebo-controlled trial. Adults undergoing cardiac surgery with cardiopulmonary bypass (CPB) are included. Patients are randomly assigned to receive either continuous infusion of a balanced mixture of amino acids in a dose of 2 g/kg ideal body weight/day or placebo (balanced crystalloid solution) from the operating room up to start of renal replacement therapy (RRT), or ICU discharge, or 72 h after the first dose. The primary outcome is the incidence of AKI during hospital stay defined by KDIGO (Kidney Disease: Improving Global Outcomes). Secondary outcomes include the need for, and duration of, RRT, mechanical ventilation; ICU and hospital length of stay; all-cause mortality at ICU, hospital discharge, 30, 90, and 180 days after randomization; quality of life at 180 days. Data will be analyzed in 3500 patients on an intention-to-treat basis.

DISCUSSION

The trial is ongoing and currently recruiting. It will be one of the first randomized controlled studies to assess the relationship between amino acids use and kidney injury in cardiac surgery. If our hypothesis is confirmed, this practice could reduce morbidity in the studied population.

STUDY REGISTRATION

This trial was registered on ClinicalTrials.gov with the trial identification NCT03709264 in October 2018.

Preoperative dipstick albuminuria is associated with acute kidney injury in high-risk patients following non-cardiac surgery: a single-center prospective cohort study

PURPOSE

This study aimed to investigate the association between preoperative dipstick albuminuria (DA) and acute kidney injury (AKI) in high-risk patients following non-cardiac surgery.

METHODS

This was a single-center prospective cohort study. Adult patients with high risk of AKI undergoing non-cardiac surgery were enrolled. The primary outcome was AKI, defined according to KDIGO criteria within 7 days following non-cardiac surgery. DA status was determined by urinalysis performed within 24 h of hospital admission. Multivariate logistic regression model was used to analyze the association between preoperative DA and postoperative AKI.

RESULTS

During the study period, 552 patients were enrolled and 8.5% of them developed postoperative AKI. The overall rate of preoperative positive DA was 26.4% with 30 and ≥ 100 mg/dL DA accounting for 19.2% and 7.2%, respectively. Patients with more severe preoperative DA had much higher rate of postoperative AKI (5.2% in patients with negative or trace DA, 13.2% in patients with 30 mg/dL DA and 30.0% in patients with ≥ 100 mg/dL DA, P < 0.001). After adjusting for several perioperative variables, preoperative 30 mg/dL DA (OR 2.575; 95% CI 1.049-6.322; P = 0.039) and ≥ 100 mg/dL DA (OR 3.868; 95% CI 1.246-12.010; P = 0.019) showed an independent association with postoperative AKI. In addition, patients with higher DA status demonstrated significantly increased level of postoperative urine biomarkers and their ratio to urine creatinine.

CONCLUSIONS

Preoperative DA was independently associated with AKI in high-risk patients following non-cardiac surgery. Preoperative routine urinalysis for determination of DA status was suggested in early risk stratification.