Prolonged Continuous Renal Replacement Therapy Research Articles

Prolonged exposure to continuous renal replacement therapy in patients with acute kidney injury.

Little is known about the process of deciding to discontinue continuous renal replacement therapy (CRRT) in patients with acute kidney injury (AKI) and the impact of CRRT duration on outcomes. We report the clinical parameters of prolonged CRRT exposure and predictors of doubling of serum creatinine or need for dialysis at 90days after CRRT with propensity score matching, including covariates that were likely to influence patients in the prolonged CRRT group. Among 104 survey responders, most use urine output (87%) to guide CRRT discontinuation, 24% use improvement in clinical or hemodynamic status. In the cohort study, of 854 included patients, 465 participated in the assessment of kidney recovery. Patients with prolonged CRRT had higher SOFA scores (11.9 vs. 11.2) and were more likely to be mechanically ventilated (99% vs. 84%) at CRRT initiation compared to patients without prolonged CRRT, p-value < 0.05. In multivariable logistic regression, daily urine output and cumulative fluid balance leading to CRRT discontinuation or day seven were independently associated with lower [OR 0.87 per 200ml/day increase] and higher odds [OR 1.03 per 1-L increase] of requiring prolonged CRRT, respectively. After propensity score matching, prolonged exposure to CRRT was independently associated with increased risk of doubling serum creatinine or dialysis at 90days, OR 3.1 (95% CI 1.23-8.3 p = 0.017). Resolution of critical illness and signs of kidney recovery are important factors when considering CRRT discontinuation. Prolonged CRRT exposure may be associated with less chance of kidney recovery among survivors.

Characteristics and Clinical Outcomes of Prolonged Continuous Renal Replacement Therapy in Critically Ill Pediatric Patients.

Paralleling improved outcomes in critically ill patients, survival for pediatric acute kidney injury has improved. Continuous renal replacement therapy is the preferred modality to optimize fluid and electrolyte management as well as nutritional support for children developing acute kidney injury in the PICU. However, some patients remain too fragile for transition to intermittent renal replacement therapies and require continuous renal replacement therapy for a prolonged period. Characteristics of this cohort and factors impacting outcomes are not well known. We aimed to describe the characteristics of pediatric patients requiring prolonged continuous renal replacement therapy and evaluate the factors impacting hospital survival. Retrospective chart review. Tertiary PICU. Children requiring prolonged continuous renal replacement therapy. Prolonged continuous renal replacement therapy was defined as continuous renal replacement therapy dependence greater than or equal to 28 days. Primary outcome was hospital mortality. None. From 2013 to 2016, 344 patients received continuous renal replacement therapy, 36 (10%) received continuous renal replacement therapy for greater than or equal to 28 days. Seventeen patients (47%) were female. Overall mortality was 44% (16/36); 69% (11/16) of nonsurvivors died of sepsis. Pediatric Logistic Organ Dysfunction score was significantly higher in nonsurvivors. Mortality rate was significantly higher in patients who were neutropenic at continuous renal replacement therapy start. Neutropenia (defined as absolute neutrophil count < 1,500/mm) at continuous renal replacement therapy start was the only independent predictor of mortality. One in four survivors did not recover renal function and remained dialysis dependent. Prolonged continuous renal replacement therapy patients are at high risk of nonrecovery of renal function and require close monitoring. The majority of nonsurvivors in the study group died from sepsis. Neutropenia at continuous renal replacement therapy initiation was associated with increased risk of mortality. Progression of underlying disease process could explain the higher death rate in patients with neutropenia; however, inadequate treatment of infectious complications could be another explanation to explore further in future studies.

Analysis of survival after initiation of continuous renal replacement therapy in patients with extracorporeal membrane oxygenation

BackgroundNo study has specifically investigated the duration of continuous renal replacement therapy (CRRT) in patients who experienced acute kidney injury during extracorporeal membrane oxygenation (ECMO) support. However, there are concerns that prolonged CRRT may be futile.MethodsWe conducted a retrospective population-based cohort study using Taiwan National Health Insurance Research Database data collected between January 1, 2007 and December 31, 2013. Patients who received ECMO and CRRT during the study period were included. We divided patients into three groups based on the duration of CRRT received: ≤ 3 days, 4–6 days, and ≥ 7 days. The outcomes were all-cause mortality, end-stage renal disease, ventilator dependency, and readmission rate.ResultsThere were 247, 134 and 187 patients who survived the hospitalization in the CRRT for ≤3 days, 4–6 days and > 7 days respectively. Survival after discharge did not differ significantly between CRRT for 4–6 days vs. ≤ 3 days (adjusted hazard ratio [aHR] 1.16, 95% confidence interval [CI] 0.85–1.57), between CRRT for > 7 days vs. ≤ 3 days (aHR 1.001, 95% CI 0.73–1.38) and between CRRT for > 7 days vs. 4–6 days (aHR 0.87, 95% CI 0.62–1.22). The patients who received CRRT for ≥7 days had a higher risk of ESRD than did those who received CRRT for ≤3 days (adjusted hazard ratio [aHR] 3.46, 95% confidence interval [CI] 1.47–8.14) and for 4–6 days (aHR 3.10, 95% CI 1.03–9.29). The incidence of ventilator dependence was higher in the patients with CRRT ≥7 days than in those with ≤3 days (aHR 2.45, 95% CI 1.32–4.54). The CRRT ≥7 days group also exhibited a higher readmission rate than did the 4–6 days and ≤ 3 days groups (aHR 1.43, 95% CI 1.04–1.96 and aHR 1.67, 95% CI 1.13–2.47, respectively).ConclusionsOur study found similar long-term survival but increased ESRD and ventilator dependency among ECMO patients who underwent CRRT for ≥7 days. These results offer reason to be concerned that this aggressive life support may maintain patient survival but do so at the cost of long-term disabilities and a lower quality of life.

Copper Deficiency: Causes, Manifestations, and Treatment.

The metabolism of the essential trace element copper remains incompletely understood and, until recently, nearly ignored in acute medicine. Menkes disease was for long the only known copper deficiency condition, but several case reports and investigations conducted over the last 2 decades have shown that deficiency is more frequent than previously suspected, with devastating individual consequences and potential public health consequences. The copper needs in healthy individuals are 0.9mg/d, which translates to 0.3mg/d intravenously in parenteral nutrition; the present review aims at gathering actual knowledge. A review of literature was conducted in PubMed and Cochrane systematic reviews to identify the most recent information about copper deficiency and generate a narrative review. Copper deficiency has hereditary and acquired origins, the latter being the most frequent. Clinical manifestations are nonspecific but affect all organs and systems, particularly the hematologic (anemia) and the neurologic (myeloneuropathy) systems. Deficiency also affects the cardiovascular, cutaneous, and immune systems. Severe copper deficiency due to reduced absorption after bariatric bypass surgery has become frequent. Deficiency is more frequent than previously recognized, probably because of changing nutrition patterns but also because of some treatments that have become very common such as bypass bariatric surgery and, in acute medicine, prolonged continuous renal replacement therapy. The patients may present with severe hematologic and neurologic complications that go untreated because copper deficiency was not considered in the differential diagnosis: These complications often need active intravenous repletion with doses 4-8 times the usual nutrition recommendations.

Massive copper and selenium losses cause life-threatening deficiencies during prolonged continuous renal replacement

ObjectiveSeveral trace elements are essential for immunity and wound healing, particularly after major burns. Continuous renal replacement therapy (CRRT), which is used to treat renal failure, causes significant trace elements losses. The aim of the present review is to update the current literature and draw attention to this type of complication, as copper deficiency is rarely suspected and diagnosed in clinical conditions and may occur in chronic critically ill patients. MethodsThis is an emblematic case report and review of literature. ResultsMajor copper and selenium deficiencies were documented in a patient with major burns complicated by renal failure. The main cause was effluent loss during prolonged CRRT. The copper deficit resulted in life-threatening bradycardia and the alteration of lipid metabolism with severe hypertriglyceridemia. The published data are scarce, but trace element losses with effluent have been previously documented, as has the affect of copper deficiency on cardiac rhythm. ConclusionThe literature regarding the specific requirements for chronically critically ill patients is limited. During prolonged CRRT, copper and selenium levels decrease and probably should be monitored during prolonged therapy. Research in this area is required.

Experience of Circuit Survival in Extracorporeal Continuous Renal Replacement Therapy Using Small-Calibre Venous Cannulae.

To describe an experience of circuit survival in extracorporeal continuous renal replacement therapy using small-calibre (< 7 French gauge [F]) venous cannulae. An observational study. A multidisciplinary, university-affiliated PICU. Case note review of all continuous renal replacement therapy episodes (1998-2010), which used vascular access cannulae of an external diameter less than 7F, was performed. Forty-nine patients underwent continuous renal replacement therapy treatment during which circuit blood flow was delivered using either 5F or 6.5F double-lumen cannulae. One hundred thirty-nine circuits were employed (median per patient, 2; interquartile range, 1-3) in providing 4,903 hours of therapy (median duration of therapy, 43 hr; interquartile range, 22-86 hr); allowing for censoring, the median circuit survival time was 40 hours (95% CI, 28-66). Eighty-one circuits (58%) failed because of clotting/technical problems, equating to a circuit failure rate of 16.5 (95% CI, 13.3-20.5) per 1,000 hours of continuous renal replacement therapy. The probability of a circuit surviving 40 hours or greater was 50% with 43% (95% CI, 34-53%) expected to survive 60 hours or more. No significant relationship between circuit survival and the calibre of the cannula deployed was identified; however, placement of venous access in an internal jugular vein was associated with improved circuit survival. Contrary to previous reports, vascular access cannulae of a caliber less than 7F can support sufficiently prolonged continuous renal replacement therapy to make them a useful means of delivering renal support in neonates and small infants.

Carnitine deficiency in chronic critical illness

New insight in mitochondrial physiology has highlighted the importance of mitochondrial dysfunction in the metabolic and neuroendocrine changes observed in patients presenting with chronic critical illness. This review highlights specifically the importance of carnitine status in this particular patient population and its impact on beta-oxidation and mitochondrial function. The main function of carnitine is long chain fatty acid esterification and transport through the mitochondrial membrane. Carnitine depletion should be suspected in critically ill patients with risk factors such as prolonged continuous renal replacement therapy or chronic parenteral nutrition, and evidence of beta-oxidation impairments such as inappropriate hypertriglyceridemia or hyperlactatemia. When fatty acid oxidation is impaired, acyl-CoAs accumulate and deplete the CoA intramitochondrial pool, hence causing a generalized mitochondrial dysfunction and multiorgan failure, with clinical consequences such as muscle weakness, rhabdomyolysis, cardiomyopathy, arrhythmia or sudden death. In such situations, carnitine plasma levels should be measured along with a complete assessment of plasma amino acid, plasma acylcarnitines and urinary organic acid analysis. Supplementation should be initiated if below normal levels (20 μmol/l) of carnitine are observed. In the absence of current guidelines, we recommend an initial supplementation of 0.5-1 g/day. Metabolic modifications associated with chronic critical illness are just being explored. Carnitine deficiency in critically ill patients is one aspect of these profound and complex changes associated with prolonged stay in ICU. It is readily measurable in the plasma and can easily be substituted if needed, although guidelines are currently missing.

Clinical course of children requiring prolonged continuous renal replacement therapy

A prospective observational study was performed to analyze the clinical course of critically ill children who require continuous renal replacement therapy (CRRT). Variables associated with prolonged CRRT were analyzed. Of the 174 children treated with CRRT, 32 (18.3%) required CRRT for >14 days and 20 (11.5%) for >21 days. Prolonged CRRT was more common in patients with heart disease and those requiring mechanical ventilation, hemodiafiltration, and higher doses of heparin. The same factors were found when patients with CRRT for >14 days and 21 days were studied. Overall mortality rate was 35.6%; it was slightly higher in patients on prolonged CRRT (43.7% with CRRT > 14 days and 45% with CRRT >21 days), though the differences were not statistically significant. We conclude that there were no differences in the pre-CRRT clinical characteristics, severity of illness, and renal function in critically ill children requiring prolonged CRRT. Prolonged CRRT was more frequently required by patients with heart disease and those on mechanical ventilation. Patients with prolonged CRRT required more frequent hemodiafiltration and higher doses of heparin. Mortality was slightly higher in children with longer CRRT, though this difference did not reach statistical significance.

Bone resorption and “relative” immobilization hypercalcemia with prolonged continuous renal replacement therapy and citrate anticoagulation

Regional citrate anticoagulation is an alternative to heparin in patients with bleeding diatheses who require continuous renal replacement therapy (CRRT). The short-term metabolic consequences that occur with citrate anticoagulation are well described and usually manageable if established protocols are followed vigilantly. Because of its customary short-term nature, the long-term consequences of CRRT with citrate are less often considered and have not been reported. The authors present the case of a woman with multisystem organ failure and prolonged acute renal failure who required CRRT for 120 days. Throughout her hospital course, adequate regional anticoagulation was achieved by blocking the coagulation cascade via the chelation of calcium by citrate. Despite an appropriate drop in the postfilter ionized calcium level, by 8 weeks after the initiation of CRRT, the patient was able to normalize serum calcium levels without the customary calcium infusion. Bone resorption owing to prolonged immobilization leading to hypercalcemia is a known complication of critically ill patients. This problem is more pronounced in patients with high bone turnover rates owing to conditions such as secondary hyperparathyroidism. In this particular case, the chelation of calcium by citrate masked the ensuing immobilization hypercalcemia, resulting in marked bone loss and bilateral spontaneous femoral fractures in the context of normal calcium levels. In critically ill patients sustained with prolonged CRRT with citrate anticoagulation, bone resorption and "relative" immobilization hypercalcemia may manifest as normal serum calcium levels in the face of falling calcium infusion rate requirements.

Copper, selenium, zinc, and thiamine balances during continuous venovenous hemodiafiltration in critically ill patients

Acute renal failure is a serious complication in critically ill patients and frequently requires renal replacement therapy, which alters trace element and vitamin metabolism. The objective was to study trace element balances during continuous renal replacement therapy (CRRT) in intensive care patients. In a prospective randomized crossover trial, patients with acute renal failure received CRRT with either sodium bicarbonate (Bic) or sodium lactate (Lac) as a buffering agent over 2 consecutive 24-h periods. Copper, selenium, zinc, and thiamine were measured with highly sensitive analytic methods in plasma, replacement solutions, and effluent during 8-h periods. Balances were calculated as the difference between fluids administered and effluent losses and were compared with the recommended intakes (RI) from parenteral nutrition. Nineteen sessions were conducted in 11 patients aged 65 +/- 10 y. Baseline plasma concentrations of copper were normal, whereas those of selenium and zinc were below reference ranges; glutathione peroxidase was in the lower range of normal. The replacement solutions contained no detectable copper, 0.01 micromol Se/L (Bic and Lac), and 1.42 (Bic) and 0.85 (Lac) micromol Zn/L. Micronutrients were detectable in all effluents, and losses were stable in each patient; no significant differences were found between the Bic and Lac groups. The 24-h balances were negative for selenium (-0.97 micromol, or 2 times the daily RI), copper (-6.54 micromol, or 0.3 times the daily RI), and thiamine (-4.12 mg, or 1.5 times the RI) and modestly positive for zinc (20.7 micromol, or 0.2 times the RI). CRRT results in significant losses and negative balances of selenium, copper, and thiamine, which contribute to low plasma concentrations. Prolonged CRRT is likely to result in selenium and thiamine depletion despite supplementation at recommended amounts.