Usefulness of continuous renal replacement therapy for correcting hypernatremia in a patient with severe congestive heart failure

Continuous renal replacement therapy (CRRT) is used as an alternative to intermittent hemodialysis (IHD) in patients who have acute kidney injury (AKI) and cannot tolerate IHD. Several studies have reported the usefulness of CRRT in treating sepsis, which is a non‐renal indication for CRRT. Recently, CRRT was also introduced as a useful tool for treating severe congestive heart failure (CHF). By using CRRT, we successfully treated hypernatremia in a patient with severe CHF, without observing any fluid overload. Therefore, we report this case to suggest that CRRT should be considered for the treatment of hypernatremia in patients with severe CHF.     

Outcome among patients with acute renal failure needing continuous renal replacement therapy: A single center study

Outcome of acute renal failure (ARF) and use of continuous renal replacement therapy (CRRT) have shown a consistently high mortality. (1) Evaluate the short-term patient survival. (2) Evaluate dialysis-free survival. (3) Evaluate risk factors associated with overall survival and the continued need for intermittent dialysis. We identified adults (≥18 years) needing CRRT, treated in the critical care units of Froedtert Medical and Lutheran Hospital from January 1, 2003 till December 31, 2005. Patients were divided into two major groups needing CRRT, end stage renal disease (ESRD) (chronic dialysis) and non-ESRD with ARF. Continuous renal replacement therapy was performed with an average of 2 L replacement fluid exchanges/h. Sigma stat software was used for analysis. Comparison was done for noncontinuous variables by chi-square and t test for categorical and continuous variables, respectively. A total of 110 (ESRD 24/non-ESRD 86) patients received CRRT during study period. Over all in-hospital mortality among non-ESRD patients was 63% vs. 46% for ESRD. Among non-ESRD patients who survived, 47% needed intermittent hemodialysis on intensive care unit discharge and 28% continued to need hemodialysis at last follow-up. Among non-ESRD patients alive at discharge, those who were dialysis dependent on last follow-up were older (64.5) than those who did not require dialysis on last follow-up (58.4) P=0.347. Non-ESRD patients who died were in the hospital for an average of 17.5 days compared with 29 days for those who were discharged from the hospital. Patients with ARF needing CRRT have high in-hospital mortality. A significant percentage of patients remained dialysis dependant on last follow-up.     

Survival to discharge among patients treated with continuous renal replacement therapy

Continuous renal replacement therapy (CRRT) is widely used in critically ill patients with acute renal failure (ARF). The survival of patients who require CRRT and the factors predicting their outcomes are not well defined. We sought to identify clinical features to predict survival in patients treated with CRRT. We reviewed the charts of all patients who received CRRT at the Toronto General Hospital during the year 2002. Our cohort (n=85) represented 97% of patients treated with this modality in 3 critical care units. We identified demographic variables, underlying diagnoses, transplantation status, location (medical-surgical, coronary, or cardiovascular surgery intensive care units), CRRT duration, baseline estimated glomerular filtration rate (eGFR), and presence of oliguria (<400 mL/day) on the day of CRRT initiation. The principal outcome was survival to hospital discharge. Among those alive at discharge, we assessed whether there was an ongoing need for renal replacement therapy. Greater than one-third (38%, 32/85) of patients survived to hospital discharge. Three (9%) survivors remained dialysis-dependent at the time of discharge. Survivors were younger than nonsurvivors (mean age 56 vs. 60 years), were on CRRT for a shorter duration (7 vs. 13 days), and had a higher baseline eGFR (74 vs. 62 mL/min/m(2)). Patient survival varied among different critical care units (medical surgical 33%, coronary 38%, and cardiovascular surgery 45%). Multivariable logistic regression revealed that shorter duration of CRRT, nonoliguria, and baseline eGFR >60 mL/min/m(2) were independently associated with survival to hospital discharge (p<0.05). Critically ill patients with ARF who require CRRT continue to have high in-hospital mortality. A shorter period of CRRT dependence, nonoliguria and higher baseline renal function may predict a more favorable prognosis. The majority of CRRT patients who survive their critical illness are independent of dialysis at the time of hospital discharge.     

Extracorporeal Support for Patients with Hepatic Failure

Extracorporeal support has been advocated for patients with acute and chronic liver failure. Patients with acute liver failure and those with decompensated cirrhosis can be broadly divided into two groups. The first group comprises those with acute liver failure and ongoing hepatic necrosis, and the second, those with long-standing chronic decompensation admitted with one or more complications of liver failure, such as encephalopathy without any evidence of a precipitating factor or accompanying acute deterioration of liver function. This second group includes patients with acute liver failure, where the insult causing hepatic necrosis has been resolved, and those patients with chronic decompensation who suffer another insult to the liver, such as acute infection or variceal hemorrhage that causes further liver injury in the setting of multiorgan failure. These two groups are likely to have different outcomes and may need to be managed differently. In the first group, liver transplantation is the only possible long-term therapeutic option, whereas in the second group, other possibilities such as extracorporeal liver support systems and/or medical therapy may allow these patients to return to their previous state before the acute insult. Over time extracorporeal support has expanded from simple peritoneal dialysis and hemodialysis, to the development of circuits designed primarily to remove both water and lipid-soluble toxins and, in addition, bioartificial devices to provide replacement synthetic hepatic function.
Because many of the patients with an acute liver insult have ongoing chronic liver disease and develop hepatorenal syndrome, this group of patients has been targeted by several groups to study the role of liver support systems.     

Continuous renal replacement therapy is associated with acute cardiac stunning in critically ill patients

Introduction: Intermittent renal replacement therapy induces cardiac stunning in chronic hemodialysis and acute kidney injury (AKI) patients. In chronic hemodialysis, recurrent stunning contributes to heart failure and cardiac death, with ultrafiltration and intradialytic hypotension being the principal determinants of this injury. Continuous renal replacement therapy (CRRT), with its lower ultrafiltration rates and improved hemodynamic profile, should protect against cardiac stunning in AKI. The objective of this study was to assess whether CRRT is associated with cardiac stunning in critically ill patients with AKI. Methods: We prospectively measured cardiac function using global and segmental longitudinal left ventricular strain using transthoracic echocardiography in 11 critically ill patients who were started on CRRT for AKI. We compared measurements at 4, 8, and 24 hours to baseline immediately prior to initiation of CRRT, with each patient serving as their own control. We also recorded blood pressure, heart rate, dose of vasoactive medications and intensive care unit mortality. Findings: Ten of 11 patients developed new regional cardiac stunning, with 8/11 within 4 hours of starting CRRT, despite stable hemodynamics. The number of affected left ventricular segments varied from 1 to 11 (out of 12). The stunning occurred both in patients with preserved and impaired baseline cardiac function, and 7/11 patients died in the intensive care unit. Discussion: Initiation of CRRT in critically ill patients with AKI is associated with cardiac stunning despite stable hemodynamics. This mechanism may explain lack of clinical benefit of CRRT over intermittent modalities and warrants further investigation to improve cardiovascular outcomes in critically ill patients with AKI.     

Who may not benefit from continuous renal replacement therapy in acute kidney injury?

This study aimed to identify factors that may predict early kidney recovery (less than 48 hours) or early death (within 48 hours) after initiating continuous renal replacement therapy (CRRT) in acute kidney injury (AKI) patients. This is a multicenter retrospective observational study of 14 Japanese Intensive care units (ICUs) in 12 tertiary hospitals. Consecutive adult patients with severe AKI requiring CRRT admitted to the participating ICUs in 2010 (n = 343) were included. Patient characteristics, variables at CRRT initiation, settings, and outcomes were collected. Patients were grouped into early kidney recovery group (CRRT discontinuation within 48 hours after initiation, n = 52), early death group (death within 48 hours after CRRT initiation, n = 52), and the rest as the control group (n = 239). The mean duration of CRRT in the early kidney recovery group and early death group was 1.3 and 0.9 days, respectively. In multivariable regression analysis, in comparison with the control group, urine output (mL/h) (odds ratio [OR]: 1.02, 95% confidence interval [CI]: 1.01–1.03), duration between ICU admission to CRRT initiation (days) (OR: 0.65, 95% CI: 0.43–0.87), and the sepsis‐related organ failure assessment score (OR: 0.87, 95% CI; 0.78–0.96) were related to early kidney recovery. Serum lactate (mmol/L) (OR: 1.19, 95% CI: 1.11–1.28), albumin (g/dL) (OR: 0.52, 95% CI: 0.28–0.92), vasopressor use (OR: 3.68, 95% CI: 1.37–12.16), and neurological disease (OR: 9.64, 96% CI: 1.22–92.95) were related to early death. Identifying AKI patients who do not benefit from CRRT and differentiating such patients from the study cohort may allow previous and future studies to effectively evaluate the indication and role of CRRT.     

Safety of arteriovenous fistulae and grafts for continuous renal replacement therapy: The Michigan experience

Introduction: Arteriovenous fistula or graft (AVF/AVG) use is widely considered contraindicated for continuous renal replacement therapy (CRRT), yet insertion of hemodialysis (HD) catheters can carry high complication risk in critically ill end‐stage renal disease (ESRD) patients. Methods: Single‐center analysis of 48 consecutive hospitalized ESRD patients on maintenance HD who underwent CRRT using AVF/AVG from 2012 to 2013. Primary outcome was access‐related complications. Findings: Mean age was 60 years, 48% were male, and 88% required vasopressor support. Median duration of AVF/AVG use for CRRT was 4 days (range 1–34). Ten (21%) patients had access complications (5 bleeding, 5 infiltration, 1 thrombosis); 5 (10.4%) required catheter placement. Overall 31 (65%) patients survived to hospital discharge and AVF/AVG access was functional at the time of discharge in 29 (94%) patients. Discussion: In our experience, use of AVF/AVG for CRRT can be performed with a low serious complication rate and low risk of access loss, potentially avoiding catheter‐related complications.     

Outcomes of patients with end‐stage renal disease (ESRD) under chronic hemodialysis requiring continuous renal replacement therapy (CRRT) and patients without ESRD in acute kidney injury requiring CRRT: A single‐center study

In most continuous renal replacement therapy (CRRT) studies, end‐stage renal disease (ESRD) patients were excluded and the outcomes of patients with ESRD treated with chronic hemodialysis (HD) were unknown. The purposes of this study were to (1) evaluate short‐term patient survival and (2) compare the survival of conventional HD patients needing CRRT with the survival of non‐ ESRD patients in acute kidney injury (AKI) requiring CRRT. We evaluated adults (>18 years) requiring CRRT who were treated in the intensive care unit (ICU) at Kosin University Gospel Hospital from January 1, 2009 to December 31, 2010. A total of 100 (24 ESRD, 76 non‐ESRD) patients underwent CRRT during the study period. Patients were divided into two major groups: patients with ESRD requiring chronic dialysis and patients without ESRD (non‐ESRD) with AKI. We compared the survival of conventional HD patients requiring CRRT with the survival of non‐ ESRD patients in AKI requiring CRRT. For non‐ESRD patients, the 90‐day survival rate was 41.6%. For ESRD patients, the 90‐day survival rate was 55.3%. Multivariate Cox proportional hazards analyses demonstrated that conventional HD was not a significant predictor of mortality (hazard ratio [HR]: 0.334, 95% confidence interval [CI]: 0.063–1.763, P = 0.196), after adjustment for age, gender, presence of sepsis, APACHE score, use of vasoactive drugs, number of organ failures, ultrafiltration rate, and arterial pH. The survival rates of non‐ESRD and ESRD patients requiring CRRT did not differ; ESRD with conventional HD patients may be not a significant predictor of mortality.     

Anticoagulation in Patients With Acute Renal Failure Treated With Continuous Renal Replacement Therapies

Although continuous renal replacement therapy (CRRT) provides greater cardiovascular and cerebrovascular stability compared to standard intermittent hemodialysis and/ or hemofiltration, to provide adequate solute removal, the CRRT circuit must function continuously. Patients with acute renal failure are usually prothrombotic, with activation of the contact coagulation cascade and reduction in the natural anticoagulants. Thus clotting within the extracorporeal circuit can be problematic. Coagulation requires activation of the coagulation protein enzymes, calcium, platelets, and contact with phospholipid cell surface or, in the case of the CRRT circuit, plastic tubing and the dialyzer membrane. This results in a platelet plug stabilized by cross-linking strands of fibrin. Anticoagulation regimes are either directed at trying to prevent contact activation of clotting factors and platelets or the administration of agents designed to prevent coagulation by blocking the coagulation cascade or platelet activation.     

Anaphylactoid reaction during hemodiafiltration on AN69 membrane in a patient with atypical hemolytic uremic syndrome: A pediatric case report

Reactions associated with hemodiafiltration can be life threatening if not recognized early in the course of dialysis. AN69 (acrylonitrile and sodium methallyl sulfonate copolymer) membrane-associated reactions during hemodialysis have been documented in adult patients receiving angiotensin converting enzyme inhibitors, which are thought to be triggered by the negative charge of the AN69 membrane. Here, we present a 5-month-old girl requiring continuous renal replacement therapy (CRRT) for acute kidney injury secondary to atypical hemolytic uremic syndrome who experienced acute cyanosis, angioedema, tachycardia, and impaired circulation during CRRT. After switching to a different type of hemofiltration membrane, her clinical findings improved and she was able to tolerate hemodialysis. We concluded that she had experienced an anaphylactoid reaction to the AN69 membrane. To our knowledge, this case is the first pediatric case report of AN69 membrane-associated anaphylactoid reaction.     

Intraoperative dialysis during liver transplantation with citrate dialysate

Liver transplantation for acutely ill patients with fulminant liver failure carries high intraoperative and immediate postoperative risks. These are increased with the presence of concomitant acute kidney injury (AKI) and intraoperative dialysis is sometimes required to allow the transplant to proceed. The derangements in the procoagulant and anticoagulant pathways during fulminant liver failure can lead to difficulties with anticoagulation during dialysis, especially when continued in the operating room. Systemic anticoagulation is unsafe and regional citrate anticoagulation in the absence of a functional liver carries the risk of citrate toxicity. Citrate dialysate, a new dialysate with citric acid can be used for anticoagulation in patients who cannot tolerate heparin or regional citrate. We report a case of a 40-year-old female with acetaminophen-induced fulminant liver failure with associated AKI who underwent intraoperative dialytic support during liver transplantation anticoagulated with citrate dialysate during the entire procedure. The patient tolerated the procedure well without any signs of citrate toxicity and maintained adequate anticoagulation for patency of the dialysis circuit. Citrate dialysate is a safe alternative for intradialytic support of liver transplantation in fulminant liver failure.     

Carnitine deficiency in children receiving continuous renal replacement therapy

Carnitine deficiency is known to occur in chronic hemodialysis; however, the effect of continuous renal replacement therapy (CRRT) on carnitine homeostasis has not been studied. We hypothesized that children receiving CRRT are at risk for deficiency because of continuous removal, absent intake, decreased production, and comorbidities related to critical illness. Records of patients with acute kidney injury receiving CRRT at Children's National Health System between 2011 and 2014 were reviewed for total carnitine (TC), free carnitine (FC), feeding modality, severity of illness, and survival outcome. The proportion of carnitine‐deficient patients at baseline, 1, 2, and ≥3 weeks on CRRT were compared by chi‐square, and relationships with other variables assessed by Pearson's correlation and logistic regression. The study group included 42 CRRT patients, age 7.9 + 1.1 years. At baseline, 30.7% and 35.7% of patients were TC and FC deficient. Within 1 week, 64.5% (P = 0.03) and 70% (P = 0.03) were TC and FC deficient, and prevalence of deficiency increased to 80% (P = 0.01) and 90% (P = 0.008) by 2 weeks; 100% of patients were TC and FC deficient after being on CRRT for ≥3 weeks (P = 0.005 and P = 0.01, respectively, vs. baseline). TC and FC levels negatively correlated with days on CRRT (r = ?0.39, P = 0.001 and r = ?0.35, P = 0.005). Patients with TC and FC deficiency had 5.9 and 4.9 greater odds of death than those with normal levels (P = 0.02 and P = 0.03). Carnitine is significantly and rapidly depleted with longer time on CRRT, and carnitine deficiency is associated with increased mortality. Consequences of deficiency and benefits of supplementation in the pediatric CRRT population should be investigated.     

A case of hypothermia on CRRT

A 64‐year‐old Asian man, with past medical history of hypertension, hypothyroidism, and hyperlipidemia, presented with 3 days history of fever associated with cough and worsening shortness of breath. Subsequent clinical course was complicated by acute lung injury leading to acute respiratory distress syndrome requiring positive pressure ventilation, septic shock requiring inotropic support, and acute kidney injury requiring continuous renal replacement therapy (CRRT). On day 3 of CRRT, the patient developed significant hypothermia (temporal temperature 27.5°C), which was successfully managed. Continuous renal replacement therapy was subsequently discontinued as renal function recovered and the patient was discharged home after a prolonged hospital stay. He currently remains off dialysis and is being followed as an outpatient for chronic kidney disease. In this article, we examine various aspects of pathophysiology and management of hypothermia on CRRT and review relevant literature in this field.     

High sodium continuous veno‐venous hemodialysis with regional citrate anticoagulation and online dialysate generation in patients with acute liver failure and cerebral edema

Introduction: Acute liver failure is associated with a high mortality rate. Induction of plasma hypertonicity with mannitol or hypertonic saline remains the cornerstone in the management of resultant cerebral edema. Significant disadvantages of this approach include poor or unpredictable control of serum sodium concentration and volume expansion, among others. Methods: We used high sodium continuous veno‐venous hemodialysis with regional citrate anticoagulation and online dialysate generation to accurately control the serum sodium in eleven patients with acute liver failure, renal failure, and cerebral edema. We used a Fresenius 2008 K/K2 machine in hemodialysis mode to deliver a blood flow of 60 ml/minute and dialysate flow of 400 ml/minute. Our previously published protocol results in complete removal of infused citrate by the dialyzer. On‐line clearance calculations were used to model the time required to reach the target serum sodium. Findings: All patients achieved serum sodium within 2 mEq/L of target without fluctuations or rebound. Nine patients survived without requiring liver transplantation and two died despite reaching the prescribed serum sodium target. We did not encounter any citrate toxicity. Discussion: We describe a novel approach for delivering continuous osmotherapy to patients with acute liver failure, renal failure, and cerebral edema. In comparison to standard therapy, the described modality enables precise titration of serum sodium without undesirable fluctuations in extracellular fluid volume. A particular advantage is zero delivery of citrate to this vulnerable group of patients with acute liver failure.     

Early Start of Dialysis Therapy is Beneficial for Patients with Acute Renal Failure following Cardiac Surgery

Acute renal failure requiring dialysis therapy after cardiac surgery occurs in 1–5% of patients; however, the optimal timing for the initiation of dialysis therapy still remains undetermined. To assess the validity of early start of dialysis therapy, we studied the comparative survival between 14 patients who started to receive dialysis therapy with the timing of decrease of urine volume less than 30 mL/h and other 14 patients who waited to begin dialysis therapy until the level of urine volume of less than 20 mL/h during 14 days. Overall mortality of those patients was 50%. Twelve of 14 patients who received the early intervention survived. In contrast, only 2 of 14 patients in the other group survived. There was a significant difference of p < 0.01 between the two groups. Between the two groups, there were no significant differences in age, sex ratio, the score of APACHE (Acute Physiologic and Chronic Health Evaluation) II, and the levels of serum creatinine at the start of dialysis therapy (2.9 + 0.2 vs. 3.1 + 0.2 mg/dL) as well as in the levels of serum creatinine at admission. The start timing for the treatment of acute renal failure following cardiac surgery would be determined by the decrease of urine volume but not by the levels of serum creatinine. The early start of dialysis therapy might be preferable for the improvement of survival of the patients suffering from acute renal failure following cardiac surgery.     

Hemodialysis Systems for Intermittent,Semi-Continuous,and Continuous Therapies in Acute Renal Failure

As is the case in end-stage renal disease (ESRD), both intermittent and continuous renal replacement therapies (RRTs) are employed in acute renal failure (ARF). In fact, a continuum of treatment options is available in ARF. At one end of the ARF RRT spectrum is conventional intermittent hemodialysis (IHD), in which relatively high blood and dialysate flow rates are used (typically ≥250 and 500 mL/min, respectively). Continuous renal replacement therapies (CRRTs), which employ much lower flow rates, comprise the other end of the spectrum. Finally, hybrid therapies, which combine characteristics of both IHD and CRRT, have recently been described. These therapies’ removal mechanisms for solutes over a broad molecular weight range are discussed. An understanding of these mechanisms is important when determining the amount of therapy that can be provided by any RRTs. Additional studies are required to improve the understanding of solute removal by the various RRT used in ARF.     

Kinetic Modeling of “Go Slow” Dialysis in Acute Renal Failure

Go slow” dialysis is a gentle, intermittent hemodialysis therapy for acute renal failure patients, with advantages compared to slow, continuous therapies. It employs a recirculating closed dialysate circuit. A two-pool urea kinetic model is elaborated to determine kinetic parameters from blood and dialysate concentrations. This will allow quantification of the therapy. Variable clearance is included to accurately describe the kinetic process. The model is tested in an acute renal failure patient. Solute removals, as determined from direct dialysis quantification and by the model, are comparable. Variable clearance is not required to determine the kinetic parameters, because the constant mean clearance delivers equal results. The dialysis dose, as defined, allows comparison with chronic renal therapies. It requires solute removal determined from dialysate sampling and time-averaged concentration (TAC) from the urea kinetic modeling. In the test patient, dialysis dose is lower compared to standard thrice-weekly therapies because of its lower efficiency and higher TAC, a result of his highly catabolic state.     

Importance of early dialysis for acute renal failure after an open-heart surgery

Coronary artery disease is a major cause of death in patients with a renal dysfunction. Among the patients who undergo coronary artery bypass grafting, renal dysfunction is known to be a major predictor of in-hospital and out-of-hospital mortality. From 2004 to 2007, we performed elective open-heart surgeries on 2380 patients in whom there was no primary renal failure. Of those patients, only 185 in whom acute renal failure (ARF) was developed were included in the study. The patients were divided into 2 groups: a late dialysis group (n=90) and an early dialysis group (n=95). The mean age of the patients was 62.3±6.4 in the late dialysis group and 64.5±5.2 in the early dialysis group. There were 32 female and 58 male patients in the late dialysis group and 36 female and 59 male patients in the early dialysis group. Acute renal failure developed only in 185 patients out of 2380 open-heart surgery patients. The overall mortality in the 2380 open-heart surgery patients was 1.97%. Mortality among the ARF patients was 5.9%. However, there was no significant difference in hospital mortality between the 2 groups. Major complications, such as postoperative pneumonia, prolonged ventilation time, arrhythmia, the number of times postoperative hemodialysis was performed, development of chronic renal failure, time spent in the intensive care unit and the period of hospitalization, sepsis, and low cardiac output, were significantly higher in the late dialysis group. There was no difference in mortality between the 2 groups. Early dialysis for open-heart surgery patients who develop ARF postoperatively does not decrease mortality. However, it decreases morbidity, the amount of time spent in intensive care, and the period of hospitalization and thus reduces patient costs.     

Early start on continuous hemodialysis therapy improves survival rate in patients with acute renal failure following coronary bypass surgery

Acute renal failure requiring dialysis therapy after cardiac surgery occurs in 1% to 5% of patients; however, the optimal timing for initiation of dialysis therapy still remains undetermined. To assess the validity of early start of dialysis therapy, we studied the comparative survival between 14 patients who started to receive dialysis therapy when urine volume decreased to less than 30 mL/hr and another group of 14 patients who waited to begin dialysis therapy until the level of urine volume was less than 20 mL/hr for 14 days following coronary bypass graft surgery. Twelve of 14 patients who received early intervention survived. In contrast, only 2 of 14 patients in the late‐dialysis group survived. There was a significant difference in survival between the two groups (p < 0.01). There were no significant differences between the two groups with respect to age, sex ratio, the APACHE (Acute Physiologic and Chronic Health Evaluation) II score, and the levels of serum creatinine at the start of dialysis therapy (2.9 ± 0.2 mg/dL vs. 3.1 ± 0.2 mg/dL), as well as the levels of serum creatinine at admission. We propose that the timing of the start for treatment of acute renal failure following cardiac surgery should be determined by the decrease of urine volume and not the levels of serum creatinine. Early start of dialysis therapy may help improve the survival of patients with acute renal failure following cardiac surgery.