Diagnostic performance of salivary urea nitrogen dipstick to detect and monitor acute kidney disease in patients with malaria

BACKGROUND: Acute kidney injury (AKI) is a common complication of malaria. In low resource settings, a lack of diagnostic tools and delayed treatment of malaria associated AKI lead to significant morbidity and mortality. The aim of this study was to assess the diagnostic performance of salivary urea nitrogen (SUN) dipstick to detect and monitor kidney disease [KD = AKI or acute kidney disease (AKD) without AKI] in malaria patients in Angola. METHODS: Patients 11–50 years old admitted with malaria at the Josina Machel (Maria-Pia) Hospital, Luanda, Angola, between 2nd March and 10th May 2016 were enrolled in this study. All participants had serum creatinine (sCr), blood urea nitrogen (BUN) and SUN dipstick tested at the time of recruitment and daily for up to 4 days. AKD without AKI refers to acute renal impairment which do not fulfilled the main criteria for AKI (increases in the baseline serum creatinine and/or decreases in urine output) according defined by the kidney disease improving global outcomes (KDIGO) guideline. RESULTS: Eight-six patients were admitted with malaria diagnosis (mean age 21.5 ± 9.4 years, 71% male) and 27 (32%) were diagnosed with KD. The mean (± SD) sCr and BUN of the KD group at admission (day 0) were 5.38 (± 5.42) and 99.4 (± 61.9) mg/dL, respectively. Three (3.5%) patients underwent haemodialysis and eight (9.3%) died within the first 4 days of hospital admission [5 (62.5%) with KD; 3 (37.5%) without kidney disease; p = 0.047]. The SUN threshold for KD diagnosis was tested pad #5 (SUN > 54 mg/dL). At this threshold, the SUN dipstick had a sensitivity of 67% and specificity of 98% to diagnose KD. The area under the receiver operating characteristics curve (ROC) for KD diagnosis on admission was 0.88 (95% CI 0.79–0.96). The SUN dipstick was most accurate at higher levels of BUN. CONCLUSION: The SUN dipstick had reasonable sensitivity and excellent specificity when used to diagnose KD in a cohort of patients with malaria in a resource-limited setting. Given the severity of presenting illness and kidney injury, the SUN dipstick diagnostic threshold was high (test pad #5). SUN may be used to detect AKI in patients with malaria in low resources settings, thus facilitating earlier access to adequate treatment, which may improve survival

Diagnostic Performance of a Saliva Urea Nitrogen Dipstick to Detect Kidney Disease in Malawi

Introduction: Kidney disease (KD), including acute kidney injury, is common, severe and leads to significant mortality in the developing world. However, simple tools to facilitate diagnosis and guide treatment are lacking. We studied the diagnostic performance of saliva urea nitrogen (SUN) measured by dipstick to diagnose KD in a low-resource setting. Methods: Medical admissions to a tertiary hospital in Malawi had serum creatinine tested at presentation; SUN was measured using a dipstick. Patients with serum creatinine above normal range underwent serial measurements of SUN and blood urea nitrogen for up to 7 days. Hospital outcome was recorded in all patients. Results: A total of 742 patients were included (age 41 ± 17·3 years, 56.1% male); 146 (19.7%) had KD, including 114 (15.4%) with acute kidney injury. SUN >14 mg/dl had a sensitivity of 0.72 and a specificity of 0.87 to diagnose KD; specificity increased to 0.97 when SUN levels were combined with self-reported urine output. The diagnostic performance of SUN was comparable with the one of blood urea nitrogen (SUN area under curve, 0.82; 95% confidence interval, 0.78–0.87; blood urea nitrogen area under curve, 0.82; 95% confidence interval, 0.59–1.0). SUN >14 mg/dl on admission was an independent predictor of all-cause mortality (hazard ratio = 2.43 [95% confidence interval, 1.63–3.62]). Discussion: SUN measured by dipstick can be used to identify patients with KD in a low-resource setting. SUN is an independent predictor of mortality in this population

Determination of fluid status in haemodialysis patients with whole body and calf bioimpedance techniques

Aim: The aim of this study was to demonstrate the ability of widely used bioimpedance techniques to assess dry weight (DW) and to predict a state of normal hydration in haemodialysis patients whose post-dialysis weight had been gradually reduced from baseline in successive treatments over time. Methods: Calf bioimpedance spectroscopy (cBIS) was employed to determine DW (DWcBIS) as defined by flattening of an intradialytic continuously measured resistance curve and by normalized resistivity (nRho) being in the gender-specific normal range. The wECV/ TBW ratio was determined by ` classical' wrist-to-ankle whole body bioimpedance spectroscopy (wBIS); in addition, a novel whole body model (WBM) based on wBIS was used to predict normal hydration weight (NHWWBM). Results: Twenty-one haemodialysis patients were studied; 11 1 6 measurements were performed per patient. Nine patients reached DWcBIS (DWcBIS group), while 12 patients remained fluid-overloaded (non-DWcBIS group). Change in wECV as measured by wBIS accounted for 46 1 23% in DWcBIS group, which was higher than in non-DWcBIS group (33 1 48%, P < 0.05) of actual weight loss at the end of study. In both groups the wECV/ TBW ratio did not change significantly between baseline and study end. Mean predicted NHWWBM at baseline was 3.55 1 1.6 kg higher than DWcBIS. The difference in DWcBIS and NHWWBM was 1.97 1 1.0 kg at study end. Conclusion: WBM could be useful to predict a target range of normal hydration weight particularly for patients with substantial fluid overload. The cBIS provides an accurate reference for the estimation of DW so that combined use of cBIS and WBM is promising and warrants further studies