Early warning of citric acid overdose and timely adjustment of regional citrate anticoagulation based on machine learning methods

Background Regional citrate anticoagulation (RCA) is an important local anticoagulation method during bedside continuous renal replacement therapy. To improve patient safety and achieve computer assisted dose monitoring and control, we took intensive care units patients into cohort and aiming at developing a data-driven machine learning model to give early warning of citric acid overdose and provide adjustment suggestions on citrate pumping rate and 10% calcium gluconate input rate for RCA treatment. Methods Patient age, gender, pumped citric acid dose value, 5% NaHCO3 solvent, replacement fluid solvent, body temperature value, and replacement fluid PH value as clinical features, models attempted to classify patients who received regional citrate anticoagulation into correct outcome category. Four models, Adaboost, XGBoost, support vector machine (SVM) and shallow neural network, were compared on the performance of predicting outcomes. Prediction results were evaluated using accuracy, precision, recall and F1-score. Results For classifying patients at the early stages of citric acid treatment, the accuracy of neutral networks model is higher than Adaboost, XGBoost and SVM, the F1-score of shallow neutral networks (90.77%) is overall outperformed than other models (88.40%, 82.17% and 88.96% for Adaboost, XGBoost and SVM). Extended experiment and validation were further conducted using the MIMIC-III database, the F1-scores for shallow neutral networks, Adaboost, XGBoost and SVM are 80.00%, 80.46%, 80.37% and 78.90%, the AUCs are 0.8638, 0.8086, 0.8466 and 0.7919 respectively. Conclusion The results of this study demonstrated the feasibility and performance of machine learning methods for monitoring and adjusting local regional citrate anticoagulation, and further provide decision-making recommendations to clinicians point-of-care.

Low bicarbonate replacement fluid normalizes metabolic alkalosis during continuous veno-venous hemofiltration with regional citrate anticoagulation

Background Metabolic alkalosis is a frequently occurring problem during continuous veno-venous hemofiltration (CVVH) with regional citrate anticoagulation (RCA). This study aimed to evaluate the effectiveness of switching from high to low bicarbonate (HCO3−) replacement fluid in alkalotic critically ill patients with acute kidney injury treated by CVVH and RCA. Methods A retrospective-comparative study design was applied. Patients who underwent CVVH with RCA in the ICU between 09/2016 and 11/2017 were evaluated. Data were available from the clinical routine. A switch of the replacement fluid Phoxilium® (30 mmol/l HCO3−) to Biphozyl® (22 mmol/l HCO3−) was performed as blood HCO3− concentration persisted ≥ 26 mmol/l despite adjustments of citrate dose and blood flow. Data were collected from 72 h before the switch of the replacement solutions until 72 h afterwards. Results Of 153 patients treated with CVVH during that period, 45 patients were switched from Phoxilium® to Biphozyl®. Forty-two patients (42 circuits) were available for statistical analysis. After switching the replacement fluid from Phoxilium® to Biphozyl® the serum HCO3− concentration decreased significantly from 27.7 mmol/l (IQR 26.9–28.9) to 25.8 mmol/l (IQR 24.6–27.7) within 24 h (p < 0.001). Base excess (BE) decreased significantly from 4.0 mmol/l (IQR 3.1–5.1) to 1.8 mmol/l (IQR 0.2–3.4) within 24 h (p < 0.001). HCO3− and BE concentration remained stable from 24 h till the end of observation at 72 h after the replacement fluid change (p = 0.225). pH and PaCO2 did not change significantly after the switch of the replacement fluid until 72 h. Conclusions This retrospective analysis suggests that for patients developing refractory metabolic alkalosis during CVVH with RCA the use of Biphozyl® reduces external HCO3− load and sustainably corrects intracorporeal HCO3− and BE concentrations. Future studies have to prove whether correcting metabolic alkalosis during CVVH with RCA in critically ill patients is of relevance in terms of clinical outcome.

Current Concepts in Fluid Therapy in Horses

Despite the frequent inclusion of fluid therapy in the treatment of many conditions in horses, there are limited studies available to provide evidenced-based, species-specific recommendations. Thus, equine fluid therapy is based on the application of physiology and extrapolation from evidence in other veterinary species and human medicine. The physiologic principles that underly the use of fluids in medicine are, at first glance, straightforward and simple to understand. However, in the past 20 years, multiple studies in human medicine have shown that creating recommendations based on theory in combination with experimental and/or small clinical studies does not consistently result in best practice. As a result, there are ongoing controversies in human medicine over fluid types, volumes, and routes of administration. For example, the use of 0.9% NaCl as the replacement fluid of choice is being questioned, and the theoretical benefits of colloids have not translated to clinical cases and negative effects are greater than predicted. In this review, the current body of equine research in fluid therapy will be reviewed, connections to the controversies in human medicine and other veterinary species will be explored and, where appropriate, recommendations for fluid therapy in the adult horse will be made based on the available evidence. This review is focused on the decisions surrounding developing a fluid plan involving crystalloids, synthetic colloids, and plasma.

Improvised Field Expedient Method for Renal Replacement Therapy in a Porcine Model of Acute Kidney Injury

ABSTRACT Objective: Dialysis patients may not have access to conventional renal replacement therapy (RRT) following disasters. We hypothesized that improvised renal replacement therapy (ImpRRT) would be comparable to continuous renal replacement therapy (CRRT) in a porcine acute kidney injury model. Methods: Following bilateral nephrectomies and 2 hours of caudal aortic occlusion, 12 pigs were randomized to 4 hours of ImpRRT or CRRT. In the ImpRRT group, blood was circulated through a dialysis filter using a rapid infuser to collect the ultrafiltrate. Improvised replacement fluid, made with stock solutions, was infused pre-pump. In the CRRT group, commercial replacement fluid was used. During RRT, animals received isotonic crystalloids and norepinephrine. Results: There were no differences in serum creatinine, calcium, magnesium, or phosphorus concentrations. While there was a difference between groups in serum potassium concentration over time (P < 0.001), significance was lost in pairwise comparison at specific time points. Replacement fluids or ultrafiltrate flows did not differ between groups. There were no differences in lactate concentration, isotonic crystalloid requirement, or norepinephrine doses. No difference was found in electrolyte concentrations between the commercial and improvised replacement solutions. Conclusion: The ImpRRT system achieved similar performance to CRRT and may represent a potential option for temporary RRT following disasters.

P1058COMPARISON OF THE REMOVAL EFFICIENCY AND THE BIOCOPATIBILITY BETWEEN PRE- AND POST-DILUTION ON-LINE HEMODIAFILTRATION

Background and Aims On-line HDF (OL-HDF) performed in Japan is characterized by the fact that pre-dilution OL-HDF (pre-HDF) accounts for 95% of the cases. In Europe, post-dilution OL-HDF (post-HDF) is the mainstream mode, and particularly high-volume post-HDF is reportedly associated with a favorable prognosis in patients. Last year, we reported favorable biocompatibility and removal efficiency of low-volume post-HDF using high-performance hemodiafilters. Here, we performed pre-HDF and post-HDF for 4 weeks each under the same conditions in the previous study and compared the removal efficiency and the biocompatibility. Method Nine stable dialysis patients who had received pre-HDF for at least 6 months (age, 60.8±15.4 years; dry weight, 54.5±9.5 kg) were included in this study. Fineflux-210 Seco (asymmetric triacetate membrane, NIPRO) was used as a hemodiafilter. Post-HDF (replacement fluid rate, 12 L/session) was performed in the first session and pre-HDF (replacement fluid rate, 60 L/session) in the second, each lasting 4 weeks. Each study parameter was evaluated on the last day of each session. In either session, HDF was performed at a blood flow rate of 250 mL/min and a total dialysate flow rate of 500 mL/min. Each HDF cycle lasted 4 h. The removal efficiency was evaluated in terms of Kt/V, as well as the removal rates and removal volumes of urea, creatinine, β2-microglobulin (MG), and α1-MG. Biocompatibility was evaluated in terms of the rates of changes in the levels of CRP, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), pentraxin-3 (PTX3), and intercellular adhesion molecule-1 (ICAM-1) before and after dialysis. Changes in the levels of CD62P during dialysis were also examined. Paired t-test was used for statistical analysis. Results Removal efficiency results: The removal efficiency for small molecular weight solutes was significantly higher in post-HDF. The removal rate (%) and removal volume (g/session) of β2-MG were 81.4±3.6 and 0.224±0.051 in post-HDF and 80.7±3.3 and 0.218±0.029 in pre-HDF, respectively. The removal rate (%) and removal volume (g/session) of α1-MG were 37.0±4.0 and 0.151±0.024 in post-HDF and 33.3±4.1 and 0.133±0.026 in pre-HDF, respectively. The amount of albumin leakage (g/session) was 3.7±0.6 in post-HDF and 3.1±0.7 in pre-HDF, indicating a significant difference. Biocompatibility results: There were no significant differences between the two modes in the rates of changes in the levels of CRP, PTX3, IL-6, TNF-α, or ICAM-1 before and after treatment. The rate of expression of CD62P was also not significantly different. Conclusion Under the present conditions using high-performance filters, post-HDF and pre-HDF demonstrated favorable removal efficiency for both small and large molecular weight solutes, and the biocompatibility was also favorable, indicating no significant differences between the two modes.

MO079SECURITY OF THERAPEUTIC APHERESIS IN PEDIATRICS. PROSPECTIVE STUDY DURING 2018 IN 171 APHERESIS SESSSIONS

Background and Aims Identify hypocalcemia and hemodynamic disorders related to apheresis in pediatrics either complications in vascular access or related to anticoagulation and adverse reactions with replacement fluid. Method Prospective and descriptive study of 171 sessions for therapeutic apheresis in pediatrics during 2018. Inclusion criteria was based on the 2016 Clinical-Practice-of-Therapeutic-Apheresis-guidelines(ASFA). The apheresis technique was selected also based on the 2016 ASFA Guidelines and the expertise in our center. Results The 171 sessions were distributed as follows: 73% were immunoadsorption(IA), 12% were cytoapheresis, 10.5% were LDL-apheresis and 4.5% therapeutic plasma exchange(TPE). The average age was 9 years and 58% were women. 50, 33 and 17% were due to Nephrological, Neurological and Digestive pathology respectively. 83% of the nephrological indications correspond to a category I of the ASFA Guidelines, as well as 25% of the neurological indications and all indications of Digestive pathology correspond to a category II. 58, 25 and 17% used temporary catheter, permanent catheter and needles respectively. Only one patient is accidentally removed from the temporary jugular catheter and it has not been related to vascular access or by the apheresis technique itself. Sixty-six percent had individual anticoagulation with citrate/calcium plus heparin and the remaining 33%, only once. Any case of bleeding related to catheter or others. Only 3 sessions of IA in the hypocalcemia objective, being symptomatic in only one of them. Of all 8 sessions of TPE, we performed 6 with frozen fresh plasma as replacement fluid with no adverse reactions. Conclusion The apheresis techniques in pediatrics had been presented with few complications in our center, none derived from vascular access, anticoagulation, infections or adverse effects due to use of replacement fluid. The training of medical and nursing staff is essential to identify risk situations. The use of protocols and international guidelines ensure safety in pediatrics.

Continuous veno-venous hemofiltration in the treatment of severely burned patients with acute hypernatremia: A retrospective study of 13 cases

Objectives: This study aimed to evaluate the clinical effects of continuous veno-venous hemofiltration in the treatment of severely burned patients with acute hypernatremia. Methods: A total of 13 severely burned patients with acute hypernatremia admitted to Xijing Hospital were included in this study. All patients received continuous veno-venous hemofiltration treatment in addition to conventional treatment. The original sodium level in the replacement fluid was set to be lower than the serum sodium level by 8 mmol/L and subsequently undergoes a reduction rate of 2.16 ± 0.18 mmol/L every 4 h. Patients’ clinical features, serum laboratory tests, hemodynamic variables, changes in sodium levels in serum, and replacement fluid during continuous veno-venous hemofiltration treatment were monitored. Results: Patients had an average total burn surface area of 66.69% ± 20.28%. Two patients died of systematic Pseudomonas aeruginosa infections, and 11 patients survived. After continuous veno-venous hemofiltration treatment, patients showed a significant reduction in the serum sodium level (168.91 ± 4.88 mmol/L vs 144.62 ± 2.98 mmol/L, p < 0.01). Likewise, the serum levels of urea and creatinine decreased from 24.8 ± 6.5 mmol/L to 14.9 ± 8.3 mmol/L and from 278.6 ± 155.3 μmol/L to 152.6 ± 29.7 μmol/L, respectively (p < 0.05). The patients also displayed improvements in the Acute Physiology and Chronic Health Evaluation II and Glasgow scores (p < 0.05) and showed a significant reduction in hemoglobin and serum albumin levels (p < 0.05), but no obvious change in levels of platelets, alanine aminotransferase, and aspartate aminotransferase (p > 0.05). Conclusion: Our results indicate that continuous veno-venous hemofiltration with gradient sodium replacement fluid is effective in treating hypernatremia in severely burned patients with the controllable sodium reduction rate and satisfactory clinical outcomes.

Overexposure to Bisphenol A and Its Chlorinated Derivatives of Patients with End-Stage Renal Disease during Online Hemodiafiltration

The health safety conditions governing the practice of online hemodiafiltration (OL-HDF) do not yet incorporate the risks related to the presence of endocrine disruptors such as bisphenol A (BPA). The aim of this study was to assess, for the first time, the exposure to BPA but also to its chlorinated derivatives (ClxBPA) (100 times more estrogenic than BPA) during OL-HDF. We demonstrated that BPA is transmitted by the different medical devices used in OL-HDF: ultrafilters, dialysis concentrate cartridges (and not only dialyzers, as previously described). Moreover, BPA has been found in dialysis water as well as in ultrapure dialysate and replacement fluid due to contamination of water coming from municipal network. Indeed, due to contaminations provided by both ultrafilters and water, high levels of BPA were determined in the infused replacement fluid (1033 ng.L−1) from the beginning of the session. Thus, our results demonstrate that dialysis water must be considered as an important exposure source to endocrine disruptors, especially since other micropollutants such as ClxBPA have also been detected in dialysis fluids. While assessment of the impact of this exposure remains to be done, these new findings should be taken into account to assess exposure risks in end-stage renal disease patients.