Comparative Study on Trace Element Excretions between Nonanuric and Anuric Patients Undergoing Continuous Ambulatory Peritoneal Dialysis.

Few studies have been reported on alterations of trace elements (TE) in peritoneal dialysis patients. Our objective was to investigate and assess the characteristics of daily TE excretions in continuous ambulatory peritoneal dialysis (CAPD) patients. This cross-sectional study included 61 CAPD patients (nonanuric/anuric: 45/16) and 11 healthy subjects in Wuhan, China between 2013 and 2014. The dialysate and urine of patients and urine of healthy subjects were collected. The concentrations of copper (Cu), zinc (Zn), selenium (Se), molybdenum (Mo), and arsenic (As) in dialysate and urine were determined using inductively coupled plasma mass spectrometer (ICP-MS). Various clinical variables were obtained from automatic biochemical analyzer. Daily Cu, Zn, Se, and Mo excretions in nonanuric patients were higher than healthy subjects, while arsenic excretion in anuric patients was lower. A strong and positive correlation was observed between Se and Mo excretion in both dialysate (ß = 0.869, p < 0.010) and urine (ß = 0.968, p < 0.010). Furthermore, the clinical variables associated with Se excretion were found to be correlated with Mo excretion. Our findings indicated that nonanuric CAPD patients may suffer from deficiency of some essential TEs, while anuric patients are at risk of arsenic accumulation. A close association between Se and Mo excretion was also found.

Overestimation of Glomerular Filtration Rate Among Critically Ill Adults With Hospital-Acquired Oligoanuric Acute Kidney Injury.

BACKGROUND: Medication use in the intensive care unit (ICU) depends on creatinine-based glomerular filtration rate (GFR) estimates. Urine output deterioration may precede the creatinine rise resulting in delayed recognition of GFR reductions. Our objective was to quantify the disparity between estimated GFR (eGFR) and true GFR in ICU patients with hospital-acquired oligoanuric acute kidney injury (hAKI). METHODS: This single-center cohort study examined adults who met the Acute Kidney Injury Network stage III urine output criterion ≥48 hours after ICU admission. True GFR was ≤15 mL/min/1.73 m(2), and eGFR was described by 6 different creatinine-based equations. True GFR and eGFR were compared on the day of hAKI diagnosis and followed for 4 days using multivariable linear regression with generalized estimating equations, adjusting for day and method. RESULTS: Of the 691 patients screened, we enrolled 61 patients. After adjustment for multiple comparisons and day, there were significant differences in eGFR between the estimation methods and true GFR (P < .001). After day adjustment, eGFR overestimated true GFR by 17 to 50 mL/min/1.73 m(2) and overestimation persisted through the fourth day of hAKI (P ≤ .001). CONCLUSION: Creatinine-based equations overestimated GFR in ICU patients with hAKI. This study highlights a population at risk of medication misadventures in whom systems optimization should be considered.

Aminophylline improves urine flow rates but not survival in childhood oliguric/anuric acute kidney injury.

INTRODUCTION: Acute kidney injury (AKI) morbidity and mortality rates remain high. Variable AKI outcomes have been reported in association with aminophylline treatment. This study evaluated AKI outcome in a group of Nigerian children treated with aminophylline. METHODS: This is a retrospective study of AKI in children treated with (N=9) and without (N=8) aminophylline. Studied outcome indices comprised urine flow rate (UFR), duration of oliguria/anuria, progression through AKI stages, number of patients requiring dialysis and mortality. RESULTS: Mean ages for the control and aminophylline arms were 4.6±2.7 and 4.9±2.1 years (P=0.7), respectively. All patients progressed to stage-3 AKI. Baseline median UFRs in the aminophylline and control arms were similar (0.13 Vs 0.04 ml/kg/hour respectively, P=0.5). The median UFR was significantly higher on day-5 (0.8 Vs 0.1; P=0.03), day-6 (1.0 Vs 0.2; P=0.02), and day-7 (1.2 Vs 0.2; P=0.03) in the aminophylline than the control arm, respectively. Short duration of oliguria/anuria (≤ 6 days) was more frequently observed in aminophylline- treated patients compared to controls (77.8% Vs 25.0%; odds ratio 0.09; 95% CI: 0.01-0.89; P=0.04). Only the aminophylline group maintained steady serum creatinine levels. Four out of five patients in the control group were dialyzed compared to only one out of eight patients in the aminophylline group (odds ratio 0.16; 95% CI: 0.04-0.71; P=0.03). Mortality rates were similar in aminophylline- treated and control patients (33% Vs 25%; hazard ratio 0.8; 95% CI: 0.1-5.5; P=0.8). CONCLUSION: Aminophylline therapy was beneficial for patients with AKI in terms of improved UFR and reduced need for dialysis, but failed to impact positively on survival.

A device for automatically measuring and supervising the critical care patient's urine output.

Critical care units are equipped with commercial monitoring devices capable of sensing patients' physiological parameters and supervising the achievement of the established therapeutic goals. This avoids human errors in this task and considerably decreases the workload of the healthcare staff. However, at present there still is a very relevant physiological parameter that is measured and supervised manually by the critical care units' healthcare staff: urine output. This paper presents a patent-pending device capable of automatically recording and supervising the urine output of a critical care patient. A high precision scale is used to measure the weight of a commercial urine meter. On the scale's pan there is a support frame made up of Bosch profiles that isolates the scale from force transmission from the patient's bed, and guarantees that the urine flows properly through the urine meter input tube. The scale's readings are sent to a PC via Bluetooth where an application supervises the achievement of the therapeutic goals. The device is currently undergoing tests at a research unit associated with the University Hospital of Getafe in Spain.

Tubule recovery after obstructive nephropathy relief: the value of enzymuria and microproteinuria.

The recovery of tubules after relief of obstructive nephropathy may be investigated through serial assessment of the urinary excretion of tubular enzymes alpha-glucosidase, gamma-glutamyl-transferase and N-acetyl glucosaminidase as well as of the microprotein beta-2-microglobulin. We studied 21 patients in whom obstructive nephropathy was relieved by operative or nonoperative methods. Anuria persisted from 2 to 14 days. In these patients urinary excretion of alpha-glucosidase, gamma-glutamyl-transferase, N-acetyl glucosaminidase and beta-2-microglobulin, as well as the serum creatinine were assessed weekly. Serum creatinine was the earliest index to return to normal (within 9 to 26 days). Enzymuria returned to normal within 35 to 45 days, whereas normal urinary excretion of beta-2-microglobulin occurred more than 100 days after relief of obstructive nephropathy. N-acetyl glucosaminidase and gamma-glutamyl-transferase proved to be more reliable than alpha-glucosidase in detecting recovery of the luminal membrane of the proximal tubule. The return to normal of urinary beta-2-microglobulin levels has been shown to occur later, since more specific and complex intracellular functions underlie this index. The pathophysiological aspects of recovery of obstructive nephropathy may be considered similar to those observed in ischemic acute renal failure, since in both instances hemodynamic changes are involved.

The use of urinary diagnostic indices in pre-eclampsia-associated oliguria.

A case is presented of severe pregnancy-induced hypertension that was complicated by oliguria and managed with the aid of a pulmonary artery catheter. This case illustrates that urinary diagnostic indices may be unreliable in predicting the etiology of oliguria. Although urinary diagnostic tests are advocated routinely as reliable in the nonobstetric literature, possible misinterpretation of these values in severe pre-eclampsia with oliguria may require confirmation with hemodynamic data obtained from a pulmonary artery catheter.

Urinary diagnostic indices in preeclampsia-associated oliguria: correlation with invasive hemodynamic monitoring.

Seven oliguric women with preeclampsia were identified among patients admitted for obstetric care at Jefferson Davis or Hermann Hospitals in Houston, Texas. Urinary diagnostic indices (including urine-to-plasma ratios of creatinine, urea nitrogen, and osmolality) were generally consistent with a prerenal etiology for the observed oliguria. Conversely, invasive hemodynamic monitoring revealed a volume replete state in five of seven preeclamptic women studied. All patients were observed to have markedly elevated urinary sodium concentrations. The transient oliguria observed in these patients spontaneously resolved without diuretic or hyperosmolar agents. We conclude that oliguria is a poor index of volume status in preeclamptic women. Urinary diagnostic indices may also be misleading if used to guide fluid management in these patients. Finally, the clinical significance and therapeutic alternatives relating to preeclampsia-associated oliguria are discussed.

Plasma retinol and retinol binding protein concentrations in patients on maintenance haemodialysis with and without vitamin A supplements.

Plasma retinol and retinol-binding protein (RBP) concentrations have been estimated in patients on maintenance haemodialysis over a 4-year period. For the first 2 years multivitamin supplements containing vitamin A were taken, and for the second 2 years no vitamin A supplements were given. Mean plasma retinol concentrations decreased significantly but only from 3.8 times normal to 3.1 times normal after vitamin A supplements stopped. There was no significant change in th high plasma RBP levels. Ultracentrifugation of plasma at a salt density of 1.21 showed that nearly all the retinol was associated with RBP in the high density protein fraction, as it is with normal subjects. Column chromatography confirmed that there was no increase in plasma retinyl esters in the renal failure patients, as is found in hypervitaminosis A due to drug overdosage. The high plasma retinol and RBP levels remained remarkably stable in individual patients throughout the 4-year study. The increase in plasma RBP was possibly related to residual urine output. The results are compatible with a feedback mechanism whereby the extent of the increase in plasma RBP as renal failure develops controls the consequent high plasma level of retinol.

Studies on djenkol bean poisoning (djenkolism) in experimental animals.

Djenkolic acid was extracted from djenkol beans with 70% ethanol and water and was quantitatively determined by paper chromatography. Djenkol beans contained 0.3-1.3 gm% djenkolic acid and about 93% of this acid occurred in the free state. The toxicity of djenkol beans was studied in 5 rhesus monkeys, 9 albino rats and 22 mice fed with 70% ethanol extracts. The total urinary output decreased. There was an increase in specific gravity of the urine during the period of feeding monkeys with djenkol beans. Urinary samples of the experimental animals were turbid and contained some red cells, white cells, epithelial cells, albumin and amorphous particles. One of 22 mice excreted sharp needle-shaped crystals in the urine on day 3 after feeding. Histological examination of kidneys of rats and mice showed mild to severe acute tubular necrosis with some glomerular cell necrosis.