Continuous Ultrafiltration Research Articles

Extracorporeal organ support for critically ill patients: Overcoming the past, achieving the maximum at present, and redefining the future

Extracorporeal organ support (ECOS) has made remarkable progress over the last few years. Renal replacement therapy, introduced a few decades ago, was the first available application of ECOS. The subsequent evolution of ECOS enabled the enhanced support to many other organs, including the heart [veno-arterial extracorporeal membrane oxygenation (ECMO), slow continuous ultrafiltration], the lungs (veno-venous ECMO, extracorporeal carbon dioxide removal), and the liver (blood purification techniques for the detoxification of liver toxins). Moreover, additional indications of these methods, including the suppression of excessive inflammatory response occurring in severe disorders such as sepsis, coronavirus disease 2019, pancreatitis, and trauma (blood purification techniques for the removal of exotoxins, endotoxins, or cytokines), have arisen. Multiple organ support therapy is crucial since a vast majority of critically ill patients present not with a single but with multiple organ failure (MOF), whereas, traditional therapeutic approaches (mechanical ventilation for acute respiratory failure, antibiotics for sepsis, and inotropes for cardiac dysfunction) have reached the maximum efficacy and cannot be improved further. However, several issues remain to be clarified, such as the complexity and cost of ECOS systems, standardization of indications, therapeutic protocols and initiation time, choice of the patients who will benefit most from these interventions, while evidence from randomized controlled trials supporting their use is still limited. Nevertheless, these methods are currently a part of routine clinical practice in intensive care units. This editorial presents the past, present, and future considerations, as well as perspectives regarding these therapies. Our better understanding of these methods, the pathophysiology of MOF, the crosstalk between native organs resulting in MOF, and the crosstalk between native organs and artificial organ support systems when applied sequentially or simultaneously, will lead to the multiplication of their effects and the minimization of complications arising from their use.

#2232 Personalized kidney replacement therapy in critically ill patients: unity makes strength!

Abstract Background and Aims The complexity of the critically ill patient with kidney disease has increased in recent years. A holistic and multidisciplinary approach is, therefore, necessary in order to provide the best therapeutic guidance. Multiple modalities of kidney replacement therapies (KRT) are available in this setting, namely continuous kidney replacement therapies (CKRTs) and hybrid therapies, also such as sustained low-efficiency dialysis (SLED) and slow continuous ultrafiltration (SCUF). These techniques can be used in conjunction with other extracorporeal clearance therapies such as plasmapheresis (PF), and immunoadsorption (IA). Their prescription must be individualized according to the characteristics of each patient. In our hospital all KRT and extracorporeal techniques used are reviewed daily by a nephrologist. This study aims to describe the 20-year experience of our centre in individualized KRT prescription in intensive care. Methods A retrospective cohort, single centre study was conducted. We reviewed adult patients (age ≥18 years) admitted in all the ICUs of our hospital centre between January 2002 and December 2022, who required a KRT. We aimed to describe demographic data, different stages of kidney disease [AKI, AKI in CKD, chronic hemodialysis (HD), peritoneal dialysis (PD), kidney transplant (KT), rapidly progressive kidney failure (RPKF), other causes], the KRT used and the main outcomes. Results During the study period, 1578 patients who required a KRT were admitted to the ICU. Median age was 65 (IQR: 45-81) years old and 59.9% were male. Among these patients 715 (45.3%) had AKI, 380 (24.1%) were in HD, 315 (20%) had AKI in CKD, 130 (8.2%) had a KT and 31 (2%) were in PD. Four patients had RPKF and 3 patients had other causes for KRT, such as hyperammonemia and sodium valproate poisoning. The main KRT performed were: SLED—1365 (86.5%) patients; continuous venovenous hemodiafiltration (cvvHDF)—120 (7.6%) patients; SLED + cvvHDF—66 (4.2%). Other KRT executed were SLED + PF (11 patients), continuous venovenous hemofiltration (cvvHF) (8 patients) and SCUF (2 patients). Among all patients mortality rate was 42.3%, 33% had renal recovery and 7.4% started chronic HD. In AKI group the median age was 64 (IQR: 48-80) years and 56.3% were male. 576 (80.7%) performed SLED, 91 (12.7%) did cvvHDF and 36 (5.0%). Mortality rate was of 52.1%, renal recovery 45% and 2.9% started chronic HD. Conclusion Our ICU multidisciplinary approach model with a critical care nephrology specialists team translates into a large amount of accumulated experience with SLED. Our results are comparable to centres that predominantly use CKRTs. The range of different techniques used reflects the fact that KRT has become a complex treatment for critically ill patients, which allows for the prescription to be precisely tailored to the different daily clinical needs.

In vivo measurement of pediatric extracorporeal oxygenator insensible losses; a single center pilot study.

Fluid overload on Extracorporeal Membrane Oxygenation (ECMO) is associated with worse outcomes. Previous in vitro studies have attempted to quantify oxygenator-related insensible losses, as failure to account for this fluid loss may lead to inaccurate fluid balance assessment and potentially harmful clinical management, such as unnecessary exposure to diuretics, slow continuous ultrafiltration (SCUF), or continuous kidney replacement therapy (CKRT). We performed a novel in vivo study to measure insensible fluid losses in pediatric ECMO patients. Pediatric ECMO patients were approached over eleven months in the pediatric and cardiac intensive care units. The water content of the oxygenator inflow sweep gas and exhaust gas were calculated by measuring the ambient temperature and relative humidity at frequent intervals and various sweep flow. Nine subjects were enrolled, generating 431 data points. The cohort had a median age of 11 years IQR [0.83, 13], weight of 23.2 kg IQR [6.48, 44.28], and body surface area of 0.815 m2 IQR [0.315, 1.3725]. Overall, the cohort had a median sweep of 2.5 L/min [0.9, 4], ECMO flow of 3.975 L/m2/min [0.75, 4.51], and a set ECMO temperature of 37 degrees Celsius [36.6, 37.2]. The calculated net water loss per L/min of sweep was 75.93 ml/day, regardless of oxygenator size or patient weight. There was a significant difference in median documented vs. calculated fluid balance incorporating the insensible fluid loss, irrespective of oxygenator size (pediatric oxygenator: 7.001 ml/kg/day [-12.37, 28.59] vs. -6.11 ml/kg/day [-17.44, 13.01], respectively, p = 0.005 and adult oxygenator: 14.36 ml/kg/day [1.54, 25.77] and 9.204 ml/kg/day [-1.28, 22.05], respectively, p = <0.001). We present this pilot study of measured oxygenator-associated insensible fluid losses on ECMO. Our results are consistent with prior in vitro methods and provide the basis for future studies evaluating the impact of incorporating these fluid losses into patients' daily fluid balance on patient management and outcomes.

Continuous Renal Replacement Therapy During Long-term Normothermic Machine Perfusion of Human Donor Livers for up to 7 D.

Normothermic machine perfusion (NMP) is used to preserve and test donor livers before transplantation. During NMP, the liver is metabolically active and produces waste products, which are released into the perfusate. In this study, we describe our simplified and inexpensive setup that integrates continuous renal replacement therapy (CRRT) with NMP for up to 7 d. We also investigated if the ultrafiltrate could be used for monitoring perfusate concentrations of small molecules such as glucose and lactate. Perfusate composition (urea, osmolarity, sodium, potassium, chloride, calcium, magnesium, phosphate, glucose, and lactate) was analyzed from 56 human NMP procedures without CRRT. Next, in 6 discarded human donor livers, CRRT was performed during NMP by integrating a small dialysis filter (0.2 m2) into the circuit to achieve continuous ultrafiltration combined with continuous fluid substitution for up to 7 d. Within a few hours of NMP without CRRT, a linear increase in osmolarity and concentrations of urea and phosphate to supraphysiological levels was observed. After integration of CRRT into the NMP circuit, the composition of the perfusate was corrected to physiological values within 12 h, and this homeostasis was maintained during NMP for up to 7 d. Glucose and lactate levels, as measured in the CRRT ultrafiltrate, were strongly correlated with perfusate levels (r = 0.997, P < 0.001 and r = 0.999, P < 0.001, respectively). The integration of CRRT into the NMP system corrected the composition of the perfusate to near-physiological values, which could be maintained for up to 7 d. The ultrafiltrate can serve as an alternative to the perfusate to monitor concentrations of small molecules without potentially compromising sterility.

Flux decline in crossflow ultrafiltration-based diafiltration process for lignin recovery from a deep eutectic solvent comprised of lactic acid and choline chloride

This study investigates a continuous ultrafiltration (UF)-based diafiltration (DF) method to separate and purify lignin from a deep eutectic solvent (DES) containing lactic acid and choline chloride after biomass delignification. A crossflow setup with a polyether sulfone UF membrane with a molecular weight cut off of 5000 Da was used to evaluate flux decline and fouling in this process. Under different pressure, feed flowrate, lignin, and DES concentrations, lignin rejection is around 0.90. Higher lignin and DES concentrations increase filtration resistance, and thus decrease flux at constant pressure. On the basis of a previously setup model based on dead-end filtration, a modeling approach was further developed to predict the system size required to implement UF-DF on a large scale. The results shows that at a constant pressure, the membrane system's area increases as the cake layer thickness over the membrane's surface increases.

Effects of Steady Glucose Concentration Peritoneal Dialysis on Ultrafiltration Volume and Sodium Removal: A Pilot Crossover Trial.

Volume overload is common in patients treated with peritoneal dialysis (PD) and is associated with poor clinical outcome. Steady concentration PD is where a continuous glucose infusion maintains the intraperitoneal glucose concentration and as a result provides continuous ultrafiltration throughout the dwell. The primary objective of this study was to investigate the ultrafiltration rate and glucose ultrafiltration efficiency for steady concentration PD in comparison with a standard continuous ambulatory PD (CAPD) dwell, using the novel Carry Life UF device. Eight stable patients treated with PD (six fast and two fast average transporters) were investigated four times: a standard 4-hour CAPD dwell with 2 L of 2.5% dextrose solution as control and three 5-hour steady concentration PD treatments (glucose dose 11, 14, 20 g/h, initial fill 1.5 L of 1.5% dextrose solution). All investigations were preceded by an overnight 2 L 7.5% icodextrin dwell. Intraperitoneal glucose concentration increased during the first 1-2 hours of the steady concentration PD treatments and remained stable thereafter. Ultrafiltration rates were significantly higher with steady concentration PD treatments (124±49, 146±63, and 168±78 mL/h with 11, 14, and 20 g/h, respectively, versus 40±60 mL/h with the control dwell). Sodium removal and glucose ultrafiltration efficiency (ultrafiltration volume/gram glucose uptake) were significantly higher with steady concentration PD treatments versus the control dwell, where the 11 g/h glucose dose was most efficient. Steady concentration PD performed with the Carry Life UF device resulted in higher ultrafiltration rates, more efficient use of glucose (increased ultrafiltration volume/gram glucose absorbed), and greater sodium removal compared with a standard 2.5% dextrose CAPD dwell. A Performance Analysis of the Peritoneal Ultrafiltration (PUF) Achieved With the Carry Life ® UF, NCT03724682 .

Cutting the Gordian Knot of Diuretic Resistance in Heart Failure; Combination of Continuous Ultrafiltration with Diuretic Therapy

Cutting the Gordian Knot of Diuretic Resistance in Heart Failure; Combination of Continuous Ultrafiltration with Diuretic Therapy

Using aquapheresis with continuous hematocrit monitoring to guide ultrafiltration.

Management of edema and volume overload in patients with hypoalbuminemia, either due to nephrotic syndrome or other disease processes, can be extremely challenging. We describe the management of five patients with hypoalbuminemia and severe fluid overload using the Aquadex FlexFlow device with continuous hematocrit monitoring to guide ultrafiltration. We report five pediatric patients ranging in age from 7days to 11years and in size from 2.7 to 65kg with hypoalbuminemia due to a variety of etiologies treated with slow continuous ultrafiltration with continuous hematocrit monitoring to guide ultrafiltration using the Aquadex device. Treatment allowed successful fluid removal in all cases, without hypotension or other hemodynamic complications. In a variety of clinical circumstances and in patients from infants to adolescence, we report that patients with diuretic-resistant fluid overload can be treated with Aquadex using continuous hematocrit monitoring to guide management to allow fluid removal without hemodynamic instability or other complications. A higher resolution version of the Graphical abstract is available as Supplementary information.

Novel inflammatory mediator profile observed during pediatric heart surgery with cardiopulmonary bypass and continuous ultrafiltration

BackgroundCardiopulmonary bypass (CPB) is associated with systemic inflammation, featuring increased levels of circulating pro-inflammatory cytokines. Intra-operative ultrafiltration extracts fluid and inflammatory factors potentially dampening inflammation-related organ dysfunction and enhancing post-operative recovery. This study aimed to define the impact of continuous subzero-balance ultrafiltration (SBUF) on circulating levels of major inflammatory mediators.MethodsTwenty pediatric patients undergoing cardiac surgery, CPB and SBUF were prospectively enrolled. Blood samples were collected prior to CPB initiation (Pre-CPB Plasma) and immediately before weaning off CPB (End-CPB Plasma). Ultrafiltrate effluent samples were also collected at the End-CPB time-point (End-CPB Effluent). The concentrations of thirty-nine inflammatory factors were assessed and sieving coefficients were calculated.ResultsA profound increase in inflammatory cytokines and activated complement products were noted in plasma following CBP. Twenty-two inflammatory mediators were detected in the ultrafiltrate effluent. Novel mediators removed by ultrafiltration included cytokines IL1-Ra, IL-2, IL-12, IL-17A, IL-33, TRAIL, GM-CSF, ET-1, and the chemokines CCL2, CCL3, CCL4, CXCL1, CXCL2 and CXCL10. Mediator extraction by SBUF was significantly associated with molecular mass < 66 kDa (Chi2 statistic = 18.8, Chi2 with Yates’ correction = 16.0, p < 0.0001). There was a moderate negative linear correlation between molecular mass and sieving coefficient (Spearman R = − 0.45 and p = 0.02). Notably, the anti-inflammatory cytokine IL-10 was not efficiently extracted by SBUF.ConclusionsCPB is associated with a burden of circulating inflammatory mediators, and SBUF selectively extracts twenty of these pro-inflammatory factors while preserving the key anti-inflammatory regulator IL-10. Ultrafiltration could potentially function as an immunomodulatory therapy during pediatric cardiac surgery.Trial registration ClinicalTrials.gov, NCT05154864. Registered retrospectively on December 13, 2021. https://clinicaltrials.gov/ct2/show/record/NCT05154864.

P243 EXTRACORPOREAL CONTINUOUS VENO–VENOUS ULTRAFILTRATION IN PATIENTS WITH ACUTE HEART FAILURE REFRACTORY TO DIURETIC THERAPY: A SINGLE–CENTER PILOT EXPERIENCE

Abstract Introduction Congestive Acute Heart Failure (C–AHF) is characterized by extracellular fluid overload. Extensive use of loop diuretics may induce worsening renal function, electrolyte imbalance, symptomatic hypotension and diuretic resistance. Extracorporeal veno–venous ultrafiltration (UF) may represent a useful adjunctive therapy. Despite a few randomized clinical trials have been carried out, the results are controversial; aim of this study is to describe our pilot experience using UF. Methods We enrolled consecutive patients with C–AHF refractory to diuretic therapy treated with UF from January to December 2022; patients affected by concomitant acute coronary syndrome were excluded. UF was delivered using a modern device specifically designed for fluid removal in C–AHF patients through slow continuous UF (Fig.1). According to our protocol, the initial UF rate was based on baseline systolic arterial pressure (250cc/h if&amp;gt;120mmHg, 100–120cc/h if 100–120mmHg and &amp;lt;100cc/h if&amp;lt;100mmHg; contra–indicated if&amp;lt;90mmHg). Laboratories values, urinary output and fluid balance were monitored at baseline, after 6 hours (T6) and when UF was stopped (T0). Variables are expressed as medians with 25p–75p. Results Seven patients were enrolled in the study (5M;2F); in each a femoral central venous catheter (20cm/14G) was placed to perform UF. A standard anticoagulation regimen based on UFH bolus + infusion was adopted aiming to an ACT of 180–220. Median age and LVEF were respectively 40[20–50] and 79[73–85]; 3 patients were diabetics, 2 smokers and 4 hypertensive. Median rate of hospitalization in the previous 12 months was 1 [0–2]; domiciliary dosage of furosemide was 75mg [50–125]. Baseline, T6h and T0 creatinine values were respectively 1.2 [1.1–2], 1.3 [1.1–1.8] and 1.4 [1.1–1.9]. Heart rate and blood pressure were stable during the treatment. UF parameters in the patients of the study are summarized in Tab.1; congestion was resolved or improved in 6/7 patients, no severe complication (bleeding, AKI, death) occurred while 1 premature filter clot is reported. Conclusions Our initial experience with UF is promising. Modern heart failure specific devices appear safe, easy to use and require only minimal training. Compared to extensive i.v. diuretic use, predictable fluid removal through UF may be beneficial as it is characterized by higher excretion of sodium, limited neuro–hormonal activation, enhanced spontaneous diuresis and restoration of diuretic response.

Con: Modified Ultrafiltration Should Not Be Routinely Used in Adult Cardiac Surgery

CARDIOPULMONARY BYPASS (CPB) is known to induce a systemic proinflammatory state and may contribute to postoperative organ dysfunction, primarily through complement activation secondary to blood passing through an artificial extracorporeal circuit. 1 Hall RI Smith MS Rocker G. The systemic inflammatory response to cardiopulmonary bypass: Pathophysiological, therapeutic, and pharmacological considerations. Anesth Analg. 1997; 85: 766-782 Crossref PubMed Google Scholar , 2 Wang W Huang HM Zhu DM et al. Modified ultrafiltration in paediatric cardiopulmonary bypass. Perfusion. 1998; 13: 304-310 Crossref PubMed Scopus (39) Google Scholar , 3 Thapmongkol S Masaratana P Subtaweesin T et al. The effects of modified ultrafiltration on clinical outcomes of adult and pediatric cardiac surgery. Asian Biomedicine. 2015; 9: 591-599 Crossref Scopus (4) Google Scholar Ultrafiltration may minimize some of the impact of the CPB-induced systemic inflammatory response. 4 Huang H Yao T Wang W et al. Continuous ultrafiltration attenuates the pulmonary injury that follows open heart surgery with cardiopulmonary bypass. Ann Thorac Surg. 2003; 76: 136-140 Abstract Full Text Full Text PDF PubMed Scopus (85) Google Scholar Traditionally, ultrafiltration may be conventional (CUF) or modified (MUF). Conventional ultrafiltration has been employed extensively during CPB, and involves hemoconcentration of both the priming volume and patient's blood volume at any point during CPB. 5 Darup J Bleese N Kalmar P et al. Hemofiltration during extracorporeal circulation (ECC). Thorac Cardiovasc Surg. 1979; 27: 227-230 Crossref PubMed Scopus (30) Google Scholar ,6 Klineberg PL Kam CA Johnson DC et al. Hematocrit and blood volume control during cardiopulmonary bypass with the use of hemofiltration. Anesthesiology. 1984; 60: 478-480 Crossref PubMed Scopus (19) Google Scholar In the early 1990s, Naik et al. introduced the concept of MUF 7 Elliott MJ. Ultrafiltration and modified ultrafiltration in pediatric open heart operations. Ann Thorac Surg. 1993; 56: 1518-1522 Abstract Full Text PDF PubMed Scopus (205) Google Scholar ,8 Andreasson S Gothberg S Berggren H et al. Hemofiltration modifies complement activation after extracorporeal circulation in infants. Ann Thorac Surg. 1993; 56: 1515-1517 Abstract Full Text PDF PubMed Scopus (88) Google Scholar ,9 Naik SK Knight A Elliott MJ. A successful modification of ultrafiltration for cardiopulmonary bypass in children. Perfusion. 1991; 6: 41-50 Crossref PubMed Scopus (164) Google Scholar in which the patient's blood volume is hemoconcentrated after separation from CPB. 10 Wang S Palanzo D Undar A. Current ultrafiltration techniques before, during and after pediatric cardiopulmonary bypass procedures. Perfusion. 2012; 27: 438-446 Crossref PubMed Scopus (40) Google Scholar Naik et al. postulated it may permit blood-free cardiac surgery. 11 Naik SK Knight A Elliott M. A prospective randomized study of a modified technique of ultrafiltration during pediatric open-heart surgery. Circulation. 1991; 84 (III422-31) PubMed Google Scholar Blood is typically removed from the arterial cannula and returned through the venous cannula. Others employ a modified technique in which blood is removed from the right atrium and infused into the aorta, potentially reducing concerns about cerebral shunting. 12 Myers GJ Leadon RB Mitchell LB et al. Simple modified ultrafiltration. Perfusion. 2000; 15: 447-452 Crossref PubMed Scopus (16) Google Scholar

A case series of Slow continuous ultrafiltration for COVID-19 patients on extracorporeal membrane oxygenation

A case series of Slow continuous ultrafiltration for COVID-19 patients on extracorporeal membrane oxygenation

CONTINUOUS FORMS OF INTRA-OPERATIVE ULTRAFILTRATION ENHANCE RECOVERY AFTER ADULT CARDIAC SURGERY WITH CARDIOPULMONARY BYPASS: A SYSTEMATIC REVIEW AND META-ANALYSIS OF RANDOMIZED CONTROLLED TRIALS

CONTINUOUS FORMS OF INTRA-OPERATIVE ULTRAFILTRATION ENHANCE RECOVERY AFTER ADULT CARDIAC SURGERY WITH CARDIOPULMONARY BYPASS: A SYSTEMATIC REVIEW AND META-ANALYSIS OF RANDOMIZED CONTROLLED TRIALS

Ultrafiltration-based diafiltration for post-delignification fractionation of lignin from a deep eutectic solvent comprised of lactic acid and choline chloride

Lignocellulosic biomass is a valuable renewable resource that has the potential to be refined into multiple fractions of valuable biomaterials. Extracting and purifying lignin without compromising cellulose quality is a challenging goal. Deep Eutectic Solvents (DESs) have been reported as suitable delignification solvents, and for process development for cellulose extraction, lignin removal is essential. This work describes an investigation on continuous ultrafiltration (UF)-based diafiltration (DF) for recovering and purifying lignin dissolved in a DES-pulping stream comprising lactic acid and choline chloride following lignocellulose delignification. Experiments have been carried out in a stirred dead-end setup. The results indicate that lignin with a molecular weight of 200 g/mol or higher can be rejected by a polyethersulfone UF membrane with a molecular weight cutoff of 5000, reaching rejection values close to 0.85 for the feed solution with lignin concentration ranging from 4.5 to 30 g/L. It was discovered that membrane fouling and flux decline are DES concentration-dependent. A modeling approach was developed to predict the system size and operating conditions necessary to conduct the diafiltration process on a large scale, for which experimental data on lignin fouling at various feed concentrations and hydrodynamic flow characteristics were used. Based on the modeling results, lignin dissolved in DES-dark liquor (lignin-loaded DES) may well be separated and purified by a continuous UF-DF system.

Early initiation of slow continuous ultrafiltration (SCUF) in a case of pregnancy induced hypertension (PIH) with acute decompensated heart failure (ADHF) refractory to standard medical therapy: A case report

Acute pulmonary edema may occur in approximately 3% of women with pre-eclampsia, with 70% of cases occurring after birth. Acute decompensated heart failure (ADHF) patients with refractory edema unresponsive to diuretic therapy may be considered for ultrafiltration. Judicious use of BiPAP with helmet as interface coupled with meticulous hemodynamic monitoring may be a key to successful outcome.

In vitro use of standard fluid infusion central venous catheter for slow continuous ultrafiltration feasibility assessment.

Slow continuous ultrafiltration (SCUF) by central venous catheter (CVC) for hemodialysis is a simple extracorporeal ultrafiltration that can reduce and control fluid overload in patients with chronic or acute chronic heart failure unresponsive to medical therapy. In order to avoid complications and risks related to the catheterization with a standard CVC for hemodialysis to provide the SCUF, considering that hospitalized patients affected by congestive heart failure commonly undergo CVC placement for medications delivering, we tested an in vitro model to use a standard CVC for infusion to perform SCUF. We performed an in vitro SCUF experimental model through two different lumens of a triple (8Fr × 20 cm Tri-lumen catheter Kit-Envans Extra) and a quad-lumen CVC (8.5Fr × 20 cm Quad-lumen catheter kit-Benefis Medical Devices) commonly used in our Intensive Care Unit for fluids and medications infusions. We used Prismaflex with the HF-20 set (Baxter, IL, USA) to perform the SCUF treatment. Our in vitro data confirm the technical feasibility of the use of standard CVC for fluid infusion to perform a SCUF treatment with a theoretical weight loss of up to 200 ml/h by a blood flow ranging from 30 to 45 ml/min. The use of standard infusion CVC could be utilized in the intensive care unit to perform SCUF not exposing patients to the risks and complications related to the placement and permanence of CVC for hemodialysis.

Continuous Renal Replacement Therapy: A Review

Kidney is an important organ to maintain hemodynamic stability inside the human body. In patient with acute kidney injury (AKI) there was a decreased kidney function that could interfere hemodynamic stability which can lead to multi organ failure even death. Around 5-10% patients with AKI required renal replacement therapy (RRT) to support their decreased renal function. Continuous renal replacement therapy (CRRT) is one of RRT modality that commonly used for patients with AKI who are hemodynamically unstable or in critically ill conditions.CRRT could divided into 4 mode, slow continuous ultrafiltration (SCUF), continuous veno-venous hemofiltration (CVVH), continuous veno-venous hemodialysis (CVVHD) and continuous veno-venous hemodialfiltration (CVVHDF). CRRT used based on renal and nonrenal indication. Several studies are still trying to prove nonrenal indication of RRT, to ascertain whether CRRT could be used as therapy effectively. Therefore the indication, the mechanism and the comparison of renal replacement therapy are very important to be understood.

Do continuous forms of intra-operative ultrafiltration enhance recovery after adult cardiac surgery with cardiopulmonary bypass? A protocol for systematic review and meta-analysis of randomized controlled trials

BackgroundCardiac surgery with cardiopulmonary bypass (CPB) is associated with a systemic inflammatory syndrome that adversely impacts cardiopulmonary function and can contribute to prolonged postoperative recovery. Intra-operative ultrafiltration during CPB is a strategy developed by pediatric cardiac specialists, aiming to dampen the inflammatory syndrome by removing circulating cytokines and improving coagulation profiles during the cardiac operation. Although ultrafiltration is commonly used in the pediatric population, it is not routinely used in the adult population. This study aims to evaluate if randomized evidence supports the use of continuous intra-operative ultrafiltration to enhance recovery for adults undergoing cardiac surgery with CPB.MethodsThis systematic review and meta-analysis will include randomized controlled trials (RCT) that feature continuous forms of ultrafiltration during adult cardiac surgery with CPB, specifically assessing for benefit in mortality rates, invasive ventilation time and intensive care unit length of stay (ICU LOS). Relevant RCTs will be retrieved from databases, including MEDLINE, Embase, CENTRAL and Scopus, by a pre-defined search strategy. Search results will be screened for inclusion and exclusion criteria by two independent persons with consensus. Selected RCTs will have study demographics and outcome data extracted by two independent persons and transferred into RevMan. Risk of bias will be independently assessed by the Revised Cochrane Risk-of-Bias (RoB2) tool and studies rated as low-, some-, or high- risk of bias. Meta-analyses will compare the intervention of continuous ultrafiltration against comparators in terms of mortality, ventilation time, ICU LOS, and renal failure. Heterogeneity will be measured by the χ2 test and described by the I2 statistic. A sensitivity analysis will be completed by excluding included studies judged to have a high risk of bias. Summary of findings and certainty of the evidence, determined by the GRADE approach, will display the analysis findings.DiscussionThe findings of this systematic review and meta-analysis will summarize the evidence to date of continuous forms of ultrafiltration in adult cardiac surgery with CPB, to both inform adult cardiac specialists about this technique and identify critical questions for future research in this subject area.Systematic review registrationThis systematic review and meta-analysis is registered in PROSPERO CRD42020219309 (https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020219309).

Обоснование мероприятий интенсивной терапии и экстракорпоральной детоксикации при комбинированных отравлениях метадоном

Актуальность. Острые отравления метадоном в сочетании с другими психоактивными веществами, в частности этанолом, нередко осложняются синдромом компрессии мягких тканей и острым повреждением почек, что требует использования методов экстракорпоральной детоксикации. Цель исследования — изучение эффективности раннего применения гемодиализа с ультрафильтрацией, мембранного плазмафереза и озонирования крови в комплексной терапии острых отравлений метадоном тяжелой степени. Материалы и методы. Проведен анализ результатов лечения 186 пациентов с отравлением метадоном в возрасте от 21 до 43 лет обоих полов, которые составляли три группы исследования. Лечение проводилось на базе отделении интенсивной терапии и экстракорпоральной детоксикации Киевской городской клинической больницы скорой медицинской помощи в 2018–2019 гг. Использованы клинические, биохимические, функциональные, химико-аналитические, статистические методы исследования. Показатели в группах сравнивали с помощью t-критерия Стьюдента для независимых выборок; различия считали статистически значимыми при р ≤ 0,05. Результаты. По результатам проведенного клинического, функционального и лабораторного обследования пациентов с комбинированными отравлениями метадоном выявлена токсическая гепатонефропатия у 34,3 % пациентов, синдром ишемии мягких тканей и олигурия/анурия — у 22,9 %. Причинами развития почечной недостаточности были как преренальные (гиповолемия, низкий сердечный выброс, снижение тонуса почечных сосудов), так и ренальные факторы (токсическое поражение паренхимы почек). Показанием для гемодиализа был симптомокомплекс: олигурия/анурия в течение 24 часов, повышение уровня КФК плазмы крови, увеличение уровня креатинина, мочевины, лактата, АСАТ, АЛАТ, ЛДГ, водно-электролитный дисбаланс, ишемия мягких тканей (≥ 5 % площади тела), отек мозга, угроза сосудистого тромбоза вследствие усиления компрессии в зоне ишемии мягких тканей. Применены вено-венозный гемодиализ и ультрафильтрация (CVVHD) у 86 пациентов с острым повреждением почек. Выводы. Разнообразие нарушений гомеостаза при комбинированном отравлении метадоном, в частности с наличием синдрома ишемии мягких тканей, требует раннего использования (в течение 24–48 часов) методов экстракорпоральной терапии. Среди таких методов эффективными являются пролонгированный вено-венозный гемодиализ с ультрафильтрацией, мембранный плазмаферез и озонотерапия (внутривенное введение физиологического раствора и аутогемотрансфузия озонированной крови).

Single Pass Tangential Flow Filtration (SPTFF) of monoclonal antibodies: Experimental studies and theoretical analysis

Single Pass Tangential Flow Filtration (SPTFF) enables continuous ultrafiltration and diafiltration for inline concentration and buffer exchange in downstream bioprocessing of monoclonal antibody (mAb) products. However, the high conversion in SPTFF modules leads to large variations in local flow rate, protein concentration, and transmembrane pressure drop, significantly complicating the design of effective SPTFF modules/processes. In this study, a recent concentration polarization model for the filtrate flux in protein ultrafiltration that accounts for protein-protein interactions has been extended to the analysis of SPTFF, specifically including the effects of the mAb and membrane properties as well as the long path-length. Model calculations are in good agreement with experimental data for the filtrate flux and pressure drop in two commercial SPTFF systems with very different module geometries. The model was then used to analyze the design of SPTFF processes for inline mAb concentration, providing additional insights into the underlying physical phenomena governing the performance and optimization of SPTFF modules for bioprocessing.