Automated regional citrate anticoagulation system based on individualized dosing models in nonliver failure patients undergoing PIRRT therapy.

INTRODUCTION: Regional citrate anticoagulation is a preferred option for renal replacement therapy in critically ill patients. However, current implementations ignore individual differences that may exist in the fluctuation of patients' ionized calcium levels. To address this problem, individualized citrate and calcium supplementation models were established based on the pharmacokinetic and clearance characteristics of citrate, and an automated regional citrate anticoagulation system was built with these models as its core to facilitate the treatment of clinical patients. This study was designed to preliminarily evaluate the safety and efficacy of this system, the SuperbMed® RCA-SP100 automated regional citrate anticoagulation system, in prolonged intermittent renal replacement therapy. METHODS: Seven patients undergoing prolonged intermittent renal replacement therapy completed treatment with the SuperbMed® RCA-SP100 system. In vivo and in vitro ionized calcium levels were measured every hour before and after the start of dialysis. The accuracy and alarm sensitivity of the pumps were also monitored. RESULTS: During seven treatments, the average extracorporeal ionized calcium level was 0.34 ± 0.02 mmol/L, and the mean ionized calcium level in vivo was 1.09 ± 0.07 mmol/L. No patient required intervention, and there was no filter coagulation. The pumps all had an absolute accuracy less than 5%, and alarms could be triggered precisely. CONCLUSIONS: We reported on an automated system that allows for individualized citrate and calcium supplementation in prolonged intermittent renal replacement therapy and enables the precise and secure implementation of regional citrate anticoagulation.

A therapeutic regimen of ceftazidime-avibactam for a critical patient receiving prolonged intermittent renal replacement therapy.

The present report firstly described a critically ill patient receiving a dosing regimen of ceftazidime-avibactam (CAZ-AVI) (1.875g q24h) to eliminate multidrug-resistant Klebsiella pneumoniae and a scheduled time for prolonged intermittent renal replacement therapy (PIRRT) every 48h (6h-session beginning 12h after the previous dosage on hemodialysis day). This dosing regimen for CAZ-AVI and a scheduled time for PIRRT allowed pharmacodynamic parameters of ceftazidime and avibactam to have little difference on hemodialysis and non-hemodialysis days so that we can maintain a relatively stable drug concentration. Our report highlighted not only the importance of dosing regimens in patients with PIRRT but also the significance of hemodialysis time points during the dosing interval. The innovative therapeutic plan proved to be suitable for patients infected with Klebsiella pneumoniae when on PIRRT according to the trough plasma concentrations of ceftazidime and avibactam which were maintained above the minimum inhibitory concentration during the dosing interval.

Prolonged Intermittent Renal Replacement Therapy Combined with Hemoperfusion Can Improve Early Recovery of Moderate and Severe Acute Pancreatitis, Especially in Patients with Acute Kidney Injury.

INTRODUCTION: The aim of this study was to investigate the efficacy of prolonged intermittent renal replacement therapy (PIRRT) plus hemoperfusion (HP) in treating moderately severe acute pancreatitis (MSAP) and severe acute pancreatitis (SAP). METHODS: A total of 105 MSAP and SAP patients were enrolled. Sixty of them received routine internal medical therapy (control group), and 45 received PIRRT and HP in addition to routine internal medical therapy (PIRRT + HP group). The vital signs, laboratory results, and the Acute Physiology and Chronic Health Evaluation II (APACHE II) score were compared between the two groups before treatment and on the 3rd and 7th days of treatment. RESULTS: No deaths or treatment-related serious adverse reactions occurred in both groups. After 3 and 7 days of treatment, the APACHE II score decreased more significantly in the PIRRT + HP group than in the control group (3 days: 5.47 [±3.30] vs. 7.53 [±3.89], p = 0.005. 7 days: 4.82 [±3.49] vs. 6.87 [±3.54], p = 0.004). After 3 days of treatment, the inflammatory combination parameters systemic immune-inflammation index (SII) and neutrophil-to-lymphocyte ratio (NLR) in the PIRRT + HP group decreased more significantly than those in the control group (SII: 1,239.00 [737.80-1,769.00] vs. 2,013.00 [1,260.00-3,167.00], p = 0.001. NLR: 8.78 [±4.52] vs. 11.88 [±7.30], p = 0.009). After 7 days of treatment, SII, NLR, and hypersensitive C-reactive protein decreased significantly compared with baseline, but no statistical differences between the two groups were observed. AST in both groups remained stable with treatment. There was no significant difference in baseline creatinine between the two groups of AKI patients, but after 3 and 7 days of treatment, the proportion of acute kidney injury (AKI) patients in the PIRRT + HP group whose creatinine decreased by 50% from baseline or fell to the normal range was significantly higher than that in the control group (p < 0.05). CONCLUSION: PIRRT + HP therapy could not only improve the general conditions, as measured by APACHE II score, but also reduce the inflammatory cascade of patients with acute pancreatitis. For MSAP and SAP patients complicated with AKI, this therapy may accelerate the recovery of renal function.

Short-term prognostic models for severe acute kidney injury patients receiving prolonged intermittent renal replacement therapy based on machine learning.

BACKGROUND: As an effective measurement for severe acute kidney injury (AKI), the prolonged intermittent renal replacement therapy (PIRRT) received attention. Also, machine learning has advanced and been applied to medicine. This study aimed to establish short-term prognosis prediction models for severe AKI patients who received PIRRT by machine learning. METHODS: The hospitalized AKI patients who received PIRRT were assigned to this retrospective case-control study. They were grouped based on survival situation and renal recovery status. To screen the correlation, Pearson's correlation coefficient, partial ETA square, and chi-square test were applied, eight machine learning models were used for training. RESULTS: Among 493 subjects, the mortality rate was 51.93% and the kidney recovery rate was 30.43% at 30 days post-discharge, respectively. The indices related to survival were Sodium, Total protein, Lactate dehydrogenase (LDH), Phosphorus, Thrombin time, Liver cirrhosis, chronic kidney disease stage, number of vital organ injuries, and AKI stage, while Sodium, Total protein, LDH, Phosphorus, Thrombin time, Diabetes, peripherally inserted central catheter and AKI stage were selected to predict the 30-day renal recovery. Naive Bayes has a good performance in the prediction model for survival, Random Forest has a good performance in 30-day renal recovery prediction model, while for 90-day renal recovery prediction model, it's K-Nearest Neighbor. CONCLUSIONS: Machine learning can not only screen out indicators influencing prognosis of AKI patients receiving PIRRT, but also establish prediction models to optimize the risk assessment of these people. Moreover, attention should be paid to serum electrolytes to improve prognosis.

Bivalirudin dosing during prolonged intermittent renal replacement therapy: a case report.

As patients transition between dialysis modalities, and from the intra- to the inter-dialytic period, medications with a narrow therapeutic index that are cleared in dialysis may require dose adjustments and close monitoring. Three cases of patients receiving bivalirudin while converting from continuous to prolonged intermittent renal replacement therapy are reported. Details provided include flow rates and ultrafiltrate volume. In these cases, it appears pre-emptive dose adjustments may be unwarranted, and clinicians should be aware of potential rebound after cessation of dialysis.

Association between Prolonged Intermittent Renal Replacement Therapy and All-Cause Mortality in COVID-19 Patients Undergoing Invasive Mechanical Ventilation: A Retrospective Cohort Study.

BACKGROUND: The mortality rate of critically ill patients with coronavirus disease 2019 (COVID-19) was high. We aimed to assess the association between prolonged intermittent renal replacement therapy (PIRRT) and mortality in patients with COVID-19 undergoing invasive mechanical ventilation. METHODS: This retrospective cohort study included all COVID-19 patients receiving invasive mechanical ventilation between February 12 and March 2, 2020. All patients were followed until death or March 28, and all survivors were followed for at least 30 days. RESULTS: For 36 hospitalized COVID-19 patients receiving invasive mechanical ventilation, the mean age was 69.4 (±10.8) years, and 30 patients (83.3%) were men. Twenty-two (61.1%) patients received PIRRT (PIRRT group), and 14 cases (38.9%) were managed with conventional strategy (non-PIRRT group). There were no differences in age, sex, comorbidities, complications, treatments, and most of the laboratory findings. During the median follow-up period of 9.5 (interquartile range 4.3-33.5) days, 13 of 22 (59.1%) patients in the PIRRT group and 11 of 14 (78.6%) patients in the non-PIRRT group died. Kaplan-Meier analysis demonstrated prolonged survival in patients in the PIRRT group compared with that in the non-PIRRT group (p = 0.042). The association between PIRRT and a reduced risk of mortality remained significant in 3 different models, with adjusted hazard ratios varying from 0.332 to 0.398. Increased IL-2 receptor, TNF-α, procalcitonin, prothrombin time, and NT-proBNP levels were significantly associated with an increased risk of mortality in patients with PIRRT. CONCLUSION: PIRRT may be beneficial for the treatment of COVID-19 patients with invasive mechanical ventilation. Further prospective multicenter studies with larger sample sizes are required.

The landscape of renal replacement therapy in Veterans Affairs Medical Center intensive care units.

BACKGROUND: Outpatient dialysis is standardized with several evidence-based measures of adequacy and quality that providers aim to meet while providing treatment. By contrast, in the intensive care unit (ICU) there are different types of prolonged and continuous renal replacement therapies (PIRRT and CRRT, respectively) with varied strategies for addressing patient care and a dearth of nationally accepted quality parameters. To eventually describe appropriate quality measures for ICU-related renal replacement therapy (RRT), we first aimed to capture the variety and prevalence of basic strategies and equipment utilized in the ICUs of Veteran Affairs (VA) medical facilities with inpatient hemodialysis capabilities. METHODS: Via email to the dialysis directors of all VA facilities that provided inpatient hemodialysis during 2018, we requested survey participation regarding aspects of RRT in VA ICUs. Questions centered around the mode of therapy, equipment, solutions, prescription authority, nursing, anticoagulation, antimicrobial dosing, and access. RESULTS: Seventy-six centers completed the questionnaire, achieving a response rate of 87.4%. Fifty-five centers reported using PIRRT or CRRT in addition to intermittent hemodialysis. Of these centers, 42 reported being specifically CRRT-capable. Over half of respondents had the capabilities to perform PIRRT. Twelve centers (21.8%) were equipped to use slow low efficient dialysis (SLED) alone. Therapy was largely prescribed by nephrologists (94.4% of centers). CONCLUSIONS: Within the VA system, ICU-related RRT practice is quite varied. Variation in processes of care, prescription authority, nursing care coordination, medication management, and safety practices present opportunities for developing cross-cutting measures of quality of intensive care RRT that are agnostic of modality choice.

Pharmacokinetics and dosing of vancomycin in patients undergoing sustained low efficiency daily diafiltration (SLEDD-f): A prospective study.

BACKGROUND/PURPOSE: The pharmacokinetics of vancomycin in patients who undergo sustained low efficiency daily diafiltration (SLEDD-f) is not clear. This study aimed to determine the appropriate vancomycin dosage regimen for patients receiving SLEDD-f. METHODS: This prospectively observational study enrolled critically ill patients older than 18 years old that used SLEDD-f as renal replacement therapy and received vancomycin treatment. An 8-h SLEDD-f was performed with FX-60 (high-flux helixone membrane, 1.4 m2). Serial blood samples were collected before, during, and after SLEDD-f to analyse vancomycin serum concentrations. Effluent fluid samples (a mixture of dialysate and ultrafiltrate) were also collected to determine the amount of vancomycin removal. RESULTS: Seventeen patients were enrolled, and 10 completed the study. The amount of vancomycin removal was 447.4 ± 88.8 mg (about 78.4 ± 18.4% of the dose administered before SLEDD-f). The vancomycin concentration was reduced by 57.5 ± 14.9% during SLEDD-f, and this reduction was followed by a rebound with duration of one to three hours. The elimination half-life of vancomycin decreased from 64.1 ± 35.7 h before SLEDD-f to 7.0 ± 3.0 h during SLEDD-f. CONCLUSION: Significant amount of vancomycin removed during SLEDD-f. Despite the existence of post-dialysis rebound, a sufficient supplemental dose is necessary to maintain therapeutic range.

Accelerated Venovenous Hemofiltration as a Transitional Renal Replacement Therapy in the Intensive Care Unit.

BACKGROUND: Continuous renal replacement therapy (CRRT) is commonly employed in the intensive care unit (ICU), though there are no guidelines around the transition between CRRT and intermittent hemodialysis (iHD). Accelerated venovenous hemofiltration (AVVH) is a modality utilizing higher hemofiltration rates (4-5 L/h) with shorter session durations (8-10 h) to "accelerate" the clearance and volume removal that normally is spread out over a 24-h period in CRRT. We examined AVVH as a transition therapy between CRRT and iHD, with the aim of decreasing time on CRRT and providing a more graduated transition for hemodynamically unstable patients requiring RRT. METHODS: Retrospective cohort study describing the clinical outcomes and quality initiative experience of the integration of AVVH into the CRRT program at an academic tertiary care center. Outcomes of interest included mortality, ICU length of stay and readmission rates, and technical characteristics of treatments. RESULTS: In total, 97 patients received a total of 298 AVVH treatments (3.1 ± 3.3 treatments per patient). Totally, 271/298 (91%) treatments were completed successfully. During an average treatment time of 9.5 ± 1.6 h with 4.2 ± 0.5 L/h -replacement fluid rate, urea reduction ratio was 23 ± 26% per 10-h treatment, and net ultrafiltration volume was 2.4 ± 1.3 L/treatment. Inpatient mortality was 32%, mean total hospital length of stay was 54 ± 47 days. Sixty-four out of 97 (66%) patients recovered renal function by discharge. Among those who transferred out of the ICU, 7/62 (11%) patients required readmission to the ICU after developing hypotension on iHD. CONCLUSION: AVVH can serve as a transition therapy between CRRT and iHD in the ICU and has the potential to decrease total time on CRRT, improve patient mobility, and sustain low ICU readmission rates. Future study is needed to analyze the implications on resource use and cost of this modality.

Prolonged intermittent renal replacement therapy in children.

Wide ranges of age and weight in pediatric patients makes renal replacement therapy (RRT) in acute kidney injury (AKI) challenging, particularly in the pediatric intensive care unit (PICU), wherein children are often hemodynamically unstable. Standard hemodialysis (HD) is difficult in this group of children and continuous veno-venous hemofiltration/dialysis (CVVH/D) has been the accepted modality in the developed world. Unfortunately, due to cost constraints, CVVH/D is often not available and peritoneal dialysis (PD) remains the common mode of RRT in resource-poor facilities. Acute PD has its drawbacks, and intermittent HD (IHD) done slowly over a prolonged period has been explored as an alternative. Various modes of slow sustained IHD have been described in the literature with the recently introduced term prolonged intermittent RRT (PIRRT) serving as an umbrella terminology for all of these modes. PIRRT has been widely accepted in adults with studies showing it to be as effective as CVVH/D but with an added advantage of being more cost-effective. Pediatric data, though scanty, has been promising. In this current review, we elaborate on the practical aspects of undertaking PIRRT in children as well as summarize its current status.

Polyethyleneimine-treated polyacrylonitrile membrane hemofilter for critically ill patients receiving anticoagulant-free prolonged intermittent renal replacement therapy: a single-center, prospective, self-controlled pilot study.

BACKGROUND: Critically ill patients requiring renal replacement therapy (RRT) are at risk of disease-related bleeding. Systemic heparinization should be avoided. AN69ST, a polyethyleneimine-treated polyacrylonitrile (AN69) membrane hemofilter, can be primed with heparin, improving its local anticoagulative activity. Prolonged intermittent RRT (PI-RRT) is of shorter duration and cheaper, considered as an alternative to continuous RRT. This study was performed to compare the success rate of anticoagulant-free PI-RRT using AN69ST versus AN69 membrane hemofilter. We also evaluated risk factors for filter clotting. METHODS: This crossover, double-blind, randomized study included patients requiring PI-RRT but at high bleeding risk treated with AN69ST and AN69 hemo filters. The success rate of RRT, filter lifespan and severity of filter clotting were compared between the hemo filters. Factors associated with the filter clotting risk were analyzed with a Cox proportional hazards model. RESULTS: This study included 60 patients (mean age, 68.1 ± 15.8 years). Thirty-three (55.0%) patients were in the intensive care unit, 34 (56.8%) had disease-related thrombocytopenia, and 14 (23.3%) had local hemorrhagic diseases. The success rate of PI-RRT with the AN69ST and AN69 hemofilter was 51.7% and 50.9%, respectively (P > 0.05). The mean PI-RRT duration was 543.1 ± 119.0 min in the completed sessions and 387.3 ± 140.8 min in the prematurely terminated sessions, without significant difference between AN69ST and AN69 hemofilters. Cox regression analysis showed that age (odds ratio [OR], 1.023 per year), platelet count (OR, 1.07 per 10 × 109/L), hemoglobin concentration (OR, 1.035 per 1 g/L), and activated partial thromboplastin time (aPTT; OR, 0.973 per second) were associated with a hemofilter clotting risk. The AN69ST hemofilter lifespan was significantly prolonged averaging an extra 251.7 min in patients with an aPTT of <35.3 s, hemoglobin concentration of >83 g/L and platelet count of <70 × 109/L. CONCLUSIONS: Anticoagulant-free PI-RRT by a heparin-primed AN69ST hemofilter reached a 51.7% success rate. The risk of premature clotting of the extracorporeal circuit remains unsatisfactory. For select patients at high risk of bleeding, the heparin-primed AN69ST hemofilter may be more appropriate for anticoagulation-free PI-RRT. TRIAL REGISTRATION: https://www.clinicaltrials.gov ; study number: NCT02355873 . Release Date 01/21/2015.

Impact of dialysis practice patterns on outcomes in acute kidney injury in Intensive Care Unit.

AIM: Recent advances in dialysis therapy have made an impact on the clinical practice of renal replacement therapy (RRT) in acute kidney injury (AKI) in Intensive Care Unit (ICU). We studied the impact of RRT practice changes on outcomes in AKI in ICU over a period of 8 years. SUBJECTS AND METHODS: AKI patients requiring RRT in ICU referred to a nephrologist during two different periods (period-1: Between May 2004 and May 2007, n = 69; period-2: Between August 2008 and May 2011, n = 93) were studied. The major changes in the dialysis practice during the period-2, compared to period-1 were introduction of prolonged intermittent RRT (PIRRT), early dialysis for metabolic acidosis, early initiation of RRT for anuria and positive fluid balance and use of bicarbonate-based fluids for continuous RRT (CRRT) instead of lactate buffer. The primary study outcome was 28-day hospital mortality. RESULTS: The mean age was 53.8 ± 16.1 years and 72.6% were male. Introduction of PIRRT resulted in 37% reduction in utilization of CRRT during period-2 (from 85.5% to 53.7%). The overall mortality was high (68%) but was significantly reduced during period-2 compared to period-1 (59% vs. 79.7%, P = 0.006). Metabolic acidosis but not the mode of RRT, was the significant factor which influenced mortality. CONCLUSIONS: Adaption of PIRRT resulted in 37% reduction of utilization of CRRT. The mortality rate was significantly reduced during the period of adaption of PIRRT, possibly due to early initiation of RRT in the latter period for indications such as anuria and metabolic acidosis.

Vancomycin removal and pharmacokinetics during accelerated venovenous hemofiltration.

INTRODUCTION: Vancomycin pharmacokinetics are affected by renal replacement therapy and physiologic changes in critically ill patients. Literature regarding vancomycin removal and pharmacokinetics during accelerated venovenous hemofiltration (AVVH), a form of prolonged intermittent renal replacement therapy, is limited. OBJECTIVE: To describe the removal and pharmacokinetics of vancomycin during AVVH. METHODS: Eighteen critically ill adults receiving vancomycin and AVVH were included. Vancomycin serum concentrations were obtained within 4 h before and 2-6 h after the AVVH session. Patients' serum concentrations were plotted against time, and individual pharmacokinetic parameters were determined by a one-compartmental analysis. Continuous data are reported as a median (interquartile range [IQR]) and categorical data as a percentage. RESULTS: The median AVVH effluent rate was 39.3 mL/kg/h (IQR 35.5-48 mL/kg/h) for a duration of 9 h (IQR 8-9.75 h). AVVH decreased vancomycin concentrations by 29.8% (IQR 24.9%-35.9%), at a rate of 3.4% per hour (IQR 3.1%-4.3% per hour) of AVVH. The vancomycin elimination rate constant and half-life were 0.039 h-1 (IQR 0.036-0.053 h-1 ) and 17.6 h (IQR 13.1-18.8 h), respectively. The area under the curve during AVVH was 171.7 mg*h/L (IQR 149.1-190 mg*h/L). The volume of distribution in 10 patients was 1 L/kg (IQR 0.73-1.1 L/kg). After AVVH, vancomycin 1000 mg (IQR 750-1000 mg) was needed to maintain a serum trough concentration ≥15 mg/L. CONCLUSION: Vancomycin is significantly removed by AVVH, which requires supplemental dosing after completion of the AVVH session to maintain desired serum concentrations. Therapeutic drug monitoring of vancomycin serum concentrations is recommended for patients undergoing AVVH.

Long-term arteriovenous fistula prognosis for maintenance hemodialysis patients who accepted PIRRT by using arteriovenous fistula.

BACKGROUND: Maintenance hemodialysis (MHD) patients are often admitted to the hospital for severe morbidities. Prolonged intermittent renal replacement therapy (PIRRT) is required during the hospital staying. There are controversial opinions on the use of arteriovenous fistula (AVF) as vascular access for PIRRT in MHD patients. METHODS: Patients with AVF who accepted PIRRT in our center between January 2014 and June 2021 were retrospectively screened. AVF dysfunction and patient mortality were assessed as endpoints. Univariate and multivariate regression models were employed to identify the risk factors of AVF dysfunction. RESULTS: About 162 patients were included in our present study. Twenty-six experienced AVF dysfunction, of whom 53.8%, 19.2%, and 27.0% had percutaneous transluminal balloon angioplasty, surgical revision, and AVF reconstruction, respectively. The accumulated AVF dysfunction rates were 11.8%, 16.2%, and 21.0% in 1, 2, and 3 years, respectively. Multivariate analysis revealed that smoking (HR 2.750, 95% CI 1.181-6.402, p = 0.019), higher platelet (PLT, HR 1.009, 95% CI 1.000-1.017, p = 0.047), higher prothrombin activity (PTA, HR 1.039, 95% CI 1.012-1.066, p = 0.004), and lower diastolic blood pressure (DBP, HR 0.963, 95% CI 0.932-0.996, p = 0.026) were independent risk factors for AVF dysfunction. During the follow-up period, 37 patients died. CONCLUSIONS: Overall, the use of AVF for PIRRT might not dramatically increase the incidence of AVF dysfunction. And, Smoking, lower DBP, higher PLT, and higher PTA were associated with increased AVF dysfunction.

Population pharmacokinetics of vancomycin in critically ill patients receiving prolonged intermittent renal replacement therapy.

OBJECTIVES: The aim of this study was to describe the population pharmacokinetics of vancomycin during prolonged intermittent renal replacement therapy (PIRRT) in critically ill patients with acute kidney injury. METHODS: Critically ill patients prescribed vancomycin across two sites had blood samples collected during one to three dosing intervals during which PIRRT was performed. Plasma samples were assayed with a validated immunoassay method. Population pharmacokinetic analysis and Monte Carlo simulations were performed using Pmetrics®. The target vancomycin exposures were the area under the concentration-time curve within a 24-h period (AUC0-24)/minimum inhibitory concentration (MIC) ratio of 400 for efficacy and AUC0-24 700 for toxicity. RESULTS: Eleven critically ill patients (seven male) were enrolled and contributed 192 plasma samples. The patient's mean ± standard deviation (SD) age, weight and body mass index (BMI) were 57 ± 13 years, 98 ± 43 kg and 31 ± 9 kg/m2, respectively. A two-compartment linear model adequately described the data. The mean ± SD population pharmacokinetic parameter estimates were PIRRT clearance (CL) 3.47 ± 1.99 L/h, non-PIRRT CL 2.15 ± 2.07 L/h, volume of distribution of the central compartment (Vc) 41.85 ± 24.33 L, distribution rate constant from central to peripheral compartment 5.97 ± 7.93 per h and from peripheral to central compartment 5.29 ± 6.65 per h. Assuming a MIC of 1 mg/L, vancomycin doses of 25 mg/kg per day are suggested to be efficacious, whilst minimising toxic, exposures. CONCLUSIONS: This is the first population pharmacokinetic study of vancomycin in patients receiving PIRRT and we observed large pharmacokinetic variability. Empirically, weight-based doses that are appropriate for the duration of PIRRT, should be selected and supplemented with therapeutic drug monitoring.

Use of Monte Carlo Simulations to Determine Optimal Carbapenem Dosing in Critically Ill Patients Receiving Prolonged Intermittent Renal Replacement Therapy.

Pharmacokinetic/pharmacodynamic analyses with Monte Carlo simulations (MCSs) can be used to integrate prior information on model parameters into a new renal replacement therapy (RRT) to develop optimal drug dosing when pharmacokinetic trials are not feasible. This study used MCSs to determine initial doripenem, imipenem, meropenem, and ertapenem dosing regimens for critically ill patients receiving prolonged intermittent RRT (PIRRT). Published body weights and pharmacokinetic parameter estimates (nonrenal clearance, free fraction, volume of distribution, extraction coefficients) with variability were used to develop a pharmacokinetic model. MCS of 5000 patients evaluated multiple regimens in 4 different PIRRT effluent/duration combinations (4 L/h × 10 hours or 5 L/h × 8 hours in hemodialysis or hemofiltration) occurring at the beginning or 14-16 hours after drug infusion. The probability of target attainment (PTA) was calculated using ≥40% free serum concentrations above 4 times the minimum inhibitory concentration (MIC) for the first 48 hours. Optimal doses were defined as the smallest daily dose achieving ≥90% PTA in all PIRRT combinations. At the MIC of 2 mg/L for Pseudomonas aeruginosa, optimal doses were doripenem 750 mg every 8 hours, imipenem 1 g every 8 hours or 750 mg every 6 hours, and meropenem 1 g every 12 hours or 1 g pre- and post-PIRRT. Ertapenem 500 mg followed by 500 mg post-PIRRT was optimal at the MIC of 1 mg/L for Streptococcus pneumoniae. Incorporating data from critically ill patients receiving RRT into MCS resulted in markedly different carbapenem dosing regimens in PIRRT from those recommended for conventional RRTs because of the unique drug clearance characteristics of PIRRT. These results warrant clinical validation.

Prolonged Intermittent Renal Replacement Therapy.

Prolonged intermittent renal replacement therapy (PIRRT) is becoming an increasingly popular alternative to continuous renal replacement therapy in critically ill patients with acute kidney injury. There are significant practice variations in the provision of PIRRT across institutions, with respect to prescription, technology, and delivery of therapy. Clinical trials have generally demonstrated that PIRRT is non-inferior to continuous renal replacement therapy regarding patient outcomes. PIRRT offers cost-effective renal replacement therapy along with other advantages such as early patient mobilization and decreased nursing time. However, due to lack of standardization of the procedure, PIRRT still poses significant challenges, especially pertaining to appropriate drug dosing. Future guidelines and clinical trials should work toward developing consensus definitions for PIRRT and ensure optimal delivery of therapy.