Renal failure and its treatment

Acute kidney injury (AKI) is a common complication of acute illness. It is associated with significant morbidity and mortality as well as a high cost to healthcare systems. There are a broad range of causes of AKI which should be considered in a systematic fashion to avoid missing multiple potential causative factors. These include pre-renal causes from hypovolaemia, intrinsic renal causes such as glomerular diseases and post-renal obstructive causes. In the intensive care unit, two-thirds of AKI cases result from renal hypoperfusion, sepsis, contrast and nephrotoxic agents; up to 5% will require renal replacement therapy. Modalities of renal replacement therapy include intermittent haemodialysis, peritoneal dialysis and continuous haemofiltration. Continuous haemofiltration is usually favoured in the intensive care setting as it has greater haemodynamic stability and greater capacity to extract fluid from patients with fluid overload. Anticoagulation is recommended with haemodialysis and haemofiltration and systemic heparin, regional citrate or zero anticoagulation are the usual options.     

Renal and respiratory failure in Scottish ICUs

The purpose of this study was to define the outcome of patients receiving both renal replacement therapy and mechanical ventilation in 16 Scottish intensive care units over a 2-year period. Patients were identified from the Scottish Intensive Care Society's database. Survivors developing end-stage renal failure were identified after examination of the Scottish Renal Registry's database. Mortality was 64.2% (392/612) for all patients receiving renal replacement therapy and mechanical ventilation. End-stage renal failure developed in 1.6% (3/188) of the survivors of acute renal failure and in 33% (4/11) of the survivors with pre-existing chronic renal failure. Mortality has not improved when compared with earlier studies. End-stage renal failure rarely develops following acute renal failure in the intensive care unit.     

Beneficial effect of thyroxin in the treatment of ischemic acute renal failure

To evaluate the effect of thyroxin (T₄) on recovery from ischemic acute renal failure, rats were treated with T₄ (10 or 20 g/100 g body wt.) or normal saline (NS) either immediately prior to, immediately after or 24 h after 45 min of renal ischemia. Animals given T₄ prior to ischemia had no significant increase in Inulin clearance (C_in) (377±40 l/min per 100 g body wt.) as compared with saline-treated ischemic controls (306±54). In contrast, animals treated immediately after ischemia with either dose of T₄ demonstrated significantly better kidney function (C_in 515±59 l/min per 100 g body wt., U_osm 842±88 mosmol/kg, FE_Na 0.52%±0.12% and C_in 543±71, U_osm 939±103, FE_Na 0.48±0.12, for 10 and 20 g/100 g body wt., respectively). Moreover, the improvement in renal function was sustained and C_in was significantly better at day 3 (748±70) and day 7 (990±75) compared with saline controls (560±30 and 732±45, respectively). Animals which received T₄ 24 h after ischemia showed significantly higher C_in when compared with ischemic controls. To assess the impact of T₄ on recovery of renal ATP,³¹P-NMR was used. T₄-treated rats demonstrated 90%±5% recovery of renal ATP by 120 min of reflow, whereas NS animals had only 64%±1%. In addition, cellular morphology was better preserved in T₄ animals. These data indicate that animals treated postischemically with T₄ showed accelerated and sustained recovery from acute renal failure. This beneficial effect appears to be related to cellular mechanisms which are essential for the restoration of sublethally injured cells.     

Bioartificial kidney in the treatment of acute renal failure associated with sepsis

Acute renal failure (ARF) associated with sepsis has a high rate of mortality. It is not merely a surrogate marker for severity of disease but also an independent predictor of mortality and a separate pathogenic entity, even when nearly physiological doses of fluid and small-molecule clearance are maintained with currently available renal replacement therapies (RRT). The techniques to remove cytokines, including high-volume haemofiltration, haemodialysis using high-cut-off haemofilters, and absorptive techniques, lead to some improvement in outcome but are still insufficient to reverse the complicated biological dysregulation resulting from ARF associated with sepsis. The novel and exciting technique of cell therapy, which is based on the principle of using functional cells to replace a greater range of renal functions, may add significant benefit to current RRT in dealing with this disease process. Because renal tubule cells appear to play critical roles in immunoregulation, renal tubule cell therapy during ARF associated with sepsis should alter the detrimental multiple-organ consequences of sepsis. The development of a bioartificial kidney consisting of a conventional haemofiltration cartridge in series with a renal tubule assist device containing renal proximal tubule cells represents a new therapeutic approach to this clinical disorder. The results to date of large animal studies and recent Phase I/II and Phase II clinical trials show that such a device replaces multiple kidney functions and modifies the sepsis condition to improve survival in ARF.     

Endothelin in chronic renal failure.

The aims of the present study were to determine plasma endothelin (ET) in chronically uraemic patients, the renal clearance of endogenous ET in normal dog and man, and the effect of acute volaemic expansion on ET. The mean plasma ET concentration in haemodialysis patients was 57.5 +/- 5 pg/ml before haemodialysis and remained unchanged at 52.5 +/- 5 pg/ml after haemodialysis. They were thus significantly elevated both before and after haemodialysis (P less than 0.01) compared with plasma ET in normal subjects of 20.8 +/- 0.8 pg/ml. There was no evidence of ET clearance across the cuprophane membrane of the dialyser. Resting plasma ET values in the 15 non-dialysed uraemic patients ranged between 20 and 52.5 pg/ml (mean 38.2 +/- 2.3 pg/ml), significantly greater than those observed in controls (P less than 0.01). In CAPD patients, plasma ET was also significantly (P less than 0.01), elevated (63 +/- 10 pg/ml) when compared to controls, and similar to those observed in patients before haemodialysis. In dogs, mean ET did not diminish between the aorta and the renal vein (28.1 +/- 1 versus 28.4 +/- 2 pg/ml). In man mean ET did not significantly decline between the renal artery and the renal vein (17 +/- 3 to 13 +/- 0.8 pg/ml). In the seven healthy subjects who received 2000 ml of isotonic saline intravenously ET remained unchanged (24 +/- 2; 23 +/- 1 and 23 +/- 2 pg/ml before and 1 and 2 h after starting hydration respectively). We have thus shown that plasma ET is elevated in patients with chronic renal failure especially those on dialysis and CAPD.(ABSTRACT TRUNCATED AT 250 WORDS)     

Continuous treatment modalities in acute renal failure

Continuous treatment modalities have become well establishedin the treatment of severely ill patients with acute renal failuresince the introduction of continuous arteriovenous haemofiltration.However, this simple blood-pressure-driven treatment often failsto control azotaemia, especially in haemodynamically unstablepatients with hypercatabolism. The common feature of furtherdevelopments in continuous treatment modalities, such as continuousarteriovenous haemodialysis, venovenous haemofiltration, orvenovenous haemodialysis is their higher efficacy in controllingazotaemia. Venovenous forms of treatment involve considerablyhigher technical requirements. The main advantages of continuous forms of treatment as opposedto intermittent haemodialysis are greater haemodynamic stabilityand the possibility of adapting nutrition without restrictionto the needs of the critically ill. The uninterrupted necessityfor anticoagulants is the most important disadvantage. The questionof whether patients may profit from the continuous eliminationof mediators involved in acute renal or multiple organ failureis still open. In retrospective analysis continuous methods appear to reducemortality in acute renal failure, but prospective randomizedstudies are necessary to clearly demon strate a benefit of thesemethods as opposed to intermittent haemodialysis.     

连续性肾脏替代与间歇性血液透析治疗急性肾功能衰竭的生存率分析

目的 探讨连续性肾脏替代与间歇性血液透析治疗急性肾功能衰竭的生存率分析.方法 按照纳入标准搜集国内运用连续性肾脏替代和间歇性血液透析对比治疗急性肾功能衰竭的文献.使用Rev Man 5.0统计软件完成Meta分析,以SAS 8.0软件计算失安全系数.结果 按照纳入标准及排除标准,最后纳入6篇文献,包括受试患者476例进...     

Kinetics of carbamylated haemoglobin in acute renal failure.

BACKGROUND: Carbamylation of proteins by isocyanic acid, the reactive form of cyanate derived from urea, is increased in uraemia and may contribute to uraemic toxicity. Kinetics of carbamylation that may reflect uraemic toxicity is not clearly defined in acute renal failure (ARF). METHODS: Twenty-eight patients with ARF and 13 with chronic renal failure (CRF) were included in the study in order to determine changes in carbamylated haemoglobin concentration (CarHb) in ARF. The usefulness of this parameter for differentiating ARF from CRF was also investigated. CarHb was measured by high-performance liquid chromatography after acid hydrolysis. RESULTS: Mean CarHb level (expressed as microg carbamyl valine per gram (CV/g) Hb) was significantly higher in ARF (54.3+/-5.2) than in normal subjects (31.6+/-1.3). On admission, CarHb level was correlated with duration of ARF prior to hospitalization in the intensive care unit (r(2)=0.723, P<0.001). CarHb was significantly higher at recovery in the subgroup of patients requiring haemodialysis than in the subgroup not requiring haemodialysis (82. 4+/-11.3 vs 46.7+/-5.2, P<0.01). Similarly dialysis patients lost more weight (8.6+/-1.4 vs 2.7+/-0.5 kg, P<0.005) and had higher averaged blood urea levels in the 20 days prior to recovery (17. 6+/-1.9 vs 11.3+/-1.8 mol/l, P<0.05). After recovery, CarHb level decreased at a rate of 0.219 microg CV/g Hb per day in patients with reversible renal insufficiency. CarHb concentration was higher in patients with CRF. A cut-off CarHb value of 100 microg CV/g Hb had a sensitivity of 94% and a positive predictive value of 94% for differentiating ARF from CRF. CONCLUSIONS: Kinetics of CarHb showed a near normal red blood cell life span in ARF. Changes in CarHb enabled, with a good sensitivity, the distinction to be made between patients who recovered from ARF and those with sustained renal impairment, whether due to prior CRF or resulting from parenchymal sequelae. Measurement of CarHb is valuable at clinical presentation of ARF in patients with an unknown medical history of renal disease.     

Acute Renal Failure as a Complication of Acute Pancreatitis

To assess the prevalence of acute renal failure (ARF) inpatients with acute pancreatitis, as well as the factors predictive of a lethal outcome, we retrospectively studied the data of all patients admitted to our hospital over a 5-year period. Between 1989 and 1993, 554 patients presented with acute pancreatitis, of which 24 (4.4%) subsequently developed ARF. Death occurred in 14/24 (58%) of patients with ARF, and was associated with an increased incidence of multiorgan failure. There was no statistically significant difference in the age, admission blood pressure, or admission pulse rate of the patients who survived and those who died. In contrast, death was associated with a higher Ranson score, and the increased prevalence of multiorgan failure. The length of hospitalization of the nonsurviving group was significantly shorter. Acute renal failure is not a common finding in patients with acute pancreatitis. However, when it occurs, it is associated with a poor prognosis, and is predicted by a higher Ranson score and the presence of multiorgan failure.     

Renal failure after anti-D globulin treatment of idiopathic thrombocytopenic purpura

Idiopathic thrombocytopenic purpura (ITP) is a disorder of rapid destruction of antibody-coated platelets. Anti-D immune globulin has been used for treatment of ITP in the United States since 1995. Initial studies identified no significant side effects of treatment. However, a recent report highlighted occasional episodes of intravascular hemolysis after anti-D immune globulin. We describe two children with ITP who developed acute renal failure (ARF) after treatment with anti-D immune globulin and also analyze ten additional cases of ARF reported to the manufacturer, Cangene Corporation, through postmarketing surveillance. All episodes of ARF were associated with intravascular hemolysis. Four patients required dialysis. Patient age ranged from 1 to 82 years, but those requiring dialysis were all under age 15 years. Several patients with ARF had preexisting creatinine elevation. Three of the patients with ARF had serologic evidence of acute Epstein-Barr virus (EBV) infection. Renal biopsy in one patient showed acute tubular necrosis, with findings consistent with pigment nephropathy. Anti-D immune globulin, used to treat ITP, may be associated with intravascular hemolysis and resultant ARF. Renal function should be monitored in patients with evidence of intravascular hemolysis. Children and adolescents may have increased risk of ARF requiring dialysis. Received: 30 March 2001 / Revised: 17 September 2001 / Accepted: 18 September 2001     

危重症患者肾功能与凝血功能变化的关系

目的:探讨危重症患者肾功能与凝血功能变化关系.方法:通过检测危重症患者肾功能(Scr和BUN)和凝血功能指标(TT、PT、APTT、PLG、FIB、Ⅷ:C、ATⅢ、VWF、D-D和3P试验),根据血肌酐值分为正常组(N组,Scr＜130 μmol/L)和血肌酐异常组(A组,Scr≥130 μmol/L),采用t检验分析两组凝血功能各项指标差异.结果:在全部63例入选病例中,有27例发生急性肾衰竭(acute renal failure,ARF),确诊弥散性血管内凝血(disseminated intravascular coagulation,DIC)有10例.3P试验阳性率N组为1.7%,A组为12.7%,A组显著高于N组.A组PT明显延长,与N组比较有统计学差异(P＜0.01).FIB、PLG和ATⅢ明显下降,D-D升高,与N组比较有统计学差异(P＜0.01).Ⅷ:C和VWF均较正常高值显著升高.与N组比较,A组Ⅷ:C轻度降低,VWF轻度升高,但均无统计学差异(P＞0.05),而A组Ⅷ:C/VWF比值明显降低,有统计学差异(P＜0.01).结论:危重症患者发生ARF时,常合并凝血功能的异常,凝血功能异常可能参与了ARF的进展.     

Rhabdomyolysis and secondary renal failure in critically ill surgical patients

Background

Rhabdomyolysis accounts for up to 28% of the causes of posttraumatic acute renal failure requiring dialysis. Clinically significant rhabdomyolysis is poorly characterized biochemically and difficult to diagnose.

Methods

A retrospective review of all surgical, trauma, burn, and pediatric surgical patients admitted to Grady Memorial Hospital in Atlanta, GA, from January 1995, through April 2002 was performed. Patients were screened for serum creatinine, base deficit, serum creatine kinase (CK) ≥1,000, presence of myoglobinuria, or if they had a clinical diagnosis of rhabdomyolysis by an attending surgeon.

Results

The sequential addition of admission laboratory values for serum creatinine ≥1.5 mg/dL (positive predictive value [PPV] = 33%), base deficit ≤−4 (PPV = 52%), serum CK level ≥5,000 U/L (PPV = 80%), and myoglobinuria increases the ability to predict which patients will develop dialysis-requiring acute renal failure after an episode of rhabdomyolysis. Patients with maximum CK ≥5,000 are also at increased risk for persistent renal insufficiency (Cr ≥2.0 mg/dL).

Conclusions

An algorithm for testing at-risk surgical patients was developed and may aid in the early diagnosis of clinically significant rhabdomyolysis.     

肾活检在老年急性肾衰竭临床应用的探讨

目的：探讨肾活检术对老年急性肾衰竭的应用价值,提高老年急性肾衰竭的诊治水平。方法：66例不明原因老年急性肾衰竭均行实时超声引导肾自动穿刺活检术,分析其成功率、并发症,总结肾活检后诊断和治疗的修正率。结果：66例肾活检取材均成功;其中取材不良4例（6.1%）,取材良好62例（93.9%）;3例出现轻度并发症（4.5%）,其中肉眼血尿2例,肾周血肿1例,未出现严重并发症;66例中病因误诊19例,26例治疗方案有较大调整。结论：老年急性肾衰竭患者行经皮肾脏穿刺活检术安全且成功率高;相当部分老年急性肾衰竭病因被误诊,对不明原因老年急性肾衰竭应及时行肾活检术,以免延误诊治。     

肾移植术后早期急性肾功能衰竭的救治：附9例报告

为探讨肾移植术后早期急性肾功能衰竭（ＡＲＦ）的发病原因及救治方法，报告同种异体肾移植术后并发ＡＲＦ９例，其中为有效循环血容量不足所致者６例，高血磷中毒所致者３例。经过积极治疗，除１例因术后并发感染救治无效而摘除移植肾外，其余８例均恢复了肾功能，取得较好效果。并就肾移植术后早期ＡＲＦ的发病原因进行了分析，总结治疗上的一些体会。认为有效循环血容量不足和高血磷中毒为ＡＲＦ的主要病因；针对不同病因分别采取     

Mortality in Elderly Patients with Acute Renal Failure

In a retrospective study, we identified 55 elderly patients with acute renal failure (ARF) admitted to our hospital during an 8-year period from 1985 to 1993. Information about the etiology, complications, laboratory data, and treatment course were obtained from the clinical history. Of the 200 patients with ARF admitted to the hospital during this period, 28% were patients more than 60 years old (41 male and 14 female) with an average age of 68.5 ± 7 years. The main causes of ARF were sepsis, volume depletion, low cardiac output, arterial hypotension, nephrotoxicity by antibiotics, and obstructive uropathy. The global mortality of elderly patients with ARF was 53%. The mortality rate of the different types of the ARF were: prerenal 35%, intrinsic 64% (oliguric 76%, nonoliguric 50%), and postrenal 40%. Mortality as a result of sepsis occurred in 18 patients (62%), by cardiovascular disease in 4 patients (13%), by acute respiratory failure in 2 patients (7%), and by other causes in 5 patients (18%). In the cases of sepsis, Pseudomonas was detected in 7 cases (39%), Escherichia coli in 2 cases (11%), Gram-negative nonspecific in 3 cases (17%), Klebsiella in 1 case (5%), and in 5 cases (16%), the hemoculture was negative. The patient survival rate was 47% (26 of 55 patients). Of these patients, 19 recovered their normal renal function (73%), but 7 patients remained with renal failure (27%). In conclusion, the global mortality in the elderly patients without considering the types of ARF was 53%. The oliguric form had the highest mortality rate with 76%. The main causes for mortality were sepsis with 62%, cardiovascular disease with 13%, and other causes 18%.     

Renal replacement therapy for acute renal failure in children: European Guidelines

Acute renal failure (ARF) is uncommon in childhood and there is little consensus on the appropriate treatment modality when renal replacement therapy is required. Members of the European Pediatric Peritoneal Dialysis Working Group have produced the following guidelines in collaboration with nursing staff. Good practice requires early discussion of patients with ARF with pediatric nephrology staff and transfer for investigation and management in those with rapidly deteriorating renal function. Patients with ARF as part of multi-organ failure will be cared for in pediatric intensive care units where there should be access to pediatric nephrology support and advice. The choice of dialysis therapy will therefore depend upon the clinical circumstances, location of the patient, and expertise available. Peritoneal dialysis has generally been the preferred therapy for isolated failure of the kidney and is universally available. Intermittent hemodialysis is frequently used in renal units where nursing expertise is available and hemofiltration is increasingly employed in the intensive care situation. Practical guidelines for and the complications of each therapy are discussed.This paper is written on behalf of the European Pediatric Peritoneal Dialysis Working Group. The group includes Alberto Edefonti, I Clinici di Perfezionamento, Milan, Italy; Michel Fischbach, Hôpital de Hautepierre, Strasbourg, France; Günter Klaus, University of Marburg, Marburg, Germany; Constantinos J. Stefanidis, A. and P. Kyriakou Childrens Hospital, Athens, Greece; Cornelis Schröder, Wilhelmina Kinderziekenhuis, Utrecht, The Netherlands; Eva Simkova, I. Detska klinika FN v Motole, Prague, Czech Republic; Kai Ronnholm, Hospital for Children and Adolescents, Helsinki, Finland; Mesiha Ekim, Ankara University Hospital, Ankara, Turkey; Johann Vande Walle, University Hospital, Ghent, Belgium; Franz Schaefer, University of Heidelberg, Germany; Aleksandra Zurowska, Gdansk University Medical School, Poland     

Chronic renal failure and its treatment in tuberous sclerosis

BACKGROUND.: Chronic renal failure is rare in tuberous sclerosis, but itsprecise frequency is not known and treatment modalities havenot been evaluated. METHODS.: A questionnaire was addressed to the 260 French dialysis centresand the characteristics of 65 patients with tuberous sclerosisand chronic renal failure were analysed. RESULTS.: In France the approximate prevalence of tuberous sclerosis withend-stage renal failure is 0.7 cases per million and that ofend-stage renal failure in tuberous sclerosis 1 per 100. Tuberoussclerosis with chronic renal failure was more frequent in females(63.1%) and was diagnosed at a mean age of 29 years. Renal impairmentwas the first manifestation of tuberous sclerosis in about halfthe cases. Renal tumours were frequent, with angiomyolipomasin 15 cases (23.1%), cysts in 12 cases (18.5%), and both in35 cases (53.8%). Malignancies were associated in nine cases(13.8%). Nephrectomy was done before dialysis in 21 cases (32.3%),and after the start of dialysis in six cases (9.2%). All butone of the 48 patients with end-stage renal failure were treatedby dialysis; 20 were transplanted, with good results. CONCLUSIONS.: Tuberous sclerosis with end-stage renal failure is rare. Thesepatients require dialysis and renal transplantation, but werecommend binephrectomy after starting dialysis and before transplantation,given the risk of cancer and bleeding related to angiomyolipomas.     

Influence of haemodialysis and left ventricular failure on peripheral A(2A) adenosine receptor expression.

BACKGROUND: Haemodialysis (HD) sometimes accelerates left ventricular failure (LVF). As adenosine (ADO) is strongly implicated in cardiovascular functions, particularly via A(2A) receptor activation and as changes of peripheral A(2A) receptors mirror changes occurring in the cardiovascular system, we examined the influence of HD and LVF on both ADO plasma concentration and the expression of A(2A) receptors (i.e. Bmax, K(D) and mRNA amount) of peripheral blood mononuclear cells. METHODS: This cross-sectional study included 61 chronic renal failure (CRF) patients: 41 without LVF (24 haemodialysed and 17 undialysed) and 20 with LVF (9 haemodialysed and 11 undialysed). Ten LVF patients without CRF and 10 healthy subjects were also examined. RESULTS: (i) Bmax values of CRF patients without LVF were significantly decreased in undialysed patients compared with haemodialysed patients, and compared with controls (69 +/- 25 vs 98 +/- 33 vs 180 +/- 60 fmol/mg of protein, P < 0.05). Bmax values of CRF patients with LVF were lower in undialysed patients than in haemodialysed patients (60 +/- 27 vs 101 +/- 27 fmol/mg of protein, P < 0.05). Bmax values of LVF patients without CRF were lower than in controls (51 +/- 19 vs 180 +/- 60 fmol/mg of protein). (ii) A(2A) mRNA expression was increased in haemodialysed patients compared with controls (20.2 +/- 0.75 vs 17.6 +/- 1.3, P < 0.05). (iii) ADO plasma levels were high in haemodialysed patients and further increased during the HD sessions. CONCLUSION: The number of A(2A) receptors was decreased by CRF with or without LVF. However, this decrease was less important in haemodialysed patients. The changes in peripheral A(2A) receptor expression suggest a significant inflammatory response to HD and heart or kidney failure. Whether these changes do reflect alterations in cardiomyocytes needs further investigation.     

Renal replacement modalities for childhood end-stage renal failure

Summary: An overview is presented of the current management of children with end-stage renal disease (ESRD), focusing on specific therapies such as haemodialysis, peritoneal dialysis and renal transplantation. Also discussed is the overall management of such children, with attention directed at growth, nutrition and development.