A simple prognostic index for patients with acute renal failure requiring dialysis. French Multicentric Prospective Study on Furosemide in Acute Renal Failure Requiring Dialysis

The Frequency and Outcome of Acute Kidney Injury in a Tertiary Hospital: Which Factors Affect Mortality?

Acute kidney injury (AKI) is a major cause of mortality and morbidity in hospitalized patients. Incidence and mortality rates vary from country to country, and according to different in-hospital monitoring units and definitions of AKI. The aim of this study was to determine factors affecting frequency of AKI and mortality in our hospital. We retrospectively evaluated data for 1550 patients diagnosed with AKI and 788 patients meeting the Kidney Disease: Improving Global Outcomes (KDIGO) guideline AKI criteria out of a total of 174 852 patients hospitalized in our institution between January 1, 2007 and December 31, 2012. Staging was performed based on KDIGO Clinical Practice for Acute Kidney Injury and RIFLE (Risk, Injury, Failure, Loss of kidney function and End-stage renal failure). Demographic and biochemical data were recorded and correlations with mortality were assessed. The frequency of AKI in our hospital was 0.9%, with an in-hospital mortality rate of 34.6%. At multivariate analysis, diastolic blood pressure (OR 0.89, 95% CI 0.87-0.92; P < 0.001), monitoring in the intensive care unit (OR 0.18, 95% CI 0.09-0.38; P < 0.001), urine output (OR 4.00, 95% CI 2.03-7.89; P < 0.001), duration of oliguria (OR 1.51, 95% CI 1.34-1.69; P < 0.001), length of hospitalization (OR 0.83, 95% CI 0.79-0.88; P < 0.001), dialysis requirement (OR 2.30, 95% CI 1.12-4.71; P < 0.05), APACHE II score (OR 1.16, 95% CI 1.09-1.24; P < 0.001), and albumin level (OR 0.32, 95% CI 0.21-0.50; P < 0.001) were identified as independent determinants affecting mortality. Frequency of AKI and associated mortality rates in our regional reference hospital were compatible with those in the literature. This study shows that KDIGO criteria are more sensitive in determining AKI. Mortality was not correlated with staging based on RIFLE or KDIGO. Nonetheless, our identification of urine output as one of the independent determinants of mortality suggests that this parameter should be used in assessing the correlation between staging and mortality.

Small increases in serum creatinine are associated with prolonged ICU stay and increased hospital mortality in critically ill patients with cancer

PURPOSE

Declining kidney function has been associated with adverse hospital outcome in cancer patients. ICU literature suggests that small changes in serum creatinine are associated with poor outcome. We hypothesized that reductions in renal function previously considered trivial would predict a poor outcome in critically ill patients with malignant disease. We evaluated the effects on hospital mortality and ICU length of stay of small changes in creatinine following admission to the intensive care unit.

METHODS

We conducted a retrospective cohort study utilizing clinical, laboratory and pharmacy data collected from 3,795 patients admitted to the University of Texas M.D. Anderson Cancer Center's Intensive Care Unit. We conducted univariate and multivariate regression analysis to determine those factors associated with adverse ICU and hospital outcome.

RESULTS

Increases in creatinine as small as 10% (0.2 mg/dl) were associated with prolonged ICU stay (5 days vs 6.6 days, p < 0.001) and increased mortality (14.6% vs 25.5%, p < 0.0001). Patients with a 25% rise in creatinine during the first 72 h of ICU admission were twice as likely to die in the hospital (14.3% vs 30.1%, p < 0.001). RIFLE criteria were accurate predictors of outcome, though they missed much of the risk of even smaller increases in creatinine.

CONCLUSIONS

Even small rises in serum creatinine following admission to the ICU are associated with increased morbidity and mortality in oncologic patients. The poor outcome in those with rising creatinine could not be explained by severity of illness or other risk factors. These small changes in creatinine may not be trivial, and should be regarded as evidence of a decline in an individual patient's condition.

Benefits and risks of furosemide in acute kidney injury

Furosemide, a potent loop diuretic, is frequently used in different stages of acute kidney injury, but its clinical roles remain uncertain. This review summarises the pharmacology of furosemide, its potential uses and side effects, and the evidence of its efficacy. Furosemide is actively secreted by the proximal tubules into the urine before reaching its site of action at the ascending limb of loop of Henle. It is the urinary concentrations of furosemide that determine its diuretic effect. The severity of acute kidney injury has a significant effect on the diuretic response to furosemide; a good 'urinary response' may be considered as a 'proxy' for having some residual renal function. The current evidence does not suggest that furosemide can reduce mortality in patients with acute kidney injury. In patients with acute lung injury without haemodynamic instability, furosemide may be useful in achieving fluid balance to facilitate mechanical ventilation according to the lung-protective ventilation strategy.

Prognosis of acute renal failure in children

Acute renal failure (ARF) is the acute loss of renal function over a period of hours or days. Given the poor prognosis of ARF among children, there is some urgency to identifying more effective prognostic indicators for detecting disease onset. Such indicators would help provide the means of selecting patients who would benefit the most from early aggressive treatment. In this study we assessed the etiologic and prognostic indicators of ARF, including several risk factors such as sepsis, respiratory distress, age, among others, in 300 children who were admitted to the Ali Asghar Children's Hospital, Tehran, Iran, from 1990 to 2003. Statistical analysis was performed using multiple regression and chi-square methods, and a score to determine the prognosis of ARF in children was developed.

RESULT

Based on the results of this study the three common causes of ARF are acute tubular necrosis (ATN, 38%), acute glumerulonephritis (24%) and hemolytic uremic syndrome (24.1%). The overall mortality rate among our patients was 24.7%, with the highest risk group being those patients suffering from ischemic ATN. In addition, the correlation (p<0.0005) between the etiology and mortality rate was particularly high in patients with ischemic ATN. Mortality was also high (68%) in children younger than 2 years. Multiple regression models revealed that among those factors that significantly differed between the survivors and nonsurvivors, only the necessity of dialysis (p<0.0005), the use of mechanical ventilation (p=0.05) and disseminated intravascular coagulation (p=0.038) can be regarded as independent determinants of ARF prognosis in children.

Relationship of urine output to dialysis initiation and mortality in acute renal failure

BACKGROUND

A non-oliguric state is considered a good prognostic indicator in acute renal failure (ARF), and may lead to withholding renal replacement therapy in anticipation of recovery. The present study explores the relationship between urine volume and the start of dialysis and hospital mortality in patients with ARF.

METHODS

In a non-concurrent cohort of patients with ARF treated exclusively with intermittent hemodialysis (IHD), demographic, clinical and laboratory characteristics were collected at the time of the first nephrology consultation and at the start of dialysis. Multiple linear and logistic regression analyses were used to identify factors associated with the time to initiation of dialysis and hospital mortality, respectively.

RESULTS

Urine volume correlated with the time from admission to start of dialysis (r = 0.60; p < 0.001). Higher urine volume, lower serum creatinine and lower APACHE II score were independently associated with increased time from admission to start of dialysis. Hospital mortality was independently associated with a higher urine volume (odds ratio, OR 3.8, 95% confidence interval, CI, 1.1-12.8, p = 0.03), a higher MOF score (OR 4.9, 95% CI 1.1-21.6, p = 0.03) and a higher number of dialysis treatments performed in the 1st week (OR 3.7, 95% CI 1.2-11.3, p = 0.03).

CONCLUSIONS

Among patients with ARF requiring IHD, increased urine output is associated with higher mortality. This observation may reflect physician bias toward later initiation of dialysis in non-oliguric ARF. Further research is needed to help identify patients with non-oliguric ARF who require early dialytic support.

Effect of mechanical ventilation on the kidney

Mechanical ventilation is a standard component of intensive care unit management of critically ill patients and is widely used for respiratory support. Recent animal and clinical studies have shown that positive pressure ventilation can worsen pre-existing lung injury and produce ventilator-induced lung injury, which has been linked with the development of systemic inflammation and multi-system organ dysfunction, including renal failure. Although the physiological consequences of mechanical ventilation on pulmonary and cardiovascular function have been extensively studied, its effects on renal function are not as well defined. Previous experimental studies and few clinical reports have shown a significant effect of mechanical ventilation on renal function. Interestingly, recent data are emerging which suggest that renal dysfunction also has a direct, adverse effect on pulmonary function. This chapter reviews the information in these areas and provides a framework for future investigation in this field.

Mechanical ventilation and renal function: an area for concern?

Mechanical ventilation is a standard component of intensive care unit management of critically ill patients and widely used for respiratory support. Patients requiring ventilation often have renal dysfunction that can occur as a consequence of the underlying disease or be related to the therapy. Although the physiological consequences of mechanical ventilation on pulmonary and cardiovascular function have been extensively studied, its effects on renal function are not as well defined. Previous experimental studies and few clinical reports have shown a significant effect of mechanical ventilation on renal function. This review compiles the information in this area and provides a framework for future investigation in this field.

Acute renal failure in the intensive care unit. Therapy overview, patient risk stratification, complications of renal replacement, and special circumstances

This article provides a basic definition of severity scoring among patients with acute renal failure and extends the definition into the types of dialysis support that are generally used in intensive care unit acute renal failure. Acute dialysis dosing and the problems that create a difference between chronic renal failure and acute renal failure support are described, the dialytic techniques and side effects and complications of each are compared, and nonrenal-based special situations in which extracorporeal therapy has been found to be helpful are defined.

A simple and early prognostic index for acute renal failure patients requiring renal replacement therapy

Recent advances in technology have not substantially changed the high mortality rate associated with acute renal failure (ARF). To obtain a simple, valid prognostic index, we retrospectively evaluated the relative importance of demographic data, causes (acute insults) of renal failure, and comorbid clinical conditions for the outcome in 102 ARF patients who received renal replacement therapy with an overall mortality rate of 65% (66 of 102). There were no significant differences between survivors and nonsurvivors in age and gender. Mortality according to acute insults was similar to that of the whole population studied. Of the 10 clinical conditions at the time of the first renal replacement therapy, mechanical ventilation (p = 0.0002), cardiac failure (p = 0.0006), hepatic failure (p = 0.003), central nervous system dysfunction (p = 0.005), and oliguria (p = 0.04) were found to be significantly related to mortality by univariate analysis. Furthermore, multivariate analysis demonstrated that only mechanical ventilation, cardiac failure, and hepatic failure were significant risk factors. Survival was directly related to the number of significant variables in univariate analysis: zero, 89% (8 of 9); one, 62% (21 of 34); two, 19% (5 of 27); three, 10% (2 of 20); four, 0% (0 of 8); five, 0% (0 of 4). This simple and early prognostic index, derived from the assessment of clinical conditions which were easily determined at the patient's bedside, could be useful for outcome prediction in ARF patients requiring renal replacement therapy.