Effects Of Low Dose Furosemide On Preventing Contrast-Induced Nephropathy At The Basic Of Adequate Hydration In Patients Undergoing Coronary According To Brain Natriuretic Peptide Levels

Objectives： So far about Contrast-induced nephropathy (CIN) diagnosticcriteria of no consensus, definition of currently widely used in the world is theEuropean urogenital radiology contrast agents released guidelines: in2005invascular contrast agents used in3d of kidney damage, main show is elevatedserum creatinine level is the basic level44.2mu mol/L or from the basic levelincreased by25%, and with the exception of the kidney damage caused byother reasons. Generally in24~48h before and after the application ofcontrast agent, the rise in serum creatinine after3~5d peak, can return tonormal within7~10d. CIN the exact pathogenesis is unclear, but accordingto a large number of research results summarized up, contrast to the kidneyfunction main performance for renal hemodynamic changes caused byischemic injury and contrast agents direct toxic effect of renal tubule. Atpresent there are hydration methods to prevent recognized contrast agent andcontrol risk factors. In addition application N-acetylcysteine, fenoldopam,theophylline drugs for the prevention of contrast nephropathy remainscontroversial..Furosemide as loop diuretics, inhibit prostaglandin decompositionenzyme activity, make the higher content of prostaglandin E2, which canexpand the renal blood vessels, reduce renal vascular resistance, make therenal blood flow, especially the renal cortex increased blood flow to the deep.Furosemide increased renal tubular fluid flow and glomerular filtration ratedoes not decline. Experiments prove that on the basis of fully hydrated givingsmall doses of furosemide can prevent contrast-induced nephropathy.B-type natriuretic peptide (BNP) is also sometimes called brain natriuretic peptide, is acomposed with32amino acid polypeptide, containing acircular structure of17amino acids, it is a peptide hormone secreted by theheart. When ventricular enlargement and load increase, the BNP secretionincreased and then release the person blood, with renin-angiotensin-aldoster-o-ne system(RAAS), aldosterone antagonist role to control the dynamic balanceof body fluids and electrolytes. BNP is the result of134amino acids inmyocardial cells Prepro-BNP, after enter the blood circulation, degradation toproduce bioactive BNP and an inactive fragment NT-proBNP76amino acids.The BNP has diastolic blood vessels, natriuretic and diuretic, step-down,inhibiting renin-angiotensin-aldosterone system and the sympathetic nervoussystem and various physiological functions.When the BNP as105pm/mljudge heart failure point, has a high sensitivity (about95%) and specific (86%).Conclusion BNP is important clinical reference value for diagnosis of heartfailure.An prospective experiments show that the BNP in PCI postoperative,application of BNP in patients with serum creatinine in48hours after the peakbegan to decline,7hours to normal levels. But they are not so in the controlgroup. At24,48,72hours after PCI, the application of the BNP group serumcreatinine level was lower than those of control group. After the application ofcontrast agent, glomerular filtration rate usually fell to the lowest in48hours,and then began to rise. Application of BNP in patients with glomerularfiltration rate than the control group high, the incidence of CIN was lower thanthose of control group. In a word, the prophylactic use of BNP can improvekidney.Function, reduce the happening of the CIN.This experiment is to use the BNP as constraints, giving small doses offurosemide, to prevent any further significance of contrast-inducednephropathy.Methods：Choose between September2009and January2014in ourhospital coronary angiography and (or) coronary artery stent implantation(PCI) patients, and ruled out heart failure (NYHA) class Ⅳ or other seriousillness not appropriate hydration in patients with a total of226cases. Among which78were female, male148cases, the average weight of72.57kg (10.41),the average age was57.38(9.48), intraoperative use iodine amine injection onthe street (370), the average amount of82.65ml (39.82). Selected patientswere randomly divided into experimental group and control group,experimental group112cases, control group114cases. Coronary angiographybefore check serum creatinine level, on the basis of glomerular filtration ratein the MDRD formula: GFR (ml/min/1.73m2)=186×(Scr)-1.154×(age)-0.203（×0.742women); On the basis of Cockcroft-Gault formula serum creatinineclearance: the Ccr (ml/min)=[(140-age)×(0.85women)] weight/72×(Scr).Preoperative patients with4hours begin to1ml/kg/h of physiological salinehydration, the experimental group according to the BNP resultspostoperatively furosemide (Postoperative BNP>100pg/ml or preoperativeBNP values more than50%, to20mg Furosemide), control group not guidedby the BNP were given20mg Furosemide. After two groups continue to1ml/kg/h saline hydration continues to24hours. Record during the patient’sintake and output.48hours after review of the serum creatinine levels, tocalculate the glomerular filtration rate and serum creatinine clearance.Contrast nephropathy is defined as the application of contrast agents within48hours after the serum creatinine increases of25%or higher earlier0.5mg/dL.Using SPSS17.0software for statistical analysis. Compare two groups of48hours in patients with preoperative and postoperative serum creatinine, serumcreatinine clearance, the change of glomerular filtration rate, incidence ofcontrast nephropathy have similarities and differences. Measurement datausing mean+/-standard deviation (x+s) or the median (interquartile range);Classification information adoption rate (%). Serum creatinine, serumcreatinine clearance between the two groups and glomerular filtration ratecompared to repeated measurement was analyzed; Within each operation.Results：Clinical situations, gender, age, weight and height with PCI surgerypatients, the use of imaging, diabetes patients, preoperative creatinine levels,in patients with acute myocardial infarction (ami) no significant differencebetween experimental group and the control group (P>0.05). Patients with multivessel disease, high blood pressure, statins application differencesbetween experimental group and the control group (P<0.05). Patients serumcreatinine, glomerular filtration rate higher than that of preoperative,postoperative was statistically significant (P<0.001), the patients serumcreatinine clearance compared with preoperative and postoperative had nostatistical significance (P=0.76); Control group is higher than the preoperative,postoperative serum creatinine was statistically significant (P<0.001) andcontrol group in glomerular filtration rate, serum creatinine clearance is lowerthan the preoperative, postoperative was statistically significant (P<0.001).Experimental group compared with the control group compared with thepreoperative serum creatinine has no statistical significance (P=0.58).Experimental group and control group in serum creatinine level before andafter operation, the changes of glomerular filtration rate and serum creatinineclearance at different levels, compared with the experimental group, controlgroup in the level of serum creatinine, glomerular filtration rate and serumcreatinine clearance decreased the extent of the more obvious (P<0.001).Experimental results show that the incidence of contrast nephropathy was5.67%, the control group results suggest that the incidence of contrastnephropathy was32.56%, with statistical significance (P<0.001).Conclusion: on the basis of fully hydrated with brain natriuretic peptidelevels as restrictions have guiding significance for the prevention of contrastnephropathy.