Acute kidney injury can predict in-hospital and long-term mortality in elderly patients undergoing hip fracture surgery

Key Considerations for Frail Patients Undergoing Hip Fracture Surgery

Improving preoperative care for elderly patients with hip fractures is crucial for achieving the best outcomes. A multidisciplinary team that can improve overall care quality by addressing patient's medical conditions, analgesia, timely surgery, and early postoperative mobilization is required. This narrative review provides insights regarding the extent of preoperative optimization needed for hip fracture surgery.

Comparison of estimated glomerular filtration rate using five equations to predict acute kidney injury following hip fracture surgery

BACKGROUND

Decreased estimated glomerular filtration rate (eGFR) is associated with acute kidney injury (AKI) following hip fracture surgery. Delaying surgery for preoperative treatment of comorbidities is controversial in this patient population. The purpose of this study was 1) to assess differences in demographics and comorbidities between AKI and non-AKI groups, 2) to analyze equations used in calculating eGFR, and 3) to identify the equation which best predicts the development of AKI following hip fracture surgery. We hypothesize that one of the equations used to calculate eGFR will be superior to the others.

PATIENTS AND METHODS

124,002 cases of hip fracture surgery were performed from 2012 to 2019, based upon a query of the National Surgical Quality Improvement Program (NSQIP). Preoperative eGFR was calculated using the following: Modification of Diet in Renal Disease (MDRD) II, re-expressed MDRD II, Chronic Kidney Disease Epidemiology Collaboration, Mayo quadratic, and Cockcroft-Gault equations. Independent associations between preoperative eGFR and postoperative renal failure were evaluated using multivariate regression analysis. The predictive ability of each equation was determined using the Akaike information criterion (AIC).

RESULTS

AKI was diagnosed in 584 (0.71%) out of the 82,326 patients following hip fracture surgery. The AKI and no AKI cohorts differed significantly by patient sex (p = <0.001), race (p = <0.001), BMI (p = < 0.001), preoperative hematocrit (p = <0.001), preoperative albumin (p = <0.001), diabetes mellitus (p = <0.001), hypertension (p = <0.001), and congestive heart failure (p = <0.001). The Mayo equation (84.0 ± 23.7) was the equation with the highest calculated mean eGFR, followed by the CKD-EPI equation (83.6 ± 20.0), MDRD II equation (83.0 ± 38.9), CG equation (74.7 ± 35.5), and finally the re-expressed MDRD II equation (68.5 ± 36.0) which had the lowest calculated mean eGFR.. All five equations detected that a decrease in preoperative eGFR was associated with an increased risk of postoperative AKI. Lower preoperative eGFR, as calculated by each of the five equations, was significantly associated with an increased risk of AKI following surgical fixation of hip fracture. The AIC was the lowest in the Mayo equation, demonstrating the best fit of the equations to predict postoperative AKI CONCLUSIONS: We propose that using the equation that best identifies those at risk of developing postoperative AKI may help with perioperative decision making and treatment to improve outcomes, which we found to be the Mayo equation. The risk of postoperative AKI was independently associated with decreased preoperative eGFR. The results of this study may warrant further investigation utilizing prospective studies.

LEVEL OF EVIDENCE

III; retrospective cohort study.

Predictive value of the early postoperative hemoglobin-to-red blood cell distribution width ratio for acute kidney injury in elderly intertrochanteric fracture patients

BACKGROUND

Hemoglobin-to-red blood cell distribution width ratio (HRR) had great predictive value for the prognosis of malignant tumors and cardiovascular disease. However, its predictive value for the occurrence of acute kidney injury (AKI) in elderly intertrochanteric fracture patients remains unclear. This study aims to analyze the correlation between the early postoperative HRR and the risk of postoperative AKI in elderly intertrochanteric fracture patients.

METHODS

We reviewed the medical records of 307 elderly intertrochanteric fracture patients in this single-center retrospective cohort study. We performed univariate analysis on the relevant parameters, and parameters with significant differences were included in the following logistic regression model for multivariate analysis. Then, we used a receiver operating characteristic (ROC) curve to evaluate the predictive value of the early postoperative HRR level for AKI in elderly intertrochanteric fracture patients. Patients were divided into a high HRR group and a low HRR group according to the cutoff point determined by ROC curve analysis. Subsequently, the relevance between postoperative HRR and AKI was further determined using propensity score matching (PSM) and inverse probability of treatment weighting (IPTW).

RESULTS

The area under the curve of the early postoperative HRR for predicting postoperative AKI was 0.714 (95% CI: 0.618-0.809). The cutoff value was 5.44. The sensitivity was 72.7%, and the specificity was 70.8%. Patients were divided into low HRR (⩽ 5.44) and high HRR (> 5.44) groups according to the cutoff value. PSM and IPTW analysis indicated that the risk of AKI in the low HRR group was significantly higher than that in the high HRR group in both the matched cohort (OR = 6.914, 95% CI: 1.714-46.603, p = 0.016) and the weighted group (OR = 2.784, 95% CI: 1.415-5.811, p = 0.040).

CONCLUSIONS

Early postoperative HRR is an accurate, accessible, and economical blood test parameter that can predict the risk of postoperative AKI in elderly patients with femoral intertrochanteric fracture.

Preoperative inflammatory biomarkers reveal renal involvement in postsurgical mortality in hip fracture patients: an exploratory study

Background

Hip fractures in frail patients result in excess mortality not accounted for by age or comorbidities. The mechanisms behind the high risk of mortality remain undetermined but are hypothesized to be related to the inflammatory status of frail patients.

Methods

In a prospective observational exploratory cohort study of hospitalized frail hip fracture patients, 92 inflammatory markers were tested in pre-operative serum samples and markers were tested against 6-month survival post-hip fracture surgery and incidence of acute kidney injury (AKI). After correcting for multiple testing, adjustments for comorbidities and demographics were performed on the statistically significant markers.

Results

Of the 92 markers tested, circulating levels of fibroblast growth factor 23 (FGF-23) and interleukin-15 receptor alpha (IL15RA), both involved in renal disease, were significantly correlated with 6-month mortality (27.5% overall) after correcting for multiple testing. The incidence of postoperative AKI (25.4%) was strongly associated with 6-month mortality, odds ratio = 10.57; 95% CI [2.76-40.51], and with both markers plus estimated glomerular filtration rate (eGFR)- cystatin C (CYSC) but not eGFR-CRE. The effect of these markers on mortality was significantly mediated by their effect on postoperative AKI.

Conclusion

High postoperative mortality in frail hip fracture patients is highly correlated with preoperative biomarkers of renal function in this pilot study. The effect of preoperative circulating levels of FGF-23, IL15RA, and eGFR-CYSC on 6-month mortality is in part mediated by their effect on postoperative AKI. Creatinine-derived preoperative renal function measures were very poorly correlated with postoperative outcomes in this group.

Comorbidities, acute kidney injury and long-term mortality in elderly patients hospitalized because of hip fracture: a moderation analysis

INTRODUCTION

Femoral fractures in elderly individuals present significant health challenges, often leading to increased morbidity and mortality. Acute kidney injury (AKI) during hospitalization further complicates outcomes, yet the interaction between AKI severity and comorbidities, as quantified by the Charlson Comorbidity Index (CCI), remains poorly understood in this population. This study aimed to assess the associations between AKI severity and the CCI and between AKI severity and one-year mortality postfemoral fracture in elderly patients.

METHODOLOGY

This study utilized data from the Multiparameter Intelligent Monitoring in Intensive Care (MIMIC-IV) database and focused on elderly patients (> 65 years) admitted with hip fractures. Patients were categorized based on AKI stage according to the KDIGO criteria and CCI scores. The primary outcome assessed was all-cause mortality one year after hospital discharge. The statistical analyses included logistic regression, Cox proportional hazards regression and moderation analysis with the Johnson-Neyman technique to evaluate associations between AKI and long-term mortality and between the CCI and long-term mortality.

RESULTS

The analysis included 1,955 patients and revealed that severe AKI (stages 2 and 3) was independently associated with increased one-year mortality. Notably, the CCI moderated these associations significantly. A lower CCI score was significantly correlated with greater mortality in patients with severe AKI. The impact of severe AKI was greater for those with a CCI as low as 3, more than doubling the observed one-year mortality rate. In contrast, higher CCI scores (≥8) did not significantly impact mortality. Sensitivity analyses supported these findings, underscoring the robustness of the observed associations.

CONCLUSION

This study elucidates the complex interplay between AKI severity and comorbidities and long-term mortality in elderly hip fracture patients. These findings underscore the importance of considering both AKI severity and comorbidity burden in prognostic assessments and intervention strategies for this vulnerable population. Targeted interventions tailored to individual risk profiles may help mitigate the impact of AKI on mortality outcomes, ultimately improving patient care and outcomes. Further research is warranted to explore the underlying mechanisms involved and refine risk stratification approaches in this population.

The Nomogram Model and Factors for the Postoperative Mortality of Elderly Patients with Femoral Neck Fracture Undergoing Artificial Hip Arthroplasty: A Single-Institution 6-Year Experience

OBJECTIVE

Artificial hip arthroplasty (AHA) is widely accepted in elderly patients with femoral neck fractures, but it is associated with high risk of death and various postoperative complications due to old age and accompanying chronic diseases. Therefore, this study aimed to explore the risk factors for death in elderly patients with femoral neck fractures after AHA and to establish a nomogram risk prediction model, which is expected to reveal high-risk patients and improve the postoperative quality of life and survival rate of patients.

METHODS

Elderly patients who underwent AHA for femoral neck fractures in our hospital from September 2014 to May 2021were retrospectively analyzed. These patients were divided into a survival group and a death group according to their clinical outcomes. The following clinical data were recorded for the patients in the two groups: sex, age, underlying diseases, smoking and drinking history, preoperative nutritional risk score (NRS) and American Society of Anesthesiologists (ASA) score, as well as relevant indicators about the operation. These data were subject to univariate analysis and then logistic analysis to determine the risk factors of death. Subsequently, a nomogram risk prediction model was established and further validated with the receiver operating characteristic curve (ROC) and the Hosmer-Lemeshow test. Finally, the effects of predictive risk factors were analyzed using the Kaplan-Meier survival curve.

RESULTS

Follow-up was completed by 260 patients, including 206 patients in the survival group and 54 patients in the death group; the overall death rate was 20.77%, and the follow-up time, age, postoperative 1, 3 and 5-year death rates were 3.47 ± 1.93 years, 75.32 ± 9.12 years, 5.77%, 12.51%, and 25.61%, respectively. The top three causes of death in 54 patients were respiratory disease, cerebrocardiovascular disease, and digestive disease, respectively. The logistic analysis indicated that elderly patients with femoral neck fractures, the risk factors for death after AHA were age ≥ 80 years, preoperative NRS ≥ 4, HB ≤ 90 g/L, CR ≥ 110 umol/L, and ASA score ≥ 3, as well as postoperative albumin ≤ 35 g/L, the nomogram was established, and then its predictive performance was successfully validated using the ROC curve (AUC = 0.814, 95% confidence interval = 0.749-0.879) and the Hosmer-Lemeshow test (p = 0.840). Furthermore, Kaplan-Meier survival curve analysis revealed that the abovementioned six indicators were correlated with the post-AHA survival time of elderly patients with femoral neck fractures (pLog Rank  < 0.05).

CONCLUSION

Old age, preoperatively high NRS and ASA score, anemia, poor renal function, and postoperative hypoproteinemia are the major risk factors for death in elderly patients with femoral neck fractures after AHA; they are also associated with postoperative survival. Early identification and effective interventions for optimization of modifiable risk factors are recommended to improve the postoperative quality of life and survival rates.

The role of neutrophil percentage to albumin ratio in predicting 1-year mortality in elderly patients with hip fracture and external validation

Objectives

This study aimed to investigate the association between the neutrophil percentage to albumin ratio (NPAR) on the day of admission and mortality 1 year after surgery in elderly patients with hip fractures.

Methods

Clinical characteristics and blood markers of inflammation were retrospectively collected from October 2016 to January 2022 in elderly patients with hip fractures at two different regional tertiary medical centers. It is divided into a training set and an external validation set. Multivariate Nomogram models such as NPAR were constructed using the least absolute shrinkage and selection operator (LASSO) regression results and multi-factor logistic regression analysis. In addition, multivariate Cox regression analysis and Kaplan-Meier survival curves were used to explore the relationship between NPAR values and mortality within 1 year in elderly patients with hip fractures. The predictive performance of the Nomogram was evaluated using the concordance index (C Index) and receiver operating characteristic curve (ROC) and validated by Bootstrap, Hosmer-Lemesow goodness of fit test, calibration curve, decision curve, and clinical impact curve analysis.

Results

The study included data from 1179 (mean age, 80.34 ± 8.06 years; 61.4[52.1%] male) patients from the Guangzhou Red Cross Hospital affiliated with Jinan University and 476 (mean age, 81.18 ± 8.33 years; 233 [48.9%] male) patients from the Xiaogan Central Hospital affiliated with Wuhan University of Science and Technology. The results showed that NPAR has good sensitivity and specificity in assessing patients' prognosis 1 year after surgery. Multivariate logistic regression models based on influencing factors such as NPAR have good discrimination and calibration ability (AUC=0.942, 95% CI:0.927-0.955; Hosmer-Lemeshow test: P >0.05). Kaplan-Meier survival curves for the training and validation sets showed that patients in the high NPAR group had a higher mortality rate at 1 year compared to the low NPAR group (P< 0.001). Multivariate Cox regression showed that high NPAR values were an independent risk factor for death within 1 year in elderly hip fracture patients (P< 0.001, HR =2.38,95%CI:1.84-3.08).

Conclusion

Our study showed that NPAR levels were significantly higher in patients who died within 1 year after surgery in both the training and validation sets. NPAR has good clinical value in assessing 1-year postoperative prognosis in elderly patients with hip fractures.

Advances of perioperative acute kidney injury in elderly patients undergoing non-cardiac surgery

The risk of developing perioperative acute kidney injury (AKI) in elderly patients increases with age. The combined involvement of aging kidneys, coexisting multiple underlying chronic diseases, and increased exposure to potential renal stressors and nephrotoxic drugs or invasive procedures constitute susceptibility factors for AKI in elderly patients. The perioperative AKI in elderly patients undergoing noncardiac surgery has its own specific population characteristics, so it is necessary to further explore the characteristics of AKI in elderly patients in terms of epidemiology, clinical diagnosis, risk factors, and preventive and curative measures to provide meaningful clinical advice to improve prognosis, accelerate recovery, and reduce medical burden in elderly patients. Since AKI has the fastest-growing incidence in older patients and is associated with a worse prognosis, early detection, early diagnosis, and prevention of AKI are important for elderly patients in the perioperative period. Large, multicenter, randomized controlled clinical studies in elderly non-cardiac surgery patients with AKI can be conducted in the future, with the aim of providing the evidence to reduce of the incidence of AKI and to improve the prognosis of patients.

Development and validation of a novel nomogram of 1-year mortality in the elderly with hip fracture: a study of the MIMIC-III database

OBJECTIVE

Hip fracture is a prevalent condition with a significant death rate among the elderly. We sought to develop a nomogram-based survival prediction model for older patients with hip fracture.

DESIGN

A retrospective case-control study.

SETTING

The data from Medical Information Mart for Intensive Care III (MIMIC-III V.1.4).

PARTICIPANTS

The clinical features of elderly patients with hip fracture, including basic information, comorbidities, severity score, laboratory tests and therapy, were filtered out based on the MIMIC-III V.1.4.

METHODS AND MAIN OUTCOME MEASURES

All patients included in the study were from critical care and randomly divided into training and validation sets (7:3). On the basis of retrieved data, the least absolute shrinkage and selection operator (LASSO) regression and multiple logistic regression analysis were used to identify independent predictive variables of 1-year mortality, and then constructed a risk prediction nomogram. The predictive values of the nomogram model were evaluated by the concordance indexes (C-indexes), receiver operating characteristic curve, decision curve analysis (DCA) and calibration curve.

RESULTS

A total of 341 elderly patients with hip fracture were included in this study; 121 cases died within 1 year. After LASSO regression and multiple logistic regression analysis, a novel nomogram contained the predictive variables of age, weight, the proportion of lymphocyte count, liver disease, malignant tumour and congestive heart failure. The constructed model proved satisfactory discrimination with C-indexes of 0.738 (95% CI 0.674 to 0.802) in the training set and 0.713 (95% CI 0.608 to 0.819) in the validation set. The calibration curve shows a good degree of fitting between the predicted and observed probabilities and the DCA confirms the model's clinical practicability.

CONCLUSIONS

The novel prediction model provides personalised predictions for 1-year mortality in elderly patients with hip fractures. Compared with other hip fracture models, our nomogram is particularly suitable for predicting long-term mortality in critical patients.

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.

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.

Acute kidney injury after hip fracture in organ transplant recipients

BACKGROUND

This study aimed to investigate the incidence and risk factors of acute kidney injury (AKI) after hip fracture in organ transplant recipients.

METHODS

In this single-center retrospective cohort study, 795 elderly patients who underwent hip fracture surgery were enrolled. AKI was defined according to Acute Kidney Injury Network criteria. Among the 795 patients, 23 underwent kidney transplantation (KT) and 20 underwent liver transplantation (LT). The incidence of AKI, dialysis requirement, and renal recovery rate were investigated.

RESULTS

AKI occurred in 83 patients (10.5%), of whom 9 (39.1%), 3 (15%), and 71 (9.5%) were in the KT, LT, and non-transplantation groups, respectively. The incidence rates of AKI and severe AKI (17.4% vs. 1.4%) were significantly higher in the KT group than in the non-transplantation group (p = 0.001 for both). The renal recovery rate was significantly lower in the KT group than in the non-transplantation group (p = 0.033). The multivariate analysis revealed that male; body mass index; CKD; alkaline phosphatase; intraoperative hypotension; and history of KT were independent predictors of AKI development.

CONCLUSIONS

AKI and severe AKI after hip fracture occurred more frequently in the KT recipients with lower renal recovery rates. Transplanted kidneys are more vulnerable to AKI after hip fracture. This article is protected by copyright. All rights reserved.

Comparison of Short, Intermediate, and Long Cephalomedullary Nail Length Outcomes in Elderly Intertrochanteric Femur Fractures

Cephalomedullary nail (CMN) length for intertrochanteric femur fractures without subtrochanteric extension has been an ongoing debate. The authors hypothesize that increasing nail length would result in increasing surgical time, greater incidence of acute kidney injury (AKI), postoperative anemia, and blood loss requiring transfusion due to increased intramedullary reaming and pressurization of the canal with nail insertion.

Chronic liver disease and cirrhosis increase morbidity in geriatric patients treated surgically for hip fractures: analysis of the US Nationwide Inpatient Sample

Background

This study aimed to evaluate the impact of chronic liver disease and cirrhosis on inpatient outcomes of geriatric hip fracture surgery.

Materials and methods

Using population-based retrospective study design, this study extracted data from the US Nationwide Inpatient Sample (NIS) database 2005–2014, identifying patients aged ≥ 65 years undergoing hip fracture repair. Main outcomes were in-hospital mortality, any/specific complications, non-routine discharge, extended length of stay (LOS) and hospital costs. Associations between cirrhosis, non-cirrhotic chronic liver disease and outcomes were determined using regression analysis.

Results

Data of 347,363 hip fracture patients included 344,035 without liver disease, 1257 with non-cirrhotic chronic liver disease and 2,071 with cirrhosis. After adjustments, non-cirrhotic chronic liver disease was significantly associated with non-routine discharge (OR: 1.247, 95% CI: 1.038–1.498), acute kidney injury (OR: 1.266, 95% CI: 1.039–1.541), extended LOS (OR: 1.285, 95% CI: 1.122–1.473) and hospital costs (beta: 9173.42, 95% CI: 6925.9–11,420.95) compared to no liver disease; while cirrhosis was significantly associated with higher risk of in-hospital mortality (OR: 2.325, 95% CI: 1.849–2.922), any complication (OR: 1.295, 95% CI: 1.143–1.467), acute kidney injury (OR: 1.242, 95% CI: 1.177–1.433), non-routine discharge (OR: 1.650, 95% CI: 1.412–1.928), extended LOS (OR: 1.405, 95% CI: 1.263–1.562) and hospital costs (beta: 6680.24, 95% CI: 4921.53–8438.95) compared to no liver disease.

Conclusion

In geriatric hip fracture patients undergoing surgical repair, non-cirrhotic chronic liver disease and cirrhosis independently predict non-routine discharge, acute kidney injury, prolonged LOS and greater hospital costs, and cirrhosis is also significantly associated with greater risk of any complication and in-hospital mortality.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-02832-y.

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.

The Association of On-Admission Blood Hemoglobin, C-Reactive Protein, and Serum Creatinine With 2-Year Mortality of Patients With Femoral Neck Fractures

Introduction

The mortality of femoral neck fracture (FNF) is high and every effort should be made to identify and manage any possible risk factors. The aim of this study was to evaluate whether on-admission hemoglobin (Hb) level, C-reactive protein (CRP), and serum creatinine were associated with 2-year mortality after FNF.

Patients and Methods

In this retrospective observational cohort study, we considered for inclusion all displaced FNF patients 65 years and above treated with hemi-arthroplasty between February 2011 and May 2015. We documented the age, sex, cognitive status, and American Society of Anesthesiologists (ASA) classification. The Hb level, CRP, and serum creatinine were measured. The medical records were followed up for 2 years. We fitted different crude and adjusted Cox proportional hazards models to examine whether Hb level <100 g/L, CRP >20 mg/L, and serum creatinine >100 μmol/L were associated with the 2-year mortality, adjusted for age, sex, and ASA class.

Results

A total of 290 patients [208 females (72%), mean age 84 years] were included in the study. More than 50% of patients had impaired cognition and ASA class 3–4. Of the 290 patients, 38.3% (n = 111) had died within 2 years after surgery. Mortality among males was 46.3% (n = 38) while mortality among females was 35,1% (n = 73), p = 0.07. We found that on-admission Hb level <100 g/L was associated with 2-year mortality (HR = 3.3, 95% CI: 1.3–8.3, p < 0.01) while CRP >20 mg/L and serum creatinine >100 μmol/L were not associated with 2-year mortality (p = 0.89 and p = 0.31, respectively).

Conclusion

On-admission Hb level <100 g/L, but not CRP >20 mg/L and serum creatinine >100 μmol/L, was associated with 2-year mortality. These results can help healthcare providers identify high-risk FNF patients who probably would benefit from optimized perioperative medical management.

Risk factors and associated outcomes of acute kidney injury in hip fracture patients

Purpose

To assess risk factors and associated outcomes of acute kidney injury (AKI) in hip fracture patients.

Methods

Risk factors for AKI were identified by multivariate logistic regression. AKI patients were matched to patients who did not experience AKI using a validated trauma triage score. Comparative analyses between matched groups were performed.

Results

Risk factors of AKI included increasing Charlson Comorbidity Index and use of anticoagulation medications. AKI was associated with increased likelihood of medical complications and longer, more costly hospital stays.

Discussion

Patients with identified risk factors for AKI may benefit from consultation with nephrology and closer lab monitoring.

Body Mass Index Is Associated with the Severity and All-Cause Mortality of Acute Kidney Injury in Critically Ill Patients: An Analysis of a Large Critical Care Database

Background

Acute kidney injury (AKI) is a common clinical syndrome carrying high morbidity and mortality. Body mass index (BMI) is a common health indicator, and a high BMI value-obesity has been shown to be associated with the outcomes of several diseases. However, the relationship between different BMI categories and mortality in all critically ill patients with AKI is unclear and needs further investigation. Therefore, we evaluated the ability of BMI to predict the severity and all-cause mortality of AKI in critically ill patients.

Methods

We extracted clinical data from the MIMIC-III v1.4 database. All adult patients with AKI were initially screened. The baseline data extracted within 24 hours after ICU admission were presented according to WHO BMI categories. Logistic regression models and the Cox proportional hazards models were, respectively, constructed to assess the relationship between BMI and the severity and all-cause mortality of AKI. The generalized additive model (GAM) was used to identify nonlinear relationships as BMI was a continuous variable. The subgroup analyses were performed to further analyze the stability of the association between BMI category and 365-day all-cause mortality of AKI.

Result

A total of 15,174 patients were extracted and were divided into four groups according to BMI. Obese patients were more likely to be young and male. In the fully adjusted logistic regression model, we found that overweight and obesity were significant predictors of AKI stage III (OR, 95 CI: 1.17, 1.05-1.30; 1.32, 1.18-1.47). In the fully adjusted Cox proportional hazards model, overweight and obesity were associated with significantly lower 30-day, 90-day, and 365-day all-cause mortality. The corresponding adjusted HRs (95 CIs) for overweight patients were 0.87 (0.77, 0.99), 0.84 (0.76, 0.93), and 0.80 (0.74, 0.88), and for obese patients, they were 0.87 (0.77, 0.98), 0.79 (0.71, 0.88), and 0.73 (0.66, 0.80), respectively. The subgroup analyses further presented a stable relationship between BMI category and 365-day all-cause mortality.

Conclusions

BMI was independently associated with the severity and all-cause mortality of AKI in critical illness. Overweight and obesity were associated with increased risk of AKI stage III; however, they were predictive of a relatively lower mortality risk in these patients.

A novel machine-learning algorithm for predicting mortality risk after hip fracture surgery

INTRODUCTION

Although several risk stratification models have been developed to predict hip fracture mortality, efforts are still being placed in this area. Our aim is to (1) construct a risk prediction model for long-term mortality after hip fracture utilizing the RSF method and (2) to evaluate the changing effects over time of individual pre- and post-treatment variables on predicting mortality.

METHODS

1330 hip fracture surgical patients were included. Forty-five admission and in-hospital variables were analyzed as potential predictors of all-cause mortality. A random survival forest (RSF) algorithm was applied in predictors identification. Cox regression models were then constructed. Sensitivity analyses and internal validation were performed to assess the performance of each model. C statistics were calculated and model calibrations were further assessed.

RESULTS

Our machine-learning RSF algorithm achieved a c statistic of 0.83 for 30-day prediction and 0.75 for 1-year mortality. Additionally, a COX model was also constructed by using the variables selected by RSF, c statistics were shown as 0.75 and 0.72 when applying in 2-year and 4-year mortality prediction. The presence of post-operative complications remained as the strongest risk factor for both short- and long-term mortality. Variables including fracture location, high serum creatinine, age, hypertension, anemia, ASA, hypoproteinemia, abnormal BUN, and RDW became more important as the length of follow-up increased.

CONCLUSION

The RSF machine-learning algorithm represents a novel approach to identify important risk factors and a risk stratification models for patients undergoing hip fracture surgery is built through this approach to identify those at high risk of long-term mortality.

The prevalence and risk factors of acute kidney injury in patients undergoing hip fracture surgery: a meta-analysis

Acute kidney injury (AKI) was a frequent complication following hip fracture surgery, but recent studies reported inconsistent findings. Our study was aimed at clarifying the prevalence and risk factors of AKI after hip fracture surgery. Pubmed, Embase, and Web of Science were systematically searched from the inception to March 2020 to identify observational studies investigating the prevalence and risk factors of AKI in patients undergoing hip fracture surgery. Pooled prevalence and odds ratios (ORs) with 95% confidence intervals (CIs) were estimated using a random-effects model. Publication bias was evaluated with a funnel plot and statistical test. All the statistical analyses were performed using Stata version 12.0. A total of 11 studies with 16,421 patients was included in the current meta-analysis. The pooled prevalence of AKI in patients undergoing hip fracture surgery was 17% (95%CI, 14%-21%) with substantial heterogeneity (I² = 95%). Postoperative serum albumin (OR 1.80; 95%CI, 1.38-2.36) was a significant predictor for AKI. Age (OR 1.01; 95%CI, 0.95-1.07) and ACE inhibitors (OR 1.38; 95%CI, 0.92-2.07) were associated with increased the risk of AKI, but the results were not statistically significant. No significant publication bias was identified through statistical tests (Egger's test, p = 0.258 and Begg's test, p = 0.087). In conclusion, our findings indicated that the pooled AKI following hip fracture surgery was approximately 17%. Postoperative serum albumin was a potential significant risk factor for AKI.

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

BACKGROUND

The present study aimed to summarize the predictors of acute kidney injury (AKI) in patients after hip surgery.

METHODS

A literature search was performed using PubMed, EMBASE, Cochrane Library, and Web of Science for studies assessing the predictors of AKI after hip fracture surgery. Pooled odds ratio (OR) and mean difference (MD) of those who experienced AKI compared to those who did not were calculated for each variable. Evidence was assessed using the Newcastle-Ottawa Scale.

RESULTS

Ten studies with 34 potential factors were included in the meta-analysis. In the primary analysis, 12 factors were associated with AKI, comprising males (OR 1.25; 95% confidence interval (CI) 1.14-1.36), advanced age (MD 2.28; 95% CI 0.80-3.75), myocardial infarction (OR 1.39; 95% CI 1.18-1.63), hypertension (OR 1.46; 95% CI 1.13-1.89), diabetes (OR 1.84; 95% CI 1.40-2.42), chronic kidney disease (OR 3.66; 95% CI 2.21-6.07), hip arthroplasty (OR 1.35; 95% CI 1.22-1.50), angiotensin-converting enzyme inhibitors/angiotensin receptor blockers use (OR 2.28; 95% CI 1.68-3.08), more intraoperative blood loss (MD 44.06; 95% CI 2.88-85.24), higher preoperative blood urea nitrogen levels (MD 5.29; 95% CI 3.38-7.20), higher preoperative serum creatinine levels (MD 0.4; 95% CI 0.26-0.53), and lower preoperative estimated glomerular filtration rate (MD -19.59; 95% CI -26.92--12.26). Another 13 factors related to AKI in individual studies were identified in the systematic review.

CONCLUSION

Related prophylaxis strategies should be implemented in patients involved with the above-mentioned characteristics to prevent AKI after hip surgery.

ACUTE KIDNEY INJURY FOLLOWING SURGERY FOR HIP FRACTURE

Objective:

An observational study was carried out to determine the rate of acute kidney injury (AKI) following surgery for hip fracture at our institution and to look for factors associated with AKI.

Methods:

Preoperative creatinine values were compared to post-operative results for all patients who underwent surgery for hip fracture at our institution between 1^st January 2015 and 30^th September 2016. AKI was defined as an increase in postoperative creatinine, greater than or equal to 1.5 times the preoperative value within 7 days. Chi-squared test and Student’s t-test were used to look for factors associated with AKI.

Results:

Out of 500 patients, 96 developed an AKI (19.2%). Patients with chronic kidney disease (CKD) were more likely to develop AKI (30.8%) that those without it (17.2%, p = 0.018). Similarly, patients with 2 or more comorbidities were more likely to develop AKI (22.0%) than those without it (12.4%, p = 0.009). No statistically significant association was observed between type of surgery and AKI.

Conclusion:

A large proportion of patients following surgery for hip fracture developed AKI. Patients with CKD and the presence of 2 or more comorbidities had significantly higher rates of AKI. Level III evidence, Retrospective comparative study.

Estimated glomerular filtration rate predicts 30-day mortality in medical emergency departments: Results of a prospective multi-national observational study

BACKGROUND

Renal failure is common in patients seeking help in medical emergency departments. Decreased renal function is associated with increased mortality in patients with heart failure or sepsis. In this study, the association between renal function (reflected by estimated glomerular filtration rate (eGFR) at the time of admission) and clinical outcome was evaluated.

METHODS/OBJECTIVES

Data was used from a prospective, multi-national, observational cohort of patients treated in three medical emergency departments of tertiary care centers. The eGFR was calculated from the creatinine at the time of admission (using the Chronic Kidney Disease-Epidemiology Collaboration equation,CKD-EPI). Uni- and multivariate regression models were used for eGFR and 30-day mortality, in hospital mortality, length of stay and intensive care unit admission rate.

RESULTS

6983 patients were included. The 30-day mortality was 1.8%, 3.5%, 6.9%, 11.1%, 13.6%, and 14.2% in patients with eGFR of above 90, 60-89, 45-59, 30-44, 15-29, and <15 ml/min/1.73m2, respectively. Using multivariate regression, the adjusted odds ratio (OR) was 2.31 (for 15-29 ml/min/1.73m2, 95% confidence interval 1.36 to 3.90, p = 0.002) and 3.73 (for eGFR <15ml/min/1.73m2 as compared to >90 ml/min/1.73m2, 95% CI 2.04 to 6.84, p<0.001). For 10 ml/min/1.73m2 decrease in eGFR the OR for the 30-day mortality was 1.15 (95% CI1.09 to 1.22, p<0.001).The eGFR was also significantly associated with in-hospital mortality, the percentage of ICU-admissions, and with a longer hospital stay. No association was found with hospital readmission within 30 days. As limitations, only eGFR at admission was available and the number of patients on hemodialysis was unknown.

CONCLUSION

Reduced eGFR at the time of admission is a strong and independent predictor for adverse outcome in this large population of patients admitted to medical emergency departments.

Effects of accelerated versus standard care surgery on the risk of acute kidney injury in patients with a hip fracture: a substudy protocol of the hip fracture Accelerated surgical TreaTment And Care tracK (HIP ATTACK) international randomised controlled trial

INTRODUCTION

Inflammation, dehydration, hypotension and bleeding may all contribute to the development of acute kidney injury (AKI). Accelerated surgery after a hip fracture can decrease the exposure time to such contributors and may reduce the risk of AKI.

METHODS AND ANALYSIS

Hip fracture Accelerated surgical TreaTment And Care tracK (HIP ATTACK) is a multicentre, international, parallel-group randomised controlled trial (RCT). Patients who suffer a hip fracture are randomly allocated to either accelerated medical assessment and surgical repair with a goal of surgery within 6 hours of diagnosis or standard care where a repair typically occurs 24 to 48 hours after diagnosis. The primary outcome of this substudy is the development of AKI within 7 days of randomisation. We anticipate at least 1998 patients will participate in this substudy.

ETHICS AND DISSEMINATION

We obtained ethics approval for additional serum creatinine recordings in consecutive patients enrolled at 70 participating centres. All patients provide consent before randomisation. We anticipate reporting substudy results by 2021.

TRIAL REGISTRATION NUMBER

NCT02027896; Pre-results.

Functional Outcomes After Hip Fracture in Independent Community-Dwelling Patients

OBJECTIVES

To determine predictors of new activities of daily living (ADLs) disability and worsened mobility disability and secondarily increased daily care hours received, in previously independent hip fracture patients.

DESIGN

Retrospective cohort study.

SETTING

Academic hospital with ambulatory follow-up.

PARTICIPANTS

Community-dwelling adults 65 years or older independent in ADLs undergoing hip fracture surgery in 2015 (n = 184).

MEASUREMENTS

Baseline, 3- and 6-month ADLs, mobility, and daily care hours received were ascertained by telephone survey and chart review. Comorbidities, medications, and characteristics of hospitalization were extracted from patient charts. Models for each outcome used logistic regression with a backward elimination strategy, adjusting a priori for age, sex, and race.

RESULTS

Predictors of new ADL disability at 3 months were dementia (odds ratio [OR] = 11.81; P = .001) and in-hospital delirium (OR = 4.20; P = .002), and at 6 months were age (OR = 1.04; P = .014), dementia (OR = 9.91; P = .001), in-hospital delirium (OR = 3.00; P = .031) and preadmission opiates (OR = 7.72; P = .003). Predictors of worsened mobility at 3 months were in-hospital delirium (OR = 4.48; P = .001) and number of medications (OR = 1.13; P = .003), and at 6 months were age (OR = 1.06; P = .001), preadmission opiates (OR = 7.23; P = .005), in-hospital delirium (OR = 3.10; P = .019), and number of medications (OR = 1.13; P = .013). Predictors of increased daily care hours received at 3 and 6 months were age (3 months: OR = 1.07; P = .014; 6 months: OR = 1.06; P = .017) and number of medications (3 months: OR = 1.13; P = .004; 6 months: OR = 1.22; P = .013). The proportion of patients with ADL disability and care hours received did not change from 3 to 6 months, yet there were significant improvements in mobility.

CONCLUSION

Age, dementia, in-hospital delirium, number of medications, and preadmission opiate use were predictors of poor outcomes in independent older adults following hip fracture. Further investigation is needed to identify factors associated with improved mobility measures from 3 to 6 months to ultimately optimize recovery.

Diastolic dysfunction and acute kidney injury in elderly patients with femoral neck fracture

Background

Femoral neck fracture is common in the elderly population. Acute kidney injury (AKI) is an important risk factor for mortality in patients who have had such fracture. We evaluated the incidence of AKI in patients who had femoral neck fracture and identified risk factors for AKI and mortality.

Methods

This was an observational cohort study including 285 patients who were ≥ 65 years of age and who underwent femoral neck fracture surgery between 2013 and 2017.

Results

The mean age was 78.63 ± 6.75 years. A total of 67 (23.5%) patients developed AKI during the hospital stay: 57 (85.1%), 5 (7.5%), and 5 (7.5%) patients were classified as having stage 1, 2, and 3 AKI, respectively. Patients with AKI had a lower baseline estimated glomerular filtration rate and higher left atrial dimension, left ventricular mass index, pulmonary artery pressure, and the ratio of early mitral inflow velocity to early diastolic mitral annulus velocity (E/e’) and were more likely to have diabetes or hypertension (HTN) (P < 0.05). The presence of HTN (odds ratio [OR], 4.570; 95% confidence interval [CI], 1.632–12.797) higher E/e’ (OR, 1.105; 95% CI, 1.019–1.198), and lower hemoglobin (OR, 0.704; 95% CI, 0.528–0.938) were independently associated with a higher risk for developing AKI. Severe AKI (OR, 24.743; 95% CI, 2.822–212.401) was associated with a higher risk of mortality.

Conclusion

Elderly patients with femoral neck fracture had a high incidence of AKI. Diastolic dysfunction was associated with AKI. Severe AKI was associated with in-hospital mortality.

Doppler resistive index to reflect risk of acute kidney injury after major abdominal surgery: A prospective observational trial

Background and Aims

Doppler renal resistive index (RI) has been studied to find its association with postoperative acute kidney injury (AKI). This study was conducted to evaluate the usefulness of preoperative RI, postoperative RI and RI variation before and after surgery expressed as a percentage (% RI) for early AKI detection in major abdominal surgery.

Methods

This was a single-centre, prospective observational trial performed in the critical care unit of an academic hospital. Eligible patients posted for major abdominal surgery under general anaesthesia using intraperitoneal approach with at least two predefined risk factors for AKI were included in the study. Renal RI was measured preoperatively and on postoperative day zero. Statistical comparisons were performed for various parameters between the AKI and the non-AKI groups. Pre- and postoperative RI receiver operating characteristics (ROC) curves were drawn and areas under the curves computed. Positive and negative predictive values, sensitivity, specificity and positive and negative likelihood ratios were calculated.

Results

A total of 69 subjects were enrolled, of which 14 developed AKI in the postoperative period. The mean resistive indices measured were 0.65 ± 0.09 and 0.74 ± 0.09 in the pre- and postoperative periods, respectively. The area under the ROC curve in the postoperative RI was 0.732 with 95% confidence intervals of 0.592-0.871. This most accurate cut-off value to detect postoperative AKI with sensitivity 57.1% and specificity of 85.5% was 0.77.

Conclusion

Postoperative RI can detect early AKI after major abdominal surgery.