Hamadah, Abdurrahman

Background and objectives AKI is classified as prerenal, intrinsic, and postrenal. Prerenal AKI and intrinsic AKI represent the most common causes for AKI in hospitalized patients. This study aimed to examine the accuracy of the fractional excretion of sodium for distinguishing intrinsic from prerenal AKI. Design, setting, participants, & measurements We searched MEDLINE, Embase, Cochrane Central Register of Controlled Trials, the Cochrane Library, and Scopus for all available studies that met the criteria until December 31, 2021. We included studies that evaluated fractional excretion of sodium in differentiating AKI etiologies in adults, whereas studies that did not have sufficient data to extract a 2×2 table were excluded. We assessed the methodologic quality using the Quality Assessment of Diagnostic Accuracy Studies-2 tool and extracted the diagnostic accuracy data for all included studies. We conducted a meta-analysis using the bivariate random effects model. We performed subgroup analysis to investigate sources of heterogeneity and the effect of the relevant confounders on fractional excretion of sodium accuracy. Results We included 19 studies with 1287 patients. In a subset of 15 studies (872 patients) that used a threshold of 1%, the pooled sensitivity and specificity for differentiating intrinsic from prerenal AKI were 90% (95% confidence interval, 81% to 95%) and 82% (95% confidence interval, 70% to 90%), respectively. In a subgroup of six studies (511 patients) that included CKD or patients on diuretics, the pooled sensitivity and specificity were 83% (95% confidence interval, 64% to 93%) and 66% (95% confidence interval, 51% to 78%), respectively. In five studies with 238 patients on diuretics, the pooled sensitivity and specificity were 80% (95% confidence interval, 69% to 87%) and 54% (95% confidence interval, 31% to 75%), respectively. In eight studies with 264 oliguric patients with no history of CKD or diuretic therapy, the pooled sensitivity and specificity were 95% (95% confidence interval, 82% to 99%) and 91% (95% confidence interval, 83% to 95%), respectively. Conclusions Fractional excretion of sodium has a limited role for AKI differentiation in patients with a history of CKD or those on diuretic therapy. It is most valuable when oliguria is present.

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.

Kidney disease is common in patients with multiple myeloma. Patients often present with acute kidney failure most commonly the result of light chain cast nephropathy. Presentation can also be in the form of nephrotic syndrome associated with immunoglobulin light chain amyloidosis or monoclonal immunoglobulin deposition disease and tubulopathy as in acquired light chain Fanconi syndrome. We present a case of a 56-year-old male with multiple myeloma who presented with chronic kidney disease and uric acid stones. Chemical analysis of the nephrolithiasis showed it to be entirely composed of uric acid. Fractional excretion of uric acid was elevated at 35.9%. Kidney biopsy was consistent with light chain proximal tubulopathy. Bone marrow biopsy showed 30% kappa light chain–restricted plasma cells. Genetic sequencing identified the light chain to be from the Vk1-33 subgroup. The patient was treated with bortezomib, cyclophosphamide, and dexamethasone, with improvement of his kidney function. This case illustrates a rare presentation of multiple myeloma.

Abstract Background Fluoroquinolones (FQ) are among the most commonly prescribed antibiotics. Nephrotoxicity related to FQ use is infrequently reported and the mechanism of renal injury is incompletely elucidated. We describe clinical manifestations and outcome of patients with biopsy proven acute interstitial nephritis (AIN) associated with FQ use at our institution. Methods We conducted a retrospective review of biopsy-proven AIN attributed to FQ use at Mayo Clinic Rochester from 1993 to 2016. Cases were reviewed by a renal pathologist and attributed to FQ use by an expert nephrologist. We also reviewed and summarized all published case reports of biopsy proven AIN that were attributed to FQ use. Results We identified 24 patients with FQ-related biopsy-proven AIN. The most commonly used FQ was ciprofloxacin (71%) with median antibiotic treatment duration of 7 days (Figure 1). The median duration between starting FQ and the diagnosis of AIN was 8.5 (IQR: 17). Common clinical manifestations included fever (50%), flank pain (8%), and skin rash (21%). However, 17% of the patients were asymptomatic at the time of diagnosis (Figure 2). Majority (58%) of the patients recovered following discontinuation of antibiotics and returned to baseline renal function at a median of 20.5 (IQR: 15.5). Six patients required temporary hemodialysis and 9 patients received steroids. Conclusion Onset of FQ-related AIN can be delayed and a high index of suspicion is needed by physicians prescribing these agents. Overall outcomes are favorable with recovery to baseline renal function within 3 weeks of discontinuing the offending drug. Disclosures All authors: No reported disclosures.

ABSTRACT Intravenous radiographic contrast medium and amphotericin B are commonly required in the care of patients with fungal infections. Both interventions have proposed nephrotoxicity through similar mechanisms. We systematically examined patients who received coadministration of liposomal amphotericin B (AmBisome; GE Healthcare) and intravenous contrast medium within a 24-h period and compared the results for those patients with the results for patients who underwent non-contrast medium studies. We found 114 cases and 85 controls during our study period. Overall, no increased risk of renal injury was seen with coadministration of these 2 agents. Adjustment for age, baseline kidney function, and other clinical factors through propensity score adjustment did not change this result. Our observations suggest that, when clinically indicated, coadministration of contrast medium and liposomal amphotericin B does not present excess risk compared with that from the administration of liposomal amphotericin B alone.