Regional Citrate Anticoagulation for Continuous Kidney Replacement Therapy With Calcium-Containing Solutions: A Cohort Study

OBJECTIVE

Regional citrate anticoagulation (RCA) is the preferred anticoagulation method for continuous kidney replacement therapy (CKRT) recommended by KDIGO. Limited availability of calcium-free solutions often imposes challenges to the implementation of RCA for CKRT (RCA-CKRT). The principal purpose of this study was to characterize the outcomes of RCA-CKRT using calcium-containing solutions.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

We evaluated the safety and efficacy of RCA-CKRT with calcium-containing dialysate and replacement fluid used for 128 patients. A total of 571 filters and 1,227 days of CKRT were analyzed.

EXPOSURES

Liver disease, sepsis in the absence of liver disease, and sepsis with liver disease.

OUTCOMES

Filter life and metabolic complications per 100 CKRT days.

ANALYTICAL APPROACH

Linear mixed-effects model and generalized linear mixed-effects models.

RESULTS

The majority of patients were male (91; 71.1%), 32 (25%) had liver disease, and 29 (22.7%) had sepsis without liver disease. Median filter life was 50.0 (interquartile range, 22.0-118.0) hours, with a maximum of 322 hours, and was significantly lower (33.5 [interquartile range, 17.5-60.5] h) in patients with liver disease. Calcium-containing replacement solutions were used in 41.6% of all CKRT hours and reduced intravenous calcium requirements by 31.7%. Hypocalcemia (ionized calcium<0.85mmol/L) and hypercalcemia (total calcium>10.6mg/dL) were observed in 6.0 and 6.7 per 100 CKRT days, respectively. Citrate accumulation was observed in 13.3% of all patients and was associated with metabolic acidosis in 3.9%, which was not significantly different in patients with liver disease (9.3%; P = 0.2).

LIMITATIONS

Lack of control groups that used calcium-free dialysate and replacement solutions with RCA-CKRT. Possible overestimation of filter life from incomplete data on cause of filter failure.

CONCLUSIONS

Our study suggests that RCA-CKRT with calcium-containing solutions is feasible and safe in critically ill patients, including those with sepsis and liver disease.

Feasibility and efficacy of modified fixed citrate concentration protocol using only commercial preparations in critically ill patients: a prospective cohort study with a historical control group

BACKGROUND

The cumbersome program and the shortage of commercial solution hindered the regular application of regional citrate anticoagulation (RCA). It is urgent to simplify the protocol using only commercial preparations. The aim of this study was to explore the feasibility and efficacy of the modified protocol for continuous veno-venous hemofiltration (CVVH) in unselected critically ill patients.

METHODS

A prospective cohort study was conducted in 66 patients who received a new protocol combining fixed citrate concentration with modified algorithm for supplements (i.e., fixed protocol), and compared the efficacy, safety and convenience for this group to a historical control group with a traditional protocol (n = 64), where citrate was titrated according to the circuit ionized calcium concentration (i.e., titrated protocol). The convenience was defined as the demand for monitoring test and dose adjustment of any supplement.

RESULTS

The filter lifespan was 63.2 ± 16.1 h in the fixed group and 51.9 ± 17.7 h in the titrated group, respectively. Kaplan-Meier survival analysis demonstrated longer circuit lifetime for fixed group (log-rank, p = 0.026). The incidence of circuit clotting was lower in the fixed protocol (15.2% vs. 29.7% in the titrated protocol, p = 0.047). Moreover, compared with the titrated group, patients with fixed protocol had less demand for monitoring test and dose adjustment of any supplement (the number of times per person per day) (3.3 [IQR 2.3-4.5] vs. 5.7 [IQR 3.3-6.9], p = 0.001 and 1.9 [IQR 0.5-2.7] vs. 6.3 [IQR 4.2-7.9], p < 0.001; respectively). No new onset bleeding complications occurred in all patients. The overall incidence of suspected citrate accumulation was 4.6% and there was no difference between the two groups (p = 0.969), yet a lower rate of metabolic alkalosis was found in the fixed group (3.0% vs. 14.1%, p = 0.024).

CONCLUSIONS

Our modified fixed citrate concentration protocol is feasible, safe and effective to enhance the circuit lifespan and the convenience of implementation while maintaining a similar safety when compared to the traditional protocol. Using only commercial preparations may be helpful for widespread application of RCA.

TRIAL REGISTRATION

Clinicaltrials.gov. NCT02663960 . Registered 26 January 2016.