BackgroundThe timing of initiation of renal replacement therapy (RRT) in severe acute kidney injury (AKI) remains controversial, with early initiation resulting in unnecessary therapy for some patients while expectant therapy may delay RRT for other patients. The furosemide stress test (FST) has been shown to predict the need for RRT and therefore could be used to exclude low-risk patients from enrollment in trials of RRT timing. We conducted this multicenter pilot study to determine whether FST could be used to screen patients at high risk for RRT and to determine the feasibility of incorporating FST into a trial of early initiation of RRT.MethodsFST was performed using intravenous furosemide (1 mg/kg in furosemide-naive patients or 1.5 mg/kg in previous furosemide users). FST-nonresponsive patients (urine output less than 200 mL in 2 h) were then randomized to early (initiation within 6 h) or standard (initiation by urgent indication) RRT.ResultsFST was completed in all patients (100%). Only 6/44 (13.6%) FST-responsive patients ultimately received RRT while 47/60 (78.3%) nonresponders randomized to standard RRT either received RRT or died (P <  0.001). Among 118 FST-nonresponsive patients, 98.3% in the early RRT arm and 75% in the standard RRT arm received RRT. The adherence to the protocol was 94.8% and 100% in the early and standard RRT group, respectively. We observed no differences in 28-day mortality (62.1 versus 58.3%, P = 0.68), 7-day fluid balance, or RRT dependence at day 28. However, hypophosphatemia occurred more frequently in the early RRT arm (P = 0.002).ConclusionThe furosemide stress test appears to be feasible and effective in identifying patients for randomization to different RRT initiation times. Our findings should guide implementation of large-scale randomized controlled trials for the timing of RRT initiation.Trial registrationclinicaltrials.gov, NCT02730117. Registered 6 April 2016.Electronic supplementary materialThe online version of this article (10.1186/s13054-018-2021-1) contains supplementary material, which is available to authorized users.

Introduction: Renal biopsy is a useful diagnostic procedure. In developing countries, two techniques of renal biopsy, blind percutaneous renal biopsy and real-time ultrasound-guided percutaneous renal biopsy, have been performed. The majority of studies compared these using different types and sizes of biopsy needle. The aim of this study was to compare both techniques in resource constraint country. Method: We reviewed renal biopsy database, between 1 January 2014 to 30 June 2017. The primary outcome was the total number of glomeruli. The other outcomes were tissue adequacy and bleeding complications. We also analyzed multivariable logistic regression to find factors associated with tissue adequacy and bleeding complications. Result: Of the 204 renal biopsies, 100 were blind percutaneous renal biopsy and 104 real-time ultrasound-guided percutaneous renal biopsy. The number of native renal biopsies was 169 (82.8%). Baseline characteristics of two groups were comparable. The mean number of total glomeruli from real-time ultrasound-guided percutaneous renal biopsy was significantly more than blind percutaneous renal biopsy (20.8 ± 12.1 vs 16.0 ± 13.0, p = 0.001). The real-time ultrasound-guided percutaneous renal biopsy obtained more adequate tissues than blind percutaneous renal biopsy (45.2% vs 16%, p < 0.001) and was the only factor associated with adequate tissue. Moreover, 16 renal biopsies from blind percutaneous renal biopsy obtained inadequate tissue. The overall bleeding complications were not statistically different. We found being female, lower eGFR and lower hematocrit were associated with bleeding complications. Conclusion: In comparison with blind percutaneous renal biopsy, real-time ultrasound-guided percutaneous renal biopsy obtained more adequate tissue and number of glomeruli. While the complications of both were comparable. We encourage to practice and perform real-time ultrasound-guided percutaneous renal biopsy in resource constraint countries.

Background. Aging is associated with a high risk of acute kidney injury (AKI), and the elderly with AKI show a higher mortality rate than those without AKI. In this study, we compared AKI outcomes between elderly and nonelderly patients in a university hospital in a developing country. Materials and Methods. This retrospective cohort study included patients with AKI who were admitted to the medical intensive care unit (ICU) between January 1, 2012, and December 31, 2017. The patients were divided into the elderly (eAKI; age ≥65 years; n = 158) and nonelderly (nAKI; n = 142) groups. Baseline characteristics, comorbidities, principle diagnosis, renal replacement therapy (RRT) requirement, hospital course, and in-hospital mortality were recorded. The primary outcome was in-hospital mortality. Results. The eAKI group included more females, patients with higher Acute Physiology and Chronic Health Evaluation II scores, and patients with more comorbidities than the nAKI group. The etiology and staging of AKI were similar between the two groups. There were no significant differences in in-hospital mortality (p=0.338) and RRT requirement (p=0.802) between the two groups. After adjusting for covariates, the 28-day mortality rate was similar between the two groups (p=0.654), but the 28-day RRT requirement was higher in the eAKI group than in the nAKI group (p=0.042). Conclusion. Elderly and nonelderly ICU patients showed similar survival outcomes of AKI, although the elderly were at a higher risk of requiring RRT.