Acute kidney injury in urology patients: incidence, causes and outcomes

Obstructive uropathy: Overview of the pathogenesis, etiology and management of a prevalent cause of acute kidney injury

Obstructive uropathy is defined as the structural or functional interruption of urinary outflow at any level in the urinary tract. It is regarded as one of the most prevalent causes of acute kidney injury (AKI), accounting for 5%-10% of cases. Acute severe obstruction of the urinary tract is a potentially threatening situation for the kidneys and therefore requires prompt identification and management to relieve obstruction. The aim of the present article is to review and synthesize available evidence on obstructive uropathy, providing a clinical guideline for clinicians. A literature review on obstructive uropathy in the context of AKI was performed, focusing on the least clarified aspects regarding diagnosis and management. Recent literature searching was conducted in English and top-level evidence articles including systematic reviews, metanalyses and large series were prioritized. Acute obstruction of the urinary tract is a diagnostic and therapeutical challenge that may lead to important clinical complications together with direct structural and hemodynamic damage to the kidney. Early recognition of the leading cause and its exact location is essential to ensure prompt urinary drainage together with the most suitable drainage technique selection. A multidisciplinary approach, including urologists, nephrologists, and other medical specialties, is best suited to correctly manage concomitant hemodynamic changes, fluid and electrolyte imbalances, and other related issues. Obstructive uropathy is one of the leading causes of AKI. Recognition of patients suitable for early diversion and feasibility or adequate selection of the indicated technique is sometimes challenging. A thorough understanding of the physiopathology behind the development of urinary obstruction is vital for correct diagnosis and management.

Predictors of acute kidney injury after percutaneous nephrolithotomy in adult patients: prospective observational study

PURPOSE

To assess the frequency and the predictive factors of Acute Kidney injury (AKI) in patients undergoing percutaneous nephrolithotomy (PNL).

METHODS

A prospective observational work. Demographic, preoperative laboratory data, stone characteristics, and intraoperative and postoperative data were gathered. Perioperative AKI had been defined as an elevation in serum creatinine by ≥ 0.3 mg/dl within 48 h, or ≥ 1.5 times baseline, or urine volume less than 0.5 ml/ kg/hour for 6 hours. A multivariate logistic regression analysis was performed to determine the predictive factors of AKI. ROC curves were utilized to determine the cutoff values of the risk variables. P-values were deemed statistically significant when they were less than 0.05.

RESULTS

A total of 418 participants had been involved. The frequency of AKI was 13.9, and 17.2% of patients with AKI developed CKD. The risk factors were age > 46.5 years, smoking, BMI > 28.5 kg/m2, hypertension, diabetes, utilization of angiotensin-converting enzyme inhibitors (ACEI), haemoglobin < 10.8 gm/dl, baseline creatinine > 1.41 mg/dl, eGFR < 65.2 ml/min./1.73 m2, serum uric acid > 5.2 mg/dl, stone volume > 1748 mm3, large tract size, long operative time, and intra-operative bleeding. Patients with AKI had a notably extended duration of hospitalization (3.2 days ± 0.45 vs 2.1 ± 0.42, p < 0.001).

CONCLUSIONS

Perioperative AKI occurred in 13.9% of individuals undergoing PNL. Identification and optimization of the risk factors and meticulous technique during PNL procedures should be attempted to decrease the risk of AKI.

Acute kidney injury after robot-assisted laparoscopic prostatectomy: A meta-analysis

BACKGROUND

We investigated the rates of acute kidney injury (AKI) post robot-assisted laparoscopic prostatectomy (RALP).

METHODS

A comprehensive search was conducted to identify studies that reported the rates of AKI post-RALP. A random effects model was used, and the pooled rates of AKI were calculated.

RESULTS

We identified 10 studies with 60,937 patients to be included. The mean age was 65.1 years. The mean anaesthesia time was 234.3 min (95% CI: 177.8-290.9). The mean operation time was 212.2 min (95% CI: 188.7-235.6). The mean estimated blood loss was 314.1 mL (95% CI: 153-475.3). The mean intraoperative IV fluids administered were 1985 mL (95% CI: 1516.3-2453.7). The pooled rate of AKI post RALP was 7.2% (95% CI 19-23.9).

CONCLUSIONS

The rates of AKI after RALP are significant. Further studies are needed to detect the risk factors for AKI and to determine the rates of chronic kidney disease post-RALP.

Prevalence of acute kidney injury following percutaneous nephrolithotomy

Background

The objective is to evaluate the prevalence of acute kidney injury (AKI) as an early complication of the percutaneous nephrolithotomy (PCNL) procedure.

Materials and Methods

From May 2022 to October 2022, we conducted a retrospective study on patients undergoing PCNL procedures in two of the tertiary medical centers affiliated with Isfahan University of Medical Sciences. Patients' baseline characteristics, laboratory values, perioperative data, and stone features were documented. AKI was defined either as a ≥0.3 mg/dL increase in the serum creatinine level within 2 days, or a ≥1.5-fold increase in baseline serum creatinine level within 7 days after the operation. Laboratory values were measured 1 day before PCNL and daily thereafter until discharge. Patients were followed 1 week later to detect all of the possible cases of AKI.

Results

The final analysis was performed on 347 individuals. AKI developed in 16 (4.61%) cases. The two groups were comparable regarding age (P = 0.887), gender (P = 0.566), and underlying comorbidities including diabetes mellitus (P = 0.577) and hypertension (P = 0.383). The mean body mass index (BMI) (P < 0.001) and both frequency and severity of hydronephrosis (P < 0.001) were significantly different. A higher mean PCNL duration (P < 0.001), period of hospitalization (P < 0.001), and blood loss volume (P < 0.001) were observed in those who developed AKI. Overall, 56.3% (9) of patients in the AKI group and 2.7% (9) in the non-AKI group required the establishment of more than one access tract, during the procedure (P < 0.001). A lower preoperative hemoglobin level was observed in the AKI group (P < 0.001). Those with AKI had significantly larger stones (3.08 ± 0.46 vs. 2.41 ± 0.23 cm, P < 0.001) and higher Hounsfield units (P < 0.001). In addition, in the AKI group, most of the calculi (81.3%, 13) were of staghorn type, whereas in the non-AKI group, calculi were most frequently located in the middle calyx (30.2%, 100), (P < 0.001).

Conclusion

The prevalence of post-PCNL AKI is approximately 4.61%. The mean BMI, preoperative hemoglobin level, PCNL duration, intraoperative blood loss volume, and hospitalization period were significantly higher among patients who developed AKI. Those with AKI had significantly larger stones with higher Hounsfield units and more frequently of staghorn type. The two groups were not statistically different regarding age, gender, and presence of comorbidities (hypertension and diabetes mellitus).

Clinical Considerations for Patients Experiencing Acute Kidney Injury Following Percutaneous Nephrolithotomy

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

Genitourinary Cancer: Updates on Treatments and Their Impact on the Kidney

Genitourinary cancers are diverse in their presentation, prevalence, and mortality risk. Although there have been significant advancements in medical (eg, immune checkpoint inhibitors and tyrosine kinase inhibitors) and surgical treatments of genitourinary cancers, patients are still at risk for chronic kidney disease, hypertension, and electrolyte derangements in the short and long term. In addition, pre-existing kidney disease may increase the risk of developing some genitourinary cancers. This review focuses on the kidney-related effects of treatments for renal cell carcinoma and bladder and prostate cancers.

Oncosurgery-Related Acute Kidney Injury

Oncosurgery is a surgical specialty that focuses on the diagnosis, staging, and management of cancer and cancer-related complications. Acute kidney injury is a common and important complication related to oncologic surgery, associated with longer hospital length of stay, greater costs, increased risk of incident or progressive chronic kidney disease (CKD), and higher mortality. The pathogenesis of oncosurgery-related acute kidney injury is multifactorial and determined by different variables, including patient characteristics (comorbidities, volume status, age, pre-existing CKD), specific cancer type or location, surgical procedure involved, as well as intrinsic neuroendocrine and hemodynamic responses to anesthesia and/or surgery. Early nephrology evaluation may be helpful to assist with preservation of kidney function and prevention of further kidney injury.

Clinical Profile of Adult Patients Presenting With Renal Dysfunction to a Tertiary Hospital Emergency Department

Background Renal dysfunction is a potentially life-threatening condition that is commonly encountered in the emergency department (ED). This study aimed to describe the clinical profile of patients presenting with renal dysfunction to a tertiary-level hospital ED. Methods Medical records of patients presenting to the ED with renal dysfunction over a six-month period (July-December 2017) were reviewed. A descriptive analysis of the data was performed. Results Serum creatinine levels were measured in 7,442 (69.9%) of the 10,642 patients that were triaged into the ED. Of these, 208 (2.8%) were identified with renal dysfunction, of which 192 consented to study participation. The median age of study subjects was 49.5 (IQR 38.8-63.0) years; 108 (56.3%) were male; proteinuria on urine dipsticks was demonstrated in 108 (56.3%); 72 (37.5%) were HIV-positive; 66 (39.6%) required dialysis; 11 (5.7%) were admitted to the ICU; and 59 (30.7%) died prior to hospital discharge. More patients presented with acute kidney injury (AKI) (46.9%) compared to chronic kidney disease (CKD) (27.6%) and acute on chronic kidney disease (AoCKD) (25.5%). Sepsis was the most common precipitant of AKI (42.2%) and AoCKD (30.6%), while chronic hypertension (35.8%) and diabetes mellitus (34.0%) were the most common comorbidities in subjects with CKD. Conclusion Patients presenting to the ED with various risk factors and comorbidities, including HIV, sepsis, hypertension, and diabetes mellitus, may have underlying renal dysfunction. ED clinicians should therefore adopt a low threshold to screen for renal dysfunction in these patients.

Acute kidney injury and percutaneous nephrolithotomy: incidence and predictive factors

INTRODUCTION AND OBJECTIVE

Percutaneous nephrolithotomy (PCNL) is the treatment of choice for patients with large stones. The risk of acute kidney injury (AKI) has not been reported in the Western world. Our objective was to assess the frequency of AKI in patients undergoing PCNL and to identify independent predictors of AKI.

METHODS

A retrospective review of PCNL cases performed between January 2014 and June 2019 was reformed. Demographic, laboratory, and intraoperative date were obtained. Perioperative AKI was defined as (1) Increase in serum creatinine by ≥ 0.3 mg/dL (≥ 26.5 micromol/L) within 48 h, or (2) increase in serum creatinine to ≥ 1.5 times baseline. Multivariable logistic regression analysis was performed to determine the factors influencing AKI. A p value of 0.05 was considered significant.

RESULTS

A total of 566 patients were included. Mean age was 58 ± 14.4 years. The frequency of AKI was 4.4% (n = 25). The risk factors for AKI after PCNL were having a baseline creatinine > 1.54 mg/dl (p = 0.03, odds ratio [OR] = 2.66, confidence interval [CI] = 1.07-6.6), and a preoperative hemoglobin of less than 10.6 g/dL (p = 0.02, odds ratio [OR] = 2.47, confidence interval [CI] = 1.09-5.5). Patients without AKI had a median hospitalization of 2 days, while those with an AKI were hospitalized for a median of 3 days, and this difference was statistically significant (p < 0.001).

CONCLUSIONS

Perioperative AKI occurs in 4.4% of patients undergoing PCNL. Preoperative hemoglobin and serum creatinine can identify those at increased risk, in whom it may be important to avoid nephrotoxic agents.

THE FUNCTIONAL STATE OF THE RENAL PARENCHYMA AFTER VARIOUS VIDEO ENDOSURGICAL METHODS OF TREATMENT OF PATIENTS WITH LARGE AND COMPLEX KIDNEY STONES

The work is based on the analysis of literature data devoted to the problem of preserving the functional state of the kidneys with various video endoscopic methods of surgical treatment of large and complex kidney stones. The purpose of the review is to highlight the likelihood of deterioration in the functional state of the kidneys in the postoperative period. A detailed analysis of postoperative outcomes in various minimally invasive methods of treatment of patients with large and complex kidney stones was carried out, with an overview of the possibility of using dynamic nephroscintigraphy as a method of objectively assessing the functional state of the kidneys.

Immune-related adverse events and kidney function decline in patients with genitourinary cancers treated with immune checkpoint inhibitors

BACKGROUND

In patients with genitourinary cancers, the effect of immune checkpoint inhibitors (ICIs) on kidney function is unknown.

PATIENTS AND METHODS

This is a retrospective cohort study of patients with renal cell carcinoma (RCC) and urothelial carcinoma who received ICIs at two major cancer centers between 2012 and 2018. Cumulative incidence and Fine and Gray subdistribution hazard models were performed to determine predictors of the co-primary outcomes, (1) acute kidney injury (AKI) and (2) sustained estimated glomerular filtration rate (eGFR) loss, defined as a >20% decline in eGFR sustained ≥90 days. We also determined the association between immune-related adverse events (irAE) and adverse kidney outcomes among patients surviving ≥1 year.

RESULTS

637 patients were included; 320 (50%) patients had RCC and 317 (50%) patients had urothelial carcinoma. Half of the cohort had eGFR<60 mL/min/1.73 m² at baseline. irAEs, AKI, and sustained eGFR loss were common, occurring in 33%, 25% and 16%, respectively. Compared to patients with urothelial carcinoma, patients with RCC were more likely to develop irAEs (aHR 1.61, 95% CI 1.20-2.18) and sustained eGFR loss (aHR 1.97, 95% CI 1.24-3.12), but not AKI (aHR 1.53, 95% CI 0.97-2.41). Among patients surviving ≥1 years, experiencing a non-renal irAE was associated with a significantly higher risk of sustained eGFR loss (aHR 1.71, 95% CI 1.14-2.57).

CONCLUSION

AKI and sustained eGFR loss are common in patients with genitourinary cancers receiving ICIs. irAEs may be a novel risk factor for kidney function decline among patients receiving ICIs.

Impact of comorbidities on acute kidney injury and renal function impairment after partial and radical tumor nephrectomy

BACKGROUND

To test for the impact of patient comorbidities and medical risk factors on kidney function after partial (PN) or radical nephrectomy (RN) in renal cell carcinoma (RCC) patients with normal preoperative renal function.

MATERIALS AND METHODS

From January 2011 to December 2014, 195 consecutive RCC patients with a preoperative estimated glomerular filtration rate (eGFR) > 60 ml/min/1.73 m² underwent PN or RN. Stratification was performed according to postoperative acute kidney injury (AKI) vs. no AKI. Moreover, logistic regression models tested for risk factors predicting postoperative AKI and subsequent new-onset chronic kidney disease (eGFR < 60 or < 45 ml/min/1.73 m²).

RESULTS

Of all eligible patients, 127 (65.1%) exhibited AKI. AKI patients underwent more frequently RN (44.9 vs. 13.2% PN) and harbored more often preoperative diabetes (17.3 vs. 5.9% no diabetes), hypertension (46.5 vs. 23.5% no hypertension) and larger median tumor size (4.5 vs. 2.5 cm, all p < 0.05) than non-AKI patients. Moreover, after median follow-up of 14 months, 18.9% of AKI patients exhibited an eGFR < 60 ml/min/1.73 m² vs. 7.4% non-AKI patients (p = 0.01). In multivariable models, hypertension and RN were risk factors for postoperative AKI (both p < 0.01). Age > 60 years and RN as well as preoperative diabetes were risk factors for postoperative eGFR < 60 or < 45 ml/min/1.73 m² (all p < 0.05), respectively.

CONCLUSIONS

Postoperative AKI is a non-negligible event especially after RN that can be further triggered by comorbidities such as diabetes and hypertension. Comorbidities should be considered in clinical decision-making for RCC surgery and patients need to be counseled about the increased risk of consecutive renal function impairment.

Acute Kidney Injury Post-Percutaneous Nephrolithotomy (PNL): Prospective Outcomes from a University Teaching Hospital

Acute Kidney Injury (AKI) after percutaneous nephrolithotomy (PNL) is a significant complication, but evidence on its incidence is bereft in the literature. The objective of this prospective observational study was to analyze the incidence of post-PNL AKI and the potential risk factors and outcomes. Demographic data collected included age, gender, body mass index (BMI), comorbidities (hypertension, diabetes mellitus), and drug history-particularly angiotensin converting enzyme inhibitors (ACE inhibitors), angiotensin II receptor blockers and beta blockers. Laboratory data included serial serum creatinine measured pre- and postoperation (12, 24, and 48 h), hemoglobin (Hb), total leucocyte count (TLC), Prothrombin time (PT), serum uric acid and urine culture. Stone factors were assessed by noncontrast computerized tomography of kidneys, ureter and bladder (NCCT KUB) and included stone burden, location and Hounsfield values. Intraoperative factors assessed were puncture site, tract size, tract number, operative time, the need for blood transfusion and stone clearance. Postoperative complications were documented using the modified Clavien-Dindo grading system and patients with postoperative AKI were followed up with serial creatinine measurements up to 1 year. Among the 509 patients analyzed, 47 (9.23%) developed postoperative AKI. Older patients, with associated hypertension and diabetes mellitus, those receiving ACE inhibitors and with lower preoperative hemoglobin and higher serum uric acid, had higher incidence of AKI. Higher stone volume and density, staghorn stones, multiple punctures and longer operative time were significantly associated with postoperative AKI. Patients with AKI had an increased length of hospital stay and 17% patients progressed to chronic kidney disease (CKD). Cut-off values for patient age (39.5 years), serum uric acid (4.05 mg/dL) and stone volume (673.06 mm3) were assessed by receiver operating characteristic (ROC) curve analysis. Highlighting the strong predictors of post-PNL AKI allows early identification, proper counseling and postoperative planning and management in an attempt to avoid further insult to the kidney.

Renal outcomes in adult patients with horseshoe kidney

BACKGROUND

Horseshoe kidney (HSK) is a congenital disorder that is usually asymptomatic, but that increases the risks of kidney stones and infectious disease. However, renal outcomes such as end-stage renal disease (ESRD) in patients with HSK remain unclear.

METHODS

In total, 146 patients with HSK (age of ≥20 years) from two tertiary hospitals were included in this study. Control individuals who underwent medical check-ups were selected by matching for age, sex, serum creatinine level, hypertension and diabetes. The hazard ratios (HRs) for the risks of ESRD and all-cause mortality were calculated after adjustment for multiple variables.

RESULTS

The proportions of HSK-related complications for obstruction, kidney stones, urinary tract infection and urogenital cancer were 26, 25, 19 and 4%, respectively. During the median follow-up period of 9 years (maximum 32 years), the incidence of ESRD was 2.6/10 000 person-years. The risk of ESRD in patients with HSK was higher than in control individuals [adjusted HR = 7.6; 95% confidence interval (CI) 1.14-50.47]. All-cause mortality did not differ between the two groups (adjusted HR = 0.6; 95% CI 0.08-4.29).

CONCLUSIONS

Patients with HSK are at risk of ESRD, which may be attributable to the high prevalence of complications. Accordingly, these patients should be regarded as having chronic kidney disease and require regular monitoring of both kidney function and potential complications.

Acute Kidney Injury Caused by Obstructive Nephropathy

Acute kidney injury secondary to obstructive nephropathy is a frequent event that accounts for 5 to 10% of all acute kidney injury cases and has a great impact on the morbidity and mortality in those affected. The obstruction in the urinary tract has a profound impact on kidney function due to damage produced by ischemic and inflammatory factors that have been associated with intense fibrosis. This pathology is characterized by its effects on the management of fluids, electrolytes, and the acid-base mechanisms by the renal tubule; consequently, metabolic acidosis, hyperkalemia, uremia, and anuria are seen during acute kidney injury due to obstructive nephropathy, and after drainage, polyuria may occur. Acute urine retention is the typical presentation. The diagnosis consists of a complete medical history and should include changes in urinary voiding and urgency and enuresis, history of urinary tract infections, hematuria, renal lithiasis, prior urinary interventions, and constipation. Imaging studies included tomography or ultrasound in which hydronephrosis can be seen. Management includes, in addition to drainage of the obstructed urinary tract system, providing supportive treatment, correcting all the metabolic abnormalities, and initiating renal replacement therapy when required. Although its recovery is in most cases favorable, it seems to be an undervalued event in nephrology and urology. This is because it is mistakenly believed that the resolution and recovery of kidney function is complete once the urinary tract is unobstructed. It can have serious kidney sequelae. In this review, we report the epidemiology, incidence, pathophysiological mechanisms, diagnosis, and treatment of acute kidney injury due to obstructive nephropathy.

Acute Kidney Injury in Asia: Disease Burden

Acute kidney injury (AKI) is a common and critical clinical disorder with non-negligible morbidity and mortality and remains a large public health problem. Asia, as the world's largest and most populous continent, is crucial in eliminating unsatisfactory outcomes of AKI. The diversities in climate, customs, and economic status lead to various clinical features of AKI across Asia. In this review, we focus on the epidemiologic data and clinical features of AKI in different Asian countries and clinical settings, and we show the huge medical and economic burden of AKI in Asian countries. Drugs and sepsis are the most common etiologies for AKI, however, an adequate surveillance system has not been well established. There is significant undertreatment of AKI in many regions, and medical resources for renal replacement therapy are not universally available. Although substantial improvement has been achieved, health care for AKI still needs improvement, especially in developing regions.

Global epidemiology and outcomes of acute kidney injury

Acute kidney injury (AKI) is a commonly encountered syndrome associated with various aetiologies and pathophysiological processes leading to decreased kidney function. In addition to retention of waste products, impaired electrolyte homeostasis and altered drug concentrations, AKI induces a generalized inflammatory response that affects distant organs. Full recovery of kidney function is uncommon, which leaves these patients at risk of long-term morbidity and death. Estimates of AKI prevalence range from <1% to 66%. These variations can be explained by not only population differences but also inconsistent use of standardized AKI classification criteria. The aetiology and incidence of AKI also differ between high-income and low-to-middle-income countries. High-income countries show a lower incidence of AKI than do low-to-middle-income countries, where contaminated water and endemic diseases such as malaria contribute to a high burden of AKI. Outcomes of AKI are similar to or more severe than those of patients in high-income countries. In all resource settings, suboptimal early recognition and care of patients with AKI impede their recovery and lead to high mortality, which highlights unmet needs for improved detection and diagnosis of AKI and for efforts to improve care for these patients.

Risk factors for acute kidney injury after percutaneous nephrolithotomy: Implications of intraoperative hypotension

Percutaneous nephrolithotomy (PNL) is a minimally invasive technique for renal stone removal but can cause renal parenchymal injury. Renal stones can also affect renal function. We evaluated the risk factors for acute kidney injury (AKI) after PNL.The study cohort included 662 patients who underwent PNL. Patient characteristics, preoperative laboratory values, intraoperative data, and stone characteristics were collected. Univariate and multivariate logistic regression analyses were performed to identify risk factors for AKI after PNL. Postoperative outcomes such as hospitalization, intensive care unit admission rate and stay duration, and chronic kidney disease were also evaluated.Of the total study series, there were 107 (16.2%) cases of AKI after PNL (AKI group), and 555 (83.8%) patients who showed no injury (no-AKI group). The risk factors for AKI after PNL were found to be a higher preoperative serum uric acid level [odds ratio (OR) = 1.228; 95% confidence interval (95% CI) = 1.065-1.415; P = .005], longer operation time (OR = 1.009; 95% CI = 1.004-1.014; P < .001), and intraoperative hypotension (OR = 12.713; 95% CI = 7.762-20.823; P < .001). Hospitalization and intensive care unit stay duration were significantly longer in the AKI group (8.7 ± 5.2 vs 6.6 ± 2.8 days, P < .001; 0.34 ± 1.74 vs 0.07 ± 0.48 days, P = .002, respectively). Chronic kidney disease was also significantly higher in the AKI group (63.6% vs 32.7%, P = .024).As intraoperative hypotension is an important risk factor for AKI after PNL, which leads to poor postoperative outcomes, it should be prevented or managed vigorously during PNL.

Association and prognostic value of serum Cystatin C, IL-18 and Uric acid in urological patients with acute kidney injury

PURPOSE

To assess the role of serum Cystatin C, IL-18 and Uric acid in acute kidney injury (AKI) in urological patients, along with their prognostic significance.

MATERIALS AND METHODS

Prospective observational study included 61 cases, admitted in urology ward with baseline serum creatinine ≤1.5 mg/dL. All patients had at least one or more predisposing factors for AKI. Daily urine output and creatinine level were checked. Serum levels of biomarkers were measured at baseline and postoperatively after 24 h. Development of AKI and its outcome were analysed.

RESULTS

Thirty nine patients (63.9%) developed AKI in the study. Patients with AKI were found to have a greater percentage rise of Cystatin C (118.7% v/s 81.8%, p = 0.005), IL-18 (59.0% v/s 25.5%, p = 0.004) and Uric acid (34.3% v/s 19.2%, p = 0.008) after 24 h. Absolute Uric acid level at day 1 was also significantly associated with AKI (5.18 ± 0.91 v/s 4.45 ± 0.86, p = 0.003). Risk stratification of AKI was poor for all biomarkers. Area under curve for Cystatin C, IL-18 and Uric acid was 0.715, 0.696 and 0.734 respectively. Renal function after 3 months, had a positive correlation with baseline creatinine and baseline Cystatin C levels (r = 0.56 & 0.39).

CONCLUSIONS

Postoperative serum Cystatin C, IL-18 and Uric acid after 24 h were significantly associated with AKI. Baseline Cystatin C had moderate capability to predict short term renal function.

Early term effect of ureterorenoscopy (URS) on the Kidney: research measuring NGAL, KIM-1, FABP and CYS C levels in urine

Aim:

URS is a very commonly used procedure for treatment of ureter stones. Increased hydrostatic pressure in the collecting system linked to fluids used during the procedure may cause harmful effects on the kidney. The aim of this study is to determine whether the URS procedure has a negative effect on the kidney by investigating NGAL, KIM-1, FABP and Cys C levels in urine.

Material and Methods:

This study included 30 patients undergoing ureterorenoscopy (URS) for ureter stones. Urine samples were collected 5 times; before the URS procedure (control) and at 1, 3, 5 and 12 hours following the procedure. NGAL, KIM-1, FBAP and Cys C levels were measured in urine and compared with the control values.

Results:

The NGAL levels in urine before the procedure and at 1, 3, 5 and 12 hours after the procedure were 34.59±35.34; 62.72±142.32; 47.15±104.48; 45.23±163.16 and 44.99±60.79ng/mL, respectively (p=0.001). Similarly, the urinary KIM-1, FABP and Cys C levels were found to increase compared to control values; however this increase did not reach statistical significance (p >0.05).

Conclusions:

After the URS procedure, there were important changes in NGAL, FABP, KIM-1 and Cys C levels. These changes reached statistical significance for NGAL, but did not reach significance for the other parameters. In conclusion, the URS procedure significantly affects the kidney; however, this effect disappears over time.

Outcomes of acute kidney injury in a department of internal medicine in ABIDJAN (cote D'IVOIRE)

AIM

To investigate the prognostic factors of acute kidney injury (AKI) in our daily practice.

METHODS

We analyzed the cohort of patients hospitalized for AKI in the period from January 2010 to December 2015 in the Department of Internal Medicine, University Hospital of Treichville. Kaplan-Meier curves were built for survival analysis. Cox regression analysis was used to identify independent predictors of mortality.

RESULTS

We collected 414 cases of AKI during the study period. The mean age was 48.3 ± 16.8 years. We observed a male predominance with a sex ratio (236/178) of 1.32. In multivariate analysis, the predictive factors of death were age ≥ 65 years (HR = 2.13; 95% CI = 1.28-3.55; P = 0.004), AKI stage 3 (HR = 1.69; 95%CI = 1.13-2.50; P = 0.009), haemoglobin <8 g/dL (HR = 2.91; 95% CI = 1.79-4.72; P = 0.0001), infection (HR = 1.85; 95% CI = 1.21-2.83; P = 0.004) and drug-induced AKI (HR = 3.23; 95% CI = 1.65-6.29; P = 0.001). Factors associated with incomplete recovery or non-recovery of renal function beyond 3 months were age ≥ 65 years (OR = 4.76; 95% CI = 1.85-12.50;P = 0.001), hypertension (OR = 2.17; 95% CI = 1.07-4.34; P = 0.03), haemoglobin <8 g/dL (OR = 6.66; 95% CI = 2.94-8.28; P < 0.001), AKI stage 3 (OR = 9.09; 95% CI = 4.54-16.66; P < 0.001) malignant hypertension (OR = 5; 95% CI = 1.67-7.27; P = 0.005) and cancer (OR = 4.69; 95% CI = 2.22-6.63; P = 0.001).

CONCLUSION

The aetiologies are dominated by infections. The fatality rate is high and its risk factors are advanced age, low haemoglobin level, severe AKI, infection and drug intake. Prevention is essential.

Acute kidney injury burden in different clinical units: Data from nationwide survey in China

Background

The inpatient morbidity and mortality of acute kidney injury (AKI) vary considerably in different clinical units, yet studies to compare the difference remain limited.

Methods

We compared the clinical characteristics of AKI in Intensive Care Unit (ICU), medical and surgical departments by using the data derived from the 2013 nationwide cross-sectional survey of AKI in China to capture variations among different clinical departments in recognition, management, and outcomes of AKI. Suspected AKI patients were identified based on changes in serum creatinine during hospitalization, and confirmed by reviewing medical records.

Results

The detection rate of AKI was the highest in ICU (22.46%), followed by the rates in medical (1.96%) and surgical departments (0.96%). However, the absolute number of cases was the largest in medical departments, which contributed to 50% of the cases. In medical departments, 78% of AKI cases were extensively distributed in cardiac, nephrology, oncology, gastroenterology, pneumology and neurology departments. In contrast, 87% of AKI cases in surgical departments were mainly from urology, general surgery and cardiothoracic departments. The in-time recognition rates were extremely low in all departments except nephrology. Only 10.5~15.0% AKI patients from non-nephrology departments received renal referral. Among all the death cases, 50% and 39% came from ICU and medical departments while only 11% from surgical departments. Older age, higher AKI stage and renal replacement therapy indication were identified as risk factors for high mortality in all departments. Delayed recognition and no renal referral were significantly associated with increased mortality in medical and ICU patients.

Conclusions

These findings suggest that ICU and medical departments are major affected departments in China with a large number of AKI cases and subsequent high mortality. The reality is more alarming considering the low awareness of AKI and the paucity of effective interventions in the high-risk patients in these departments.

International Criteria for Acute Kidney Injury: Advantages and Remaining Challenges

Nicholas Selby and colleagues describe how the definition of acute kidney injury brings opportunities and challenges in identifying patients at higher risk of adverse outcomes.

Impact of perioperative administration of 6 % hydroxyethyl starch 130/0.4 on serum cystatin C-derived renal function after radical prostatectomy: a single-centre retrospective study

Background

Hydroxyethyl starch (HES) is used for repletion of acute intravasal volume loss in surgical patients. However, in critically ill patients, HES is associated with acute kidney injury. We aimed to evaluate the effect of HES on perioperative cystatin C (cystC)-derived estimated glomerular filtration rates (eGFR_cystC) in patients undergoing open and robot-assisted radical prostatectomy.

Methods

In this retrospective study we included 179 patients who underwent general anaesthesia for radical prostatectomy received HES perioperatively, and had complete cystC and fluid therapy data available. CystC and corresponding eGFR_cystC at postoperative days 1, 3, and 5 were compared with preoperative baseline using Wilcox rank-sum test.

Results

In 179 eligible patients, 6 % HES 130/0.4 was administered in a median (25th to 75th percentile) dose of 1000 mL (1000 to 1000 mL). Baseline eGFR_cystC was 109.4 mL/min (100.3 to 118.7 mL/min). eGFR_cystC on postoperative days 1, 3, and 5 was 120.4 mL/min (109.4 to 134.0 mL/min), 120.4 mL/min (109.4 to 132.9 mL/min), and 117.9 mL/min (106.6 to 129.8 mL/min), respectively (p < 0.001 compared with baseline, each). No patient had an eGFR_cystC-decrease of ≥25 % from baseline.

Conclusions

The results indicate that the administration of a median dose of 1000 mL of 6 % HES 130/0.4 is not associated with a postoperative deterioration of renal function in patients with normal to near-normal baseline renal function undergoing radical prostatectomy.

Trends of acute kidney injury after radical or partial nephrectomy for renal cell carcinoma

OBJECTIVES

To investigate the prevalence, temporal trends, and predictors of postoperative acute kidney injury (AKI) in a large cohort of patients with renal cell carcinoma treated with radical or partial nephrectomy.

METHODS

Between January 1998 and December 2010, patients who underwent radical or partial tumor nephrectomy were identified within the Nationwide Inpatient Sample. First, prevalence and temporal trends of AKI were analyzed. Second, predictors of AKI were identified using multivariable regression analyses. Third, associations between AKI and in-hospital complications, length of stay, hospital costs, and in-hospital mortality were evaluated using logistic regression models adjusted for clustering.

RESULTS

Of total 253,046 patients, 5.5% (14,303 in radical and 3,525 in partial nephrectomy) experienced AKI. Rates of AKI significantly increased from 2.0% in 1998 to 10.4% in 2010 (P<0.001). Predictors of AKI included male sex, radical nephrectomy, more contemporary years (2004-2010), older age, black race, higher comorbidities, higher preoperative chronic kidney disease stage, Medicare insurance status, and nephrectomy at urban hospitals (all P<0.01). Postoperative AKI during hospitalization was associated with an increased rate of in-hospital mortality, any complications, transfusion, prolonged length of stay, and higher hospital costs (all P<0.001).

CONCLUSIONS

Rising rates of in-hospital AKI after radical and partial nephrectomy were observed. Increasing awareness of AKI, identification of patients at risk before surgery, early postoperative AKI diagnosis, collaboration with nephrologists, implementation of renoprotective strategies, long-term renal functional follow-up, and a well-designed prospective study, may be warranted.

Pyelonephritis and obstructive uropathy: a case of acute kidney injury

We present a case of a man in his late 50s with a history of metastatic prostate carcinoma requiring bilateral ureteric stenting. He was admitted with increasing confusion and lethargy. He was diagnosed with sepsis and an acute kidney injury (AKI). Clinical suspicions of an obstructive component to his AKI were not confirmed by an ultrasound scan, which showed a unilateral hydronephrosis unchanged from a scan 1 month previously. A nephrostomy was performed, and frank pus aspirated. The patient's clinical state improved steadily thereafter. Patients who are dehydrated, or who have suffered from malignant or fibrotic processes affecting the retroperitoneum, may present with urinary obstruction without a corresponding increase in urinary tract dilation. Additionally, there must be a suspicion of pyonephrosis in a symptomatic patient with known hydronephrosis. Clinicians should be aware that clinical suspicions of urinary obstruction not demonstrated on ultrasound scanning require further investigation.

Novel biomarkers of acute kidney injury: Evaluation and evidence in urologic surgery

Patients undergoing urologic surgery are at risk of acute kidney injury (AKI) and consequently long-term deterioration in renal function. AKI is further associated with significantly higher odds of perioperative complications, prolonged hospital stay, higher mortality and costs. Therefore, better awareness and detection of AKI, as well as identification of AKI determinants in the urological surgery setting is warranted to pre-empt and mitigate further deterioration of renal function in patients at special risk. New consensus criteria provide precise definitions of diagnosis and description of the severity of AKI. However, they rely on serum creatinine (SCr), which is known to be an inaccurate marker of early changes in renal function. Therefore, several new urinary and serum biomarkers promise to address the gap associated with the use of SCr. Novel biomarkers may complement SCr measurement or most likely improve the diagnostic accuracy of AKI when used in combinations. However, novel biomarkers have to prove their clinical applicability, accuracy, and cost effectiveness prior to implementation into clinical practice. Most preferably, novel biomarkers should help to positively improve a patient’s long-term renal functional outcomes. The purpose of this review is to discuss currently available biomarkers and to review their clinical evidence within urologic surgery settings.

Incidence and Risk Factors of Acute Kidney Injury after Radical Cystectomy: Importance of Preoperative Serum Uric Acid Level

BACKGROUND

Acute kidney injury (AKI) is a common complication after surgery and increases costs, morbidity, and mortality of hospitalized patients. While radical cystectomy associates significantly with an increased risk of serious complications, including AKI, risk factors of AKI after radical cystectomy has not been reported. This study was performed to determine the incidence and independent predictors of AKI after radical cystectomy.

METHODS

All consecutive patients who underwent radical cystectomy in 2001-2013 in a single tertiary-care center were identified. Their demographics, laboratory values, and intraoperative data were recorded. Postoperative AKI was defined and staged according to the Acute Kidney Injury Network criteria on the basis of postoperative changes in creatinine levels. Independent predictors of AKI were identified by univariate and multivariate logistic regression analyses.

RESULTS

Of the 238 patients who met the eligibility criteria, 91 (38.2%) developed AKI. Univariate logistic regression analyses showed that male gender, high serum uric acid level, and long operation time associated with the development of AKI. On multivariate logistic regression analysis, preoperative serum uric acid concentration (odds ratio [OR] = 1.251; 95% confidence interval [CI] = 1.048-1.493; P = 0.013) and operation time (OR = 1.005; 95% CI = 1.002-1.008; P = 0.003) remained as independent predictors of AKI after radical cystectomy.

CONCLUSIONS

AKI after radical cystectomy was a relatively common complication. Its independent risk factors were high preoperative serum uric acid concentration and long operation time. These observations can help to prevent AKI after radical cystectomy.

Prostatic surgery associated acute kidney injury

Acute kidney injury (AKI) is associated with extended hospital stays, high risks of in-hospital and long-term mortality, and increased risk of incident and progressive chronic kidney disease. Patients with urological diseases are a high-risk group for AKI owing to the coexistence of obstructive uropathy, older age, and preexistent chronic kidney disease. Nonetheless, precise data on the incidence and outcomes of postoperative AKI in urological procedures are lacking. Benign prostatic hyperplasia and prostate cancer are common diagnoses in older men and are frequently treated with surgical procedures. Whereas severe AKI after prostate surgery in general appears to be unusual, AKI associated with transurethral resection of the prostate (TURP) syndrome and with rhabdomyolysis (RM) after radical prostatectomy have been frequently described. The purpose of this review is to discuss the current knowledge regarding the epidemiology, risk factors, outcomes, prevention, and treatment of AKI associated with prostatic surgery. The mechanisms of TURP syndrome and RM following prostatic surgeries will be emphasized.