Risk factors associated with acute kidney injury in a cohort of 20,575 arthroplasty patients

Impact of bedside ultrasound to reduce the incidence of acute renal injury in high-risk surgical patients: a randomized clinical trial

PURPOSE

This study aimed to determine whether performing bedside ultrasound impacts the occurrence of acute kidney injury (AKI) in the immediate postoperative period (POP) of high-risk surgery patients.

METHODS

POP patients were randomly assigned to two groups: (i) ultrasound (US) group, in which hemodynamic management was guided with clinical parameters supplemented with the bedside US findings; (ii) control group, hemodynamic management based solely on clinical parameters. Two exams were performed in the first 24 h of admission.

RESULTS

Fifty-one patients were randomized to the US group and 60 to the control group. There was no significant difference for incidence of AKI in both groups assessed 12 h (31.4% vs 35.0%, P = 0.84), 24 h (27.5% vs 23.3%, P = 0.66), or 7 days (17.6 vs 8.3%, P = 0.16) after surgery. No difference was found in the amounts of volume administered over the first 12 h (1000 [500-2000] vs. 1000 [500-1500], P = 0.72) and 24 h (1000 [0-1500] vs. 1000 [0-1500], P = 0.95) between the groups. Patients without AKI in the control group received higher amounts of volume during the ICU stay.

CONCLUSION

The use of bedside US in the immediate postoperative period of high-risk surgery did not show benefits in reducing AKI incidence.

Machine learning for acute kidney injury: Changing the traditional disease prediction mode

Acute kidney injury (AKI) is a serious clinical comorbidity with clear short-term and long-term prognostic implications for inpatients. The diversity of risk factors for AKI has been recognized in previous studies, and a series of predictive models have been developed using traditional statistical methods in conjunction with its preventability, but they have failed to meet the expectations in limited clinical applications, the rapid spread of electronic health records and artificial intelligence machine learning technology has brought new hope for the construction of AKI prediction models. In this article, we systematically review the definition and classification of machine learning methods, modeling ideas and evaluation methods, and the characteristics and current status of modeling studies. According to the modeling objectives, we subdivided them into critical care medical setting models, all medical environment models, special surgery models, special disease models, and special nephrotoxin exposure models. As the first review article to comprehensively summarize and analyze machine learning prediction models for AKI, we aim to objectively describe the advantages and disadvantages of machine learning approaches to modeling, and help other researchers more quickly and intuitively understand the current status of modeling research, inspire ideas and learn from experience, so as to guide and stimulate more research and more in-depth exploration in the future, which will ultimately provide greater help to improve the overall status of AKI diagnosis and treatment.

Acute kidney injury after hip fracture surgery in patients over 80 years of age

BACKGROUND

The aim of the study is to determine the rate of acute kidney injury (AKI) after hip fracture surgery over the age of 80 and to investigate the factors associated with AKI.

METHODS

From January 2015 to January 2020, 589 patients who underwent surgery of hip fractures at our institution were retrospectively reviewed. Serum creatinine (sCr) was analysed daily pre- and postoperatively during the hospital stay. Patients were divided into groups; AKI and non-AKI based on KDIGO (Kidney Disease Global Outcomes) criteria. The incidence, risk factors, and mortality of postoperative AKI were investigated.

RESULTS

Out of 589 patients, 58 developed an AKI (9.8%). Smoking (p: 0.004), pre and postoperative low albumin level (p < 0.05), pre- and postoperative high potassium level (p < 0.05), pre- and postoperative high urea levels (p < 0.05), high amount of intra-operative bleeding (p: 0.003) and prolonged surgery time (p: 0.003) were found to be risk factors associated with AKI. Although the mortality rate was higher in the AKI group, it was not statistically significant (p > 0.05).

CONCLUSION

AKI is a temporary but common complication following hip fracture surgery, which can also be predicted if risk factors are adequately observed. It typically increases the length of hospital stays, mortality and morbidity.

LEVEL OF EVIDENCE

Level III evidence, Retrospective comparative study.

Improving Postoperative Acute Kidney Injury Rates Following Primary Total Joint Arthroplasty

BACKGROUND

Perioperative hip and knee arthroplasty complications remain a significant clinical and financial burden. Our institution has shifted to developing protocols to decrease these perioperative complications. This study focuses on acute kidney injury (AKI) rate status post primary total joint arthroplasty (TJA). Current literature demonstrates a 2%-15% incidence of AKI following TJA. However, there is a paucity of published literature on protocols that have effectively reduced AKI rates following TJA. The purpose of this study is to evaluate the effect that our institutionally developed perioperative renal protocol had on the postoperative AKI rates.

METHODS

A retrospective cohort study was performed. Patient demographics, baseline creatinine, and postoperative creatinine values during the patient's hospitalization were collected and analyzed. The preintervention cohort data contained all patients at our institution who underwent a primary TJA from November 1, 2016 to January 1, 2018. The postintervention cohort included all primary TJA patients from July 1, 2018 to February 2, 2020. AKI was defined using the AKI Network classification system comparing baseline and postoperative creatinine values. A multivariate analysis was performed to determine the statistical significance of our results.

RESULTS

Before intervention 1013 patients underwent a primary TJA with 68 patients developing an AKI postoperatively. After intervention 2169 patients underwent primary TJA with 90 patients developing an AKI (6.71% vs 4.15%; P = .0015, odds ratio = 0.59, 95% confidence interval = 0.42-0.82).

CONCLUSION

This study demonstrated that implementation of a perioperative renal protocol can significantly reduce AKI rates. A reduction in AKI rates following TJA will result in improved outcomes and secondarily decrease the financial impact of postoperative complications seen following TJA.

Incidence and risk factors for acute kidney injury after total joint arthroplasty

BACKGROUND

Acute kidney injury (AKI) is one of the most common medical causes for readmission following total joint arthroplasty (TJA). This study aimed to (1) examine whether the incidence of AKI has changed over the past decade with the adoption of modern perioperative care pathways and (2) identify the risk factors and concomitant adverse events (AEs) associated with AKI.

METHODS

535,291 primary TJA procedures from the American College of Surgeons National Surgical Quality Improvement Program from 2011 to 2018 were retrospectively reviewed. The annual incidence of AKI was analyzed for significant changes over time. Matched cohort analyses were performed to identify the risk factors and AEs associated with AKI using multivariate logistic regression.

RESULTS

The mean incidence of AKI was 0.051%, which remained unchanged during the study period (P = 0.121). Factors associated with AKI were diabetes (OR 1.96, P = 0.009), bilateral procedure (OR 6.93, P = 0.030), lower preoperative hematocrit level (OR 1.09, P = 0.015), body mass index (OR 1.04, P = 0.025), and higher preoperative BUN (OR 1.03, P = 0.043). AKI was associated with length of stay (LOS) > 2 days (OR 4.73, P <  0.001), non-home discharge (OR 0.25, P <  0.001), 30-day readmission (OR 12.29, P <  0.001), and mortality (OR 130.7, P <  0.001).

CONCLUSIONS

The incidence of AKI has not changed over the past decade, and it remains a major bundle buster resulting in greater LOS, non-home discharge, readmissions, and mortality. Avoidance of bilateral TJA in patients with DM and high BMI as well as preoperative optimization of anemia and BUN levels are advised.

Preventing Acute Kidney Injury and Hypotension After Elective Total Joint Arthroplasty Is Possible: An Update to an Established Multidisciplinary Protocol

INTRODUCTION

Based on preoperative and perioperative risk factors that have been found to correlate with the development of acute kidney injury (AKI), our institution developed a protocol aimed at managing and improving outcomes in all elective THA and TKA patients. This article highlights the continued success and growth of our protocol aimed at decreasing AKI and hypotension in elective total joint arthroplasty patients.

METHOD

A multidisciplinary team comprising orthopaedic surgeons, nephrologists, anesthesiologists, cardiologists, and internal medicine hospitalists created a comprehensive protocol aimed at decreasing complications after elective joint arthroplasty and improving clinical outcomes across multiple hospitals. Patient demographics, hospital length of stay, readmission rates, mortality, and postoperative AKI and hypotension incidences were recorded and compared between preprotocol phase I (initial protocol implementation) and phase II (protocol expansion across 10 hospitals) patient cohorts.

RESULTS

Overall, 3,222 patients over 56 months and 10 hospitals were included. Our phase II AKI rate (0.6%) was significantly lower than our preprotocol rate (6.2%, P < 0.01) and statistically similar to our phase I rate (1.2%, P = 0.61). Our hypotension rate in phase II (6.8%) was significantly lower than our preprotocol rate (12.7%, P < 0.01) but statistically similar to our phase I rate (5.9%, P = 0.40). Furthermore, a significant decrease was observed in hospital length of stay (P < 0.01) over time, but no difference was observed in readmission (P = 0.59) and mortality rates (P = 1.00) over time.

DISCUSSION

This protocol-driven interventional study provides a detailed and successful multidisciplinary method to manage and decrease rates of AKI and hypotension in a large patient cohort across multiple hospital centers.

Perioperative acute kidney injury and urine output in lower limb arthroplasties

BACKGROUND

This study aimed to evaluate the occurrence and perioperative risk factors of acute kidney injury (AKI) in primary elective hip and knee and emergency hip arthroplasty patients. We also aimed to assess the effect of urine output (UOP) as a diagnostic criterion in addition to serum creatinine (sCr) levels. We hypothesized that emergency arthroplasties are prone to AKI and that UOP is an underrated marker of AKI.

METHODS

This retrospective, register-based study assessed 731 patients who underwent primary elective knee or hip arthroplasty and 170 patients who underwent emergency hip arthroplasty at Oulu University Hospital, Finland, between January 2016 and February 2017.

RESULTS

Of the elective patients, 18 (2.5%) developed AKI. The 1-year mortality rate was 1.5% in elective patients without AKI and 11.1% in those with AKI (P = .038). Of the emergency patients, 24 (14.1%) developed AKI. The mortality rate was 16.4% and 37.5% in emergency patients without and with AKI, respectively (P = .024). In an AKI subgroup analysis of the combined elective and emergency patients, the mortality rate was 31.3% (n = 5) in the sCr group (n = 16), 23.5% (n = 4) in the UOP group (n = 17), and 22.2% (n = 2) in AKI patients who met both the sCr and UOP criteria (n = 9).

CONCLUSION

Emergency hip arthroplasty is associated with an increased risk of AKI. Since AKI increases mortality in both elective and emergency arthroplasty, perioperative oliguria should also be considered as a diagnostic criterion for AKI. Focusing solely on sCr may overlook many cases of AKI.

Does chronic kidney disease affect implant survival after primary hip and knee arthroplasty?

AIMS

To investigate whether chronic kidney disease (CKD) is associated with the risk of all-cause revision or revision due to a periprosthetic joint infection (PJI) after primary hip or knee arthroplasty.

METHODS

This retrospective cohort study comprised 18,979 consecutive hip and knee arthroplasties from a single high-volume academic hospital. At a median of 5.6 years (interquartile range (IQR) 3.5 to 8.1), all deaths and revisions were counted. To overcome the competing risk of death, competing risk analysis using the cumulative incidence function (CIF) was applied to analyze the association between different stages of CKD and revisions. Confounding factors such as diabetes and BMI were considered using either a stratified CIF or the Fine and Gray model.

RESULTS

There were 2,111 deaths (11.1%) and 677 revisions (3.6%) during the follow-up period. PJI was the reason for revision in 162 cases (0.9%). For hip arthroplasty, 3.5% of patients with CKD stage 1 (i.e. normal kidney function, NKF), 3.8% with CKD stage 2, 4.2% with CKD stage 3, and 0% with CKD stage 4 to 5 had undergone revision within eight years. For knee arthroplasty, 4.7% with NKF, 2.7% with CKD stage 2, 2.4% with CKD stage 3, and 7% of CKD stage 4 to 5 had had undergone revision. With the exception of knee arthroplasty patients in whom normal kidney function was associated with a greater probability of all-cause revision, there were no major differences in the rates of all-cause revisions or revisions due to PJIs between different CKD stages. The results remained unchanged when diabetes and BMI were considered.

CONCLUSION

We found no strong evidence that CKD was associated with an increased risk of all-cause or PJI-related revision. Selection bias probably explains the increased amount of all-cause revision operations in knee arthroplasty patients with normal kidney function. The effect of stage 4 to 5 CKD was difficult to evaluate because of the small number of patients. Cite this article: Bone Joint J 2021;103-B(4):689-695.

Risk Factors and Effect of Acute Kidney Injury on Outcomes Following Total Hip and Knee Arthroplasty

BACKGROUND

Development of acute kidney injury (AKI) following primary total joint arthroplasty (TJA) is a potentially avoidable complication associated with negative outcomes including discharge to facilities and mortality. Few studies have identified modifiable risk factors or strategies that the surgeon may use to reduce this risk.

METHODS

We identified all patients undergoing primary TJA at a single hospital from 2005 to 2017, and collected patient demographics, comorbidities, short-term outcomes, as well as perioperative laboratory results. We defined AKI as an increase in creatinine levels by 50% or 0.3 points. We compared demographics, comorbidities, and outcomes between patients who developed AKI and those who did not. Multivariate regressions identified the independent effect of AKI on outcomes. A stochastic gradient boosting model was constructed to predict AKI.

RESULTS

In total, 814 (3.9%) of 20,800 patients developed AKI. AKI independently increased length of stay by 0.26 days (95% confidence interval [CI] 0.14-0.38, P < .001), in-hospital complication risk (odds ratio = 1.73, 95% CI 1.45-2.07, P < .001), and discharge to facility risk (odds ratio = 1.26, 95% CI 1.05-1.53, P = .012). Forty-one predictive variables were included in the predictive model, with important potentially modifiable variables including body mass index, perioperative hemoglobin levels, surgery duration, and operative fluids administered. The final predictive model demonstrated excellent performance with a c-statistic of 0.967.

CONCLUSION

Our results confirm that AKI has adverse effects on outcome metrics including length of stay, discharge, and complications. Although many risk factors are nonmodifiable, maintaining adequate renal perfusion through optimizing preoperative hemoglobin, sufficient fluid resuscitation, and reducing blood loss, such as through the use of tranexamic acid, may aid in mitigating this risk.

Determining the risk of acute kidney injury in patients who underwent total joint replacement: A retrospective study

OBJECTIVES

Total joint replacement (TJR) is a commonly performed procedure worldwide, and postoperative acute kidney injury (AKI) is one of the complications that determine the overall prognosis in various surgical settings. We aimed to identify the risk of AKI after TJR (primary and revision) and determine the factors associated with postoperative AKI.

METHODS

We performed a retrospective study of 1068 patients (>18 years) who underwent TJR between 2014 and 2019 at a tertiary medical center. Patients' demographic, clinical, and laboratory data were reviewed.

RESULTS

A total of 1068 patients were included in this study [mean age, 60.5 ± 13 years; 260 men (24.3%); 808 women (75.7%)]. A total of 962 patients (90.1%) underwent primary joint replacement (PJR) and 106 underwent joint revision (9.9%). Sixty-six patients (6.2%) had postoperative AKI. Primary total hip replacement patients had a lower risk of AKI than patients with other types of TJR (3.0%; p = 0.024). The factors associated with AKI (adjusting for known confounders) included male gender [adjusted odds ratio (AOR): 1.751; 95% confidence interval (CI): 1.01-3.03; p = 0.046], diabetes mellitus (DM) [AOR: 2.806; 95% CI: 1.687-5.023; p ≤ 0.001], hypertension (HTN) [AOR: 1.751; 95% CI: 1.159-3.442; p = 0.013], and the use of vancomycin as a prophylactic antibiotic [AOR: 1.691; 95% CI: 1.1-2.913; p = 0.050]. Chronic kidney disease (CKD) [AOR: 1.00; 95% CI: 0.432-2.27; p = 0.981] was not found to be a significant risk factor.

CONCLUSION

In this study, the risk of preoperative AKI in patients who underwent TJR was 6.2%. Male gender, preoperative comorbidities such as DM and HTN, and preoperative use of vancomycin were associated with increased risk of postoperative AKI.

Risk Factors for the Development of Postoperative Acute Kidney Injury in Patients Undergoing Joint Replacement Surgery: A Meta-Analysis

A new-onset acute kidney injury (AKI) after arthroplasty impairs rehabilitation and outcome. A prior knowledge of risk factors contributes to a planned preventive management and prognostication. Although many studies have addressed the issue, our objective was to perform a meta-analysis to bring a consensus on the perioperative risk factors promoting AKI postoperatively. We conducted a systematic review and meta-analysis of observational studies reporting risk factors with odds of development of AKI according to the existing criteria after hip or knee replacement surgery. We searched the PubMed and Google Scholar databases for free English articles published until June 2018. Two authors independently screened the articles and extracted data. Discrepancies were resolved by consensus or consulting the third author. Methodological quality of the articles was assessed using the Newcastle-Ottawa Scale. A total of five studies were included in this meta-analysis. The following risk factors were found to contribute to new kidney injury: advanced age; male gender; preoperative liver, cardiac, or kidney diseases; presence of heart failure; American Society of Anesthesiologists grade ≥ 3; requirement of perioperative blood transfusion, revision arthroplasty, and knee arthroplasty; body mass index; and use of angiotensin-converting enzyme inhibitors. Diabetes, hypertension, duration of surgery, type of anesthesia, and preoperative serum creatinine were not found to be associated with renal injury. The key limitation was the availability of small number of studies. More longitudinal observational studies addressing the issue are the need of the hour, and, till then, a preventive strategy aimed at the identified risk factors should help.

Incidence and risk factors of acute kidney injury after total joint arthroplasty; a retrospective cohort study

BACKGROUND

Acute Kidney Injury (AKI) is a common complication post-arthroplasty, although it has not been extensively studied. We carried out a retrospective study to determine the incidence and risk factors of AKI in patients undergoing total joint arthroplasty (TJA).

METHOD

We reviewed the medical records of all patients who underwent elective TJA from December 2014 to January 2017 at the Salford Royal Hospital, UK. AKI was defined using the AKIN, RIFLE and KDIGO criteria in patients with worsened renal function post-arthroplasty. We analysed the association of the demographics, risk factors, medications and use of peri-operative IV fluids with AKI. A logistic regression was performed to find any correlation between these factors and incidence of AKI.

RESULTS

197 patients were included in our study, the mean age was 70.2 and male to female ratio was 6:5. Of these, 32(16.2%) developed an AKI. The multivariate logistic regression revealed 4 independent factors associated with the risk of AKI; age (P = 0.0011, OR 1.07, 95% CI 1.03-1.18), obesity (P = 0.003, OR 6.4, 95% CI 2.34-17.5), smoking (P = 0.0482, OR 3.76, 95% CI 1.01-14.0) and COPD (P = 0.0253, OR 3.85, 95% CI 1.18-12.5).

CONCLUSION

The incidence of AKI post-arthroplasty was found to be much higher than stated in other literatures. The recognition of the high incidence and multiple independent risk factors will allow a better approach to peri-operative management, limiting the risks of AKI. Our study also highlighted the importance of documenting urine output and the need to repeat the renal function test 3 months after an AKI to assess recovery.

Acute kidney injury following hip fracture

BACKGROUND

Hip fracture causes disability and excess mortality in the aging population. Acute kidney injury (AKI), is known to diminish survival of critically ill and trauma patients. AKI is also a common perioperative complication among surgical patients. We examined the effect of AKI on the survival of hip fracture patients in a Finnish hip fracture population and the risk factors for AKI in a prospective study.

METHODS

The study cohort constituted of 486 consecutive low-energy trauma hip fracture patients referred to Satakunta Central Hospital (Pori, Finland) and Turku University Hospital (Turku, Finland). The patients underwent standard diagnostics and treatment in the emergency department (ER) and were operated according to the local treatment protocol. Serum creatinine (sCr) was analyzed daily pre- and post-operatively during the hospital stay. Patients were divided into groups; AKI and non-AKI based on Kidney Disease: Improving Global Outcomes (KDIGO) criteria.

RESULTS

The incidence of AKI in the study cohort was 8.4% (40/475). Eleven patients were excluded due to missing sCr data. The baseline characteristics of AKI and non-AKI groups differed significantly concerning baseline sCr but were otherwise similar. At 90-day follow-up, the overall mortality was 14.4%. Patients with AKI had a significantly higher mortality (35.0%) than those with no AKI (12.7%) (p < 0.001). Dementia, preoperative sCr and any stage of AKI were independent predictors for mortality. Dementia and preoperative sCr were independently associated with post-operative AKI.

CONCLUSION

In this study AKI was a significant factor associated with a 3 -fold mortality during the first three months after surgery for low-energy trauma hip fracture.

[Treatment of rheumatic disease with renal insufficiency]

BACKGROUND

Reduced renal function is not rare in patients with inflammatory rheumatic diseases and is associated with an increased risk of treatment-induced and perioperative adverse events.

METHOD

A literature search was carried out for the medical treatment and perioperative management of rheumatic disease in the presence of renal insufficiency.

RESULTS

Patients with rheumatic disease and renal insufficiency have a higher risk of cardiovascular disease, bone loss and immunodeficiency than those without kidney disease. The perioperative rate of cardiovascular and infectious complications and the risk of acute kidney failure are elevated in these patients. The pharmacokinetics of many drugs used in rheumatology is influenced by the kidney function. Especially methotrexate is contraindicated in patients with an estimated glomerular filtration rate (eGFR) <45 ml/min. Nonsteroidal anti-inflammatory drugs (NSAIDS) and cyclooxygenase (COX)-2 inhibitors should not be used with renal insufficiency or only for a short term with the lowest effective dose. The treatment of osteoporosis with antiresorptive drugs may lead to adynamic bone disease in advanced kidney disease, and, therefore, the use of these drugs is controversial.

CONCLUSION

Medication should be modified in patients with rheumatic disease and kidney involvement according the grade of renal insufficiency. There is also a need for special perioperative management in these patients, with interdisciplinary cooperation of rheumatologists, nephrologists and orthopedic doctors.

Chronic kidney disease and acute kidney injury in arthroplasty patients over 65 years of age

BACKGROUND

The purpose of this study was to evaluate the prevalence of chronic kidney disease (CKD) and the incidence of perioperative acute kidney injury (AKI) in primary arthroplasty patients over 65 years of age. Risk factors, perioperative events and the outcome of surgery were evaluated.

METHODS

This retrospective, hospital register-based study consists of patients operated in 2014 in the area of Oulu, Finland. The estimated glomerular filtration rate (eGFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration formula. The incidence of AKI was evaluated based on the serum creatinine criteria of the KDIGO (Kidney Disease, Improving Global Outcomes) classification.

RESULTS

Of the 807 patients, 60.8% had mildly decreased (60-89 ml/min/1.73 m² ) and 13.5% moderately to severely decreased eGFR (<60 ml/min/1.73 m² ) preoperatively. Only 33.9% of patients with an eGFR < 60 ml/min/1.73 m² had a diagnosis of a kidney disease. In emergencies, 46.9% of patients with an eGFR < 60 ml/min/1.73 m² were deceased at the 12-month follow-up point. The measurement of postoperative sCr was not complete (477/807) and was allocated to emergencies and older patient with more comorbidities. Of those whose postoperative sCr was available, 14 (2.9%) fulfilled AKI criteria. Most of the AKI cases had a decrease in eGFR preoperatively, a diagnosed kidney disease or diabetes mellitus.

CONCLUSIONS

Impairment of kidney function was common and was related to mortality in emergency arthroplasties. Measurements of postoperative sCr were allocated to high risk patients. Preoperative kidney function, kidney disease and diabetes mellitus were important determinants for perioperative AKI.

Acute Kidney Injury in Subjects With Chronic Kidney Disease Undergoing Total Joint Arthroplasty

BACKGROUND

Chronic kidney disease (CKD) has been associated with higher incidence of complications after total joint arthroplasty (TJA) but the incidence, risk factors and outcomes of acute kidney injury (AKI) in this setting remains insufficiently understood.

METHODS

We assessed the impact of baseline CKD on the risk of developing AKI after TJA performed between 1/2012 and 12/2016 in a single-center, retrospective cohort study. CKD was defined by estimated glomerular filtration rate <60 mL/min/1.73 m² on 2 separate occasions within 3 months prior TJA. AKI was defined using a modified Kidney Disease: Improving Global Outcomes criteria based on serum creatinine (sCr) only to assess the severity of AKI. Complete AKI recovery was defined as the lowest post-AKI sCr within 20% of pre-AKI sCr values and partial recovery if within 30%, all within 90 days after TJA.

RESULTS

Twenty-four percent of the 1,212 subjects undergoing TJA had pre-existing CKD. The overall incidence of AKI in the CKD subjects was 30%; of these, 55% had stage-1 AKI, 1% had stage-2 AKI and 44% had stage-3 AKI. AKI was more common in African Americans, those with diabetes or heart failure, requiring perioperative transfusions or receiving diuretics before surgery. While 82% of the AKI subjects achieved complete recovery of kidney function, 4% had only partial recovery and 14% did not reach a post-AKI sCr level within 30% of pre-AKI values. The incidence (P < 0.001) but not the severity (P = 0.202) of AKI correlated with stages of baseline CKD.

CONCLUSIONS

The presence of CKD was associated with a high incidence of AKI after TJA. In these subjects, more than half the cases of AKI were of mild degree and had a favorable outcome. However, 18% of them did not have complete recovery of kidney function. Stages of baseline CKD were associated with increased incidence but not severity of AKI after TJA.

Routine Postoperative Laboratory Tests Are Not Necessary After Primary Total Hip Arthroplasty

BACKGROUND

Postoperative laboratory testing has been used routinely for patients undergoing total hip arthroplasty (THA). However, with modern-day improvements in perioperative care pathways, it is unclear whether this practice remains justified. The purpose of this study was to assess the utility of routine postoperative laboratory tests in primary THA.

METHODS

The electronic medical records of 351 patients who underwent primary, unilateral THA between 2015 and 2017 were retrospectively reviewed. The primary outcomes were the rates of acute blood loss anemia requiring transfusion, acute kidney injury (AKI), electrolyte abnormalities, and 90-day emergency department visits or readmissions. Multivariate logistic regression analysis was also performed to identify the risk factors associated with abnormal laboratory values.

RESULTS

Seventy-four patients (21%) had abnormal postoperative laboratory results, of which 82.4% were exclusively due to electrolyte (sodium or potassium) abnormalities. Factors associated with electrolyte abnormalities were abnormal baseline electrolyte levels (P < .001 and P = .013 for sodium and potassium, respectively), diabetes (P = .007), and lack of tranexamic acid use (P < .01). The rates of AKI and blood transfusion were 2.0% and 2.3%, respectively. Factors associated with blood transfusion were higher American Society of Anesthesiologists class and intraoperative blood loss ≥250 mL combined with either preoperative anemia or lack of tranexamic acid use. Factors associated with AKI were higher American Society of Anesthesiologists class and diabetes. Laboratory results did not change the standard course of care in 338 of 351 patients (96%). Abnormal laboratory values were not associated with increased length of stay (P = .228) or emergency department visits/readmissions (P = .21).

CONCLUSION

This study provides evidence that routine postoperative laboratory testing is not necessary in modern-day primary, unilateral THA. Instead, the decision to obtain laboratory tests after surgery should be driven by patients' risk factors.

Acute Kidney Injury in Patients Undergoing Total Hip Arthroplasty: A Systematic Review and Meta-Analysis

Background: The number of total hip arthroplasties (THA) performed across the world is growing rapidly. We performed this meta-analysis to evaluate the incidence of acute kidney injury (AKI) in patients undergoing THA. Methods: A literature search was performed using MEDLINE, EMBASE and Cochrane Database from inception until July 2018 to identify studies assessing the incidence of AKI (using standard AKI definitions of RIFLE, AKIN, and KDIGO classifications) in patients undergoing THA. We applied a random-effects model to estimate the incidence of AKI. The protocol for this meta-analysis is registered with PROSPERO (no. CRD42018101928). Results: Seventeen cohort studies with a total of 24,158 patients undergoing THA were enrolled. Overall, the pooled estimated incidence rates of AKI and severe AKI requiring dialysis following THA were 6.3% (95% CI: 3.8%–10.2%) and 0.5% (95% CI: 0.1%–2.3%). Subgroup analysis based on the countries by continent was performed and demonstrated the pooled estimated incidence of AKI following THA of 9.2% (95% CI: 5.6%–14.8%) in Asia, 8.1% (95% CI: 4.9%–13.2%) in Australia, 7.4% (95% CI: 3.2%–16.3%) in Europe, and 2.8% (95% CI: 1.2%–17.0%) in North America. Meta-regression of all included studies showed significant negative correlation between incidence of AKI following THA and study year (slope = −0.37, p <0.001). There was no publication bias as assessed by the funnel plot and Egger’s regression asymmetry test with p = 0.13 for the incidence of AKI in patients undergoing THA. Conclusion: The overall estimated incidence rates of AKI and severe AKI requiring dialysis in patients undergoing THA are 6.3% and 0.5%, respectively. There has been potential improvement in AKI incidence for patients undergoing THA over time.

Female sex reduces the risk of hospital-associated acute kidney injury: a meta-analysis

Background

Female sex has been included as a risk factor in models developed to predict the development of AKI. In addition, the commentary to the Kidney Disease Improving Global Outcomes Clinical Practice Guideline for AKI concludes that female sex is a risk factor for hospital-acquired AKI. In contrast, a protective effect of female sex has been demonstrated in animal models of ischemic AKI.

Methods

To further explore this issue, we performed a meta-analysis of AKI studies published between January, 1978 and April, 2018 and identified 83 studies reporting sex-stratified data on the incidence of hospital-associated AKI among nearly 240,000,000 patients.

Results

Twenty-eight studies (6,758,124 patients) utilized multivariate analysis to assess risk factors for hospital-associated AKI and provided sex-stratified ORs. Meta-analysis of this cohort showed that the risk of developing hospital-associated AKI was significantly greater in men than in women (OR 1.23 (1.11,1.36). Since AKI is not a single disease but instead represents a heterogeneous group of disorders characterized by an acute reduction in renal function, we performed subgroup meta-analyses. The association of male sex with AKI was strongest among studies of patients who underwent non-cardiac surgery. Male sex was also associated with AKI in studies which included unselected hospitalized patients and in studies of critically ill patients who received care in an intensive care unit. In contrast, cardiac surgery-associated AKI and radiocontrast-induced AKI showed no sexual dimorphism.

Conclusions

Our meta-analysis contradicts the established belief that female sex confers a greater risk of AKI and instead suggests a protective role.

Acute Kidney Injury Following Failed Total Hip and Knee Arthroplasty

BACKGROUND

Acute kidney injury (AKI) can complicate primary total joint arthroplasty (TJA) of the hip and knee, although the incidence of AKI following revision TJA including prosthetic joint infection (PJI) is poorly defined. We assessed the incidence and risk factors for AKI following revision TJA including surgical treatment of PJI with placement of an antibiotic-loaded cement (ALC) spacer.

METHODS

We retrospectively reviewed 3218 consecutive failed TJAs. Patients with aseptic failure were compared to those with PJI. AKI was determined by RIFLE creatinine criteria. PJIs treated with placement of ALC were compared to PJIs without. Risk factors for AKI were determined by multivariable analysis within the whole group and within those with PJI.

RESULTS

AKI developed in 3.4% of 2147 patients revised for aseptic reasons and in 45% of 281 with PJI, including 29% of 197 receiving an ALC and 82% of 84 patients treated with other procedures. By multivariable analysis, age, surgery for PJI, total number of surgeries, and estimated GFR 60-90 compared to >90 cc/min/1.73 m² were significantly associated with AKI in the whole cohort. Among PJI patients, age, Charlson comorbidity index, and reimplantation surgery were associated with AKI by multivariable analysis. No differences were found between patients with PJI treated with or without ALC. No modifiable factors were found.

CONCLUSION

AKI develops following aseptic revision TJA at a rate similar to primary TJA, but at a significantly higher rate following surgery for PJI with or without placement of ALC.

Novel renal markers for the assessment of renal integrity in patients undergoing knee arthroplasty - a pilot study

Background

The feasibility of novel kidney injury biomarkers in consecutive patients having total knee arthroplasty with local infiltration analgesia was evaluated.

Methods

We enrolled 30 patients scheduled for elective unilateral total knee arthroplasty. Paired plasma and urine samples were taken before surgery and at 4 h, 24 h and 48 h after surgery to measure creatinine, cystatin C, neutrophil gelatinase associated lipocalin, kidney injury molecule-1, interleukin-18 and liver-type fatty acid-binding protein.

Results

At baseline, 13 subjects had normal kidney function, 15 had mild and two had moderate kidney failure evaluated by calculated glomerular filtration rate. None of the subjects had all measured novel renal markers below proposed cut-off concentrations. Altogether 28/30 subjects had one (n = 3), two (n = 7) or three (n = 18) plasma neutrophil gelatinase associated lipocalin values above normal. In seven of these 28 subjects plasma creatinine, calculated glomerular filtration rate and plasma cystatin C were within the reference values. Five subjects had a low urine output, < 0.5 mL/h, indicating transient acute kidney injury, four of these had high plasma neutrophil gelatinase associated lipocalin and one high plasma cystatin C.

Conclusions

In the present study plasma neutrophil gelatinase associated lipocalin was elevated in most subjects with total knee arthroplasty and local infiltration analgesia as a marker of possible renal proximal tubular injury. Five subjects had transient low urine output, but none developed renal deterioration requiring treatment.

Staggered Rather Than Staged or Simultaneous Surgical Strategy May Reduce the Risk of Acute Kidney Injury in Patients Undergoing Bilateral TKA

BACKGROUND

The strategy for bilateral total knee arthroplasty (TKA) depends on the timing of surgery for each knee. The purpose of this study was to determine whether the type of surgical strategy for bilateral TKA (staggered, staged, or simultaneous) influences the incidence of acute kidney injury (AKI) and related complications.

METHODS

Enrolled patients from a single tertiary teaching hospital were divided into 3 groups according to the surgical strategy for bilateral TKA: staggered (≤7 days between the first and second procedure; n = 368), staged (8 days to 1 year between the first and second procedure; n = 265), or simultaneous (n = 820). The incidence of AKI as defined by the Kidney Disease Improving Global Outcomes (KDIGO) criteria was assessed. The rates of major postoperative complications, major adverse cardiovascular and cerebral events, intensive care unit (ICU) admissions, and mortality were also evaluated. To reduce the influence of possible confounding factors, inverse probability of treatment weighting based on propensity-score analysis was used.

RESULTS

The primary outcome was the incidence of AKI according to surgical strategy. The staggered group had a lower rate of AKI compared with the other 2 groups (p < 0.001): 2.4% (9 of 368 patients), 6.0% (16 of 265), and 11.2% (92 of 820) in the staggered, staged, and simultaneous groups, respectively.

CONCLUSIONS

The type of bilateral TKA strategy was an independent risk factor for the development of AKI. The assessment of additional risk factors for the development of AKI is essential before deciding on surgical strategy.

LEVEL OF EVIDENCE

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

The Incidence and Risk Factors of Acute Kidney Disease after Total Knee Arthroplasty with Early Postoperative Volume Supplement

Background

Etiology of acute kidney disease (AKD) after total knee arthroplasty (TKA) was considered as multifactorial. However, the role of early postoperative volume supplement in AKD rate has not been investigated. The purpose of this study was to evaluate the incidence and risk factors of AKD in patients with early volume supplement following TKA.

Methods

This was a retrospective study with 458 patients who underwent unilateral TKA. All the patients received 6% tetrastarch, 7.5ml/kg, early in the postoperative period. Postoperative AKD was defined as the postoperative creatinine level ≥ 1.5 times compared with preoperative data. Potential variables associated with AKD were analyzed by multivariate logistic regression model to identify the AKD risk factors in TKA patients after early postoperative volume supplement.

Results

The AKD rate was 3.3% (15 patients) in all patients. Age (OR = 1.09; P = .031) and coronary artery disease (CAD) (OR = 3.63; P = .034) were associated with increased risk of development of postoperative AKD. Other comorbidities as hypertension, diabetes, and CKD were not statistically significant risk factors.

Conclusion

Our study demonstrated that age and CAD were independent risk factors of AKD in TKA patients. However, the common risk factors as hypertension, diabetes, and CKD were not significantly associated with AKD after TKA if early postoperative supplement of tetrastarch is administered.

Cost and determinants of acute kidney injury after elective primary total joint arthroplasty

Background

Acute kidney injury (AKI) is a serious complication after major surgery, which may lead to increased morbidity and mortality. The aim of this study was to identify cost and determinants of AKI after total joint arthroplasty.

Methods

A retrospective case-controlled study was conducted with 1719 primary elective total hip or knee replacements performed from January 2004 through September 2015 at an urban teaching hospital. Patients who developed AKI were matched in a 1:3 ratio with those in a control group who did not develop AKI based on age, sex, race, operated joint, and comorbidities including hypertension and diabetes. Increased postoperative serum creatinine was considered indicative of AKI.

Results

Fifty-four patients (3.1%) had AKI that was significantly associated with increased length of hospital stay (8.07 days) compared with that of the control group (4.50 days, P < .0001) and incurred significantly higher hospital charges ($224,533) than those of the control group ($142,753, P < .0001). We identified high body mass index, undergoing bilateral surgery in one session, high estimated blood loss, and longer duration of surgery as significant risk factors for AKI in univariate analysis. Elevated preoperative creatinine, large postoperative drop in hemoglobin, and high American Society of Anesthesiologists physical status scores were significant independent predictors of AKI in multivariate analysis.

Conclusions

Health-care providers and patients should work together to manage risk factors and to lower the risk of morbidity and mortality, longer in-hospital stay, and high associated costs of AKI.

Reducing Hypotension and Acute Kidney Injury in the Elective Total Joint Arthroplasty Population: A Multi-Disciplinary Approach

BACKGROUND

When critically analyzing our hospital system's rate of hypotension and acute kidney injury (AKI) after total joint arthroplasty, our incidence rates (14.54%, 6.02%) were much higher than our peers (7.17%, 2.03%) and national rates (2.0%, 3.3%). We present a multi-disciplinary management intervention that aimed to decrease overall complication rates.

METHOD

A multi-disciplinary team implemented a protocol at our suburban hospital to limit complication rates after joint replacement surgery. Hypotension, AKI, length of stay (LOS), re-admission rates, and mortality rates were compared before the protocol was implemented, after protocol implementation, and after protocol integration into our EMR (electronic medical record).

RESULTS

In total, 1233 patients over 36 months were followed. Hypotension rates after protocol implementation into EMR (group 3) were significantly lower than rates before the protocol (group 1) (P = .002), with rates after protocol implementation without EMR (group 2) trending toward a significant decrease from group 1 (P = .064). AKI rates in group 3 were significantly lower than group 1 (P = .000) and group 2 (P = .006). No difference was seen in hypotension rates between group 2 and 3 (P = .792) or AKI rates between group 1 and 2 (P = .533). Finally, no significant difference was seen between groups in LOS (P = .560), re-admission rates (P = .378), and mortality rates (all 0.0%).

CONCLUSION

By implementing a comprehensive electronic protocol consisting of pre-operative risk stratification, multi-disciplinary medical optimization, and an evolving post-operative management plan, significant decreases in hypotension and AKI can be seen.

Chronic Kidney Diseases Among Patients Undergoing Elective Arthroplasty: Risk Groups and the Value of Serum Creatinine

BACKGROUND

In arthroplasty clinics, we tend to evaluate patient's kidney function looking at serum creatinine (SCr), while estimated glomerular filtration rate (eGFR) is recommended. We reported the prevalence of chronic kidney disease (CKD; eGFR <60 mL/min/1.73 m²) in different patient groups and investigated whether CKD is missed by evaluation based on SCr.

METHODS

Preoperative SCr values were used to calculate eGFR in 20,575 consecutive hip or knee arthroplasties.

RESULTS

Prevalence of CKD was 9%-12%. It was higher among older women, knee arthroplasty patients, and patients with hypertension, diabetes, or coronary disease. Using SCr instead of eGFR leads to missing CKD in up to 7% of the cases. In older women and older patients with body mass index <25 kg/m², half of CKD cases were missed.

CONCLUSION

Use of eGFR instead of SCr to detect CKD more accurately is recommended.