Predictors of postoperative acute kidney injury in patients undergoing hip fracture surgery: A systematic review and meta-analysis

Urinary dickkopf-3 as a predictor for postoperative acute kidney injury in the intensive care unit

BACKGROUND

As a life-threatening complication in patients undergoing surgery, acute kidney injury (AKI) is strongly associated with a worse prognosis. Urinary dickkopf-related protein 3 (DKK3) has been identified as a biomarker for predicting postoperative AKI in patients undergoing cardiac surgery.

OBJECTIVE

To investigate the predictive value of urinary DKK3 on postoperative AKI and develop a clinical model based on the predictor for predicting the development of AKI within seven days for patients undergoing noncardiac surgery.

METHODS

All patients who were admitted to the Intensive Care Unit (ICU) after noncardiac surgery from March 2023 to June 2023 were included in this study. The patients' baseline data on demographic characteristics, lifestyle risk factors, medical history, clinical features, and laboratory tests before surgery were collected at the time of admission. Besides, the blood samples for cystatin C and routine laboratory tests and the urine samples for DKK3 tests were simultaneously collected at the time of admission to the ICU. In addition, the independent predictors of postoperative AKI were identified by univariate, multivariate, and LASSO analyses. Moreover, a nomogram for predicting postoperative AKI was developed based on these independent predictors. Finally, the nomogram was evaluated through calibration and decision curve analyses.

RESULTS

A total of 166 patients with a median age of 67 years old were included in this study, including 94 (56.63%) males. Among these patients, 47 patients (28.3%) developed postoperative AKI. Additionally, 7 independent risk factors, including preoperative serum creatinine, preoperative eGFR, preoperative serum albumin, preoperative serum potassium ion, cystatin C, uDKK3/uCr, and SOFA score, were selected by univariate and multivariate regression analyses. Eventually, 4 independent risk factors (including preoperative eGFR, cystatin C, uDKK3/uCr, and SOFA score) identified in this study by LASSO analyses were used to establish the nomogram. The area under the receiver operating characteristic (ROC) curve (AUC) for the prediction model was 0.868. The calibration curve and decision curve analysis results demonstrated that the nomogram had good prediction performance.

CONCLUSIONS

Urinary DKK3/creatinine was independently associated with postoperative AKI for patients in the ICU after noncardiac surgery. The nomogram constructed based on uDKK3/uCr, preoperative eGFR, cystatin C, and SOFA score showed a higher accuracy in predicting postoperative AKI.

Effect of Colchicine on the Risk of Perioperative Acute Kidney Injury: Clinical Protocol of a Substudy of the Colchicine for the Prevention of Perioperative Atrial Fibrillation Randomized Clinical Trial

Background

Inflammation during and after surgery can lead to organ damage including acute kidney injury. Colchicine, an established inexpensive anti-inflammatory medication, may help to protect the organs from pro-inflammatory damage. This protocol describes a kidney substudy of the colchicine for the prevention of perioperative atrial fibrillation (COP-AF) study, which is testing the effect of colchicine versus placebo on the risk of atrial fibrillation and myocardial injury among patients undergoing thoracic surgery.

Objective

Our kidney substudy of COP-AF will determine whether colchicine reduces the risk of perioperative acute kidney injury compared with a placebo. We will also examine whether colchicine has a larger absolute benefit in patients with pre-existing chronic kidney disease, the most prominent risk factor for acute kidney injury.

Design and Setting

Randomized, superiority clinical trial conducted in 40 centers in 11 countries from 2018 to 2023.

Patients

Patients (~3200) aged 55 years and older having major thoracic surgery.

Intervention

Patients are randomized 1:1 to receive oral colchicine (0.5 mg tablet) or a matching placebo, given twice daily starting 2 to 4 hours before surgery for a total of 10 days. Patients, health care providers, data collectors, and outcome adjudicators will be blinded to the randomized treatment allocation.

Methods

Serum creatinine concentrations will be measured before surgery and on postoperative days 1, 2, and 3 (or until hospital discharge). The primary outcome of the substudy is perioperative acute kidney injury, defined as an increase (from the prerandomization value) in serum creatinine concentration of either ≥26.5 μmol/L (≥0.3 mg/dL) within 48 hours of surgery or ≥50% within 7 days of surgery. The primary analysis (intention-to-treat) will examine the relative risk of acute kidney injury in patients allocated to receive colchicine versus placebo. We will repeat the primary analysis using alternative definitions of acute kidney injury and examine effect modification by pre-existing chronic kidney disease, defined as a prerandomization estimated glomerular filtration rate (eGFR) <60 mL/min per 1.73 m2.

Limitations

The substudy will be underpowered to detect small effects on more severe forms of acute kidney injury treated with dialysis.

Results

Substudy results will be reported in 2024.

Conclusions

This substudy will estimate the effect of colchicine on the risk of perioperative acute kidney injury in older adults undergoing major thoracic surgery.

Clinical trial registration number

NCT03310125.

Insertion of a urinary catheter on admission lowers acute kidney injury incidence in patients with hip fractures

PURPOSE

Acute kidney injury (AKI) is a common adverse event in patients undergoing hip fracture repair surgery, increasing morbidity and mortality. Our study hypothesis was that routine insertion of a urinary catheter, on admission to the hospital or immediately before surgery, will reduce AKI incidence in hip fracture patients.

METHODS

Determined by alternating days of admission, a urinary catheter was inserted routinely on admission (catheter group) or as needed (non-catheter group) in 250 consecutive patients who presented with a hip fracture to our emergency department. The incidence of AKI according to the KDIGO criteria and morbidity and mortality were compared between the study groups.

RESULTS

The overall incidence of AKI was 11.6% (29/250). The catheter group (N = 122) had a significantly lower rate of AKI (6.6% vs. 16% p = 0.018). At 12-month follow-up, the overall mortality was 10.8% (27/250), in-hospital 7.4% (2/27), short-term (within 30 days) 7.4% (2/27), and long-term (30 days to 1 year) 85.8% (23/27). All in-hospital mortality occurred in the AKI group. Patients with no AKI had a better survival rate; however, the difference was not significant (p-value = 0.21). Mortality rate was lower in the catheter group but not significant (8.2% compared with 13.8% in the non-catheter group, p = 0.225). Post-operative respiratory and cardiac complications were more frequent in the AKI group (p = 0.02 and 0.043 accordingly).

CONCLUSIONS

Insertion of a urinary catheter upon admission or before surgery lowered AKI incidence significantly. Peri-operative AKI was associated with higher rates of post-operative complications and worse survival.

Construction and Validation of a Nomogram for Predicting Acute Kidney Injury After Hip Fracture Surgery

Background

Acute kidney injury (AKI), characterized by sudden impairment of kidney function, is an uncommon complication following hip fracture surgery that is associated with increased morbidity and mortality. We constructed a nomogram to stratify patients according to risk of AKI after hip fracture surgery to guide clinicians in the implementation of timely interventions.

Methods

Patients who received hip fracture surgery from January 2015 to December 2021 were retrospectively identified and divided into a training set (n=448, surgery from January 2015 to December 2019) and a validation set (n=200, surgery from January 2020 to December 2021). Univariate and multivariate logistic regression were used to identify risk factors for AKI after surgery in the training set. A nomogram was constructed based the risk factors for AKI, and was evaluated by receiver operating characteristic (ROC) analysis, calibration curves, and decision curve analysis (DCA).

Results

The mean age was 82.0±6.22 years-old and the prevalence of post-surgical AKI was 13.3%. Age, American Society of Anesthesiologists (ASA) score, the preexistence of chronic kidney disease (CKD), cemented surgery and the decrease of hemoglobin on the first day after surgery were identified as independent risk factors of AKI after hip fracture surgery, and a predictive nomogram was established based on the multivariable model. The predictive nomogram had good discrimination ability (training set: AUC: 0.784, 95% CI: 0.720-0.848; validation set: AUC: 0.804, 95% CI: 0.704-0.903), and showed good validation ability and clinical usefulness based on a calibration plot and decision curve analysis.

Conclusion

A nomogram that incorporated five risk factors including age, ASA score, preexisting CKD, cemented surgery and the decrease of hemoglobin on the first day after surgery had good predictive performance and discrimination. Use of our results for early stratification and intervention has the potential to improve the outcomes of patients receiving hip fracture surgery. Future large, multicenter cohorts are needed to verify the model's performance.

Trauma-related acute kidney injury during inpatient care of femoral fractures increases the risk of mortality: A claims data analysis

Objectives: Although femoral fractures can hit anyone, they carry an especially high burden in the elderly and are multifaceted in their injury pattern, related complications, and subsequent therapeutic strategies. An often underestimated posttraumatic risk is the development of trauma-related acute kidney injury (TRAKI). However, for TRAKI, no outcome study with a large data approach exists addressing fractures. Therefore, we analyzed the development of TRAKI in regard to different covariates and quantified the association of TRAKI with overall mortality. Design: Retrospective cohort study with claims data. Setting and participants: 119,000 patients from Germany with femur fracture. Methods: We calculated cumulative mortality, mortality rates per 100 person-years (both occurring within 180 days after fracture), and adjusted hazard ratios with 95%-confidence intervals (CI). Results: Patients with femur shaft fractures showed an incidence of 6.1% for TRAKI, followed by patients with femur neck fractures with an incidence of 5.7%, and by patients with distal fractures with an incidence of 4.5%, respectively. Overall, in patients with any femur fracture, we found a 3.17-times higher mortality rate (95%-CI: 3.02-3.26) during 180 days of observation in patients who developed TRAKI in comparison to patients without. The risk for development of TRAKI was significantly increased with increasing TRAKI stage, age, and time until surgical intervention. Conclusions and implications: In conclusion, patients suffering from proximal-, shaft-, and distal femoral fracture face an over 3-times higher 180 day-mortality rate in case of posttraumatic TRAKI, which should be considered in peri-traumatic care to improve the long-term outcome of these patients.

Akutes Nierenversagen

Das akute Nierenversagen oder die akute Nierenschädigung ist eine ernsthafte Erkrankung. Es gibt nur vage Zahlenangaben zum Auftreten. Im vorliegenden Beitrag wird versucht, die diabetologisch relevanten Aspekte dieser Erkrankung darzustellen. Die möglichen Ursachen werden aufgezeigt. Menschen mit Diabetes mellitus haben überwiegend ein höheres Risiko für ein akutes Nierenversagen als nicht von dieser Stoffwechselerkrankung Betroffene. Dies wird für diagnostische sowie klinisch relevante Risikokonstellationen dargestellt. Sowohl diagnostisch als auch therapeutisch ist die interdisziplinäre Kooperation insbesondere mit dem Fachgebiet Nephrologie erforderlich. Therapeutisch relevante Aspekte werden angerissen, auch medikamentöse Maßnahmen.

Perioperative acute kidney injury: impact and recent update

PURPOSE OF REVIEW

Acute kidney injury (AKI) is common in hospitalized patients and is a major risk factor for increased length of stay, morbidity, and mortality in postoperative patients. There are multiple barriers to reducing perioperative AKI - the etiology is multi-factorial and the diagnosis is fraught with issues. We review the recent literature on perioperative AKI and some considerations for anesthesiologists that examine the far-reaching effects of AKI on multiple organ systems.

RECENT FINDINGS

This review will discuss recent literature that addresses the epidemiology, use of novel biomarkers in risk stratification, and therapeutic modalities for AKI in burn, pediatrics, sepsis, trauma, cardiac, and liver disease, contrast-induced AKI, as well as the evidence assessing goal-directed fluid therapy.

SUMMARY

Recent studies address the use of risk stratification models and biomarkers, more sensitive than creatinine, in the preoperative identification of patients at risk for AKI. Although exciting, these scores and models need validation. There is a need for research assessing whether early AKI detection improves outcomes. Enhanced recovery after surgery utilizing goal-directed fluid therapy has not been shown to make an appreciable difference in the incidence of AKI. Reducing perioperative AKI requires a multi-pronged and possibly disease-specific approach.

Effect of a Perioperative Hypotension-Avoidance Strategy Versus a Hypertension-Avoidance Strategy on the Risk of Acute Kidney Injury: A Clinical Research Protocol for a Substudy of the POISE-3 Randomized Clinical Trial

Background:

Most patients who take antihypertensive medications continue taking them on the morning of surgery and during the perioperative period. However, growing evidence suggests this practice may contribute to perioperative hypotension and a higher risk of complications. This protocol describes an acute kidney injury substudy of the Perioperative Ischemic Evaluation-3 (POISE-3) trial, which is testing the effect of a perioperative hypotension-avoidance strategy versus a hypertension-avoidance strategy in patients undergoing noncardiac surgery.

Objective:

To conduct a substudy of POISE-3 to determine whether a perioperative hypotension-avoidance strategy reduces the risk of acute kidney injury compared with a hypertension-avoidance strategy.

Design:

Randomized clinical trial with 1:1 randomization to the intervention (a perioperative hypotension-avoidance strategy) or control (a hypertension-avoidance strategy).

Intervention:

If the presurgery systolic blood pressure (SBP) is <130 mmHg, all antihypertensive medications are withheld on the morning of surgery. If the SBP is ≥130 mmHg, some medications (but not angiotensin receptor blockers [ACEIs], angiotensin receptor blockers [ARBs], or renin inhibitors) may be continued in a stepwise manner. During surgery, the patients’ mean arterial pressure (MAP) is maintained at ≥80 mmHg. During the first 48 hours after surgery, some antihypertensive medications (but not ACEIs, ARBs, or renin inhibitors) may be restarted in a stepwise manner if the SBP is ≥130 mmHg.

Control:

Patients receive their usual antihypertensive medications before and after surgery. The patients’ MAP is maintained at ≥60 mmHg from anesthetic induction until the end of surgery.

Setting:

Recruitment from 108 centers in 22 countries from 2018 to 2021.

Patients:

Patients (~6800) aged ≥45 years having noncardiac surgery who have or are at risk of atherosclerotic disease and who routinely take antihypertensive medications.

Measurements:

The primary outcome of the substudy is postoperative acute kidney injury, defined as an increase in serum creatinine concentration of either ≥26.5 μmol/L (≥0.3 mg/dL) within 48 hours of randomization or ≥50% within 7 days of randomization.

Methods:

The primary analysis (intention-to-treat) will examine the relative risk and 95% confidence interval of acute kidney injury in the intervention versus control group. We will repeat the primary analysis using alternative definitions of acute kidney injury and examine effect modification by preexisting chronic kidney disease, defined as a prerandomization estimated glomerular filtration rate <60 mL/min/1.73 m².

Results:

Substudy results will be analyzed in 2022.

Limitations:

It is not possible to mask patients or providers to the intervention; however, objective measures will be used to assess acute kidney injury.

Conclusions:

This substudy will provide generalizable estimates of the effect of a perioperative hypotension-avoidance strategy on the risk of acute kidney injury.

Blood Urea Nitrogen to Serum Albumin Ratio in the Prediction of Acute Kidney Injury of Patients with Rib Fracture in Intensive Care Unit

Background

We hypothesized that the blood urea nitrogen (BUN) to serum albumin ratio (BAR) could serve as an independent predictor for incident acute kidney injury (AKI) in intensive care unit (ICU) patients with rib fracture.

Methods

Rib fracture patients in ICU were extracted from Medical Information Mart for Intensive Care IV (MIMIC-IV v1.0) database. The primary outcome in this study was the incidence of AKI. Univariate and multivariate logistic regression analyses were used to determine the relationship between BAR and AKI and propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) were also applied to assure the robustness of our results.

Results

The optimal cut-off value for BAR was 5.26 based on receiver operator characteristic curve. Among the 953 patients who diagnosed with rib fracture, 197 high-BAR group (≥5.26) patients and 197 low-BAR group (<5.26) patients who had similar propensity scores were finally included in the matched cohort. High-BAR group patients had a significantly higher incidence of AKI (odds ratio, OR, 3.85, 95% confidence index, 95% CI, 2.58–5.79, P<0.001) in the original cohort, in the matched cohort (OR, 4.47, 95% CI 2.71–7.53, P<0.001), and in the weighted cohort (OR, 4.28, 95% CI 2.80–6.53, P<0.001). Furthermore, BAR was superior to that of acute physiology score III for predicting AKI and could add more net benefit for incident AKI in critical care patients with rib fracture.

Conclusion

As an easily access and cost-effective parameter, BAR could serve as a good diagnostic predictor for AKI in ICU patients with rib fracture.

Prediction of acute kidney injury in ICU with gradient boosting decision tree algorithms

PURPOSE

To predict acute kidney injury (AKI) in a large intensive care unit (ICU) database.

MATERIALS AND METHODS

A total of 30,020 ICU admissions with 17,222 AKI episodes were extracted from the Medical Information Mart from Intensive Care (MIMIC)-III database. These were randomly divided into a training set and an independent testing set in a ratio of 4:1. Data pertaining to demographics, admission information, vital signs, laboratory tests, critical illness scores, medications, comorbidities, and intervention measures were collected. Logistic regression, random forest, LightGBM, XGBoost, and an ensemble model was used for early prediction of AKI occurrence and important feature extraction. The SHAP analysis was adopted to reveal the impact of prediction for each feature.

RESULTS

The ensemble model had the best overall performance for predicting AKI before 24 h, 48 h and 72 h. The F1 values were 0.915, 0.893, and 0.878, respectively. AUCs were 0.923, 0.903, and 0.895, respectively.

CONCLUSIONS

Based on readily available electronic medical record (EMR) data, gradient boosting decision tree models are highly accurate at early AKI prediction in critically ill patients.

The effect of intra-operative hypotension on acute kidney injury, postoperative mortality and length of stay following emergency hip fracture surgery

The association between intra-operative hypotension and postoperative acute kidney injury, mortality and length of stay has not been comprehensively evaluated in a large single-centre hip fracture population. We analysed electronic anaesthesia records of 1063 patients undergoing unilateral hip fracture surgery, collected from 2015 to 2018. Acute kidney injury, 3-, 30- and 365-day mortality and length of stay were evaluated to assess the relationship between intra-operative hypotension absolute values (≤ 55, 60, 65, 70 and 75 mmHg) and duration of hypotension. The rate of acute kidney injury was 23.7%, mortality at 3-, 30- and 365 days was 3.7%, 8.0% and 25.3%, respectively, and median (IQR [range]) length of stay 8 (6-12 [0-99]) days. Median (IQR [range]) time ≤ MAP 55, 60, 65, 70 and 75 mmHg was 0 (0-0.5[0-72.1]); 0 (0-4.4 [0-104.9]); 2.2 (0-8.7 [0-144.2]); 6.6 (2.2-19.7 [0-198.8]); 17.5 (6.6-37.1 [0-216.3]) minutes, and percentage of surgery time below these thresholds was 1%, 2.5%, 7.9%, 12% and 21% respectively. There were some univariate associations between hypotension and mortality; however, these were no longer evident in multivariable analysis. Multivariable analysis found no association between hypotension and acute kidney injury. Acute kidney injury was associated with male sex, antihypertensive medications and cardiac/renal comorbidities. Three-day mortality was associated with delay to surgery ? 48 hours, whilst 30-day and 365-day mortality was associated with delay to surgery ≥ 48 hours, impaired cognition and cardiac/renal comorbidities. While the rate of acute kidney injury was similar to other studies, use of vasopressors and fluids to reduce the time spent at hypotensive levels failed to reduce this complication. Intra-operative hypotension at the levels observed in this cohort may not be an important determinant of acute kidney injury, postoperative mortality and length of stay.