Oliguric Acute Kidney Injury Research Articles

Measuring Kt by ionic dialysance is a useful tool for assessing dialysis dose in critical patients

To evaluate the Kt assessed through ionic dializance (KtOCM) in UCI patients undergoing renal replacement therapy for acute kidney injury, comparing the results with those obtained through the urea removal rate method determined by dialyzate collection (Kturea). 18 adult UCI staying individuals suffering from renal replacement therapy requiring oliguric acute kidney injury were included in this study. RRT consisted in intermittent or extended hemodialysis performed through a Fresenius 4008E dialysis machine equipped with an on-line clearance monitor (OCM Fresenius). The KtOCM results were provided automatically. The Spearman correlation test was used to assess the relationship between the two exploratory methods and the Student s t test to compare the results obtained by the KtOCM and the Kturea. 35 treatments were analyzed. There were not statistically significant differences between the results form the KtOCM and the Kturea (34.9 +/- 10.69 vs 32.78 +/- 11.31, p = NS). A remarkable association was find between both methods (r = 0.87; 95CI, 0.76-0.94; p < 0.001). The assessment of Kt through ionic dialyzance is a simple method to estimate the dose of dialysis in critically ill patients and is and useful tool to monitor and adjust the RRT in real time according to a target dose.

Exercise-induced acute kidney injury with reversible posterior leukoencephalopathy syndrome

We report a case of a 17-year-old boy suffering from severe loin pain and oliguric acute kidney injury after strenuous exercise, with slightly elevated serum myoglobin and creatinine phosphokinase. Exercise-induced acute kidney injury (AKI) was diagnosed. We started intermittent hemodialysis thrice a week from the admission day. Four days later, he temporally lost consciousness, followed by visual agnosia and general clonic seizure. T2-weighted brain magnetic resonance images (MRI) showed multiple areas of increased signal intensity in the subcortical white matter, predominantly in the cerebrum of the posterior and parietal lobes and in the cerebellum. Clinical symptoms improved without sequelae. Follow-up MRI 1 month later showed complete resolution of the signals, and he was diagnosed with reversible posterior leukoencephalopathy syndrome (RPLS). This is the first reported case of exercise-induced AKI associated with RPLS. Vasoconstriction and endothelial dysfunction are considered as the common etiology of these diseases.

Predictors of Oliguric Acute Kidney Injury in Leptospirosis

Background: Acute kidney injury (AKI) occurs in 10 to 60% of patients with leptospirosis. The aim of this study is to investigate markers for oliguric AKI in leptospirosis. Methods: A retrospective study was performed with 196 consecutive patients with leptospirosis-associated AKI. These patients were categorized into either oliguric or non-oliguric according to their urine output. Clinical and laboratory characteristics were compared between the two groups. Results: Among these patients, 64 (32.6%) were oliguric and 132 (67.4%) nonoliguric. Markers for oliguria were age higher than 40 years (OR = 1.02, p = 0.04), hyponatremia (OR = 0.94, p = 0.03), elevated serum creatinine (OR = 1.11, p = 0.04), low arterial pH (OR = 1.0002, p = 0.01), high levels of AST (OR = 1.005, p = 0.01), crackles (OR = 3.83, p < 0.001) and direct bilirubin (OR = 1.03, p = 0.03). Elevated activated prothrombin time (OR = 0.97, p = 0.03) was a factor associated with nonoliguric AKI. Independent markers for oliguria were crackles (OR = 5.17, p = 0.0016) and direct bilirubin levels (OR = 1.051, p = 0.04). Mortality was significantly higher in oliguric than nonoliguric (27 vs. 8%, p < 0.001). Renal function at discharge was similar in oliguric and nonoliguric patients. Conclusion: Age higher than 40 years, hyponatremia, elevated serum creatinine, low arterial pH, high levels of AST, crackles and direct bilirubin levels would be useful to early identify patients with oliguric AKI in leptospirosis.

The clinical features of acute kidney injury in patients with acute paraquat intoxication

Paraquat (PQ) is a non-selective herbicide that generates reactive oxygen species in vivo. We hypothesized that acute kidney injury (AKI) in patients with acute PQ poisoning would provide a model for the clinical features of ROS-induced AKI. From January 2007 to December 2007, 278 patients with acute PQ intoxication were included in the study. AKI was defined based on the RIFLE classification. The serial changes of creatinine (Cr), the incidence of AKI and the mortality according to the RIFLE classification were analysed. An initial serum Cr >1.2 mg/dL was a significant predictor of mortality [odds ratio 9.00, 95% C.I. (4.747, 17.061), P < 0.01]. The incidence of AKI was 51.4% among the 173 patients who had an initial serum Cr < or =1.2 mg/dL. Among them, 34.7% were the failure group and oliguric AKI was observed in 10 patients. The average peak serum Cr level, among the 13 survivors in the failure group, was 4.38 mg/dL at the fifth day, after ingestion, and their Cr level normalized within 3 weeks. None of the 13 survivors had permanent loss of renal function. The estimated amount of PQ ingestion was a predictor of the incidence of AKI. The mortality risk was significantly higher in the failure group than in the group without failure. The clinical feature was characterized by fully developed AKI at the fifth day after PQ ingestion and normalized within 3 weeks without exception.

Oliguria, volume overload, and loop diuretics

Acute kidney injury (AKI) is commonly and increasingly encountered in patients with critical illness. In the past, epidemiologic studies have consistently found that oliguria further increases the risk of death from AKI. Compared with patients outside the intensive care unit (ICU), critically ill patients are more likely to have volume overload as a result of impaired solute and water excretion. Recently, broad changes have occurred in ICU practice, such as early goal-directed therapy in sepsis, which may further compound volume overload in the ICU patient with oliguric AKI. Evidence has also emerged to suggest that a positive fluid accumulation in ICU patients can unfavorably affect outcome. Thus, the ICU patient with oliguric AKI presents a dilemma with limited therapeutic options. These would include optimization of systemic hemodynamics, added fluid therapy, administration of loop diuretics, or finally, the initiation of renal replacement therapy. Interestingly, recent survey data and observational studies indicate that a majority of intensivists use loop diuretics, specifically furosemide, at some point during the course of illness in patients with AKI. Paradoxically, loop diuretics have been found in several clinical studies of patients with AKI to be potentially detrimental or, at the least, lack effectiveness for improving clinical outcomes. This contradiction between clinical practice and available evidence would suggest there is equipoise and need for higher-quality evidence to better characterize the role of loop diuretics in ICU patients with AKI.

Case mix, outcome and activity for patients with severe acute kidney injury during the first 24 hours after admission to an adult, general critical care unit: application of predictive models from a secondary analysis of the ICNARC Case Mix Programme Database

IntroductionThis study pools data from the UK Intensive Care National Audit and Research Center (ICNARC) Case Mix Programme (CMP) to evaluate the case mix, outcome and activity for 17,326 patients with severe acute kidney injury (AKI) occurring during the first 24 hours of admission to intensive care units (ICU).MethodsSevere AKI admissions (defined as serum creatinine ≥300 μmol/l and/or urea ≥40 mmol/l during the first 24 hours) were extracted from the ICNARC CMP database of 276,326 admissions to UK ICUs from 1995 to 2004. Subgroups of oliguric and nonoliguric AKI were identified by daily urine output. Data on surgical status, survival and length of stay were also collected. Severity of illness scores and mortality prediction models were compared (UK Acute Physiology and Chronic Health Evaluation [APACHE] II, Stuivenberg Hospital Acute Renal Failure [SHARF] T0, SHARF II0 and the Mehta model).ResultsSevere AKI occurred in 17,326 out of 276,731 admissions (6.3%). The source of admission was nonsurgical in 83.7%. Sepsis was present in 47.3% and AKI was nonoliguric in 63.9% of cases. Admission to ICU with severe AKI accounted for 9.3% of all ICU bed-days. Oliguric AKI was associated with longer length of stay for survivors and shorter length of stay for nonsurvivors compared with nonoliguric AKI. Oliguric AKI was associated with significantly greater ICU and hospital mortality (55.8% and 77.3%, respectively) compared with nonoliguric AKI (33.4% and 49.3%, respectively). Surgery during the 1 week before admission or during the first week in the CMP unit was associated with decreased odds of mortality. UK APACHE II and the Mehta scores under-predicted the number of deaths, whereas SHARF T0 and SHARF II0 over-predicted the number of deaths.ConclusionsSevere AKI accounts for over 9% of all bed-days in adult, general ICUs, representing a considerable drain on resources. Although nonoliguric AKI continues to confer a survival benefit, overall survival from AKI in the ICU and survival to leave hospital remains poor. The use of APACHE II score measured during the first 24 hours of ICU stay performs well as compared with SHARF T0, SHARF II0 and the Mehta score, but it lacks perfect calibration.

Evolving Practices in Critical Care and Potential Implications for Management of Acute Kidney Injury

Acute kidney injury (AKI) is a common complication in hospitalized patients, with an incidence of 3 to 10% (1–4). In-hospital mortality rates that are associated with AKI remain high, in the range of 30 to 70% (5–8), despite significant improvements in dialytic technology as well as important advances in critical care, which have resulted in improved survival for other critical illnesses, including acute lung injury and sepsis (9). These improvements include continuous renal replacement therapies, which allow for continuous removal of solutes and fluid and may be tolerated better from a hemodynamic standpoint, and biocompatible dialysis membranes, which are associated with reduced complement and granulocyte activation. In general, indications for dialysis in the acute care setting have been extrapolated from those that are applied in chronic kidney disease, including volume overload that is refractory to diuretic therapy; electrolyte abnormalities (in particular hyperkalemia); uremic complications (pericarditis or pleuritis); severe acidosis (pH < 7.20); and selected toxic ingestions, such as methanol, ethylene glycol, and other water-soluble agents (10,11). However, the evidence base supporting specific dialysis practices in the acute care setting is limited. For example, several studies that were completed in the 1960s and 1970s compared “early” and “late” initiation of dialysis, using blood urea nitrogen (BUN) to define early and late (Table 1). These studies primarily were cohort studies that used historical controls, not randomized, clinical trials. The results of these investigations, along with extrapolation from the ESRD population, promoted recent practice patterns. Currently, many nephrologists often delay dialysis in the acute care setting until the patient has an impending complication of AKI, such as hyperkalemia leading to cardiac arrhythmias, acidosis resulting in hypotension, or oliguria leading to volume overload or hypoxemia, or until the BUN exceeds 100 mg/dl (18). Given differences in protein catabolism, …