Incidence of acute kidney injury following total joint arthroplasty: a retrospective review by RIFLE criteria

Acute Kidney Injury After Total Hip and Knee Arthroplasty. What Is the Culprit?

Background

Acute kidney injury (AKI) is associated with increased complications after total hip arthroplasty (THA) and total knee arthroplasty (TKA). The purpose of this study was to determine the risk factors for AKI after THA and TKA and evaluate if preoperative use of antihypertensive drugs is a risk factor for AKI.

Methods

A retrospective review of 7406 primary TKAs and THAs (4532 hips and 2874 knees) from 2013 to 2019 was performed. The following preoperative variables were obtained from medical records: medications, chemistry 7 panel, Elixhauser comorbidities, and demographic factors. AKI was defined as an increase in serum creatinine by 26.4 μmol·L-1. Multivariate analysis was performed to identify the risk factors.

Results

The overall incidence of postoperative AKI was 6.2% (n = 459). Risk factors for postoperative AKI were found to be: chronic kidney disease (odds ratio [OR] = 7.09; 95% confidence interval [CI]: 4.8-9.4), diabetes (OR: 5.03; 95% CI: 2.8-6.06), ≥3 antihypertensive drugs (OR: 4.2; 95% CI: 2.1-6.2), preoperative use of an angiotensin receptor blockers or angiotensin-converting enzyme inhibitors (OR: 3.8; 95% CI: 2.2-5.9), perioperative vancomycin (OR: 2.7; 95% CI: 1.8-4.6), and body mass index >40 kg/m2 (OR: 1.9; 95% CI: 1.3-3.06).

Conclusions

We have identified several modifiable risk factors for AKI that can be optimized prior to an elective THA or TKA. The use of certain antihypertensive agents namely angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and multidrug antihypertensive regimens were found to significantly increase the risk of AKI. Therefore, perioperative management of patients undergoing joint replacement should include medical comanagement with a focus on careful management of antihypertensives.

Total hip arthroplasty complications in patients with chronic kidney disease: A comparison study

Background

It has been noted in the literature that there are increased complication rates following total hip arthroplasty (THA) in patients with chronic kidney disease (CKD) or end stage renal disease (ESRD). However, there is little data directly comparing outcomes in patients undergoing THA for osteoarthritis (OA) versus ESRD or CKD with OA. The objective of this study is to illustrate the risk of developing postoperative complications after THA in the CKD and ESRD populations by stage of disease when compared to a control group (OA) and thus better equip orthopaedic providers in the care of these patients.

Methods

The National Inpatient Sample (NIS) was utilized to identify patients undergoing elective THA from 2006 to 2015 with OA, ESRD, and CKD. The prevalence of preoperative comorbidities and the incidence of numerous postoperative complications broken into categories were examined.

Results

Between 2006 and 2015 the NIS database reported 4,350,961 patients diagnosed with OA, 8355 diagnosed with ESRD, and 104,313 diagnosed with CKD undergoing THA. The incidence of wound hematoma (2.5% vs. 0.8%; p < .0001), wound infection (0.7% vs. 0.4%; p = .0319), cardiac (1.3% vs. 0.6%; p = .0067), urinary (3.9% vs. 2.0%; p < .0001), and pulmonary complications (2.2% vs. 0.5%; p < .0001) occurred more frequently in patients with OA and ESRD when compared to only OA patients. For patients with OA and CKD, stages 3-5 saw at least half of the complication categories occur at significantly higher rates than OA patients.

Conclusion

This study shows that patients with ESRD and CKD have increased rates of complications after THA. This study's specific breakdown by stage and complication can benefit orthopaedic surgeons and practitioners in realistic pre and postoperative planning and provides data that could benefit decision making on bundled reimbursement for this specific patient population, as providers could better account for the postoperative complications noted above and their associated costs.

Comparing five equations to calculate estimated glomerular filtration rate to predict acute kidney injury following total joint arthroplasty

BACKGROUND

Acute kidney injury (AKI) following total joint arthroplasty (TJA) is associated with increased morbidity and mortality. Estimated glomerular filtration rate (eGFR) is used as an indicator of renal function. The purpose of this study was (1) to assess each of the five equations that are used in calculating eGFR, and (2) to evaluate which equation may best predict AKI in patients following TJA.

METHODS

The National Surgical Quality Improvement Program (NSQIP) was queried for all 497,261 cases of TJA performed from 2012 to 2019 with complete data. The Modification of Diet in Renal Disease (MDRD) II, re-expressed MDRD II, Cockcroft-Gault, Mayo quadratic, and Chronic Kidney Disease Epidemiology Collaboration equations were used to calculate preoperative eGFR. Two cohorts were created based on the development of postoperative AKI and were compared based on demographic and preoperative factors. Multivariate regression analysis was used to assess for independent associations between preoperative eGFR and postoperative renal failure for each equation. The Akaike information criterion (AIC) was used to evaluate predictive ability of the five equations.

RESULTS

Seven hundred seventy-seven (0.16%) patients experienced AKI after TJA. The Cockcroft-Gault equation yielded the highest mean eGFR (98.6 ± 32.7), while the Re-expressed MDRD II equation yielded the lowest mean eGFR (75.1 ± 28.8). Multivariate regression analysis demonstrated that a decrease in preoperative eGFR was independently associated with an increased risk of developing postoperative AKI in all five equations. The AIC was the lowest in the Mayo equation.

CONCLUSIONS

Preoperative decrease in eGFR was independently associated with increased risk of postoperative AKI in all five equations. The Mayo equation was most predictive of the development of postoperative AKI following TJA. The mayo equation best identified patients with the highest risk of postoperative AKI, which may help providers make decisions on perioperative management in these patients.

Post-operative complications of total knee arthroplasty in patients with hypertension

BACKGROUND

Hypertension is one of the most common comorbidities among patients undergoing surgery. However, few studies have focused on patients undergoing knee arthroplasty, and most of them had small sample sizes. This study aimed to analyze post-operative complications associated with hypertension in patients who underwent knee replacement surgery.

METHODS

Data from the 2019 National Inpatient Sample (NIS) database were used. Patients who underwent primary total knee arthroplasty (pTKA) and those who underwent aseptic revision total knee arthroplasty (rTKA) were analyzed separately. Propensity score matching was performed to reduce the effects of demographic factors and comorbidities other than hypertension on post-operative complications. A multinomial logistic regression that included all significantly different demographics and comorbidities was performed to verify the results and evaluate the odds ratios.

RESULTS

A total of 107,981 patients who underwent pTKA and 6571 who underwent rTKA owing to mechanical complications were identified in the 2019 NIS database. Compared with the non-hypertension group, patients with hypertension had a higher risk of developing acute renal failure and electrolyte disorders after TKA. Further analysis revealed that hyponatraemia and hypokalaemia were associated with hypertension.

CONCLUSIONS

Hypertension was associated with the incidence of acute renal failure after TKA. It is important to identify patients with risk factors for acute renal failure (in addition to hypertension) and take careful measures to prevent acute renal failure in them.

Association of N-terminal pro-B-type natriuretic peptide (NT-proBNP) and acute kidney disease in patients undergoing coronary angiography: a cohort study

BACKGROUND

Acute kidney disease (AKD) following coronary angiography (CAG) indicates a higher risk of chronic kidney disease and follow-up cardiovascular comorbidities. However, the predictive risk factor of AKD is not clear. We sought to verify whether preoperative N-terminal pro-B-type natriuretic peptide (NT-proBNP) level was associated with AKD in patients undergoing CAG.

METHOD

We analyzed 7602 patients underwent CAG in this multi-center registry cohort study. Cardiorenal ImprovemeNt II (CIN-II) in five Chinese tertiary hospitals from 2007 to 2020. The primary outcome was AKD, defined as a ≥ 50% increase of serum creatinine within 7-90 days. Multivariable logistic regressions were used to assess the association between NT-proBNP and AKD.

RESULT

1009 patients (13.27%) eventually developed AKD, who were more likely to be female, older, and with comorbidities of chronic heart failure and anemia. After adjusting to the potential confounders, the NT-proBNP level remained an independent predictor of AKD (lnNT-proBNP OR: 1.20, 95% CI 1.13-1.28, p < 0.005). Restricted cubic spline analysis demonstrated a linear relationship between elevated NT-proBNP and AKD (p for trend < 0.001). In the subgroup analysis, elevated NT-proBNP level in patients with percutaneous coronary intervention (p for interaction < 0.001) or without previous congestive heart failure (p for interaction = 0.0346) has a more significant value of AKD prediction.

CONCLUSION

Pre-operative NT-proBNP level was independently associated with the risk of AKD in patients following CAG. Perioperative strategies are warranted to prevent AKD in patients with elevated NT-proBNP levels.

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.

Postoperative Acute Kidney Injury With Dual NSAID Use After Outpatient Primary Total Joint Arthroplasty

BACKGROUND

NSAIDs have been shown to be highly effective analgesic agents in the postoperative period. NSAIDs do have several potential adverse effects, including kidney injury (AKI). Little is known about AKI in the outpatient total joint arthroplasty (TJA) setting, where patient labs are not closely monitored. The objective of this study was to evaluate the renal safety of combined use of ibuprofen for pain control and aspirin for deep vein thrombosis chemoprophylaxis after outpatient primary TJA.

METHODS

Patients undergoing primary total hip or total knee arthroplasty between January 2020 and July 2020 at a single center were included for analysis. All included patients were discharged on a standard regimen including aspirin 81 mg twice a day and ibuprofen 600 mg three times a day. Patients were ordered a serum creatinine test at 2 and 4 weeks postoperatively. Patients with postoperative acute kidney injury were identified per Acute Kidney Injury Network criteria.

RESULTS

Between January 23, 2020, and August 30, 2020, 113 patients were included in this study, of whom creatinine levels were measured in 103 patients (90.3%) at the 2-week postoperative time point, 58 patients (50.9%) at the 4-week time point, and 48 (42.1%) at combined 2- and 4-week time points. Three patients (2.9%) were found to have an AKI.

CONCLUSION

This study found a rate of AKI of 2.9% with the use of dual NSAID therapy postoperatively after primary TJA. All cases occurred at 2 weeks postoperatively and saw spontaneous resolution.

OUP accepted manuscript

The year 2021 was the last full year of Alberto Ortiz’s editorship at Clinical Kidney Journal (CKJ). On May 2022, Maria José Soler will start her term as the Editor-in-Chief. Over these years, CKJ obtained its first journal impact factor and has consolidated its position among the top journals in the field, consistently ranking among the top 25% (first quartile) journals in Urology and Nephrology. The 2020 journal impact factor rose to 4.45, becoming the top open access journal in Nephrology and the ninth ranked Nephrology journal overall. We now review the recent history of the journal and the most highly cited topics which include the epidemiology of kidney disease, chronic kidney disease topics, such as the assessment and treatment of chronic kidney disease, onconephrology, cardionephrology, glomerular disease, transplantation and coronavirus disease 2019 (COVID-19).

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.

Obesity, Angiotensin-Blocking Drugs, and Acute Kidney Injury in Orthopedic Surgery

Postoperative acute kidney injury occurs in 7% to 11% of orthopedic surgeries. The effect of preoperative angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) on the development of postoperative acute kidney injury remains controversial. Adipose tissue has its own independently regulated angiotensin system. The primary aim of this study was to examine the effects of obesity and preoperative ACEIs and ARBs on postoperative acute kidney injury. Charts were reviewed of adult elective orthopedic surgery patients during a 2-year period when patients were instructed to take their ACEI or ARB on the morning of surgery. The patients were divided into an obese cohort (body mass index [BMI] ≥30 kg/m²) and a nonobese cohort (BMI <30 kg/m²). A multivariable model was created for the outcome of acute kidney injury, using obesity as a primary predictor and adjusting for demographics, medications, comorbidities, and intraoperative parameters in a logistic regression analysis. Obesity increased the likelihood of developing acute kidney injury after orthopedic surgery (odds ratio [OR], 1.86; 95% CI, 1.07-3.22; P=.028). For every 5-unit increase in BMI, the odds of acute kidney injury were 1.43 (95% CI, 1.26-1.62; P<.001). When receiving ACEIs or ARBs, only the nonobese patients had a statistically increased likelihood of postoperative acute kidney injury (OR, 3.30; 95% CI, 1.12-9.70; P=.030). Obesity is an independent risk factor for postoperative acute kidney injury. Obesity appears to influence the effect that preoperative ACEIs and ARBs have on postoperative acute kidney injury. [Orthopedics. 2021;44(2):e253-e258.].

Acute kidney injury in patients undergoing elective primary lower limb arthroplasty

Purpose

Recent research has outlined the increasing incidence of acute kidney injury (AKI) and its effect on morbidity/mortality. There is evidence that current rates are significantly under-reported nationally, with uncertainty about pre-operative factors that might influence AKI reduction and the impact on other healthcare outcomes such as mortality and later Chronic Kidney Disease (CKD) development. We set out to help address these current deficiencies in the literature.

Methods

A retrospective cohort study was undertaken using data collected from patients undergoing elective primary lower limb arthroplasty within our institution from 01/10/16–31/09/17 with a 2-year follow-up.

Results

53/782 (6.8%) patients had an AKI during the study time period. This was associated with a longer inpatient stay (p < 0.001). There was no significant difference in 30-day mortality (p = 0.134), 30-day readmission (p = 1.00) or later CKD development (p = 0.63). Independent predictors of AKI were as follows: Diabetes (OR 2.49; 95%CI 1.15–5.38; p = 0.021), CKD (OR 4.59; 95%CI 2.37–8.92; p < 0.001) and Male sex (OR 2.61; 95%CI 1.42–4.78; p = 0.002).

Conclusions

AKI in those undergoing hip and knee arthroplasty remains under-reported at a national level. AKI development was associated with an increased length of stay, but not long-term healthcare outcomes. This may be due to the mechanism of AKI development or the low absolute numbers of AKI suffered. We have identified three pre-operative factors (Diabetes, CKD & Male Sex) that were independently predictive of AKI. Targeted interventions may reduce the risk of AKI after lower limb arthroplasty.

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.

Acute kidney injury risk in orthopaedic trauma patients pre and post surgery using a biomarker algorithm and clinical risk score

Acute kidney injury (AKI) after major trauma is associated with increased mortality. The aim of this study was to assess if measurement of blood biomarkers in combination with clinical characteristics could be used to develop a tool to assist clinicians in identifying which orthopaedic trauma patients are at risk of AKI. This is a prospective study of 237 orthopaedic trauma patients who were consecutively scheduled for open reduction and internal fixation of their fracture between May 2012 and August 2013. Clinical characteristics were recorded, and 28 biomarkers were analysed in patient blood samples. Post operatively a combination of H-FABP, sTNFR1 and MK had the highest predictive ability to identify patients at risk of developing AKI (AUROC 0.885). Three clinical characteristics; age, dementia and hypertension were identified in the orthopaedic trauma patients as potential risks for the development of AKI. Combining biomarker data with clinical characteristics allowed us to develop a proactive AKI clinical tool, which grouped patients into four risk categories that were associated with a clinical management regime that impacted patient care, management, length of hospital stay, and efficient use of hospital resources.

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.

Acute Deterioration of Kidney Function after Total Hip Arthroplasty

Introduction:

Post-operative acute kidney injury is a serious complication and identifying modifiable factors could assist in peri-operative management. This study aimed to identify the pre-operative and intra-operative factors associated with the incidence of post-operative acute kidney injury and acute deterioration of kidney function after total hip arthroplasty.

Materials and methods: This single-center, retrospective, observational study included 203 patients who underwent unilateral primary total hip arthroplasty. Acute kidney injury was determined using biochemical markers according to the risk, injury, failure, loss of kidney function, and end-stage kidney disease (RIFLE) criteria. Acute deterioration of kidney function was defined as the reduction of estimated glomerular filtration rate by ≥10ml/min/1.73m².

Results:

Prior to total hip arthroplasty, 20% of all patients met the chronic renal dysfunction criterion of glomerular filtration rates <60ml/min/1.73m² (glomerular filtration rate categories G3a-G5). Incidence rates of acute kidney injury and acute deterioration of kidney function after total hip arthroplasty were 0.49% and 6.9%, respectively. Multivariate regression analysis showed that diabetes mellitus and use of nonsteroidal anti-inflammatory drugs before total hip arthroplasty were significant risk factors for acute deterioration of kidney function. Advanced age, preoperative renal dysfunction, antihypertensive, diuretics, or statin use, operation time, total blood loss, type of anesthetic, and body mass index were not significant risk factors.

Conclusion:

Diabetes mellitus and use of nonsteroidal anti-inflammatory drugs were controllable risks, and multidisciplinary approaches are a reasonable means of minimising peri-operative acute kidney injury or acute deterioration of kidney function.

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.

Strategies to Reduce Perioperative Nephrotoxicity

Postoperative acute kidney injury (AKI) is a common complication of surgery that is associated with significant adverse outcomes, including increased morbidity and mortality. The perioperative burden of AKI risk factors is complex and potentially large, including high-risk nephrotoxic medications, hypotension, hypovolemia, radiologic contrast, anemia, and surgery-specific factors. Understanding the pathogenesis, risk factors, and potential cumulative impact of perioperative nephrotoxic exposures is particularly important in the prevention and reduction of perioperative AKI. This review outlines the possible strategies to reduce perioperative nephrotoxicity and the development of postoperative AKI.

Occurrence and predictive factors of acute renal injury following hip and knee arthroplasty

BACKGROUND

To analyze the incidence of early acute kidney injury (AKI) and perioperative factors following hip and knee joint replacement.

METHODS

A total of 6281 patients from the department of orthopedics from January 2016 to July 2018 were enrolled, and 1490 patients undergoing hip and knee arthroplasty met the inclusion criteria. The preoperative, intraoperative and postoperative parameters were recorded. The retrospective cohort study was carried out to analyze predictors for AKI and postoperative creatinine elevation following hip and knee joint replacement.

RESULTS

Eighty patients (5.4%) met AKI criteria. Age, American Society of Anesthesiologists (ASA) physical status and preoperative diabetes were identified as independent predictors for postoperative AKI in patients undergoing hip and knee arthroplasty (p < 0.05). Age, male, preoperative diabetes, hypertension, and preoperative creatinine were identified as independent predictors for postoperative creatinine elevation (p < 0.05). Patients with AKI were more likely to enter the ICU than non-AKI patients (25% vs 5.6%, p < 0.05). Compared with non-AKI patients, the total hospital stay (16 [11-22] vs 13 [10-16] days) and postoperative hospital stay (11 [8-14] vs 8 [7-11] days) for AKI patients were significantly prolonged (p < 0.05).

CONCLUSION

The study shows age, male, preoperative diabetes, hypertension, and preoperative creatinine were independent predictors for postoperative creatinine elevation. In addition, age, ASA physical status and preoperative diabetes are independent predictors for postoperative AKI in patients undergoing hip and knee joint replacement. Postoperative AKI seems to increase ICU admission and significantly prolonged hospital stay.

Acute kidney injury is associated with increased healthcare utilization, complications, and mortality after primary total knee arthroplasty

Background:

The objective of this study was to assess healthcare utilization and complications associated with acute kidney injury (AKI) in patients undergoing primary total knee arthroplasty (TKA).

Methods:

We used the 1998–2014 US National Inpatient Sample to assess whether AKI is associated with healthcare utilization or in-hospital postoperative complications post-TKA using multivariable-adjusted logistic regression analyses. We calculated odds ratios (ORs) and a 95% confidence intervals (CIs). Sensitivity analyses additionally adjusted for hospital characteristics (location/teaching status, bed size, and region).

Results:

Of the 8,127,282 people who underwent primary TKA from 1998 to 2014, 104,366 (1.3%) had a diagnosis of AKI. People with AKI had longer unadjusted mean hospital stay, 6.1 versus 3.5 days, higher mean hospital charges, US$71,385 versus US$42,067, and higher rates of all in-hospital postoperative complications, including mortality. Adjusted for age, sex, race, underlying diagnosis, medical comorbidity, income, and insurance payer, AKI was associated with a significantly higher OR (95% CI) of total hospital charges above the median, 2.76 (2.68, 2.85); length of hospital stay > 3 days, 2.21 (2.14, 2.28); and discharge to a rehabilitation facility, 4.68 (4.54, 4.83). AKI was associated with significantly higher OR (95% CI) of in-hospital complications, including infection, 2.60 (1.97, 3.43); transfusion, 2.94 (2.85, 3.03); revision, 2.13 (1.72, 2.64); and mortality, 19.75 (17.39, 22.42). Sensitivity analyses replicated the main study findings, without any attenuation of ORs.

Conclusions:

AKI is associated with a significantly higher risk of increased healthcare utilization, complications, and mortality after primary TKA. Future studies should assess significant factors associated and interventions that can prevent AKI.

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.

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.

Outcomes of total hip arthroplasty surgery in heart and lung transplant recipients

BACKGROUND

Traditionally, arthroplasty in heart and lung transplant patients has been undertaken to manage transplant-related complications. More recently, arthroplasty is increasingly being performed for end-stage osteoarthritis. This study reviewed short-term outcomes and complications of total hip arthroplasty (THA) in heart and lung transplant recipients.

METHODS

A retrospective cohort of heart and lung transplant recipients who underwent THA was identified using ICD-10 coding. Post-operative complications and hospital outcomes were collected using the patient medical record.

RESULTS

Thirteen patients underwent 17 primary THA between 2008 and 2017, including five for osteoarthritis and 12 for femoral head avascular necrosis. Of the 13 patients, nine were bilateral sequential lung transplant recipients and four were orthotopic heart transplant recipients. The mean patient age was 61 years, with nine being male. Overall, five patients had one post-operative complication with eight having two or more complications. Surgical complications included three intraoperative fractures, three patients with superficial infection and one with deep infection requiring surgery. Seven patients had significant bleeding requiring blood transfusion. Prosthetic dislocations occurred in two patients, with one patient requiring revision surgery (developing a joint infection). Other complications included one pulmonary embolism, two episodes of pneumonia and six episodes of acute kidney injury, whilst three patients developed post-operative delirium. At 6-week follow-up, five patients had ongoing pain and seven had limitations with mobility. At 12-month follow-up, three patients reported ongoing pain.

CONCLUSION

Complications following THA after transplant are common. The risks and benefits of THA should be carefully considered preoperatively in this cohort.

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.

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.

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.

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.

Epidemiology, outcomes, and management of acute kidney injury in the vascular surgery patient

OBJECTIVE

Conventional clinical wisdom has often been nihilistic regarding the prevention and management of acute kidney injury (AKI), despite its being a frequent and morbid complication associated with both increased mortality and cost. Recent developments have shown that AKI is not inevitable and that changes in management of patients can reduce both the incidence and morbidity of perioperative AKI. The purpose of this narrative review was to review the epidemiology and outcomes of AKI in patients undergoing vascular surgery using current consensus definitions, to discuss some of the novel emerging risk stratification and prevention techniques relevant to the vascular surgery patient, and to describe a standardized perioperative pathway for the prevention of AKI after vascular surgery.

METHODS

We performed a critical review of the literature on AKI in the vascular surgery patient using the PubMed and MEDLINE databases and Google Scholar through September 2017 using web-based search engines. We also searched the guidelines and publications available online from the organizations Kidney Disease: Improving Global Outcomes and the Acute Dialysis Quality Initiative. The search terms used included acute kidney injury, AKI, epidemiology, outcomes, prevention, therapy, and treatment.

RESULTS

The reported epidemiology and outcomes associated with AKI have been evolving since the publication of consensus criteria that allow accurate identification of mild and moderate AKI. The incidence of AKI after major vascular surgery using current criteria is as high as 49%, although there are significant differences, depending on the type of procedure performed. Many tools have become available to assess and to stratify the risk for AKI and to use that information to prevent AKI in the surgical patient. We describe a standardized clinical assessment and management pathway for vascular surgery patients, incorporating current risk assessment and preventive strategies to prevent AKI and to decrease its complications. Patients without any risk factors can be managed in a perioperative fast-track pathway. Those patients with positive risk factors are tested for kidney stress using the urinary biomarker TIMP-2•IGFBP7, and care is then stratified according to the result. Management follows current Kidney Disease: Improving Global Outcomes guidelines.

CONCLUSIONS

AKI is a common postoperative complication among vascular surgery patients and has a significant impact on morbidity, mortality, and cost. Preoperative risk assessment and optimal perioperative management guided by that risk assessment can minimize the consequences associated with postoperative AKI. Adherence to a standardized perioperative pathway designed to reduce risk of AKI after major vascular surgery offers a promising clinical approach to mitigate the incidence and severity of this challenging clinical problem.

Acute Kidney Injury After Prophylactic Cefuroxime and Gentamicin in Patients Undergoing Primary Hip and Knee Arthroplasty-A Propensity Score-Matched Study

BACKGROUND

Perioperative acute kidney injury (AKI) can be associated with lower limb arthroplasty and increases morbidity, length of stay, and mortality. AKI is more prevalent in some antibiotic regimes compared with others. The aim of the present study is to assess the impact of cefuroxime (CEF), with or without gentamicin (±G), on AKI rates.

METHODS

A prospective cohort study involving patients undergoing hip or knee arthroplasty was performed, between September 1, 2015 and November 30, 2016. Prophylactic intravenous antibiotics were administered according to local policy. AKI was graded according to the validated Acute Kidney Injury Network criteria based on the changes from baseline serum creatinine values. Propensity score matching was performed to identify risk factors. The local audit department approved the study. Appropriate statistical analyses were performed.

RESULTS

A total of 2560 met the inclusion criteria, with a female preponderance (1447/2560; 56.5%). The mean age was 67.5 ± 10.7 years, with males being significantly younger (65.9 ± 10.9 vs 68.7 ± 10.4 years). AKI developed in 32 cases (1.25%). There was no difference in AKI rates between CEF alone and CEF in combination with gentamicin (1.07% vs 1.36%; P = .524). Overall 31/32 cases were Acute Kidney Injury Network stage I. AKI did not affect the length of stay. Postoperative infection rate was 7/2560 (0.27%). There were no incidences of Clostridium difficile-associated diarrhea. Multivariate analysis demonstrated an increased AKI risk with the use of intravenous gentamicin.

CONCLUSION

C ± G yields low rates of infection and AKI compared with high-dose penicillin-based regimes. It is a safe and effective choice for lower limb arthroplasty.

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.

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.

Postoperative Complications of Total Joint Arthroplasty in Obese Patients Stratified by BMI

BACKGROUND

High body mass index (BMI) is associated with significant complications in patients undergoing total joint arthroplasty. Many studies have evaluated this trend, but few have looked at the rates of complications based on BMI as a continuous variable. The purpose of this study was to stratify obese patients into 3 BMI categories and evaluate their rates of complications and gauge whether transitioning from higher to lower BMI category lowers complication.

METHODS

Patients undergoing primary total joint arthroplasty were selected from the National Surgical Quality Improvement Program database from 2008-2015 and arranged into 3 groups based on BMI: O1 (BMI 30-34.9 kg/m²), O2 (BMI 35-39.9 kg/m²), and O3 (BMI >40 kg/m²). Thirty-day complications were recorded and evaluated utilizing univariate and multivariate analyses stratified by BMI.

RESULTS

A total of 268,663 patients were identified. Patients with a BMI >30 kg/m² had more infectious and medical complications compared with nonobese patients. Furthermore, there were increased complications as the BMI categories increased. Patients with a BMI >40 kg/m² (O3) had longer operating times, length of stay, higher rates of readmissions, reoperations, deep venous thrombosis, renal insufficiency, superficial infections, deep infections, and wound dehiscence. These trends were present when comparing the O2 with O1 category as well.

CONCLUSION

We have demonstrated increased rates of medical and surgical complications in obese patients. Furthermore, we demonstrated a stepwise increase in complication rates when transitioning to higher BMI groups. Based on our data, we believe that preoperative counseling and interventions to decrease BMI should be explored before offering elective surgery to obese patients.

The Rate of Acute Kidney Injury After Total Hip Arthroplasty Is Low but Increases Significantly in Patients with Specific Comorbidities

BACKGROUND

The purpose of this study was to investigate the rate and risk factors associated with the development of acute kidney injury after total hip arthroplasty, including the perioperative use of nonsteroidal anti-inflammatory drugs (NSAIDs).

METHODS

We retrospectively collected the demographic and comorbidity data of all patients who underwent total hip arthroplasty between 2004 and 2014 at our institution (n = 8,949). We conducted analyses of the entire cohort and a nested case-control subset. Subjects who developed acute kidney injury were matched by age, sex, and year of surgical procedure to subjects without acute kidney injury. Variables associated with acute kidney injury were determined using univariate and multivariate logistic regressions.

RESULTS

The mean patient age (and standard deviation) was 64.6 ± 13.8 years, 48.6% of patients were male, and 114 cases (1.1%) developed acute kidney injury, mostly stage 1 (79%). Variables associated with acute kidney injury included older age (odds ratio [OR], 1.4 per decade; p < 0.001), male sex (OR, 1.78; p = 0.005), chronic kidney disease (OR, 4.6; p < 0.001), heart failure (OR, 4.5; p < 0.001), diabetes (OR, 2.1; p < 0.001), and hypertension (OR, 2.1; p = 0.007). The results were consistent in the case-control analysis. NSAIDs were not associated with acute kidney injury (OR, 1.26; p = 0.36), but were avoided in subjects at risk, making any interpretation difficult because of confounding. A risk model for acute kidney injury after total hip arthroplasty was developed for clinical use and had good discrimination (area under the curve, 0.82; p < 0.001).

CONCLUSIONS

The rate of acute kidney injury after total hip arthroplasty is low, but increases significantly, from <1% to >20%, in those with several independent risk factors present preoperatively. Increasing awareness of these risk factors may help to decrease the risk of acute kidney injury after total hip arthroplasty.

LEVEL OF EVIDENCE

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

Management of post-operative acute kidney injury

Post-operative acute kidney injury (AKI) is a common complication of surgery with significant short- and long-term adverse consequences. The adoption of diagnostic criteria for AKI (RIFLE, AKIN and KDIGO) has facilitated comparison of data reported by different centres, confirming that even mild AKI is associated with excess mortality. It remains unclear whether this is caused by the kidney injury itself or whether AKI is simply a marker of underlying disease severity. There is no trial evidence to support the use of any specific therapeutic intervention in post-operative AKI. Best current treatment is, therefore, preventative by optimizing hydration and avoidance of nephrotoxins, emphasizing the importance of earlier detection and identification of individuals at high risk for AKI. In this review, we examine the latest literature on the management of post-operative AKI in adult patients, specifically the diagnosis and definition of AKI, epidemiology and pathogenesis and risk stratification in cardiac and non-cardiac surgery. We also review the latest evidence on pharmacological and non-pharmacological interventions.

Acute Kidney Disease After Total Hip and Knee Arthroplasty: Incidence and Associated Factors

BACKGROUND

The development of acute kidney disease (AKD) following total joint arthroplasty has not been well characterized in the literature. We sought to calculate the incidence and identify risk factors associated with postoperative AKD for patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA).

METHODS

A total of 1000 consecutive cases (860 unique patients, including revisions) of TKA or THA performed between January 2010 and May 2016 were identified. Seventy-nine cases were excluded due to pre-existing kidney dysfunction and 23 additional cases were excluded due to incomplete data, resulting in 898 cases included in the study. There were 492 females and 406 males with a mean age of 58.1 years (range, 14-93 years). The Risk, Injury, Failure, Loss of kidney function, and End-stage kidney disease criteria and serum creatinine values were used to determine AKD status. Multiple logistic regression modeling was used to identify postoperative AKD risk factors.

RESULTS

Overall incidence of postoperative AKD was 6.8% (n = 61). Use of perioperative angiotensin receptor blocker (ARBs) or angiotensin-converting enzyme inhibitors (ACEi) (odds ratio [OR] = 2.09; P = .030), increasing body mass index (BMI) (OR = 1.58 per 10 kg/m²; P = .014), and use of vancomycin perioperatively (OR = 1.91; P = .021) were associated with increased odds of development of postoperative AKD.

CONCLUSION

A 6.8% incidence rate of postoperative AKD was noted in patients undergoing TKA or THA. Perioperative use of ARBs/ACEi, perioperative vancomycin use, and increased BMI were associated with increased odds of postoperative AKD.

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

Background and purpose - Patients developing postoperative acute kidney injury (AKI) are at risk of higher morbidity and mortality. In arthroplasty patients, many pre- and perioperative factors are associated with AKI but some of the risk factors are unclear. We report the incidence of postoperative AKI, the conditions associated with it, and survival rates in AKI patients. Patients and methods - We obtained data from 20,575 consecutive hip or knee arthroplasties. Postoperative AKI, occurring within 7 days after the operation, was defined using the risk, injury, failure, loss, and end-stage (RIFLE) criteria. We analyzed independent risk factors for AKI using binary logistic regression. In addition, we reviewed the records of AKI patients and performed a survival analysis. Results - The AKI incidence was 3.3 per 1,000 operations. We found preoperative estimated glomerular filtration rate, ASA classification, body mass index, and duration of operation to be independent risk factors for AKI. Infections, paralytic ileus, and cardiac causes were the predominant underlying conditions, whereas half of all AKI cases occurred without any clear underlying condition. Survival rates were lower in AKI patients. Interpretation - Supporting earlier results, existing renal insufficiency and patient-related characteristics were found to be associated with an increased risk of postoperative AKI. Furthermore, duration of operation was identified as an independent risk factor. We suggest careful renal monitoring postoperatively for patients with these risk factors.

Stratification and Risk Reduction of Perioperative Acute Kidney Injury

Perioperative acute kidney injury (AKI) is associated with an increased morbidity and mortality. The incidence of AKI varies depending on preoperative risk factors and the surgical setting. Preoperative risk stratification is critical for informed consent and perioperative planning. Perioperative renal protection strategies are potentially invaluable in the prevention of AKI. Current advances in the development of biomarkers may offer the opportunity for early diagnosis and the implementation of therapeutic strategies. Increased awareness and concerted efforts by all perioperative physicians are needed to provide an improved outcome for surgical patients.

Surgical Risks and Costs of Care are Greater in Patients Who Are Super Obese and Undergoing THA

BACKGROUND

Patients with morbid obesity, defined as a BMI greater than 40 kg/m², and super obesity, defined as a BMI greater than 50 kg/m², increasingly present for total hip replacement. There is disagreement in the literature whether these individuals have greater surgical risks and costs for the episode of care, and the magnitude of those risks and costs. There also is no established threshold for obesity as defined by BMI in identifying increased complications, risks, and costs of care. Until recently, analysis of higher BMI data was limited to small cohorts from hospital-based data banks, based on BMI or height and weight only, often as part of a multivariate analysis. On October 1, 2010 the Centers for Medicare & Medicaid Services added a fifth digit to the BMI data, V85.xx, in the Medicare data bank, which allowed data mining of cases of patients with higher BMI. To our knowledge, our study is the first large retrospective Medicare data mining study, which allows us to examine BMI levels greater than 40 and 50 kg/m² to delineate risks, complications, and costs for these patients.

QUESTIONS/PURPOSES

We sought to quantify (1) the surgical risk, and (2) the costs associated with complications after THA in patients who were morbidly obesity (BMI ≥ 40 kg/m²) or super obese (BMI ≥ 50 kg/m²).

METHODS

This is a retrospective study of patients, using Medicare hospital claims data, who underwent THA. The ICD-9 Clinical Modification (CM) diagnosis code V85.4x was used to identify patients with morbid obesity and with super obesity from October 1, 2010 through December 31, 2014. Patients without any BMI-related diagnosis codes were used as the control group. Twelve complications occurring during the 90 days after THA were analyzed using multivariate Cox models adjusting for patient demographic, comorbidities, and institutional factors. In addition, hospital charges and payments were compared from primary surgery through the subsequent 90 days.

RESULTS

Patients with morbid obesity had increased postoperative complications including prosthetic joint infection (hazard ratio [HR], 3.71; 95% CI, 3.2-4.31; p < 0.001), revision (HR, 1.91; 95% CI, 1.69-2.16; p < 0.001), and wound dehiscence (HR, 3.91; 95% CI, 3.14-4.86; p < 0.001). In addition, patients with morbid obesity had increased risk of deep vein thrombosis (HR, 1.43; 95% CI, 1.14-1.79; p < 0.002), pulmonary embolism (HR, 1.57; 95% CI, 1.25-1.99; p < 0.001), implant failure (HR, 1.48; 95% CI, 1.3-1.68; p < 0.001), acute renal failure (HR, 1.68; 95% CI, 1.56-1.80; p < 0.001), and all-cause readmission (HR, 1.48; 95% CI, 1.40-1.56; p < 0.001). However, death (HR, 0.94 95% CI, 0.73-1.19 p < 0.592), acute myocardial infarction (HR, 0.94; 95% CI, 0.74-1.2 p < 0.631), and dislocation (HR 1.07; 95% CI, 0.85-1.34; p < 0.585) were not different between patients in the control and morbidly obese groups. Super obese patients had an increased risk of infection (HR, 6.48; 95% CI, 4.54-9.25; p < 0.001), wound dehiscence (HR, 9.81; 95% CI, 6.31-15.24; p < 0.001), and readmission (HR, 2.16; 95% CI, 1.84-2.54; p < 0.001) compared with patients with normal BMI. Controlling for patient and institutional factors, each THA had mean total hospital charges of USD 88,419 among patients who were super obese compared with USD 73,827 for the control group, a difference of USD 14,591. Medicare payment for the patients who were super obese also was higher, but only by USD 3631.

CONCLUSIONS

Patients who are super obese are at increased risk for serious complications compared with patients with morbid obesity, whose risks are elevated relative to patients whose BMI is less than 40 kg/m². Costs of care for patients who were super obese, likewise, were increased. We present BMI outcomes to allow an objective basis for patient counseling, risk stratification, maintaining access to orthopaedic surgical care, and maintaining hospital operating margins.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Greater Wound and Renal Complications in Gout Patients Undergoing Total Joint Arthroplasty

BACKGROUND

Little is known about total joint arthroplasty (TJA) outcomes in gout patients. The purpose of this study was to compare adverse events between gout and nongout patients who underwent primary TJA.

METHODS

Using our institutional database and medical records review, a retrospective case-control study was conducted. From 2000 to 2012, a total of 482 gout TJA patients were matched with nongout TJA patients in a 1:1 ratio. Length of stay, complications, 90-day emergency room visits, and 90-day readmissions in these patients were compared.

RESULTS

Gout patients had greater wound healing problems (12.2% vs 5.0%, P = .001) and renal complications (8.9% vs 3.1%, P = .0003) compared with nongout patients. There were no significant differences between gout and nongout patients in terms of mean length of hospital stay (3.82 vs 3.17 days, P = .11) and 90-day emergency room visits (5.6% vs 3.5%, P = 1.00). Subgroup analysis showed that 90-day readmission rates were higher in gout patients who underwent total hip arthroplasty compared with those in nongout THA patients (6.8% vs 2.1%, P = .02).

CONCLUSION

Gout patients undergoing TJA have greater wound healing problems and renal complications. Surgeons should be cognizant of fluid management, renal monitoring and wound issues and should be cautious when treating TJA gout patients.

The risks and benefits of patients temporarily discontinuing medications in the event of an intercurrent illness: a systematic review protocol

BACKGROUND

Acute kidney injury (AKI) is common and often leads to significant morbidity and/or death. The development of AKI, or complications associated with it, may be due to use of certain medications in at-risk patients experiencing an intercurrent illness. Implicated drugs include diuretics, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers/direct renin inhibitors, non-steroidal anti-inflammatory drugs (NSAIDs), metformin and sulfonylureas. Expert consensus opinion (and clinical guidelines) recommend considering discontinuation of diuretics, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers/direct renin inhibitors, NSAIDs, metformin and sulfonylureas in the event of an intercurrent illness to prevent AKI onset or reduce severity or complications. However, the evidence base for these recommendations is very limited. This systematic review aims to address the available evidence for the temporary discontinuation of diuretics, ACE inhibitors, angiotensin receptor blockers, direct renin inhibitors, non-steroidal anti-inflammatories and metformin and sulfonylureas for those at risk of AKI or with newly diagnosed AKI.

METHODS/DESIGN

Randomised controlled trials; non-randomised trials; cohort studies; case-control studies; interrupted time series studies; and before-and-after studies featuring adults aged 18 and over in any setting currently taking diuretics, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers/direct renin inhibitors, NSAIDs and metformin; experiencing an intercurrent illness; or undergoing a radiological/surgical procedure (planned or unplanned) will be searched for. Relevant trial registers and systematic review databases will be searched. Systematic reviews will be assessed for methodological quality using the ROBIS tool, trials will be assessed using the Cochrane risk of bias tool, and observational studies will be assessed using the ACROBAT-NRS tool. If sufficient studies assessing similar populations, study type, settings and outcomes are found, then a formal meta-analysis will be performed to estimate summary measures of effect. If not, a narrative synthesis will be adopted.

DISCUSSION

This review will synthesise evidence for the efficacy of discontinuing diuretics, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers/direct renin inhibitors, NSAIDs, metformin or sulfonylureas to prevent or delay onset of AKI or associated complications. Results will provide guidance on efficacy and safety of this strategy and potentially help to develop an intervention to test the best mechanism of guiding medication discontinuation in at-risk populations.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42015023210.