Clinical Trial Comparing the Efficacy and Safety of Regional Citrate Anticoagulation Versus Heparin in CRRT

Introduction

Heparin continues to be the most common modality of anticoagulation in CRRT. The increased risk of hemorrhagic complications associated with its use led to the emergence of regional citrate anticoagulation (RCA) as an alternative. However, the perceived complexities associated with its use and the risk of metabolic derangements have prevented it from being adopted on a larger scale. Thus, we conducted a prospective study to compare the efficacy and safety of RCA versus heparin.

Methods

Adult patients admitted to our ICU (November 2018-November 2019) with renal insufficiency and requiring CRRT were included in the study. It was an open-label study with 25 patients each being allotted to the heparin and citrate groups. Our primary outcome was the filter life span. Secondary outcomes included metabolic derangements, bleeding episodes, and patient survival. The starting dose of citrate was 2.0 mmol/L.

Results

The mean filter life span was 32.84 h in the citrate group and 30.40 h in the heparin group (p-value = 0.47). In a significant proportion of the cases, CRRT was terminated for non-filter clotting-related reasons (64% in citrate vs. 32% in heparin). Kaplan-Meir analysis was done to overcome this confounder; the filter lifespan was estimated to be 46.94 h in citrate and 40.05 h for the heparin group (p-value = 0.29). No significant metabolic derangements or bleeding episodes were noted in either group. Overall patient survival was higher in the citrate group at 52% versus 32% (p-value = 0.15) in the heparin group.

Conclusion

No significant difference in filter lifespan or risk of metabolic derangements was noted. A trend toward higher patient survival rates in the citrate group was noted, which warrants further evaluation in future trials.

Case Report of Anti-Thrombogenicity

BACKGROUND

The Toray Filtryzer™-NF is a new polymethyl methacrylate filter with improved hemocompatibility and reduced impact on platelet counts.

OBJECTIVES

This suggests that, if necessary, a reduction in anticoagulation may be possible when dialysis is performed with the Toray Filtryzer™-NF.

METHODS

In the following, we dialyzed 5 hemodialysis patients who had a contraindication to full anticoagulation postoperatively or after renal biopsy with the Filtryzer™-NF.

RESULTS

A significant reduction in heparin administration was achieved, and in 1 patient, heparin substitution was completely omitted. Despite the significantly reduced heparin doses, no thrombosis of the system occurred during the hemodialysis.

CONCLUSION

In conclusion, hemodialysis using the Toray Filtryzer™-NF is an effective alternative for patients at significantly increased risk of bleeding.

Non-anticoagulant factors affecting coagulation in the extracorporeal circulation circuit and the development of an individualized regional citrate anticoagulation protocol for hemodialysis: A real-world retrospective study

OBJECTIVE

To investigate non-anticoagulant factors that affect blood coagulation in the extracorporeal circulation (ECC) circuit of regional citrate anticoagulation (RCA) protocol for hemodialysis (HD).

METHOD

The clinical characteristics of patients undergoing an individualized RCA protocol for HD between February 2021 and March 2022 were collected; Coagulation scores, pressures in various parts of the ECC circuit, the incidence of coagulation, and citrate concentrations in the ECC circuit during treatment were determined, and non-anticoagulant factors affecting coagulation in the ECC circuit were analyzed.

RESULT

The lowest clotting rate was 2.8% in patients with arteriovenous fistula in various vascular access. Patients on Fresenius dialysis had a lower rate of clotting in the cardiopulmonary bypass line than patients on other brands of dialyzer. Low-throughput dialyzers are less likely to clot than high-throughput dialyzers. There are significant differences in the incidence of coagulation among different nurses during citrate anticoagulant hemodialysis.

CONCLUSION

In the process of citrate anticoagulant hemodialysis, non-anticoagulant factors such as coagulation status, vascular access, dialyzer selection, and operator quality will affect the anticoagulant effect.

Unapparent systemic effects of regional anticoagulation with citrate in continuous renal replacement therapy: a narrative review

The use of citrate, through reversible binding of calcium, has become the preferred choice for anticoagulation in continuous renal replacement therapy in the critically ill patient. Though generally considered as very efficacious in acute kidney injury, this type of anticoagulation can cause acid-base disorders as well as citrate accumulation and overload, phenomena which have been well described. The purpose of this narrative review is to provide an overview of some other, non-anticoagulation effects of citrate chelation during its use as anticoagulant. We highlight the effects seen on the calcium balance and hormonal status, phosphate and magnesium balance, as well as oxidative stress resulting from these unapparent effects. As most of these data on these non-anticoagulation effects have been obtained in small observational studies, new and larger studies documenting both short- and long-term effects should be undertaken. Subsequent future guidelines for citrate-based continuous renal replacement therapy should take not only the metabolic but also these unapparent effects into account.

Management of Acute Kidney Injury/Renal Replacement Therapy in the Intensive Care Unit

Common causes of acute kidney injury (AKI) in the ICU setting include acute tubular necrosis (due to shock, hemolysis, rhabdomyolysis, or procedures that compromise renal perfusion), abdominal compartment syndrome, urinary retention, and interstitial nephritis. Treatment is geared toward addressing the underlying cause. Dialysis may be required if renal injury does not resolve. Early initiation of dialysis based on the stage of AKI alone has not been shown to provide a mortality benefit. Dialysis modalities are based on the dialysis indication and the patient's clinical status. Providers should pay close attention to nutritional requirements and medication dosing according to renal function and dialysis modality.

Regional citrate anticoagulation "non-shock" protocol with pre-calculated flow settings for patients with at least 6 L/hour liver citrate clearance

BACKGROUND

Regional citrate anticoagulation (RCA) for the prevention of clotting of the extracorporeal blood circuit during continuous kidney replacement therapy (CKRT) has been employed in limited fashion because of the complexity and complications associated with certain protocols. Hypertonic citrate infusion to achieve circuit anticoagulation results in variable systemic citrate- and sodium load and increases the risk of citrate accumulation and hypernatremia. The practice of "single starting calcium infusion rate for all patients" puts patients at risk for clinically significant hypocalcemia if filter effluent calcium losses exceed replacement. A fixed citrate to blood flow ratio, personalized effluent and pre-calculated calcium infusion dosing based on tables derived through kinetic analysis enable providers to use continuous veno-venous hemo-diafiltration (CVVHDF)-RCA in patients with liver citrate clearance of at least 6 L/h.

METHODS

This was a single-center prospective observational study conducted in intensive care unit patients triaged to be treated with the novel pre-calculated CVVHDF-RCA "Non-shock" protocol. RCA efficacy outcomes were time to first hemofilter loss and circuit ionized calcium (iCa) levels. Safety outcomes were surrogate of citrate accumulation (TCa/iCa ratio) and the incidence of acid-base and electrolyte complications.

RESULTS

Of 53 patients included in the study, 31 (59%) had acute kidney injury and 12 (22.6%) had the diagnosis of cirrhosis at the start of CVVHDF-RCA. The median first hemofilter life censored for causes other than clotting exceeded 70 h. The cumulative incidence of hypernatremia (Na > 148 mM), metabolic alkalosis (HCO3- > 30 mM), hypocalcemia (iCa < 0.9 mM) and hypercalcemia (iCa > 1.5 mM) were 1/47 (1%), 0/50 (0%), 1/53 (2%), 1/53 (2%) respectively and were not clinically significant. The median (25th-75th percentile) of the highest TCa/iCa ratio for every 24-h interval on CKRT was 1.99 (1.91-2.13).

CONCLUSIONS

The fixed citrate to blood flow ratio, as opposed to a titration approach, achieves adequate circuit iCa (< 0.4 mm/L) for any hematocrit level and plasma flow. The personalized dosing approach for calcium supplementation based on pre-calculated effluent calcium losses as opposed to the practice of "one starting dose for all" reduces the risk of clinically significant hypocalcemia. The fixed flow settings achieve clinically desirable steady state systemic electrolyte levels.

Electrolyte monitoring during regional citrate anticoagulation in continuous renal replacement therapy

Patients with acute kidney injury who need continuous renal replacement therapy with locoregional citrate anticoagulation are at risk of citrate accumulation with disruption of the calcium balance. We aimed to evaluate the safety of detecting citrate accumulation and adjusting electrolyte disbalances during continuous venovenous hemodialysis (CVVHD) in critically ill patients with acute kidney injury using a blood sample frequency every 6 h. A prospective single center study in critically ill intensive care unit patients who suffered from acute kidney injury with the need of renal replacement therapy. We evaluated the deviations in pH, bicarbonate and calcium during CVVHD treatment with local regional citrate anticoagulation. Values indicate median and interquartile range. Severe hypocalcemia (below 1.04 mmol/L) or hypercalcemia (above 1.31 mmol/L) occurred in 10.5% and 4.8% respectively. During treatment changes of systemic ionized calcium, post-filter ionized calcium, pH and bicarbonate were corrected with protocolized adjustments. No arrhythmias or citrate accumulation were seen. The values stabilized after 42 h and after that no statistically significant changes were observed. After 42 h of citrate CVVHD, systemic ionized calcium, pH and bicarbonate levels stabilized. A blood sample frequency every 6 h is probably safe to detect citrate accumulation and to adjust the settings of electrolytes to avoid serious electrolyte disturbances in ICU patients without severe metabolic acidosis or severe liver failure.

Technology Innovations in Continuous Kidney Replacement Therapy: The Clinician's Perspective

Continuous kidney replacement therapy (CKRT) has improved remarkably since its first implementation as continuous arteriovenous hemofiltration in the 1970s. However, when looking at the latest generation of CKRT machines, one could argue that clinical deployment of breakthrough innovations by device manufacturers has slowed in the last decade. Simultaneously, there has been a steady accumulation of clinical knowledge using CKRT as well as a multitude of therapeutic and diagnostic innovations in the dialysis and broader intensive care unit technology fields adaptable to CKRT. These include multiple different anticlotting measures; cloud-computing for optimized treatment prescribing and delivered therapy data collection and analysis; novel blood purification techniques aimed at improving the severe multiorgan dysfunction syndrome; and real-time sensing of blood and/or filter effluent composition. The authors present a view of how CKRT devices and programs could be reimagined incorporating these innovations to achieve specific measurable clinical outcomes with personalized care and improved simplicity, safety, and efficacy of CKRT therapy.

Prevalence and predictors of adverse reactions in plateletpheresis donors with the perspective of donor safety in a tertiary care hospital of Northern India

BACKGROUND:

Plateletpheresis procedures are generally safe and associated with low adverse reactions. Although donor reactions and injuries are self-limited events, they may discourage donors from future platelet donations.

AIM:

The purpose of this study was to determine the prevalence and predictors of adverse donor reactions in plateletpheresis donors, which could serve as targets for interventions to reduce reactions.

MATERIALS AND METHODS:

The study included 106 platelet donors over a period of 2 years. The demographic, biometric, and clinical parameters were noted. The data were analyzed for predictors of adverse donor reactions.

STATISTICAL ANALYSIS USED:

The data were analyzed using independent sample t-test to correlate donor variables such as gender. To correlate other variables such as age, weight, and whole blood processed, Chi-square test was used.

RESULTS:

A total of 106 plateletpheresis donations were performed and 13.2% of vasovagal reactions were observed. The significant predictive factors for reactions were young female donors with low body weight in which more than 2.5 L volume of whole blood was processed and more than 250 ml of acid, citrate, and dextrose-A was infused and with single venous access procedures.

CONCLUSIONS:

The results of this study are encouraging and helpful in identifying donors at risk for developing adverse reactions during plateletpheresis so that proper and close observation during and after donation as well as timely intervention can prevent most of the unpleasant events of plateletpheresis donors.

[Citrate anticoagulation hemoperfusion in the treatment of 273 patients]

Early hemoperfusion in poisoned patients can remove poisons rapidly and effectively, which plays an important role in improving the prognosis of patients. The key of hemoperfusion therapy is the safe and effective anticoagulation. The local citrate anticoagulation effect acid is good, it also has little effect on the systemic coagulation mechanism and internal environment of patients, so it is worthy of promotion. We retrospectively analyzed the clinical data and treatment of 273 patients who were poisoned by citrate anticoagulant in the emergency intensive care unit of the Second Affiliated Hospital of Shandong First Medical University, aiming at perfusion of citrate anticoagulant in patients with poisoning. Provide a certain clinical reference.

[Advances in the application of regional citrate anticoagulation for continuous renal replacement therapy in patients with liver failure]

Currently, continuous renal replacement therapy (CRRT) is one of the most important means of organ support methods in critical care medicine. Anticoagulation is an essential part of the treatment process due to its prolonged duration. Patients with liver failure often have coagulation dysfunction and heparin anticoagulant can increase the risk of bleeding, but without heparin anticoagulant, coagulation can easily occur. In addition, an increased volumetric load, hemodynamic instability, nursing workload and other problems are major issues. Therefore, regional citrate anticoagulation (RCA) is the main anticoagulant method for CRRT therapy in patients with liver failure. This article reviews the mechanism, indications, advantages and disadvantages of using RCA to CRRT in hepatic failure.

The Effect of Citrate on Clot Formation, Dialyzer Reuse, and Anemia in Hemodialysis Patients

BACKGROUND

Citrate anticoagulation is increasingly favored for preventing extracorporeal circuit clotting during renal replacement therapy. This study tested the effect of citrate compared with acetate on heparin avoidance and other parameters.

METHODS

Sixty-one chronic hemodialysis (HD) patients were switched from conventional dialysis fluid (acetate) to citrate dialysis fluid and were treated in 3 phases, each lasting 4 weeks: 50%, 25%, and no heparin. Visual clotting score, erythropoiesis stimulating agent (ESA) dose, and laboratory parameters were measured.

RESULTS

Except for 2 episodes of clotting, the same dialyzers were used throughout each citrate phase. The mean visual clotting scores were comparable across study periods. Hemoglobin decreased slightly in phase 2 despite the constant ESA dose. The ionized calcium levels rose after HD in most sessions. No adverse events occurred during citrate dialysis.

CONCLUSION

During citrate dialysis in chronic HD patients, heparin can be completely avoided. The electrolyte levels, the adequacy of dialysis, and hemoglobin can be maintained without significant adverse events.

The Safety and Efficacy of Regional Citrate Anticoagulation in Albumin-Assisted Liver Dialysis for Extracorporeal Liver Support in Pediatric Patients

AIMS

To establish the safety and efficacy of regional citrate anticoagulation (RCA) for pediatric liver failure (LF) patients receiving extracorporeal liver support (ELS) with albumin-assisted dialysis.

METHODS

Retrospective review of pediatric LF patients receiving ELS from April 2014 to December 2016 at a tertiary children's hospital pediatric intensive care unit. Demographic and ELS data collected by chart review. Citrate accumulation (CA) was defined as total calcium (mmol/L): ionized calcium (mmol/L) > 2.5 (tCa:iCa). Efficacy was assessed by treatment duration. Safety was assessed by adverse events: bleeding, hemodynamic instability, arrhythmias, unplanned treatment discontinuation.

RESULTS

Fifteen patients (median age 3 [interquartile range (IQR) 0.7-8.0]) received 108 ELS treatments (median 5 [IQR 4-7.5]). Sixty-eight episodes of CA were identified. Of those, 6 coincided with intervention and 1 coincided with ELS discontinuation. There were no deaths attributed to ELS or RCA.

CONCLUSION

RCA provides safe and effective anticoagulation for pediatric LF patients requiring ELS.

Treatment dose and the elimination rates of electrolytes, vitamins, and trace elements during continuous veno-venous hemodialysis (CVVHD)

INTRODUCTION

During continuous renal replacement therapy, achievement of recommended treatment dose is important. However, relevant substrate loss may occur and recommended nutrition during critical illness could not be sufficient for higher dialysis doses. We investigated the correlation of dialysis dose and substrate loss for a broad range of dialysis doses.

METHODS

Forty critically ill patients with acute kidney injury undergoing citrate CVVHD were included in this prospective study. Three different corresponding blood flow (BF) and dialysate flow (DF) rates were applied (BF/DF: 100 ml/min, 2000 ml/h; 80 ml/min, 1500 ml/h; 120 ml/min, 2500 ml/h). Delivered effluent flow rate (DEFR) was calculated and correlated with losses of vitamins, electrolytes, and trace elements during recommended nutritional supplementation.

RESULTS

For folic acid, vitamin B12, zinc, inorganic phosphate, and magnesium, no correlation of losses and DEFR was detected. For ionized calcium, a correlation was observed and additional substitution was required.

CONCLUSION

Clinically relevant loss of folic acid, vitamin B12, zinc, inorganic phosphate, and magnesium was not observed for differently used dialysis doses of CVVHD, and the loss was covered sufficiently by daily recommended nutritional supplementation. Increased loss of ionized calcium for higher dialysis doses occurred during citrate CVVHD. Therefore, a strict protocol must maintain calcium homeostasis to avoid calcium depletion.

Application of regional citrate anticoagulation during plasma adsorption and plasma exchange for patients with liver failure at high risk of bleeding

AIM

To analyze the feasibility and safety of regional citrate anticoagulation (RCA) during plasma adsorption (PA) plus plasma exchange (PE) therapy for patients with liver failure at high risk of bleeding.

METHODS

This was a retrospective study conducted at the Center of Infectious Diseases, West China Hospital of Sichuan University from October 2016 to July 2017. The clinical data of patients with liver failure at high risk of bleeding who received RCA during PA plus PE therapy were collected. The therapeutic effects, citrate accumulation, electrolytes, and acid-base changes were retrospectively analyzed. Citrate accumulation was defined as the total calcium (Ca_tot) to ionized calcium (Ca_ion) ratio (Ca_tot/Ca_ion) ≥ 2.5.

RESULTS

Of the seven patients included, two survived and five died. Twenty four sessions of RCA for PA plus PE therapy were accomplished. The mean Ca_ionin vitro during PA therapy was 0.28 mmol/L ± 0.09 mmol/L. Citrate accumulation occurred in 45.8% (11/24) of sessions during PA therapy and in all the sessions at the end of PE therapy. Although citrate accumulation still occurred in 41.7% (10/24) of sessions 2 h after PE therapy, it had been decreased obviously when compared with that at the end of PE therapy (P < 0.01) and it was not present by the next morning. No new bleeding occurred and the original bleeding did not deteriorate during and after PA plus PE therapy. The main side effects were alkalosis and transient low level of Ca_ion and high level of Ca_tot.

CONCLUSION

Patients with liver failure still have certain ability to metabolize citrate and tolerate citrate accumulation. RCA may be feasible and safe in the PA plus PE therapy for patients with liver failure.

Accuracy of commercial blood gas analyzers for monitoring ionized calcium at low concentrations

BACKGROUND

Variable ionized calcium measurements in post filter blood samples during continuous renal replacement therapy (renal dialysis) using regional citrate anticoagulation (RCA) have been reported using commercial blood gas analyzers, resulting in analyzer-dependent differences in decisions regarding adjustment of citrate dose.

METHODS

We evaluated accuracy for measurement of iCa at low concentrations by 4 commercial blood gas analyzers using primary reference solutions formulated down to 0.15mmol/l iCa.

RESULTS

Of the 4 analyzers tested, GEM Premier 4000 demonstrates acceptable accuracy for iCa measurement with a median deviation of -6.7% (-0.01mmol/l) at 0.15mmol/l, while other analyzers tested show increasingly positive biases from +40% (+0.06mmol/l) to +60% (+0.09mmol/l) relative to target. These relative differences are consistent with discordant results reported for measurement of iCa in blood during RCA. Interference from sodium with measured iCa and carryover from system rinse solution to sample are likely contributors to variability.

CONCLUSIONS

We conclude the GEM Premier 4000 shows acceptable accuracy for measuring iCa at low concentrations required to control citrate dose during RCA. The method presented here may be used to test accuracy of any blood gas analyzer prior to use in clinical applications requiring measurement of iCa at low concentrations.

Comprehensive analysis of changes in clinically significant divalent serum cation levels during automated plateletpheresis in healthy donors in a tertiary care center in North India

BACKGROUND

Adverse effects due to apheresis are unusual. The most common apheresis-specific reaction is hypocalcemia due to citrate anticoagulation and induces ionized hypocalcemia and hypomagnesemia by chelating effect during the plateletpheresis; generally transient and self-limiting but has the potential of severely injuring donor. We have investigated total calcium (tCa(++)) and magnesium (tMg(++)) levels in sixty healthy plateletpheresis donors at different intervals during the procedure and 30 min post-procedure.

MATERIALS AND METHODS

A total of 60 procedures were performed on healthy donors. Blood samples were obtained from sterile diversion pouch placed on apheresis circuit. 5 ml sample in plain vials was obtained at different intervals during each procedure and 30 min after the end of the procedure. Samples were used for measurement of tCa(++) and tMg(++) levels.

RESULTS

There is continuous decrease in mean tCa(++) from baseline levels (9.83 ± 0.64 mg/dl) till end of procedure (8.33 ± 0.78 mg/dl), but after 30 min, levels again reached near their respective baseline values (9.42 ± 0.54 mg/dl). Similarly, mean tMg(++) fell from baseline levels (2.36 ± 0.3 mg/dl) till the end of procedure (1.39 ± 0.40 mg/dl). After 30 min, levels were again increased, their respective baseline values (2.25 ± 0.25 mg/dl).

CONCLUSION

There is continuous, gradual, and significant fall (P < 0.05) in mean tCa(++) and mean tMg(++) from baseline levels to till the end of procedure but after 30 min of completion of procedure, levels again reached near their respective baseline values.

Sustained low-efficiency dialysis with regional citrate anticoagulation in medical intensive care unit patients with liver failure: A prospective study

PURPOSE

Patients with liver failure requiring dialysis are at increased risk for citrate accumulation during sustained low-efficiency dialysis (SLED). The aim of this study was to evaluate the feasibilty of citrate SLED in critical ill patients with liver failure and investigate predictive parameters regarding citrate accumulation.

MATERIALS AND METHODS

This is a prospective study in 24 medical intensive care unit patients with liver failure and a total of 43 SLED runs (maximum of 3 runs per patient) using citrate anticoagulation. Liver function was characterized before SLED using not only laboratory parameters but also determination of the plasma disappearance rate of indocyanine green. In addition, blood gas parameters as well total calcium and citrate in serum were measured at baseline and defined time points during SLED.

RESULTS

Accumulation of citrate could be observed in all SLED runs, which were nearly normalized until the end of SLED and 24 hours after SLED, respectively. However, the critical threshold of total calcium/ionized calcium on ratio of greater than 2.5 was exceeded in only 1 patient. Equalization of initial metabolic acidosis was possible without major disturbances of acid base and electrolyte status. Liver function parameters showed poor predicitve capabilities regarding citrate accumulation.

CONCLUSIONS

Despite substantial accumulation of citrate in serum, SLED is save and feasible in patients with liver failure using a citrate anticoagulation. Careful monitoring of electrolytes and acid base status is mandatory to ensure patient safety.

Regional citrate anticoagulation for continuous renal replacement therapy in the perioperative care of liver transplant recipients: a single center experience

Kidney injury with concomitant hemodialysis is a common finding in perioperative care of liver transplant patients. The aim of this study was to evaluate disturbances in acid-base status, electrolyte balance and citrate accumulation during hemodialysis with regional citrate anticoagulation in perioperative care of liver transplant recipients. A retrospective, single center evaluation was conducted of patients with severe liver dysfunction receiving renal replacement therapy in the perioperative care of liver transplantation in a multidisciplinary ICU of a university hospital. Within 5 days of ICU stay, 89 patients undergoing liver transplantation received regional citrate anticoagulation for hemodialysis. During the study period pH (7.39 [7.33/7.43] vs. 7.44 [7.39/7.47], P-value = 0.014), base excess values (-0.9 [-5.08/2.35] vs. 4.3 [1.93/8.21], P-value = 0.001) and standard bicarbonate (23.6 [20/26.9] vs. 28.2 [26.2/32.2], P-value = 0.001) significantly increased, whereas lactate levels (2.6 [1.60/4.45] vs. 1.25 [0.98/1.9], P-value = 0.071) and Catot /Caion -ratio decreased or remained below the upper reference. Hypocalcemia appeared mostly within 48 h after dialysis initiation. Although sodium levels increased during the observation, rates of hypernatremia were comparable between hemodialysis days 1 and 5. Hemodialysis using regional citrate anticoagulation remains a challenge in the perioperative care of liver transplant recipients. Major attention must be paid to acid-base disturbances and citrate accumulation within 48 h after dialysis initiation. Nevertheless, regional citrate anticoagulation in liver dysfunction is a feasible and valuable tool, when limitations and pitfalls are adequately considered.

Incidence and outcome of metabolic disarrangements consistent with citrate accumulation in critically ill patients undergoing continuous venovenous hemodialysis with regional citrate anticoagulation

BACKGROUND

Systemic citrate accumulation is a complication of regional citrate anticoagulation (RCA) during continuous renal replacement therapy (CRRT). Our objective was to determine the incidence of clinical signs consistent with citrate accumulation in a large and representative cohort of intensive care unit patients undergoing RCA-CRRT.

METHODS

Patients treated with RCA-CRRT during 2008-2010 were retrospectively analyzed. Decreased systemic ionized calcium (iCa), increased demand for calcium substitution, elevated total calcium to iCa ratio, and metabolic acidosis were evaluated as indicators for citrate accumulation.

RESULTS

In the 3-year period, 1070 patients were treated with RCA-continuous venovenous hemodialysis. Metabolic signs of citrate accumulation occurred in 32 patients (2.99%, 64.5 ± 14.0 years, 65.6% male, Acute Physiology and Chronic Health Evaluation score 34.2 ± 9.7): systemic iCa decreased to 1.01 ± 0.10 mmol/L with a simultaneous increase of the calcium substitution rate to 129% ± 26%, and the mean total calcium to iCa ratio increased to 2.51 ± 0.54. All 32 patients had therapy-resistant shock with severe lactic acidosis (pH 7.20 ± 0.11, lactate 136 ± 61 mg/dL), indicating severe intracellular hypoxia. None of the patients survived.

CONCLUSIONS

The incidence of disarrangements consistent with citrate accumulation in patients undergoing RCA-continuous venovenous hemodialysis was low, taking place exclusively in patients with severe lactic acidosis due to multiorgan failure. This suggests that the appearance of citrate accumulation is secondary to a severe failure of cellular respiration.