***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: OBJECTIVES To investigate the renoprotective effect of nicardipine in patients undergoing robot-assisted laparoscopic radical prostatectomy ( RALRP ) in a prospect i ve trial . Superior visualization of the increasingly performed RALRP requires pneumoperitoneum and extreme head-down tilt , both of which are associated with a decrease in postoperative renal function .  Nicardipine causes preferential dilation of the renal arterioles and attenuates renal dysfunction after cardiac surgery . METHODS After we obtained institutional review board approval , we r and omly treated 100 patients undergoing RALRP with a continuous infusion of nicardipine at a rate of 0.5 microg/kg/min ( nicardipine group , n = 50 ) or with normal saline ( control group , n = 50 ) during surgery . We measured the serum creatinine ( Cr ) level and estimated glomerular filtration rate ( eGFR ) 1 day before surgery and the first and third postoperative days ( POD 1 and 3 , respectively ) . RESULTS Patients ' characteristics and operative data were similar between groups . The serum Cr was significantly higher and the eGFR was significantly lower in the control group at POD 1 . The number of patients having renal insufficiency ( eGFR < 60 mL/min/1.73 m(2 ) ) and abnormal serum creatinine level ( > 1.4 mg/dL ) was significantly greater in the control group ( 9 vs 1 , and 4 vs none , respectively ) at POD 1 . CONCLUSIONS Continuous infusion of low-dose nicardipine during RALRP seems to offset the deleterious effects of inevitable pneumoperitoneum and extreme head-down tilt on renal function in preserving the eGFR and attenuating the development of renal insufficiency in the immediate postoperative period OBJECTIVES Cardiopulmonary bypass ( CPB ) is widely regarded as an important contributor to renal failure , a well recognized complication following coronary artery surgery ( coronary artery bypass grafting ( CABG ) ) . Anecdotally off-pump coronary surgery ( OPCAB ) is considered renoprotective . We examine the extent of renal glomerular and tubular injury in low-risk patients undergoing either OPCAB or on-pump coronary artery bypass ( ONCAB ) .  METHODS Forty low-risk patients with normal preoperative cardiac and renal functions awaiting elective CABG were prospect ively r and omized into those undergoing OPCAB ( n=20 ) and ONCAB ( n=20 ) . Glomerular and tubular injury were measured respectively by urinary excretion of microalbumin and retinol binding protein ( RBP ) indexed to creatinine ( Cr ) . Daily measurements were taken from admission to postoperative day 5 . Fluid balance , serum Cr and blood urea were also monitored . RESULTS No mortality or renal complication were observed . Both groups had similar demographic makeup , Parsonnet score , functional status and extent of coronary revascularization ( 2.1+/-1.0 vs. 2.5+/-0.7 grafts ; P=0.08 ) . Serum Cr and blood urea remained normal in both groups throughout the study . A significant and similar rise in urinary RBP : Cr occurred in both groups peaking on day 1 ( 3183+/-2534 vs. 4035+/-4079 ; P=0.43 ) before reapproximating baseline levels . These trends were also observed with urinary microalbumin : Cr ( 5.05+/-2.66 vs. 6.77+/-5.76 ; P=0.22 ) . Group B patients had a significantly more negative fluid balance on postoperative day 2 ( -183+/-1118 vs. 637+/-847 ml ; P=0.03 ) . CONCLUSIONS Although renal complication or serum markers of kidney dysfunction were absent , sensitive indicators revealed significant and similar injury to renal tubules and glomeruli following either OPCAB or ONCAB . These results suggest that avoidance of CPB does not offer additional renoprotection to patients at low risk of perioperative renal insult during CABG Deterioration of renal function , which can lead to postoperative renal failure , is a complication of surgery involving the suprarenal aorta and surgery involving the renal arteries . Fifty-four patients who were at risk for developing this complication were enrolled in a double-blind , r and omized , placebo-controlled trial of insulin-like growth factor ( IGF-I ) as a therapeutic agent to prevent the decline in renal function . The primary end point was the incidence of renal dysfunction , defined as a reduction of the glomerular filtration rate ( creatinine clearance ) at each of three measurements over 72 h. IGF-I ( 100 microg/kg subcutaneously every 12 h for 6 doses ) or placebo was administered on admission to the intensive care unit immediately postoperatively . IGF-I- and placebo-treated groups were well matched for sex , age , type of surgery , renal ischemic time during surgery ( ischemic index ) , baseline creatinine clearance , and baseline serum creatinine . No patient in the study developed acute renal failure postoperatively . IGF-I was well tolerated . A smaller proportion of patients in the IGF-I group had a postoperative decline in renal function ( 22 % ) than in the placebo-treated group ( 33 % ) . There were no significant differences in levels of serum creatinine at time of discharge , length of hospital stay , length of intensive care unit stay , length of intubation , or incidence of dialysis or death . Our findings establish the feasibility and potential utility for the use of IGF-I to reduce the incidence of postoperative renal dysfunction in high-risk patients OBJECTIVES We aim ed to evaluate the renoprotective role of renal-dose dopamine on cardiac surgical patients at high risk of postoperative renal dysfunction . The latter included older patients or those with pre-existing renal disease , elevated preoperative serum creatinine ( Cr ) , poor ventricular function , hypertension , diabetes mellitus and unstable angina requiring intravenous therapy . METHODS Fifty patients undergoing cardiopulmonary bypass ( CPB ) who fulfilled the entry criteria were prospect ively r and omized into two groups : Group 1 received a ' renal-dose ' ( 3 microg kg(-1 ) min(-1 ) ) dopamine infusion starting at anaesthetic induction for 48 h whilst saline infusion acted as placebo in Group 2 . The anaesthetic and CPB regimes were st and ardized . Urinary excretion of retinol binding protein ( RBP ) indexed to Cr , an accurate and sensitive marker of early renal tubular damage , was assessed daily for 6 days . Additional outcome measures included daily fluid balance , blood urea and serum Cr . Statistical comparisons were made using ANOVA and Mann-Whitney U-test . RESULTS No significant difference was found between the groups in their age , gender , preoperative NYHA class , ejection fraction , baseline serum Cr and duration of CPB and aortic cross-clamping . Renal replacement therapy was not required in any instance . Both groups demonstrated a similar and significant rise in urinary RBP throughout the study period . Dopamine-treated patients achieved more negative average fluid balance than those on placebo ( 5 vs. 229 ml , P<0.05 ) . CONCLUSIONS Renal-dose dopamine therapy failed to offer additional renoprotection to patients considered at increased risk of renal dysfunction after CPB BACKGROUND Low-dose dopamine is commonly administered to critically ill patients in the belief that it reduces the risk of renal failure by increasing renal blood flow . However , these effects have not been established in a large r and omised controlled trial , and use of dopamine remains controversial . We have done a multicentre , r and omised , double-blind , placebo-controlled study of low-dose dopamine in patients with at least two criteria for the systemic inflammatory response syndrome and clinical evidence of early renal dysfunction ( oliguria or increase in serum creatinine concentration ) . METHODS 328 patients admitted to 23 participating intensive-care units ( ICUs ) were r and omly assigned a continuous intravenous infusion of low-dose dopamine ( 2 microg kg(-1 ) min(-1 ) ) or placebo administered through a central venous catheter while in the ICU . The primary endpoint was the peak serum creatinine concentration during the infusion . Analyses excluded four patients with major protocol violations . FINDINGS The groups assigned dopamine ( n=161 ) and placebo ( n=163 ) were similar in terms of baseline characteristics , renal function , and duration of trial infusion . There was no difference between the dopamine and placebo groups in peak serum creatinine concentration during treatment ( 245 [ SD 144 ] vs 249 [ 147 ] micromol/L ; p=0.93 ) , in the increase from baseline to highest value during treatment ( 62 [ 107 ] vs 66 [ 108 ] micromol/L ; p=0.82 ) , or in the numbers of patients whose serum creatinine concentration exceeded 300 micromol/L ( 56 vs 56 ; p=0.92 ) or who required renal replacement therapy ( 35 vs 40 ; p=0.55 ) . Duration s of ICU stay ( 13 [ 14 ] vs 14 [ 15 ] days ; p=0.67 ) and of hospital stay ( 29 [ 27 ] vs 33 [ 39 ] days ; p=0.29 ) were also similar . There were 69 deaths in the dopamine group and 66 in the placebo group . INTERPRETATION Administration of low-dose dopamine by continuous intravenous infusion to critically ill patients at risk of renal failure does not confer clinical ly significant protection from renal dysfunction Activation of the renin-angiotensin system during open heart surgery may have consequences both beneficial in sustaining blood pressure and deleterious in compromising renal hemodynamics . The influence of short-term pretreatment with captopril on blood pressure and renal function was assessed double-blind versus placebo in 18 patients without pre-existing cardiac or renal failure , and undergoing coronary artery bypass . No difference in blood pressure and fluid requirement during the surgical period was observed between groups receiving captopril or placebo .  Effective renal plasma flow and glomerular filtration rate decreased in the placebo group whereas they remained unaltered in the captopril group ; during cardiopulmonary bypass , urinary excretion of sodium was greater in patients receiving captopril than those receiving placebo . These results suggest that captopril pretreatment does not compromise the control of blood pressure and renal function during open heart surgery ; additional studies on the protective value of angiotensin-converting enzyme inhibitors are warranted in patients at higher risk for developing renal failure BACKGROUND AND OBJECTIVE Postoperative renal impairment is a recognized complication of infrarenal aortic cross-clamping . Our hypothesis was that the renal vasodilating and natriuretic effects of fenoldopam mesylate , a selective dopamine ( DA1 ) agonist , would preserve renal function in patients undergoing elective infrarenal aortic cross-clamping . METHODS A prospect i ve , r and omized , double blind controlled clinical trial was performed . Twenty-eight ASA II-III patients undergoing elective aortic surgery requiring infrarenal aortic cross-clamping were studied . According to r and om allocation , patients received either fenoldopam ( 0.1 microg kg(-1 ) min(-1 ) ) or placebo intravenously prior to surgical skin incision until release of the aortic clamp . Plasma creatinine , creatinine clearance , urinary output , fractional excretion of sodium , and free water clearance were measured : ( a ) prior to admission to hospital ; ( b ) during the period from insertion of the urinary catheter until application of the aortic cross-clamp ; ( c ) during the period of aortic cross-clamping ; ( d ) 0 - 4 h , and ( e ) 4 - 8 h after release of the clamp and on days 1 , 2 , 3 , and 5 postoperatively . RESULTS Fenoldopam ( 0.1 microg kg(-1)min(-1 ) ) administration was not associated with haemodynamic instability . On application of the aortic cross-clamp creatinine clearance decreased significantly in the placebo ( 83 + /- 20 to 42 + /- 29 mL min(-1 ) ( mean + /- SD ) ) ( P < 0.01 ) but not in the fenoldopam group , and this decrease persisted for at least 8 h after release of the cross-clamp ( 83 + /- 20 to 54 + /- 33 mL min(-1 ) ( mean + /- SD ) ) ( P < 0.05 ) . Plasma creatinine concentration increased significantly from baseline on the first postoperative day in the placebo group ( 87 + /- 12 to 103 + /- 28 micromolL(-1 ) ( mean + /- SD ) ) ( P < 0.01 ) but not in the fenoldopam group . CONCLUSIONS These findings are consistent with the hypothesis that fenoldopam possesses a renoprotective effect during and after infrarenal aortic cross-clamping In a prospect i ve r and omized trial of 16 patients undergoing abdominal vascular reconstructive procedures  , changes in plasma volume , serum on 
    Output:
    
Because of considerable clinical heterogeneity ( different clinical scenarios , as well as considerable method ological variability amongst the studies ) , we did not perform a meta- analysis on the combined data .Subgroup analysis of major interventions and surgical procedures showed no significant influence of interventions on reported mortality and acute renal injury .
No reliable evidence from the available literature suggests that interventions during surgery can protect the kidneys from damage .