Continuous peritoneal dialysis in acute renal failure from severe falciparum malaria

Severe falciparum malaria complicated by acute renal failure resulted in very high mortality. Ten patients with acute renal failure from falciparum malaria (infected rbc up to 80%) were continuously dialysed using Tenckhoff peritoneal catheter. Five were oliguric and BUN was maintained between 60 to 80 mg/dl (21.4 to 28.6 mmol/l) by hourly 1 to 1.5 liter dialysate exchange during the acute phase. The peritoneal urea clearance (mean +/- SD) was 12.1 +/- 1.2 ml/min with urea nitrogen removal of 13.4 +/- 2.3 g/day. In nonoliguric cases dialysis was also needed for additional removal of waste products since the remaining renal function could not cope with the hypercatabolic state. Peritoneal glucose absorption (135 to 565 g/day) gave considerable caloric supply without volume load and also contributed to the prevention of hypoglycemia. Varying degree of acute respiratory failure developed in all patients with 5 cases (2 oliguric and 3 nonoliguric) progressing to pulmonary edema. Swan-Ganz catheterization and hemodynamic study suggested the role of increased capillary permeability and volume overload from endogenous water formation in the development of pulmonary complication. Continuous removal of fluid and waste products minimized these problems and may prevent the progression of respiratory failure. One patient died of severe sepsis and the other nine survived. This study showed the beneficial contribution of continuous peritoneal dialysis in the management of acute renal failure from severe falciparum malaria.     

Peritoneal dialysis in acute renal failure

The definition of adequate dialysis in acute renal failure (ARF) is complex and involves the time of referral to dialysis, dose, and dialytic method. Nephrologist experience with a specific procedure and the availability of different dialysis modalities play an important role in these choices. There is no consensus in literature on the best method or ideal dialysis dose in ARF. Peritoneal dialysis (PD) is used less and less in ARF patients, and is being replaced by continuous venovenous therapies. However, it should not be discarded as a worthless therapeutic option for ARF patients. PD offers several advantages over hemodialysis, such as its technical simplicity, excellent cardiovascular tolerance, absence of an extracorporeal circuit, lack of bleeding risk, and low risk of hydro-electrolyte imbalance. PD also has some limitations, though: it needs an intact peritoneal cavity, carries risks of peritoneal infection and protein losses, and has an overall lower effectiveness. Because daily solute clearance is lower with PD than with daily HD, there have been concerns that PD cannot control uremia in ARF patients. Controversies exist concerning its use in patients with severe hypercatabolism; in these cases, daily hemodialysis or continuous venovenous therapy have been preferred. There is little literature on PD in ARF patients, and what exists does not address fundamental parameters such as adequate quantification of dialysis and patient catabolism. Given these limitations, there is a pressing need to re-evaluate the adequacy of PD in ARF using accepted standards. Therefore, new studies should be undertaken to resolve these problems.     

Adequacy of dialysis in acute renal failure

Renal replacement therapy (RRT) is currently the mainstay of management for patients with acute renal failure (ARF). Adequacy of dialysis in the setting of renal failure is defined poorly and encompasses multiple domains of clinical and biochemical outcomes. Multiple operational factors influence the delivery of adequate dialysis. No current standards exist for RRT for ARF; current RRT practices for ARF generally have been extrapolated from end-stage renal disease (ESRD) literature. The heterogeneity of patient population, variation in RRT practices, and differences in outcomes studied have made it difficult to define or study adequate dialysis in ARF or its impact on clinical outcomes.     

Dose of dialysis in acute renal failure

Acute renal failure (ARF) is a cause of significant morbidity and mortality. Despite advances in supportive care, outcomes in ARF have improved little over the past decades. The primary goals in management of patients with ARF are to optimize hemodynamic and volume status, minimize further renal injury, correct metabolic abnormalities, and permit adequate nutrition. Renal replacement therapy (RRT) is often required to achieve these goals while awaiting renal recovery, but the optimal dose of dialysis in patients with ARF is not known. Extrapolation of required dialysis dose from recommendations in chronic dialysis is unlikely to be appropriate because of the lack of a steady state and differences in distribution volume of urea that are intrinsic to ARF. The prescribed dialysis dose in ARF is often low, and actual delivered dose is often even less than prescribed. Delivery of dialysis in ARF is often hampered by the patient's hypercatabolic state, hemodynamic instability, and volume status, as well as suboptimal vascular access with temporary venous catheters. The impact of intermittent hemodialysis (IHD) versus continuous renal replacement therapy (CRRT) on outcomes in ARF is also not clear. Patient disease severity impacts more than dialysis modality in patient outcome, but when patients are stratified for equal disease severity, CRRT may have potential benefits over IHD in terms of patient survival, fluid and metabolic control, and renal recovery. Strategies associated with improved outcomes that have emerged thus far in ARF are to aim for a time-averaged blood urea nitrogen (BUN) of less than 60 mg/dl with IHD, varying IHD frequency as necessary, or to achieve a minimum ultrafiltration rate of 35 ml/kg/hr with CRRT.     

Continuous renal replacement therapy in acute renal failure

The management of acute renal failure in the critically ill patient is extremely variable and there are no published standards for the provision of renal replacement therapy in this population. Continuous renal replacement therapy seems to be the treatment of choice because of its superior metabolic and hemodynamic control. There is better organ protection by continuous treatment but no evidence for better survival or renal recovery due to continuous treatment. The debate about optimal membrane as well as about optimal dialysis dose is ongoing. An effluent flow rate of at least 35 ml/kg/h as well as lower BUN level at treatment initiation seem to be necessary to provide better survival rate. Peritoneal dialysis is a less suitable option in continuous renal replacement of the adult intensive care patient but hybrid methods such as extended daily dialysis and sustained low efficient daily dialysis need consideration with respect to continuous hemofiltration/dialysis.     

Peritoneal dialysis for acute renal failure in children

Fifty infants and children with acute renal failure were treated with acute peritoneal dialysis between 1987 and 1990. The patients were dialyzed using either a catheter introduced percutaneously over a guide-wire (n=40) or a Tenckhoff catheter (n=10). The cause of the acute renal failure was primary renal disease in 17 children, cardiac disease in 19, and trauma/sepsis in 14. Peritoneal dialysis succeeded in controlling metabolic abnormalities, improving fluid balance, and relieving the complications of uremia. The procedure had few major complications. Overall mortality was 50%, reflecting the serious nature of the underlying diseases. We conclude that acute peritoneal dialysis is a safe and effective treatment in most pediatric patients with acute renal failure. Our series of patients treated with acute peritoneal dialysis serves as a basis of comparison for the evaluation of new modalities of therapy in childhood acute renal failure.     

Continuous arteriovenous hemofiltration in acute renal failure

This extensive review describes the settings for continuous arteriovenous hemofiltration (CAVH) and attempts to compare it to traditional dialysis therapies for acute renal failure. In addition hemodynamic stability, membrane biocompatibility, nutrition, fluid and solute removal, operational characteristics, anticoagulation, replacement solutions, drug removal, complications, and trouble shooting during CAVH are all discussed in detail. The cost of CAVH v dialysis is equal. CAVH is probably the renal replacement therapy of choice for hemodynamically unstable patients with acute renal failure and contraindications to peritoneal dialysis.     

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.     

The role of intensive dialysis in acute renal failure

The efficacy of vigorous dialysis in the management of acute renal failure remains controversial. In order to examine the beneficial role of vigorous dialysis, a prospective study was carried out in 34 patients paired by acute renal failure etiology and treated with sufficient dialysis to maintain predialysis blood urea nitrogen and serum creatinine below either 60 and 5 mg/dl (intensive) or 100 and 9 mg/dl, respectively (non-intensive). Serum creatinine was at least 8 mg/dl in all patients prior to random assignment to intensive or non-intensive dialysis. Mean predialysis blood urea nitrogen and serum creatinine, respectively, were 60 +/- 23 and 5.3 +/- 1.5 mg/dl in the intensively dialyzed group and 101 +/- 18 and 9.1 +/- 1.4 mg/dl in the non-intensively dialyzed group (both p less than .001). Predialysis serum bicarbonate and blood pH were lower and serum phosphate higher in the non-intensively dialyzed patients. Daily weight changes, increases in blood urea nitrogen, protein and calorie intakes were similar. While hemorrhagic episodes tended to be more frequent in non-intensively dialyzed patients, overall complication rates were not different between the two groups. Mortality rates, which were 58.8% in the intensive and 47.1% in the non-intensive groups, also were not different. On the other hand, urine output prior to dialysis did influence survival. It is concluded that, within the limits of the study, there is no advantage to intensive dialysis in the management of acute renal failure.     

Prognosis in acute pancreatitis complicated by acute renal failure requiring dialysis

Acute pancreatitis complicated by acute renal failure (ARF) requiring dialysis is a rare condition with a mortality rate of 80%. During the period 1977-1988 419 patients were admitted to our hospital because of ARF requiring dialysis. Fourteen (3%) had ARF caused by acute pancreatitis. Ten patients developed respiratory failure, eight patients circulatory failure, four hepatic failure, and one disseminated intravascular coagulation. Three patients had complicating septicemia and two gastrointestinal bleeding. Ten patients (71%) died. All patients with four or more organ failures besides the pancreatic failure died. Median time from start of symptoms until death was 28 days. Mortality in this series does not differ from that reported over the last 40 years. The need of multicenter trials for the purpose of improving prognosis is emphasized.     

Measurement of the delivery of dialysis in acute renal failure

BACKGROUND: Recent studies in patients with acute renal failure (ARF) have shown a relationship between the delivered dose of dialysis and patient survival. However, there is currently no consensus on the appropriate method to measure the dose of dialysis in ARF patients. In this study, the dose of dialysis was measured by blood- and dialysate-based kinetic methods in a group of ARF patients who required intermittent hemodialysis. METHODS: Treatments were performed using a Fresenius 2008E volumetric hemodialysis machine with the ability to fractionally collect the spent dialysate. Single-, double-pool, and equilibrated Kt/V were determined from the pre-, immediate post-, and 30-minute post-blood urea nitrogen (BUN) measurements. The solute reduction index was determined from the collected dialysate, as well as the single- and double-pool Kt/V. RESULTS: Forty-six treatments in 28 consecutive patients were analyzed. The mean prescribed Kt/V (1.11 +/- 0.32) was significantly greater than the delivered dose estimated by single-pool (0.96 +/- 0.33), equilibrated (0.84 +/- 0.28), and double-pool (0.84 +/- 0.30) Kt/V (compared with prescribed, each P < 0.001). There was no statistical difference between the equilibrated and double-pool Kt/V (P = NS). The solute removal index, as determined from the dialysate, corresponded to a Kt/V of 0.56 +/- 0.27 and was significantly lower than the single-pool and double-pool Kt/V (each P < 0.001). CONCLUSION: Blood-based kinetics used to estimate the dose of dialysis in ARF patients on intermittent hemodialysis provide internally consistent results. However, when compared with dialysate-side kinetics, blood-based kinetics substantially overestimated the amount of solute (urea) removal.     

Continuous renal replacement therapy improves renal recovery from acute renal failure

BACKGROUND: Acute renal failure (ARF) occurs in up to 10% of critically ill patients, with significant associated morbidity and mortality. The optimal mode of renal replacement therapy (RRT) remains controversial. This retrospective study compared continuous renal replacement therapy (CRRT) and intermittent hemodialysis (IHD) for RRT in terms of intensive care unit (ICU) and hospital mortality, and renal recovery. METHODS: We reviewed the records of all patients undergoing RRT for the treatment of ARF over a 12-month period. Patients were compared according to mode of RRT, demographics, physiologic characteristics, and outcomes of ICU and hospital mortality and renal recovery using the Chi square, Student's t test, and multiple logistic regression as appropriate. RESULTS: 116 patients with renal insufficiency underwent RRT during the study period. Of these, 93 had ARF. The severity of illness of CRRT patients was similar to that of IHD patients using APACHE II (25.1 vs 23.5, P = 0.37), but they required significantly more intensive nursing (therapeutic intervention scale 47.8 vs 37.6, P = 0.0001). Mortality was associated with lower pH at presentation (P = 0.003) and increasing age (P = 0.03). Renal recovery was significantly more frequent among patients initially treated with CRRT (21/24 vs 5/14, P = 0.0003). Further investigation to define optimal timing, dose, and duration of RRT may be beneficial. CONCLUSIONS: Although further study is needed, this study suggests that renal recovery may be better after CRRT than IHD for ARF. Mortality was not affected significantly by RRT mode.     

连续性静脉-静脉血液滤过治疗妊娠合并急性肾衰竭临床分析

目的观察连续性静脉－静脉血液滤过（CVVH）治疗妊娠合并急性肾衰竭的临床疗效。方法回顾性分析26例妊娠合并急性肾衰竭患者采用CVVH治疗的资料,每例患者治疗30～89h,平均48h,滤过器采用AN69,AV600S,血流量100～150ml／min,置换液流量1500－2500ml／h,采用前稀释法。结果26例患者中,23例存活,3例转为慢性肾衰竭,治疗后血尿素氮、肌酐、尿酸明显下降,死亡3例。人工流产术4例,22例均适时终止妊娠,16例剖宫产,6例阴道分娩;胎儿存活18例。结论CVVH治疗妊娠合并急性肾衰竭安全、有效,值得推广。     

Practical peritoneal dialysis — the Tenckhoff catheter in acute renal failure

The problem of acquiring secure peritoneal access encompasses most of the history of peritoneal dialysis. We review the catheters available for children and describe a simple method of insertion of Tenckhoff catheters for acute dialysis. Two series of Tenckhoff catheters inserted in this way are presented and compared with results obtained with trocar- and guidewire-inserted catheters. Tenckhoff catheters inserted as described allow significantly longer periods of dialysis (P<0.02) with significantly fewer problem episodes (P<0.001). We conclude that the use of the Tenckhoff catheter for acute dialysis, when inserted in the way described, confers significant advantages over other catheters and permits secure peritoneal access.     

Prognosis in septicemia complicated by acute renal failure requiring dialysis.

During a 12-year period 419 patients were admitted because of acute renal failure requiring dialysis. Fifty (12%) had septicemia verified by blood culture. In a retrospective study age, sex, focus of infection, blood culture results, kidney function, mode of dialysis treatment, numbers and durations of complicating organ failures, presence of gastrointestinal bleeding, and secondary complicating events of septicemia were recorded for the purpose of establishing a prognostic index based on clinical criteria. Respiratory failure was present in 34 patients, circulatory failure in 31 patients, failure of coagulation system in 25 patients, and hepatic failure in 10 patients. Overall mortality was 46%. Highest death-rates were found during the first days of dialysis. In patients with multiple organ failures, in elderly and in patients suffering from staphylococcus aureus septicemia, a non-significant trend towards higher mortality was found. The mode of dialysis treatment did not influence patient survival. Our intention of establishing a prognostic index based on bedside clinical criteria has not been fulfilled. Even though mortality-rate increases in patients with acute renal failure complicated by failure of one or more vital organs, survival-rate in patients with four or more organ failures was 30%.