***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: CONTEXT Although acute renal failure ( ARF ) is believed to be common in the setting of critical illness and is associated with a high risk of death , little is known about its epidemiology and outcome or how these vary in different regions of the world . OBJECTIVES To determine the period prevalence of ARF in intensive care unit ( ICU ) patients in multiple countries ; to characterize differences in etiology , illness severity , and clinical practice ; and to determine the impact of these differences on patient outcomes . DESIGN , SETTING , AND PATIENTS Prospect i ve observational study of ICU patients who either were treated with renal replacement therapy ( RRT ) or fulfilled at least 1 of the predefined criteria for ARF from September 2000 to December 2001 at 54 hospitals in 23 countries . MAIN OUTCOME MEASURES Occurrence of ARF , factors contributing to etiology , illness severity , treatment , need for renal support after hospital discharge , and hospital mortality . RESULTS Of 29 269 critically ill patients admitted during the study period , 1738 ( 5.7 % ; 95 % confidence interval [ CI ] , 5.5%-6.0 % ) had ARF during their ICU stay , including 1260 who were treated with RRT . The most common contributing factor to ARF was septic shock ( 47.5 % ; 95 % CI , 45.2%-49.5 % ) . Approximately 30 % of patients had preadmission renal dysfunction . Overall hospital mortality was 60.3 % ( 95 % CI , 58.0%-62.6 % ) . Dialysis dependence at hospital discharge was 13.8 % ( 95 % CI , 11.2%-16.3 % ) for survivors . Independent risk factors for hospital mortality included use of vasopressors ( odds ratio [ OR ] , 1.95 ; 95 % CI , 1.50 - 2.55 ; P<.001 ) , mechanical ventilation ( OR , 2.11 ; 95 % CI , 1.58 - 2.82 ; P<.001 ) , septic shock ( OR , 1.36 ; 95 % CI , 1.03 - 1.79 ; P = .03 ) , cardiogenic shock ( OR , 1.41 ; 95 % CI , 1.05 - 1.90 ; P = .02 ) , and hepatorenal syndrome ( OR , 1.87 ; 95 % CI , 1.07 - 3.28 ; P = .03 ) . CONCLUSION In this multinational study , the period prevalence of ARF requiring RRT in the ICU was between 5 % and 6 % and was associated with a high hospital mortality rate Risk factors for nephrotoxicity in patients treated with aminoglycosides were determined from the case records of 214 patients in two prospect i ve , r and omized clinical trials of gentamicin and tobramycin .  Nephrotoxicity , defined as a 50 % or greater fall in calculated creatinine clearance , developed in 30 patients ( 14.1 % ) . Patients with nephrotoxicity had higher initial calculated creatinine clearances , were more often women , and were more likely to have liver disease . Using stepwise discriminant analysis , these factors were selected with the initial 1-hour post-dose aminoglycoside level , patient age , and shock . An equation was generated that was accurate in discriminating between patients with and without nephrotoxicity when vali date d in an independent population . Factors that did not add significantly to the equation were diabetes , dehydration , serum bicarbonate , bacteremia , urinary tract infection , gentamicin or tobramycin use , duration of therapy , total aminoglycoside dose , or the use of clindamycin , furosemide , or cephalothin BACKGROUND Injections of radiocontrast agents are a frequent cause of acute decreases in renal function , occurring most often in patients with chronic renal insufficiency and diabetes mellitus . METHODS We prospect ively studied 78 patients with chronic renal insufficiency ( mean [ + /- SD ] serum creatinine concentration , 2.1 + /- 0.6 mg per deciliter [ 186 + /- 53 mumol per liter ] ) who underwent cardiac angiography .  The patients were r and omly assigned to receive 0.45 percent saline alone for 12 hours before and 12 hours after angiography , saline plus mannitol , or saline plus furosemide . The mannitol and furosemide were given just before angiography . Serum creatinine was measured before and for 48 hours after angiography , and urine was collected for 24 hours after angiography . An acute radiocontrast-induced decrease in renal function was defined as an increase in the base-line serum creatinine concentration of at least 0.5 mg per deciliter ( 44 mumol per liter ) within 48 hours after the injection of radiocontrast agents . RESULTS Twenty of the 78 patients ( 26 percent ) had an increase in the serum creatinine concentration of at least 0.5 mg per deciliter after angiography . Among the 28 patients in the saline group , 3 ( 11 percent ) had such an increase in serum creatinine , as compared with 7 of 25 in the mannitol group ( 28 percent ) and 10 of 25 in the furosemide group ( 40 percent ) ( P = 0.05 ) . The mean increase in serum creatinine 48 hours after angiography was significantly greater in the furosemide group ( P = 0.01 ) than in the saline group . CONCLUSIONS In patients with chronic renal insufficiency who are undergoing cardiac angiography , hydration with 0.45 percent saline provides better protection against acute decreases in renal function induced by radiocontrast agents than does hydration with 0.45 percent saline plus mannitol or furosemide CONTEXT Acute renal failure is associated with high mortality and morbidity .  Diuretic agents continue to be used in this setting despite a lack of evidence supporting their benefit . OBJECTIVE To determine whether the use of diuretics is associated with adverse or favorable outcomes in critically ill patients with acute renal failure . DESIGN Cohort study conducted from October 1989 to September 1995 . PATIENTS AND SETTING A total of 552 patients with acute renal failure in intensive care units at 4 academic medical centers affiliated with the University of California . Patients were categorized by the use of diuretics on the day of nephrology consultation and , in companion analyses , by diuretic use at any time during the first week following consultation . MAIN OUTCOME MEASURES All-cause hospital mortality , nonrecovery of renal function , and the combined outcome of death or nonrecovery . RESULTS Diuretics were used in 326 patients ( 59 % ) at the time of nephrology consultation . Patients treated with diuretics on or before the day of consultation were older and more likely to have a history of congestive heart failure , nephrotoxic ( rather than ischemic or multifactorial ) origin of acute renal failure , acute respiratory failure , and lower serum urea nitrogen concentrations . With adjustment for relevant covariates and propensity scores , diuretic use was associated with a significant increase in the risk of death or nonrecovery of renal function ( odds ratio , 1.77 ; 95 % confidence interval , 1.14 - 2.76 ) . The risk was magnified ( odds ratio , 3.12 ; 95 % confidence interval , 1.73 - 5.62 ) when patients who died within the first week following consultation were excluded . The increased risk was borne largely by patients who were relatively unresponsive to diuretics . CONCLUSIONS The use of diuretics in critically ill patients with acute renal failure was associated with an increased risk of death and nonrecovery of renal function . Although observational data prohibit causal inference , it is unlikely that diuretics afford any material benefit in this clinical setting . In the absence of compelling contradictory data from a r and omized , blinded clinical trial , the widespread use of diuretics in critically ill patients with acute renal failure should be discouraged BACKGROUND We evaluated the effects of human atrial natriuretic peptide ( hANP ) during cardiopulmonary bypass ( CPB ) . METHODS Forty patients undergoing coronary artery bypass grafting were investigated . A group of patients given hANP for 24 hours from the start of CPB ( hANP group ) was compared with a non-hANP group . Parameters examined were hemodynamics , urine volume , dosage of furosemide , respiratory index , pleural effusion , ANP , cyclic guanosine monophosphate , renin activity ( renin ) , angiotensin-II , aldosterone , and glomerular filtration rate . RESULTS Central venous pressure , systemic vascular resistance index , and pulmonary vascular resistance index were significantly lower in the hANP group than in the non-hANP group . The hANP group showed significantly higher levels of ANP , cyclic guanosine monophosphate , glomerular filtration rate , and respiratory index , and significantly lower levels of renin , angiotensin-II , aldosterone , and pleural effusion , as compared with the non-hANP group . The dosage of furosemide was significantly lower and the urine volume was significantly larger in the hANP group . CONCLUSIONS hANP can satisfactorily compensate for the shortcomings of CPB by decreasing the peripheral vascular resistance , suppressing the renin-angiotensin-aldosterone system , and exerting a strong diuretic effect Atrial natriuretic factor ( ANF ) ameliorates renal damage in animal models of acute ischemic renal failure . Consequently , ANF could blunt acute tubular necrosis related to ischemia that occurs frequently in cadaveric renal transplants . Ten pairs of cadaveric kidneys were transplanted into 20 recipients . Paired recipients received either alpha-human ANF ( hANF ) or vehicle alone in a prospect i ve , double-blind protocol . Upon revascularization of the allograft , either hANF or vehicle was administered intravenously as a 50-micrograms bolus , followed by a 4-h infusion ( 0.1 microgram/kg/min ) . Glomerular filtration rate ( [125I]iothalamate clearance ) was measured between 4 and 7 days posttransplant and again between 14 and 21 days posttransplant . Serum creatinine was measured daily when patients were in the hospital , then twice weekly as patients were examined in the outpatient clinic . Between the groups , there was no significant difference in age of the recipients or donors , cold ischemia time , or histocompatibility leukocyte antigen match . Infusion of hANF had no adverse effects . When subjects receiving hANF were compared with those treated with vehicle alone , there were no significant differences in serum creatinine or glomerular filtration rate . Three hANF and four vehicle recipients required dialysis postoperatively . At 1 month posttransplant , 19 of 20 patients had functioning allografts ; an allograft from one hANF recipient never functioned . It was concluded that hANF , when given by the protocol of this study , had no beneficial effect on the outcome of cadaveric renal transplantation in humans This study was performed to investigate the effects of atrial natriuretic peptide ( ANP ) and mannitol on renal blood flow ( RBF ) and radiocontrast-induced nephropathy ( RCIN ) in human subjects with chronic renal failure . ANP preserves glomerular filtration rate or RBF ( or both ) in severe animal models of acute renal failure . Radiocontrast is known to substantially decrease RBF and can induce acute renal failure .  Twenty consecutive patients with chronic renal failure ( 60 % with diabetes ) were r and omized in a prospect i ve , double-blind fashion to receive either ANP ( 50 micrograms bolus , then 1 microgram/min infusion ) or mannitol ( 15 % at 100 ml/hr ) for 2 hours before and during cardiac catheterization with diatrizoate . Baseline serum creatinine level ( ANP 2.4 + /- 0.7 mg/dl , mannitol 2.5 + /- 0.8 mg/dl ) , medications , and quantity of radiocontrast were similar in both groups . Direct measurements of RBF were made with thermodilution catheters placed in the left renal vein . RBF rose significantly ( p less than 0.05 ) , to 198 % of baseline at 15 minutes and 166 % of baseline at 65 minutes in the group receiving ANP and remained stable in the group receiving mannitol .  ANP levels rose significantly from baseline at 5 , 15 , 65 and 120 minutes in both groups ( p less than 0.05 ) . Acute renal failure defined as a 0.5 mg/dl rise of creatinine within 24 hours of cardiac catheterization , developed only in patients with diabetes mellitus and was similar in both experimental groups ( ANP , 50 % ; mannitol , 30 % ) . Only patients with diabetes mellitus responded with an increase in RBF after a 5-minute infusion of either ANP or mannitol ( diabetes , 165 % + /- 28 % baseline ; no diabetes , 96 % + /- 8 % baseline ) ( p less than  
    Output:
    
Length of hospital and ICU stay were significantly shorter in the low dose ANP group .
For established AKI , there was no difference in mortality with either low or high dose ANP .
High dose ANP was associated with more adverse events ( hypotension , arrhythmias ) .
ANP was not associated with outcome improvement in either radiocontrast nephropathy or oliguric AKI .
ANP may be associated with improved outcomes when used in low doses for preventing AKI and in managing postsurgery AKI and should be further explored in these two setting s. There were no significant adverse events in the prevention studies , however in the high dose ANP treatment studies there were significant increases hypotension and arrhythmias