1、Acute Kidney Injury -Acute renal failure,Jiang Huajun. M.D, Ph.D Dept. of Nephrology, Union Hospital. HUST drhuajunjiang ,The Early Report of ARF,“The disease seems in general to come on suddenly. The peculiar symptom is a sudden diminution of secretion of urine, which soon amounts to a complete sus
2、pension of it. The affliction is probably at first considered as retention; but the catheter being employed, the bladder is found to be empty. . . after several days, the patient begins to talk incoherently, and shows a tendency to stupor. This increases gradually to perfect coma, which in a few day
3、s more is fatal. . . ” John Abercombie (1780 1828) sudden (i.e.,hours to days) reduction in urine volume,Profile,Rapid decrease in renal function over days to weeks, causing a accumulation of nitrogenous products in the blood. Often results from major trauma, illness, or surgery but in some cases is
4、 caused by a rapidly progressive, intrinsic renal disease. Symptoms include anorexia, nausea, and vomiting, progressing to seizures and coma if the condition is untreated. Fluid, electrolyte, and acid-base disorders develop quickly. Diagnosis is based on laboratory tests of renal function, including
5、 serum creatinine, renal failure index, and urinary sediment . Other tests are needed to determine the cause. Treatment is directed at the cause but also includes fluid and electrolyte management and sometimes dialysis.,Epidemiology,Variable (inconsistent definitions, different population) Based on
6、new definition, AKI occurs approximately 7% in hospitalized patients Mortality: Variable depend on etiology,The Modern Understanding of ARF,ARF to AKI Definition is based on absolute increase in serum creatinine (Scr) and oliguria,New concepts in Definition,Whats the new definition? Early single-cen
7、ter and multicenter Cohort studies , administrative database studies Definitions were different Hou et al. Am J Med 74: 243248, 1983,New concepts in Definition,The Second International Consensus Conference of the Acute Dialysis Quality Initiative (ADQI) Group. Crit Care. 2004;8:R204-R212.,De,Decreas
8、e in GFR,RIFLE criteria,New concepts in Definition,An new precise operational definition of AKI is intended to emphasize the reversible nature of most renal insults.,Acute Kidney Injury Network: report of an initiative to improve outcomes in acute kidney injury. Crit Care. 2007;11:R31.,AKIN criteria
9、,In 48 hours,New concepts in Definition KDIGO criteria,New concepts in Definition,New Biomarkers Cystatin C Neutrophil gelatinaseassociated lipocalin (NGAL) Kidney injury molecule-1 Interleukin 18,Pathophysiology,Endothelial injury from vascular perturbations Direct effect of nephrotoxins Abolishmen
10、t of renal autoregulation Formation of inflammatory mediators,Pathophysiology,Tubular obstruction necrosis and apoptosis of tubular cells Increased tubuloglomerular feedback elevated intracellular calcium levels from tubular damage cause a series of cellular-level alterations,Etiology,Pre-renal Unde
11、rperfusion of kidneys results from volume depletion, fluid sequestration, or inadequate perfusion pressures (heart failure, cirrhosis, or sepsis) hypoperfusion of functioning kidney leads to enhanced reabsorption of Na and water, resulting in oliguria with high urine osmolality and low urine Na.,Eti
12、ology-prerenal,Etiology,Renal （tubular, interstitial, glomerular, vascular） Tubule ATN Ischemia (prolonged or severe prerenal state) Nephrotoxic,Etiology, Interstitium Acute interstitial nephritis (AIN) -drug induced -certain infections： pyelonephritis, papillary necrosis -neoplastic disorders,Etiol
13、ogy, Glomerulus Primary Infectious Rheumatologic Vasculitic antineutrophilic cytoplasmic antibody antinuclear antibody test antistreptolysin O complement levels c-reactive protein cryoglobulin erythrocyte sedimentation rate hepatitis panel (ie, specifically for hepatitis B and C) renal biopsy,Etiolo
14、gy,Postrenal (10% of AKI) Urinary tract obstructions (within or outside) stones, tumors, retroperitoneal fibrosis Ultrasonography,Etiology-postrenal,Causes Examples Tubular precipitation uric acid (tumor lysis), sulfonamides, , acyclovir, methotrecxate, Ca oxalate (ethylene glycol ingestion), myelom
15、a protein, myoglobin Ureteral obstruction Intrinsic: calculi, clots, slougher renal tissue, fungus ball, edema, malignancy, congenital defects Extrinsic: malignancy, retroperitoneal fibrosis, ureteral trauma during surgery or high impact injury Bladder obstruction Mechanical: prostatic hypertrophy o
16、r cancer, bladder cancer, urethral strictures, phimosis, urethral valves, obstructed indwelling urinary catheter Neurogenic: anticholinergics, upper or lower motor neuron lesion,Symptoms and signs,Of the underlying illness or surgical procedure that precipitated renal deterioration. Uremia symptoms:
17、 anorexia, nausea, vomiting, weakness, myoclonic jerks, seizures, confusion and coma. PE: edema, palpable bladder etc.,Diagnosis,Suspected when urine output falls or serum BUN and Scr rise Seek an underlying cause Laboratory tests: CBC, BUN/Scr, electrolytes, urine tests and other needed by cause de
18、termination,Diagnostic Evaluation,Index Prerenal Postrenal ATN AGN U/P osmolality 1.5 11.5 11.5 11.5 Urine Na (mmol/L) 40 40 0.04 0.02 2 2 1,Adapted from Miller TR, et al: urinary diagnostic indices in acute renal failure.,U/P: urine/plasma Renal failure index: U/P Na + U/P creatinine,Special Scenar
19、ios,Contrast-induced nephropathy (CIN) increase in serum creatinine levels that is 25% or higher (0.5 mg/dL) within 72 hours of contrast media administration risk factors for CIN include older age, diabetes, underlying chronic CKD, multiple myeloma, and volume depletion. Vasomotor alterations ,free
20、radical formation prehydration, temporary discontinuation of ACE inhibitors, angiotensin receptor blockers, and diuretics,Special Scenarios,Sepsis 19% in moderate sepsis, 23% in severe sepsis, and 51% in septic shock AKI+sepsis: 70% mortality rate versus 45% among patients with AKI alone nitric oxid
21、e synthases, cytokines, chemokines, and adhesion molecules early goal-directed therapy, hemodialysis,Treatment,Varied and depend on etiologic factors Prerenal azotemia from volume depletion is usually responsive to isotonic saline repletion ATN requires the discontinuation of nephrotoxic agents,main
22、tenance of optimum hemodynamics, and close surveillance for complications of renal dysfunction (eg, acidosis, electrolyte abnormalities) Postrenal etiologies dictate obstruction removal,Treatment,Emergency treatment Life-threatening complications Pulmonary edema: O2, IV vasodilators Hyperkalemia: IV
23、 infusion of 10%Ca gluconate 10ml, dextrose 50g, insulin 510 units. Severe acidosis ( pH7.2 ) IV NaHCO3 ( 150mEq in 1 L of 5% D/W),Treatment,Fluid control Daily water intake= sensible dehydration volume (previous 24 hours) + insensible dehydration endogenic water (1g protein: 0.4ml; lipid: 1ml; gluc
24、ose: 0.6ml) insensible dehydration endogenic water 5001000ml/d,Treatment,Numerous pharmacologic agents: insulin-like growth factor 1, thyroxine, atrial natriuretic peptide,dopamine, and loop diuretics, effective in preventing or ameliorating experimental AKI. none of these substances has been transl
25、ated successfully to clinical practice. clinical management of AKI is primarily supportive,Treatment: Nutritional support,NUTRITIONAL STATUS IN AKI Patients with AKI in the ICU, even more than other critically ill patients, are at risk of nutritional depletion evaluation in this clinical condition i
26、s difficult as most of the commonly utilized traditional nutritional tools are often misleading protein-energy wasting (PEW) a condition of decreased body stores of protein and energy fuel stores (i.e., lean body mass and fat masses) biochemical (such as albumin or prealbumin), body weight loss, dec
27、reased muscle mass low energy and protein intakes,International Society of Renal Nutrition and Metabolism (ISRNM),Treatment: Nutritional support,AKI is associated with alterations of water, electrolyte and acid-base metabolism, and also with specific changes in protein, carbohydrate and lipid metabo
28、lism hyperglycemia and insulin resistance proteolysis of skeletal muscle proteins with increased amino acid turnover and negative nitrogen balance altered lipid metabolism TG,VLDL TC, HDL, LDL,Treatment: Nutritional support,NUTRIENT REQUIREMENTS IN AKI Macronutrients depends more on the severity of
29、underlying disease, preexisting nutritional status and acute/chronic comorbidities, than on AKI itself,Treatment: Nutritional support,GOALS OF NUTRITIONAL SUPPORT IN AKI ensure the delivery of energy and protein in such amounts as to prevent protein-energy wasting preserve lean body mass and nutriti
30、onal status avoid further metabolic derangements and complications improve wound healing support immune function and to reduce mortality,Treatment: replacement therapy,RRT is the central component of care for patients with severe AKI. generally accepted indications for RRT include volume overload, h
31、yperkalemia, metabolic acidosis, and overt uremic symptoms,Treatment: replacement therapy,For decades, continuous renal replacement therapies (CRRTs) such as continuous venovenous hemofiltration (CVVH) were thought to offer better cardiovascular stability, resulting in better survival, in critically
32、 ill patients than conventional intermittent hemodialysis (IHD) challenged by observations that if IHD is performed with low blood flow and ultrafiltration rates at the start of the treatment, reduced dialysate temperature along with other measures controlled studies and meta-analysis have not revea
33、led a definitive advantage in terms of patient survival for CRRT as compared with IHD.,Treatment: replacement therapy,the method for RRT should be based on the clinical situation, physician proficiency with the available techniques and logistical capacity of the ICU and dialysis personnel. Both conv
34、entional IHD and CRRTs have certain advantages, but also several disadvantages,Conclusion,remains a ubiquitous medical condition and is associated with a high rate of mortality clinical management of AKI remains largely supportive Future research into the mechanisms and pathophysiology as well as the found of new biomarkers.,Thanks for your attention,
