Continuous Venovenous Hemofiltration In Patients Research Articles

Fractionated plasma separation and adsorption integrated with continuous veno-venous hemofiltration in patients with acute liver failure: A single center experience from China.

To evaluate the clinical efficacy and safety of fractionated plasma separation and adsorption integrated with continuous veno-venous hemofiltration (FPSA-CVVH) treatment in patients with acute liver failure (ALF). In this retrospective study, we enrolled patients with ALF (serum total bilirubin >10 mg/dL or Model for End-Stage Liver Disease [MELD] Score >18) hospitalized between August 2017 and August 2022. All patients had at least two sessions of FPSA-CVVH. The primary measure of treatment efficacy was the reduction ratios (RRs) of bilirubin after each session of FPSA-CVVH. Seventy-eight patients with ALF were enrolled. The MELD score at baseline was 22.9 ± 7.5. The mean total bilirubin was 22.05 ± 5.94 mg/dL, direct bilirubin was 16.33 ± 4.60 mg/dL and indirect bilirubin was 3.43 ± 1.60 mg/dL. One hundred and eighty seven sessions of FPSA-CVVH treatment lasting 8 hours each were performed. After a single session, serum total bilirubin, direct bilirubin and indirect bilirubin were significantly decreased. RRs were 52.0% ± 7.6% for total bilirubin, 59.4% ± 13.0% for direct bilirubin and 36.9% ± 15.4% for indirect bilirubin. Twenty nine patients (37.2%) survived and were discharged from the hospital, 12 of them recovered their liver function while the remaining 17 patients needed intermittent artificial liver support therapy. FPSA-CVVH therapy is an effective artificial liver support therapy in patients with ALF. It may be considered as a "bridge technique" to the recovery of liver function in critical ill patients with ALF.

Clinical Efficacy of Fractionated Plasma Separation and Adsorption Integrated With Continuous Veno-Venous Hemofiltration in Patients With Liver Failure

Clinical Efficacy of Fractionated Plasma Separation and Adsorption Integrated With Continuous Veno-Venous Hemofiltration in Patients With Liver Failure

Monitoring skin blood flow to rapidly identify alterations in tissue perfusion during fluid removal using continuous veno-venous hemofiltration in patients with circulatory shock

BackgroundContinuous veno-venous hemofiltration (CVVH) can be used to reduce fluid overload and tissue edema, but excessive fluid removal may impair tissue perfusion. Skin blood flow (SBF) alters rapidly in shock, so its measurement may be useful to help monitor tissue perfusion.MethodsIn a prospective, observational study in a 35-bed department of intensive care, all patients with shock who required fluid removal with CVVH were considered for inclusion. SBF was measured on the index finger using skin laser Doppler (Periflux 5000, Perimed, Järfälla, Sweden) for 3 min at baseline (before starting fluid removal, T0), and 1, 3 and 6 h after starting fluid removal. The same fluid removal rate was maintained throughout the study period. Patients were grouped according to absence (Group A) or presence (Group B) of altered tissue perfusion, defined as a 10% increase in blood lactate from T0 to T6 with the T6 lactate ≥ 1.5 mmol/l. Receiver operating characteristic curves were constructed and areas under the curve (AUROC) calculated to identify variables predictive of altered tissue perfusion. Data are reported as medians [25th–75th percentiles].ResultsWe studied 42 patients (31 septic shock, 11 cardiogenic shock); median SOFA score at inclusion was 9 [8–12]. At T0, there were no significant differences in hemodynamic variables, norepinephrine dose, lactate concentration, ScvO2 or ultrafiltration rate between groups A and B. Cardiac index and MAP did not change over time, but SBF decreased in both groups (p < 0.05) throughout the study period. The baseline SBF was lower (58[35–118] vs 119[57–178] perfusion units [PU], p = 0.03) and the decrease in SBF from T0 to T1 (ΔSBF%) higher (53[39–63] vs 21[12–24]%, p = 0.01) in group B than in group A. Baseline SBF and ΔSBF% predicted altered tissue perfusion with AUROCs of 0.83 and 0.96, respectively, with cut-offs for SBF of ≤ 57 PU (sensitivity 78%, specificity 87%) and ∆SBF% of ≥ 45% (sensitivity 92%, specificity 99%).ConclusionBaseline SBF and its early reduction after initiation of fluid removal using CVVH can predict worsened tissue perfusion, reflected by an increase in blood lactate levels.

Efficacy of hemoperfusion combined with continuous veno-venous hemofiltration on the treatment of paraquat poisoning: a Meta-analysis

To evaluate the efficacy of hemoperfusion (HP) combined with continuous veno-venous hemofiltration (CVVH) on the treatment of acute paraquat (PQ) poisoning. Prospective randomized controlled trials and retrospective studies on the efficacy of HP combined CVVH in patients with oral PQ poisoning (poisoning time ≤ 24 hours) were found by searching from PubMed, Embase, Cochrane Library, Web of Science, SinoMed, CNKI and Wanfang databases before November 1st, 2019. The experimental group was treated with HP+CVVH, and the control group was treated with HP. Data included the general information of the literature, mortality, survival time, the incidence of respiratory failure and circulatory failure. The bias risk and the data were analyzed using the RevMan 5.3 software. A total of 1 041 literatures were retrieved, and 7 literatures were finally enrolled, including 1 199 patients, with 735 patients in the control group and 464 patients in experimental group. Meta-analysis showed that compared with HP alone, HP+CVVH could significantly reduce the short-term mortality [4-day mortality: hazard ratio (HR) = 0.52, 95% confidence interval (95%CI) was 0.38-0.71, P < 0.000 1], but no significant improvement in long-term mortality was found (28-day or 30-day mortality: HR = 0.68, 95%CI was 0.39-1.21, P = 0.19; 90-day mortality: HR = 1.13, 95%CI was 0.61-2.10, P = 0.07; total mortality: HR = 0.96, 95%CI was 0.72-1.29, P = 0.78). The survival time of patients treated with HP+CVVH was significantly longer than that of HP patients [mean difference (MD) = 2.02, 95%CI was 0.81-3.22, P = 0.001], but the heterogeneity between studies was large. According to the type of literature, a subgroup analysis showed that the survival time of patients treated with HP+CVVH in prospective randomized controlled trials and retrospective studies were significantly longer than that of HP patients (prospective studies: MD = 1.53, 95%CI was 0.94-2.12, P < 0.000 01; retrospective studies: MD = 2.40, 95%CI was 0.08-4.73, P = 0.04). Compared with HP group, HP+CVVH could significantly reduce the incidence of circulatory failure [relative risk (RR) = 0.40, 95%CI was 0.30-0.52, P < 0.00 01], but the incidence of respiratory failure significantly increased (RR = 2.75, 95%CI was 2.18-3.48, P < 0.000 01). HP combined with CVVH can reduce the short-term mortality and the incidence of circulatory failure, prolong the survival time, and save time for further rescue, but it can't improve the long-term prognosis of patients.

Regional citrate anticoagulation versus no-anticoagulation for continuous venovenous hemofiltration in patients with liver failure and increased bleeding risk: A retrospective case-control study.

ObjectiveThere are controversial opinions on anticoagulation for continuous venovenous hemofiltration (CVVH) in patients with liver failure (LF) and increased bleeding risk. Therefore, we conducted a retrospective study to evaluate the efficacy and safety of regional citrate anticoagulation (RCA) versus no-anticoagulation for CVVH in these patients.MethodsThe included patients were divided into RCA and no-anticoagulation group according to the CVVH anticoagulation strategy they accepted for CVVH. Filter lifespan, bleeding, citrate accumulation, catheter occlusion, and totCa/ionCa ratio were evaluated as outcomes.ResultsIn the original cohort, the filter lifespan of the RCA group (41 patients, 79 filters) was significantly longer than the no-anticoagulation group (62 patients, 162 filters) (> 72 hours vs 39.5 hours (IQR 31.2–47.8), P = 0.002). The adjusted results demonstrated that RCA could significantly reduce the risk of filter failure (HR = 0.459, 95%CI 0.26–0.82, P = 0.008). Four episodes of totCa/ionCa > 2.5 were observed in the RCA group and continuously accepted RCA-CVVH after the reduction of citrate dose and blood flow. No obvious citrate accumulation was observed in these patients. In the matched cohort, the filter lifespan of the RCA group was significantly longer than the no-anticoagulation group (P = 0.013) as well. No significant difference in the episodes of totCa/ionCa > 2.5 was observed between the two matched groups (P = 0.074). Both in the original cohort and the matched cohort, the bleeding, acidosis, alkalosis, and catheter occlusion incidences were not significantly different between the two groups.ConclusionsIn LF patients with increased bleeding risk who underwent CVVH, RCA could prolong the filter lifespan and be safely used with careful blood gas monitoring and citrate dose adjusting. Further prospective, randomized, control studies are warranted to obtain robust evidences.

Regional citrate anticoagulation versus low molecular weight heparin anticoagulation for continuous venovenous hemofiltration in patients with severe hypercalcemia: a retrospective cohort study

Purpose We conducted a retrospective study to evaluate the efficacy and safety of regional citrate anticoagulation (RCA) versus those of low molecular weight heparin (LMWH) anticoagulation for CVVH in severe hypercalcemia patients. Methods Between January 2014 and May 2019, 33 severe hypercalcemia patients underwent CVVH. Patients were divided into the RCA and LMWH groups. Calcium-free replacement solution was used. Serum total calcium reduction rate (RRSeCa), filter lifespan, bleeding, totCa/ionCa ratio, citrate accumulation, and catheter occlusion were evaluated as outcomes. Results RCA and LMWH were employed for CVVH in 14 and 43 filters, respectively. RRSeCa was not significantly different between the LMWH and RCA groups (p = .320), but RCA-CVVH was more effective in reducing ionized calcium at half of the time points (p < .05). RCA significantly prolonged the median filter lifespan (>72 h vs. 24.0 h [IQR, 15.0–26.0], p = .012). The incidence of filter failure was 55.8% (24/43) in the LMWH group and 21.4% (3/14) in the RCA group (p = .033). The adjusted results demonstrated that RCA could significantly reduce the risk of filter failure (p = .043, 95% CI 0.059–0.957, HR = 0.238). No citrate accumulation or bleeding episodes were observed in the RCA-CVVH group. Seven bleeding episodes (7/43, 16.3%) occurred in the LMWH-CVVH group. Conclusions In patients with severe hypercalcemia who underwent CVVH, RCA more effectively decreased calcium levels and had a superior filter lifespan and no obvious adverse events compared with LMWH. Further prospective, randomized, controlled studies are warranted to obtain robust evidence.

Continuous veno-venous hemofiltration for severe acute pancreatitis.

Severe acute pancreatitis is associated with high rates of mortality and life-threatening complications. Continuous veno-venous hemofiltration (CVVH) has been used in some centers to reduce mortality and avoid local or systemic complications, however its efficiency and safety is uncertain. To assess the benefits and harms of CVVH in patients suffering from severe acute pancreatitis; to compare the effects of different CVVH techniques; and to evaluate the optimal time for delivery of CVVH. We searched the Cochrane Library (2019, Issue 8), MEDLINE (1946 to 13 September 2019), Embase (1974 to 13 September 2019), and Science Citation Index Expanded (1982 to 13 September 2019). We included all randomized controlled trials (RCTs) that compared CVVH versus no CVVH in participants with severe acute pancreatitis. We also included RCTs that compared different types of CVVH and different schedules for CVVH in participants with severe acute pancreatitis. Two review authors independently identified the trials for inclusion, collected the data, and assessed the risk of bias. We performed the meta-analyses using Review Manager 5. We calculated the risk ratio (RR) for dichotomous outcomes, and the mean difference (MD) for continuous outcomes, with 95% confidence intervals (CIs). We included two studies, involving a total of 94 participants, in the review.Continuous veno-venous hemofiltration versus no interventionWe included one study in which 64 participants with severe acute pancreatitis were randomized to undergo CVVH (32 participants) or no intervention (32 participants). There were no deaths in either group (very low-quality evidence). Adverse events, length of stay in the intensive care unit (ICU), length of hospital stay, total hospital cost, and quality of life were not reported in the study.One type of continuous veno-venous hemofiltration versus a different type of continuous veno-venous hemofiltrationWe included one study in which 30 participants with severe acute pancreatitis were randomized to undergo high-volume CVVH (15 participants) or standard CVVH (15 participants). High-volume CVVH may lead to little or no difference in in-hospital mortality rates (20.0% in the high-volume CVVH group versus 33.3% in the standard CVVH group; risk ratio (RR) 0.60, 95% confidence interval (CI) 0.17 to 2.07; 30 participants; 1 study; low-quality evidence). We are uncertain whether high-volume hemofiltration reduces rates of adverse events (13.3% in both groups; RR 1.00, 95% CI 0.16 to 6.20; 30 participants; 1 study; very low-quality evidence). Length of ICU stay, length of hospital stay, total hospital cost, and quality of life were not reported in the study. The quality of the current evidence is very low or low. For both comparisons addressed in this review, data are sparse. It is unclear whether CVVH has any effect on mortality or complications in patients with severe acute pancreatitis. It is also unclear whether high-volume CVVH is superior, equivalent or inferior to standard CVVH in patients with severe acute pancreatitis.

Treatment of Ventilator-associated Pneumonia with High-dose Colistin Under Continuous Veno-venous Hemofiltration.

Background and ObjectivesHigh-dose colistin (COL) ensures adequate treatment of pneumonia caused by multidrug resistant gram-negative bacteria (MDR-GNB) but must be weighed against a higher risk of nephrotoxicity. Continuous veno-venous hemofiltration (CVVH) clears COL by filtering and membrane adsorption that permits to avoid dose accumulation and excessively high peak concentrations. We evaluated clinical/microbiological efficacy of the high-dose COL treatment under CVVH in patients with newly diagnosed MDR-GNB ventilator-associated pneumonia (VAP).MethodsObservational cohort study in critically ill adult patients with MDR-GNB VAP. Colistimethate sodium (CMS) was administered as a 9 million international units (MIU) of loading dose followed by 3 × 4.5 MIU daily. CVVH was performed over a highly adsorptive membrane. Clinical and microbiological efficacies were assessed at the end of therapy. In survivors, serum creatinine level was evaluated before and at the end of therapy.ResultsFourteen patients (8 male patients, aged 57 ± 14 years) were consecutively included. Isolated pathogens were Pseudomonas aeruginosa in 7, Klebsiella pneumoniae in 5, and other Enterobacteriaceae in 2 patients. A favorable clinical response was observed in 9 patients (64%). Full and presumed microbiological eradication was observed in 12 patients (86%). Two patients were diagnosed with Stage 1 acute kidney injury.ConclusionsIn patients with MDR-GNB VAP, CVVH may represent an interesting option to enable effective high-dose COL treatment.

Effects of Changes in the Levels of Damage-Associated Molecular Patterns Following Continuous Veno-Venous Hemofiltration Therapy on Outcomes in Acute Kidney Injury Patients With Sepsis.

Background: We investigated the association of damage-associated molecular pattern (DAMP) removal with mortality in sepsis patients undergoing continuous veno–venous hemofiltration (CVVH).Methods: Circulating levels of DAMPs [mitochondrial DNA (mtDNA); nuclear DNA (nDNA); heat shock protein 70 (HSP70); and high mobility group box 1 (HMGB1)] and cytokines were measured at baseline, 6 and 12 h after initiation of CVVH. Urinary DNA levels were analyzed at baseline and end of CVVH. The expression of human leukocyte antigen (HLA)-DR was assayed at 0, 3, and 7 days after initiation of CVVH. Moreover, the effects of HSP70 and HMGB1 clearance on survival were analyzed.Results: We evaluated 43 patients with acute kidney injury (AKI) (33 sepsis patients). Twenty-two sepsis patients (67%) and three non-sepsis patients (30%) expired (P = 0.046). Significant reductions in the levels of circulating interleukin-6 (P = 0.046) and tumor necrosis factor-α (P = 0.008) were found in the sepsis group. The levels of mtDNA were increased (ND2, P = 0.035; D-loop, P = 0.003), whereas that of HSP70 was reduced (P = 0.000) in all patients during the first 12 h. The levels of DAMPs in the plasma were markedly increased after blood passage from the inlet through the dialyzer in survivor sepsis patients. The clearance rates of HSP70 and HMGB1 were good predictors of mortality [area under the curve (AUC) = 0.937, P = 0.000; AUC = 0.90, P = 0.001, respectively]. The level of HLA-DR was increased in response to higher HSP70 clearance (P = 0.006). Survival was significantly worse in groups with higher clearance rates of HSP70 and HMGB1 than the cut-off value (log-rank test: P = 0.000 for both). Higher HSP70 clearance was a significant independent predictor of mortality (odds ratio = 1.025, 95% confidence interval [CI]: 1.012–1.039, P = 0.000). The urinary nDNA (β-globin) level before CVVH was an independent risk factor for the duration of CVVH in patients with sepsis (sRE = 0.460, 95% CI: 1.720–8.857, P = 0.005).Conclusion: CVVH removes inflammatory factors, reduces urinary DAMPs, and removes plasma DAMPs. However, survival decreases in response to higher HSP70 clearance.

Evaluation of pre- and post-dilution continuous veno-venous hemofiltration on leukocyte and platelet function in patients with sepsis.

We investigated the differences in biocompatibility pre- and post-dilution during continuous veno-venous hemofiltration in patients with sepsis, focusing on leukocyte and platelet function. Subjects were 12 patients with septic shock who underwent veno-venous hemofiltration for acute kidney injury between March 2016 and September 2017. The first six patients received pre-dilution veno-venous hemofiltration, and the next six patients received post-dilution veno-venous hemofiltration. The blood flow rate and filtration flow rate for veno-venous hemofiltration using a polysulfone hemofilter were set to 150 and 35 mL/min, respectively. Leukocyte and platelet counts were determined at 0 and 24 h after veno-venous hemofiltration commencement. Serum interleukin-6 and interleukin-10 levels, the induction rates of regulatory T cells, the expression rate of monocyte HLA-DR, neutrophil phagocytic and sterilizing ability, and platelet P-selectin expression rate were determined at 0, 6, and 24 h after veno-venous hemofiltration commencement. There were no significant differences in patient characteristics between the two groups. Serum interleukin-6 decreased over time during pre- and post-dilution veno-venous hemofiltration. Serum interleukin-10 levels decreased during pre-dilution veno-venous hemofiltration, but remained unchanged during post-dilution veno-venous hemofiltration. The Treg and platelet P-selectin expression rates significantly increased at 24 h compared to 0 h during post-dilution veno-venous hemofiltration. Neutrophil phagocytic ability at 24 h was significantly decreased compared to that at 0 h during post-dilution veno-venous hemofiltration. No significant changes in leukocyte and platelet function were observed during pre-dilution veno-venous hemofiltration. Pre-dilution veno-venous hemofiltration demonstrates superior biocompatibility in terms of decreased leukocyte function and platelet activation in septic shock patients with acute kidney injury.

Study in the protective role of continuous veno-venous hemofiltration in patients with diuretic-ineffective cardiac insufficiency

Objective To study the protective role of continuous veno-venous hemofiltration (CVVH) in cardiac insufficiency refractory to diuretic therapy after acute myocardial infarction. Methods A total of 104 acute myocardial infarction patients admitted from march 2012 to march 2016 were recruited. According to their wishes, the patients were divided into two groups, continuous veno-venous hemofiltration combined with routine therapy as experimental group (n=52) and conventional treatment as control group (n=52). Mortality rate within one month, the mean length of ICU stay, the mean length of hospital stay, ventilator usage and urine output volume were documented. Then the difference in BW between pre- and post-treatment was determined for evaluation of fluid retention, and blood plasma C-reactive protein (ΔCRP), interleukin 6 (ΔIL-6), interleukin 8 (ΔIL-8), tumor necrosis factor-α (ΔTNF-α) and left ventricular ejection fraction (ΔLVEF) were measured and calculated. A multiple linear regression model to predict ΔLVEF was established. Data recorded at different intervals in the same group were analyzed by ANOVA. Data of the monitoring biomarkers, the mean length of ICU stay, the mean length of hospital stay of two groups were recorded at the same given intervals were analyzed by t test. Data of mortality rate within one month, drugs and ventilator usage in two groups were analyzed by χ2 test . P value less than 0.05 was considered statistically significant. Results There were significant differences in mortality rate within one month, the mean length of ICU stay, the mean length of hospital stay, and the duration of ventilator usage between the two groups (P 0.05) as compared with those before the treatment.BW was decreased and LVEF was increased in both groups after treatment (P 0.05). However, the degrees of ΔLVEF andΔBW were greater in experiment group than those in control group (P 0.05). Multiple 1inear regression analyses showed that only ΔBW was the independent factor for ΔLVEF. Conclusion CVVH plays protective role in acute myocardial infarction patients with consequent cardiac insufficiency refractory to diuretic therapy by clearance of inflammatory cytokines and removal of retained fluid, and the removal of retained fluid is the most import mechanism to protect heart function. Key words: Continuous veno-venous hemofiltration; Acute Myocardial infarction; Acute Myocardial infarction patients with cardiac insufficiency; Diuretic resistance; Left ventricular ejection fraction; Retained fluid; Inflammatory cytokines; Study on the mechanism

Blood purification with continuous veno-venous hemofiltration in patients with sepsis or ARDS: a systematic review and meta-analysis.

Severe inflammatory conditions, as severe sepsis/septic shock and acute respiratory distress syndrome (ARDS), are related to high morbidity and mortality. We performed a meta-analysis of randomized trials to assess if blood purification with continuous veno-venous hemofiltration (CVVH) reduces mortality in these settings. Online databases were searched for pertinent studies up to March 2017. We included randomized-controlled trials on the use of CVVH as blood purification technique in comparison to conventional therapy in adult patients with severe sepsis/septic shock or ARDS but no acute kidney injury needing renal replacement therapy. Eleven studies and 679 patients were included in the analysis. Patients who received CVVH had significantly lower mortality compared to conventional therapy (96 of 351 [27.35%] patients in the CVVH group vs. 129 of 328 [39.33%] in the conventional therapy group, OR=0.58 [95% CI: 0.42, 0.81], P=0.002, I2=10%, number needed to treat: 8) at longest follow-up available. Overall, low-quality evidence indicates that blood purification with CVVH might be associated with a significant reduction in mortality when performed in patients with sepsis or ARDS. The evidence is still insufficient to support a definitive conclusion of benefit. Further high-quality randomized controlled trials, adequately powered for mortality, are needed to clarify the impact of CVVH on these conditions.

CRRT Connected to ECMO: Managing High Pressures.

Metabolic disorders and fluid overload are indications of continuous renal replacement therapy (CRRT) including continuous venovenous hemofiltration in patients on extracorporeal membrane oxygenation (ECMO). Direct connection of CRRT machine to the ECMO circuit provides many advantages. Nevertheless, because pressures in CRRT lines relate to ECMO blood flow, high ECMO blood flow may be associated with high pressures in CRRT lines. Thus, management of CRRT pressure lines becomes challenging. We evaluated a protocol for managing high CRRT pressures. Connections were performed according to a standardized protocol to maintain CRRT lines in the correct pressure ranges without modifying ECMO settings or inhibiting pressure alarms. To achieve this goal, the way of connecting of CRRT lines was adapted following a standardized protocol. Connection was first attempted between pump and oxygenator in the 12 patients. In five cases, high pressures in CRRT lines were successfully managed by changing the connection segment. Continuous renal replacement therapy parameters were within target levels and reduction of serum creatinine was 37%. In conclusion, management of high pressures in CRRT lines induced by ECMO could be achieved without modifying ECMO blood flow or inhibiting CRRT alarms. Iterative stops were avoided allowing efficient procedures.

Safety and Efficacy of Combined Extracorporeal CO2 Removal and Renal Replacement Therapy in Patients With Acute Respiratory Distress Syndrome and Acute Kidney Injury: The Pulmonary and Renal Support in Acute Respiratory Distress Syndrome Study.

To assess the safety and efficacy of combining extracorporeal CO2 removal with continuous renal replacement therapy in patients presenting with acute respiratory distress syndrome and acute kidney injury. Prospective human observational study. Patients received volume-controlled mechanical ventilation according to the acute respiratory distress syndrome net protocol. Continuous venovenous hemofiltration therapy was titrated to maintain maximum blood flow and an effluent flow of 45 mL/kg/h with 33% predilution. Eleven patients presenting with both acute respiratory distress syndrome and acute kidney injury required renal replacement therapy. A membrane oxygenator (0.65 m) was inserted within the hemofiltration circuit, either upstream (n = 7) or downstream (n = 5) of the hemofilter. Baseline corresponded to tidal volume 6 mL/kg of predicted body weight without extracorporeal CO2 removal. The primary endpoint was 20% reduction in PaCO2 at 20 minutes after extracorporeal CO2 removal initiation. Tidal volume was subsequently reduced to 4 mL/kg for the remaining 72 hours. Twelve combined therapies were conducted in the 11 patients. Age was 70 ± 9 years, Simplified Acute Physiology Score II was 69 ± 13, Sequential Organ Failure Assessment score was 14 ± 4, lung injury score was 3 ± 0.5, and PaO2/FIO2 was 135 ± 41. Adding extracorporeal CO2 removal at tidal volume 6 mL/kg decreased PaCO2 by 21% (95% CI, 17-25%), from 47 ± 11 to 37 ± 8 Torr (p < 0.001). Lowering tidal volume to 4 mL/kg reduced minute ventilation from 7.8 ± 1.5 to 5.2 ± 1.1 L/min and plateau pressure from 25 ± 4 to 21 ± 3 cm H2O and raised PaCO2 from 37 ± 8 to 48 ± 10 Torr (all p < 0.001). On an average of both positions, the oxygenator's blood flow was 410 ± 30 mL/min and the CO2 removal rate was 83 ± 20 mL/min. The oxygenator blood flow (p <0.001) and the CO2 removal rate (p = 0.083) were higher when the membrane oxygenator was placed upstream of the hemofilter. There was no safety concern. Combining extracorporeal CO2 removal and continuous venovenous hemofiltration in patients with acute respiratory distress syndrome and acute kidney injury is safe and allows efficient blood purification together with enhanced lung protective ventilation.

Continuous veno-venous hemofiltration in patients with metformin associated lactic acidosis

Metformin is frequently used by type II diabetics. A rare complication of its use is metformin associated lactic acidosis (MALA). This condition is often accompanied by extreme metabolic acidosis and hemodynamic instability for which ICU treatment is mandatory. Guidelines advice intermittent hemodialysis for correction of metabolic acidosis and to clear metformin. However, haemodynamic instability may prefer continuous veno-venous hemofiltration (CVVH). We evaluated the effect of CVVH in critically ill patients admitted with MALA.

Metabolism of albumin after continuous venovenous hemofiltration in patients with systemic inflammatory response syndrome.

Background. The systemic inflammatory response syndrome (SIRS) is characterized by a hypercatabolic state induced by inflammatory mediators. Continuous venovenous hemofiltration (CVVH) stabilizes the internal environment but also aggravates loss of amino acids. The effect of CVVH on protein dynamics is largely unknown. We adopted the stable isotopic tracer technology to investigate how CVVH changed serum albumin metabolism. Methods. Twenty SIRS patients were randomized into low- (2000 mL/h) and high- (4000 mL/h) volume CVVH groups according to the rate of replacement fluid. Eight patients with abdominal infection matched for age, sex, and laboratory index served as controls. Consecutive arterial blood samples were drawn during a primed-constant infusion of two stable isotopes to determine the albumin fractional synthesis rate (FSR) and fractional breakdown rate (FBR). Results. Before treatment, there was no significant difference of FSR and FBR among 3 groups. After CVVH, the albumin FSR in high- and low-volume groups was 7.75 ± 1.08% and 7.30 ± 0.89%, respectively, both higher than in the control (5.83 ± 0.94%). There was no significant difference in albumin FBR after treatment. Conclusions. Protein dynamic indicators could reflect protein synthesis and breakdown state directly and effectively. CVVH increased albumin synthesis, while the breakdown rate remained at a high level independently of the CVVH rate.

The plasma level and biomarker value of neutrophil gelatinase-associated lipocalin in critically ill patients with acute kidney injury are not affected by continuous venovenous hemofiltration and anticoagulation applied.

IntroductionNeutrophil gelatinase-associated lipocalin (NGAL) is a biomarker of acute kidney injury (AKI), and levels reflect severity of disease in critically ill patients. However, continuous venovenous hemofiltration (CVVH) may affect plasma levels by clearance or release of NGAL by activated neutrophils in the filter, dependent on the anticoagulation regimen applied. We therefore studied handling of NGAL by CVVH in patients with AKI.MethodsImmediately before initiation of CVVH, prefilter blood was drawn. After 10, 60, 180, and 720 minutes of CVVH, samples were collected from pre- and postfilter (in- and outlet) blood and ultrafiltrate. CVVH with the following anticoagulation regimens was studied: no anticoagulation in case of a high bleeding tendency (n = 13), unfractionated heparin (n = 8), or trisodium citrate (n = 21). NGAL levels were determined with enzyme-linked immunosorbent assay (ELISA).ResultsConcentrations of NGAL at inlet and outlet were similar, and concentrations did not change over time in any of the anticoagulation groups; thus no net removal or production of NGAL occurred. Concentrations of NGAL at inlet correlated with disease severity at initiation of CVVH and at the end of a CVVH run. Concentrations of NGAL in the ultrafiltrate were lower with citrate-based CVVH (P = 0.03) and decreased over time, irrespective of anticoagulation administered (P < 0.001). The sieving coefficient and clearance of NGAL were low and decreased over time (P < 0.001).ConclusionsThe plasma level and biomarker value of NGAL in critically ill patients with AKI are not affected by CVVH, because clearance by the filter was low. Furthermore, no evidence exists for intrafilter release of NGAL by neutrophils, irrespective of the anticoagulation method applied.

Alterations in the elastic properties of the blood clots after the application of the continuous veno-venous hemofiltration in patients submitted to on-pump cardiac surgery

Methods Over a two-year period (January 2011-January 2013), 32 (3.1%) patients who underwent on-pump cardiac surgery, presented ARF in the immediate postoperative period and submitted to CVVH. Blood samples were obtained in all patients before the start of the CVVH and at least 12 hours after the continuous passage of the blood through the hemofiltration filter of the CVVH-device. All blood samples were tested with thromboelastography in order to identify alterations in the elastic properties of the blood clots induced from the application of the CVVH. The main thromboelastographic parameters recorded were: the reaction time-R, the K-time, the maximum amplitude (MA), the G-index, the Angle and the coagulation index (CI).

Cystatin C is not a reliable marker of residual glomerular filtration rate during continuous renal replacement therapy

Dear Editor, With interest we read the recent observational cohort study by Royakkers et al. [1] that shows that higher levels of cystatin C do not predict the development of acute kidney injury (AKI) nor the need for renal replacement therapy (RRT). Apart from the hypothesis that cystatin C could detect AKI 1 or 2 days earlier than serum creatinine, which was not confirmed in the study by Royakkers, it is also thought that serum cystatin C is less influenced by RRT than creatinine, and thus better reflects residual glomerular filtration rate (GFR). Determining residual GFR is difficult to establish in the critically ill patient with no steady state in renal function and large changes in fluid balance. As creatinine is a small-sized molecule that is eliminated from the blood during RRT, it is not useful for estimating the residual GFR. Cystatin C is a medium-sized molecule (13.3 kDa). Calculated from measurements in the efferent and afferent line and from the ultrafiltrate line, it has been shown that the removal of cystatin C by continuous venovenous hemofiltration (CVVH) is less than 30% of its generation and is therefore thought not to influence serum cystatin C significantly. Although the reduction ratio of cystatin C is dependent on the type of membrane, dialysis dose, volume, and ultrafiltration rate, it is advocated that cystatin C can be used to estimate the residual GFR in patients on RRT [2]. Importantly, changes in serum cystatin C were not determined in this study. We determined serum creatinine and cystatin C in 6 patients with septic shock with AKI 48 and 24 h prior and following the initiation of CVVH. CVVH was performed using the Prismaflex (Gambro) system with an AN100 ST filter (polyacrylonitrile), a blood flow of 200 ml/min, and a predilution substitution flow of 2,000 ml/h. CVVH was started according to the criteria for initiation of RRT that were standardized by the Acute Dialysis Quality Initiative (ADQI) consensus [3]. We compared the serum creatinine and cystatin C at initiation and after 24 h of CVVH with a paired Student’s t test. We observed that serum cystatin C decreased significantly following initiation of CVVH (p = 0.04), whereas the decrease of serum creatinine within the first 24 h was not significant (ns, p = 0.66), as shown in Fig. 1. Fig. 1 Time course of serum cystatin C and serum creatinine before and after initiation of continuous venovenous hemofiltration in patients with acute kidney injury in severe sepsis or septic shock. Values are means ± SEM This observation was previously described in patients that received intermittent hemodialysis; a higher dose of dialysis resulted in a decreased level of serum cystatin C, indicating that dialysis removes cystatin C from the patient [4]. In a previous study, 3 h of intermittent hemodialysis using a polymethylmethacrylate filter decreased cystatin C concentrations by 30 ± 7% [5]. This supports the hypothesis that in different types of renal replacement therapy serum cystatin C concentrations are reduced. In addition to the inability of cystatin C to predict AKI better or earlier than serum creatinine, our finding highlights the limited value of cystatin C in assessing residual GFR in patients with sepsis-induced AKI.

Changes of the plasma amino acid level in patients with abdominal inflammation and acute renal failure during continuous veno-venous hemofiltration

Objective To evaluate the plasma amino acid level alteration and determine amino acid loss in patients with abdominal inflammation and acute renal failure during continuous veno-venous hemofiltration (CVVH). Methods Ten patients with abdominal infection and acute renal failure were admitted to the Nanjing General Hospital of Nanjing Military Command of PLA from September 2008 to September 2009. CVVH was performed with AV600S polysulfone hemofilter for 24 hours. Samples of plasma amino acid were obtained before,at 12 and 24 hours after the beginning of CVVH. High pressure liquid chromatography was used to detect amino acid concentrations in plasma and replacement fluid. All data were analyzed using t test or Wilcoxon rank sum test. Results Of the ten patients, three died of septic shock and three died of multi-organ dysfunction syndrome.The level of plasma amino acids decreased significantly after CVVH, and the levels of histidine, isoleucine, cysteine and glutamine decreased from (22.1 ±10.3), (20.0 ±7.6), (10.3±4.7), (122.3 ±72.2)μmol/L to (5.6 ±3.4), ( 6.4 ± 2.5 ), ( 2.9 ± 2.4 ), (42.5 ± 33.6) μ mol/L. The total plasma amino acid levels significantly reduced by 52% at 12 hours after the beginning of CVVH and by 59% at 24 hours after the beginning of CVVH.The mean amino acid loss was (9631± 1089)mg/d. The mean losses of essential and non-essential amino acids were ( 5072 ± 618 ) mg/d and ( 3747 ± 654 ) mg/d, respectively, with a significant difference ( t = 4. 52,P ＜0.05 ). There was a positive correlation between individual amino acid loss and the plasma concentrations of respective amino acids at 12 hours after the beginning of CVVH ( r = 0. 68, P ＜ 0.05 ). Conclusions Plasma amino acid would be cleared through hemofilter during CVVH in patients with abdominal inflammation and acuterenal failure. As a result, it is necessary to take account of the ultrafiltrate amino acid loss when setting nutritional schedule, especially increasing the non-essential amino acid content of total parenteral nutrition. Key words: Abdominal inflammation; Acute renal failure; Continuous veno-venous hemofiltration; Amino acid