肾功能检验幻灯片.pptVIP

Biochemical Assessment of renal function The kidneys are paired organs lying in the posterior abdominal wall on either side of the vertebral column. Covered in a tough fibrous capsule. In gross structure, the kidneys are divided into an outer granular cortex and an inner striated medulla Regulation of osmolality of the body fluid Regulating the volume of the extracellular fluid Regulating concentrations of electrolytes of the extracellular fluid Regulation of acid-base balance Clearance of metabolic waste products urea, uric acid, creatinine Production of special substances erythropoietin, renin, prostaglandins, and thromboxane The kidney has a remarkable ability to dilute or concentrate urine, according to an individuals changing physiological needs, and to regulate electrolyte excretion. Impaired renal function has adverse effects on blood chemistry, blood pressure, fluid balance, nutrient intake, and the persons general state of health. When kidney function becomes compromised by disease, the processes of glomerular filtration and renal tubular reabsorption and secretion become affected. Blood and urine biochemical tests reflect the extent of this dysfunction. Renal function tests are used to screen for kidney disease, to help determine the cause of kidney disease, to determine the extent of renal dysfunction. Tests of renal function 肾小球功能检查 ●内生肌酐清除率 Ccr 测定 ●血清肌酐测定 ●血清尿素氮测定 ●血清尿酸测定 ●血?2-微球蛋白测定 肾小球滤过率（glomerular filtration rate, GFR 肾清除率（renal clearance rate 清除率 某物质每分钟在尿中排出的总量 某物质在血浆中的浓度 血清肌酐测定（serum creatinine, Scr 原理：肌酐分内源性和外源性，每天肌酐的生成量较恒定。由肾小球滤过，肾小管基本不吸收且排泌量小。在摄入量稳定的情况下血中浓度主要取决于肾小球滤过能力，当肾实质损害肾小球滤过率降至临界点（GFR至正常人的1/3），血中肌酐浓度会上升。作为GFR受损的指标，较BUN灵敏，但不是早期诊断指标。 参考值：全血（88.4-176.8 ummol/L 血清或血浆 男:53-106; 女:44-97umol/L  临床意义: ★血肌酐升高 ★鉴别肾源性及非肾源性血肌酐升高 ★鉴别肾前性和肾实质性少尿 ★血肌酐降低 ★其它 内生肌酐清除率测定（Ccr 原理：肌酸（98%在肌肉，每于更新2%）在磷酸激酶作用下生成磷酸肌酸，再脱水产生肌酐，在控制饮食及肌肉运动的情况下，血肌酐的生成与排出较恒定，其变化取决于内源性肌酐。 标本：24小时尿液（4-5ml甲苯防腐） 血液2-3ml 临床意义： ★判断肾小球损害的灵敏指标（GFR降至正常的50%时Ccr