Nitric oxide delivery using nitric oxide-containing fluid in continuous hemofiltration: an in vitro study.

Administering nitrite has therapeutic effects on ischemic conditions wherein the enzymatic production of nitric oxide depends on oxygen. We developed a supplemental fluid containing nitric oxide (NO) and determined the clearance and supply between the pre- and post-dilution modes of continuous hemofiltration in vitro. Nitric oxide gas, 1000 mL or 2000 mL, at a concentration of 1000 ppm, was injected into 2020 mL of conventional supplemental fluid (experimental solution). The same volume of nitrogen gas was injected into the supplemental fluid (control solution). NO concentrations were measured using commercially available NO assay kit. Pre- or post-dilution continuous hemofiltration was performed using a control solution as supplemental fluid to determine the NO clearance. We determined the NO concentration of the outlet blood circuit to confirm the NO supply using the experimental solution as supplemental fluid. Also, using the bovine blood, white blood cell and platelet change rates and the dialysis membrane water flux during continuous hemodiafiltration were evaluated ex vivo as index of the biocompatibilities of a nitric oxide-containing solution. NO was not detected in the control solutions. The experimental solutions significantly increased in nitric oxide concentrations. NO clearance increased as the increase in supplemental and ultrafiltration flow rates using the control solution as supplemental fluid. However, using the experimental solution as supplemental fluid, nitric oxide supply showed a similar trend of NO clearance. Without any changes in biocompatibility using the supplemental fluid containing NO, it could maintain intravascular nitric oxide during continuous renal replacement therapy.

Targeted high volume hemofiltration could avoid extracorporeal membrane oxygenation in some patients with severe Hantavirus cardiopulmonary syndrome.

BACKGROUND: Hantavirus cardiopulmonary syndrome (HCPS) has a high lethality. Severe cases may be rescued by venoarterial extracorporeal membrane oxygenation (VA ECMO), alongside substantial complications. High volume hemofiltration (HVHF) is a depurative technique that provides homeostatic balance allowing hemodynamic stabilization in some critically ill patients. METHODS: We implemented HVHF before VA ECMO consideration in the last five severe HCPS patients requiring mechanical ventilation and vasoactive drugs admitted to our intensive care unit. Patients were considered HVHF-responders if VA ECMO was avoided and HVHF-nonresponders if VA ECMO support was needed despite HVHF. A targeted-HVHF strategy compounded by aggressive hyperoncotic albumin, sodium bicarbonate, and calcium supplementation plus ultrafiltration to avoid fluid overload was implemented on three patients. RESULTS: Patients had maximum serum lactate of 8.8 (8.7-12.8) mmol/L and a lowest cardiac index of 1.8 (1.8-1.9) L/min/m2 . The first two required VA ECMO. They were connected later to HVHF, displayed progressive tachycardia and declining stroke volume. The opposite was true for HVHF-responders who received targeted-HVHF. All patients survived, but one of the VA ECMO patients suffered a vascular complication. CONCLUSION: HVHF may contribute to support severe HCPS patients avoiding the need for VA ECMO in some. Early connection and targeted-HVHF may increase the chance of success.

Hyperammonemia, the Last Indication of High-Volume Hemodiafiltration in Adult and Children: A Structured Review.

Ammonia is a neurotoxic molecule that causes cerebral edema and encephalopathy. Ammonia is either produced in excess or poorly purified during severe hepatic insufficiency, poisoning, infection, and inborn errors of metabolism. During continuous renal replacement therapy, ammonia clearance is determined by the dialysate flow rate and the dialyzer surface area. Extra-renal blood purification for ammonia clearance has been studied in neonates with urea cycle disorders. Prognostic factors affecting patient outcome are thought to be the duration of coma, the patient's clinical status prior to dialysis, and the ammonia removal rate. In this review, we discuss the various dialytic modalities used for ammonia clearance as well as the thresholds for initiating dialysis and the better strategy ensures rapid patient protection from cerebral edema and herniation induced by hyperammonemia.

Extracorporeal techniques for the treatment of critically ill patients with sepsis beyond conventional blood purification therapy: the promises and the pitfalls.

Sepsis is one of the leading causes of morbidity and mortality worldwide. It is characterized by a dysregulated immune response to infections that results in life-threatening organ dysfunction and even death. Bacterial cell wall components (endotoxin or lipopolysaccharide), known as pathogen-associated molecular patterns (PAMPs), as well as damage-associated molecular patterns (DAMPs) released by host injured cells, are well-recognized triggers resulting in the elevation of both pro-inflammatory and anti-inflammatory cytokines. Understanding this complex pathophysiology has led to the development of therapeutic strategies aimed at restoring a balanced immune response by eliminating/deactivating these inflammatory mediators. Different extracorporeal techniques have been studied in recent years in the hope of maximizing the effect of renal replacement therapy in modulating the exaggerated host inflammatory response, including the use of high volume hemofiltration (HVHF), high cut-off (HCO) membranes, adsorption alone, and coupled plasma filtration adsorption (CPFA). These strategies are not widely utilized in practice, depending on resources and local expertise. The literature examining their use in septic patients is growing, but the evidence to support their use at this stage is considered of low level. Our aim is to provide a comprehensive overview of the technical aspects, clinical applications, and associated side effects of these techniques.

Clinical Benefits of High-Volume Hemofiltration in Critically Ill Pediatric Patients with Severe Sepsis: A Retrospective Cohort Study.

AIMS: The study aimed to assess the clinical benefits of high-volume hemofiltration (HVHF) in pediatric patients with severe sepsis compared with standard-volume continuous veno-venous hemofiltration (CVVH). METHODS: We retrospectively analyzed the medical records of 155 pediatric patients with severe sepsis admitted to the pediatric intensive care unit of Shanghai Children's Hospital from January 2010 to June 2016. A total of 93 patients were treated with HVHF and 62 patients were treated with CVVH. RESULTS: HVHF treatment did not significantly reduce 28-day mortality. Moreover, there was no significant difference in reducing the plasma level of inflammatory mediators and improving hemodynamic variables between HVHF and CVVH group. However, the incidence of hyperglycemia was significantly higher in HVHF group than in CVVH group. CONCLUSIONS: There is no evidence to indicate that HVHF is superior to CVVH in reducing 28-day mortality as an adjunct to the treatment of severe sepsis in pediatric patients.

High-volume hemofiltration in adult burn patients with septic shock and acute kidney injury: a multicenter randomized controlled trial.

BACKGROUND: Sepsis and septic shock occur commonly in severe burns. Acute kidney injury (AKI) is also common and often results as a consequence of sepsis. Mortality is unacceptably high in burn patients who develop AKI requiring renal replacement therapy and is presumed to be even higher when combined with septic shock. We hypothesized that high-volume hemofiltration (HVHF) as a blood purification technique would be beneficial in this population. METHODS: We conducted a multicenter, prospective, randomized, controlled clinical trial to evaluate the impact of HVHF on the hemodynamic profile of burn patients with septic shock and AKI involving seven burn centers in the United States. Subjects randomized to the HVHF were prescribed a dose of 70 ml/kg/hour for 48 hours while control subjects were managed in standard fashion in accordance with local practices. RESULTS: During a 4-year period, a total of nine subjects were enrolled for the intervention during the ramp-in phase and 28 subjects were randomized, 14 each into the control and HVHF arms respectively. The study was terminated due to slow enrollment. Ramp-in subjects were included along with those randomized in the final analysis. Our primary endpoint, the vasopressor dependency index, decreased significantly at 48 hours compared to baseline in the HVHF group (p = 0.007) while it remained no different in the control arm. At 14 days, the multiple organ dysfunction syndrome score decreased significantly in the HVHF group when compared to the day of treatment initiation (p = 0.02). No changes in inflammatory markers were detected during the 48-hour intervention period. No significant difference in survival was detected. No differences in adverse events were noted between the groups. CONCLUSIONS: HVHF was effective in reversing shock and improving organ function in burn patients with septic shock and AKI, and appears safe. Whether reversal of shock in these patients can improve survival is yet to be determined. TRIAL REGISTRATION: Clinicaltrials.gov NCT01213914 . Registered 30 September 2010.

Nomenclature for renal replacement therapy and blood purification techniques in critically ill patients: practical applications.

This article reports the conclusions of the second part of a consensus expert conference on the nomenclature of renal replacement therapy (RRT) techniques currently utilized to manage acute kidney injury and other organ dysfunction syndromes in critically ill patients. A multidisciplinary approach was taken to achieve harmonization of definitions, components, techniques, and operations of the extracorporeal therapies. The article describes the RRT techniques in detail with the relevant technology, procedures, and phases of treatment and key aspects of volume management/fluid balance in critically ill patients. In addition, the article describes recent developments in other extracorporeal therapies, including therapeutic plasma exchange, multiple organ support therapy, liver support, lung support, and blood purification in sepsis. This is a consensus report on nomenclature harmonization in extracorporeal blood purification therapies, such as hemofiltration, plasma exchange, multiple organ support therapies, and blood purification in sepsis.

Early High-Volume Hemofiltration versus Standard Care for Post-Cardiac Surgery Shock. The HEROICS Study.

RATIONALE: Post-cardiac surgery shock is associated with high morbidity and mortality. By removing toxins and proinflammatory mediators and correcting metabolic acidosis, high-volume hemofiltration (HVHF) might halt the vicious circle leading to death by improving myocardial performance and reducing vasopressor dependence. OBJECTIVES: To determine whether early HVHF decreases all-cause mortality 30 days after randomization. METHODS: This prospective, multicenter randomized controlled trial included patients with severe shock requiring high-dose catecholamines 3-24 hours post-cardiac surgery who were randomized to early HVHF (80 ml/kg/h for 48 h), followed by standard-volume continuous venovenous hemodiafiltration (CVVHDF) until resolution of shock and recovery of renal function, or conservative standard care, with delayed CVVHDF only for persistent, severe acute kidney injury. MEASUREMENTS AND MAIN RESULTS: On Day 30, 40 of 112 (36%) HVHF and 40 of 112 (36%) control subjects (odds ratio, 1.00; 95% confidence interval, 0.64-1.56; P = 1.00) had died; only 57% of the control subjects had received renal-replacement therapy. Between-group survivors' Day-60, Day-90, intensive care unit, and in-hospital mortality rates, Day-30 ventilator-free days, and renal function recovery were comparable. HVHF patients experienced faster correction of metabolic acidosis and tended to be more rapidly weaned off catecholamines but had more frequent hypophosphatemia, metabolic alkalosis, and thrombocytopenia. CONCLUSIONS: For patients with post-cardiac surgery shock requiring high-dose catecholamines, the early HVHF onset for 48 hours, followed by standard volume until resolution of shock and recovery of renal function, did not lower Day-30 mortality and did not impact other important patient-centered outcomes compared with a conservative strategy with delayed CVVHDF initiation only for patients with persistent, severe acute kidney injury. Clinical trial registered with www.clinicaltrials.gov (NCT 01077349).

[Septic shock in intensive care units. Current focus on treatment]. / Shock séptico en unidad de cuidados intensivos. Enfoque actual en el tratamiento.

Essential therapeutic principles in children with septic shock persist over time, although some new concepts have been recently incorporated, and fully awareness of pediatricians and intensivists is essential. Fluid resuscitation is a fundamental intervention, but the kind of ideal fluid has not been established yet, as each of these interventions has specific limitations and there is no evidence supportive of the superiority of one type of fluid. Should septic shock persists despite adequate fluid resuscitation, the use of inotropic medication and/or vasopressors is indicated. New vasoactive drugs can be used in refractory septic shock caused by vasopressors, and the use of hydrocortisone should be considered in children with suspected adrenal insufficiency, as it reduces the need for vasopressors. The indications for red blood cells transfusion or the optimal level of glycemia are still controversial, with no consensus on the threshold value for the use of these blood products or the initiation of insulin administration, respectively. Likewise, the use of high-volume hemofiltration is a controversial issue and further study is needed on the routine recommendation in the course of septic shock. Nutritional support is crucial, as malnutrition is a serious complication that should be properly prevented and treated. The aim of this paper is to provide update on the most recent advances as concerns the treatment of septic shock in the pediatric population.

Carnitine Deficiency in Intensive Care Unit Patients Undergoing Continuous Renal Replacement Therapy: A Single-center Retrospective Study.

Introduction: Carnitine deficiency is common in patients undergoing intermittent hemodialysis and may also occur during continuous renal replacement therapy (CRRT). We evaluated intensive care unit (ICU) patients undergoing CRRT for carnitine deficiency and its associated risk factors. Methods: This was a single-center, retrospective, observational study performed between June 2019 and March 2020. The primary outcome was the incidence of carnitine deficiency in ICU patients undergoing CRRT. Results: Eighty-eight patients underwent 103 blood carnitine concentration measurements. The median age was 68 years (interquartile range: 55-80), Acute Physiology and Chronic Health Evaluation II score was 28 (24-33), Sequential Organ Failure score was 8.5 (5-11), Nutrition Risk in Critically Ill score was 6 (5-7), and blood carnitine concentration was 66.1 µmol/L (51.8-83.3). In total, 34 of 88 patients (38.6%) were found to have carnitine deficiency; however, there was no significant difference in the proportions of patients with carnitine deficiency characterized by disease. CRRT was performed in 44 (50%) patients, and the median blood total carnitine concentration measured after 24 h of CRRT without changing the settings was 65.5 µmol/L (48.6-83.3). The purification volume of CRRT and blood carnitine concentration were negatively correlated (R = -0.63; P = 0.02). Conclusions: Carnitine deficiency is seen in patients receiving CRRT and may increase in incidence as the purification volume increases, requiring regular monitoring.

High-volume hemofiltration does not protect human kidney endothelial and tubular epithelial cells from septic plasma-induced injury.

High volume hemofiltration (HVHF) could remove from plasma inflammatory mediators involved in sepsis-associated acute kidney injury (SA-AKI). The IVOIRE trial did not show improvements of outcome and organ dysfunction using HVHF. The aim of this study was to evaluate in vitro the biological effects of plasma of patients treated by HVHF or standard volume hemofiltration (SVHF). We evaluated leukocyte adhesion, apoptosis and functional alterations of endothelial cells (EC) and tubular epithelial cells (TEC). In vitro data were correlated with plasma levels of TNF-α, Fas-Ligand (FasL), CD40-Ligand (CD40L), von Willebrand Factor (vWF) and endothelial-derived microparticles. An experimental model of in vitro hemofiltration using LPS-activated blood was established to assess cytokine mass adsorption during HVHF or SVHF. Plasma concentrations of TNF-ɑ, FasL, CD40L and von Willebrand Factor (vWF) were elevated at the start (d1h0) of both HVHF and SVHF, significantly decreased after 6 h (d1h6), remained stable after 12 h (d1h12) and then newly increased at 48 h (d3h0). Plasma levels of all these molecules were similar between HVHF- and SVHF-treated patients at all time points considered. In addition, the levels of endothelial microparticles remained always elevated, suggesting the presence of a persistent microvascular injury. Plasma from septic patients induced leukocyte adhesion on EC and TEC through up-regulation of adhesion receptors. Moreover, on EC, septic plasma induced a cytotoxic and anti-angiogenic effect. On TEC, septic plasma exerted a direct pro-apoptotic effect via Fas up-regulation and caspase activation, loss of polarity, altered expression of megalin and tight junction molecules with an impaired ability to internalize albumin. The inhibition of plasma-induced cell injury was concomitant to the decrease of TNF-α, Fas-Ligand and CD40-Ligand levels. The protective effect of both HVHF and SVHF was time-limited, since a further increase of circulating mediators and plasma-induced cell injury was observed after 48 h (d3h0). No significant difference of EC/TEC damage were observed using HVHF- or SVHF-treated plasma. The in vitro hemofiltration model confirmed the absence of a significant modulation of cytokine adsorption between HVHF and SVHF. In comparison to SVHF, HVHF did not increase inflammatory cytokine clearance and did not reverse the detrimental effects of septic plasma-induced EC and TEC injury. Further studies using adsorptive membranes are needed to evaluate the potential role of high dose convective therapies in the limitation of the harmful activity of plasma soluble factors involved in SA-AKI.Trial registration IVOIRE randomized clinical trial; ClinicalTrials.gov (NCT00241228) (18/10/2005).

Extracorporeal therapies in sepsis.

The treatment of sepsis is an ongoing challenge for clinicians; despite the wide choice of effective antibiotics to treat infection, sepsis remains the leading cause of morbidity and mortality for patients admitted to an intensive care unit. Dysregulation of the immune response is now recognized to be a key factor in multiple organ dysfunction, yet our therapy for inflammation remains ineffective. It has been advocated for more than a decade that cytokine reduction in blood compartment could lead to a reduction in mortality in sepsis. Over the years, multiple extracorporeal techniques have evolved, with the intent of influencing the circulating levels of inflammatory mediators like cytokines and chemokines, the complement system, as well as factors of the coagulation system. These include high-volume hemofiltration, use of high cutoff membranes, and systems based on adsorption, such as coupled plasma filtration adsorption and the polymyxin-B column. In addition, new experimental systems that utilize human phagocytic cells and immobilized antibodies for targeted immunomodulation have emerged. In the context of limited resources and growing expansion in the availability of technologies, a better understanding of these therapies is required before they can be properly integrated into standard clinical practice in the hope of influencing major clinical outcomes. In this article, we will provide a concise overview of selected extracorporeal modalities currently in clinical use and briefly introduce some new promising techniques for sepsis.

Effect of high-volume hemofiltration on children with sepsis.

BACKGROUND: Sepsis has always been a challenge in pediatric intensive care unit (PICU) with poor prognosis. In order to evaluate the effect between routine continuous renal replacement therapy (CRRT) and high-volume hemofiltration (HVHF) in children with sepsis, we performed out this prospective, randomized, controlled, open-label trial. METHODS: Forty-seven children with sepsis were enrolled from January 2015 to December 2016. Twenty-two patients in Control group received routine CRRT and 25 patients in HVHF group received HVHF within 6 hours after the diagnosis of sepsis. The oxygenation index, serum creatinine, urea, lactate, inflammatory cytokines (IL-6, IL-10, and TNF-α), pediatric risk of mortality III (PRISM III) and 28-day mortality rate were collected and compared. RESULTS: The oxygenation index in HVHF group and Control group was significantly increased at 48 hours (P<0.01) and 72 hours after treatment (P<0.05). The same result of arterial lactate was observed. Serum creatinine, urea, IL-6, IL-10, TNF-α and PRISM III score were significantly ameliorated after 72 hours treatment in HVHF group (P<0.01), while there was no significant difference in Control group. After 72 hours of treatment, the oxygenation index, lactate, serum creatinine, urea, TNF-α, IL-6, IL-10 and PRISM III score in HVHF group were significantly improved compared with Control group (P<0.01). There is no significant difference on 28-day mortality between the two groups (P>0.05). CONCLUSIONS: HVHF might be an effective treatment for children with sepsis.

The therapeutic effect of high-volume hemofiltration on sepsis: a systematic review and meta-analysis.

BACKGROUND: Sepsis remains the leading cause of death in the intensive care unit (ICU), despite the treatment of sepsis has progressed. As a mode in continuous renal replacement therapy (CRRT), continuous veno-venous hemofiltration (CVVH) has been widely used in the treatment of sepsis. Whether high ultrafiltrate volume in CVVH is beneficial for sepsis survival remains controversial. We performed a systematic review and meta-analysis to evaluate the treatment effect of high-volume hemofiltration (HVHF) on sepsis. METHODS: A systematic search was conducted on the Medline, Embase, and Cochrane library to June 21, 2019, the keywords included "sepsis" "continuous blood purification" "continuous renal replacement therapy" "continuous veno-venous hemofiltration" and "continuous veno-venous hemodiafiltration". Summery statistic in this review was risk ratio (RR) and was performed by RevMan 5.2. RESULTS: Five randomized controlled trials (RCT) were included which contained 241 participants. Mortality related endpoints and other observations (length of stay, organ function evaluation, effect on hemodynamics, cytokine clearance and respiratory function) were used to assess the treatment effect of HVHF in sepsis. Three trials reported 28-day mortality, one of three trails also reported 60- and 90-day mortality; one trail did not specify the type of mortality; the fifth article reported hospital mortality. The pooled risk ratio for three trails of 28-day mortality was 0.96 (0.67, 1.38). Three trails reported length of stay related data. Four trails reported organ failure related scores. All trails reported the effect of HVHF on hemodynamics. Three trails reported cytokine clearance. Only two trails reported respiratory function related indicators. After analysis, the risk of bias in all trails was low. CONCLUSIONS: The meta-analysis results suggested that treatment programs contained HVHF did not change the outcomes of patients with sepsis. So far, related studies on the use of HVHF in critically ill patients with sepsis or septic shock is rare. Researchers should consider additional large multicenter randomized controlled trials.

Pharmacokinetics and Pharmacodynamics of Anti-infective Agents during Continuous Veno-venous Hemofiltration in Critically Ill Patients: Lessons Learned from an Ancillary Study of the IVOIRE Trial.

BACKGROUND: Hemofiltration rate, changes in blood and ultrafiltration flow, and discrepancies between the prescribed and administered doses strongly influence pharmacokinetics (PK) and pharmacodynamics (PD) of antimicrobial agents during continuous veno-venous hemofiltration (CVVH) in critically ill patients. METHODS: Ancillary data were from the prospective multicenter IVOIRE (hIgh VOlume in Intensive caRE) study. High volume (HV, 70 mL/kg/h) was at random compared with standard volume (SV, 35 mL/kg/h) CVVH in septic shock patients with acute kidney injury (AKI). PK/PD parameters for all antimicrobial agents used in each patient were studied during five days. RESULTS: Antimicrobial treatment met efficacy targets for both percentage of time above the minimal inhibitory concentration and inhibitory quotient. A significant correlation was observed between the ultrafiltration flow and total systemic clearance (Spearman test: P < 0.005) and between CVVH clearance and drug elimination half-life (Spearman test: P < 0.005). All agents were easily filtered. Mean sieving coefficient ranged from 38.7% to 96.7%. Mean elimination half-life of all agents was significantly shorter during HV-CVVH (from 1.29 to 28.54 h) than during SV-CVVH (from 1.51 to 33.85 h) (P < 0.05). CONCLUSIONS: This study confirms that CVVH influences the PK/PD behavior of most antimicrobial agents. Antimicrobial elimination was directly correlated with convection rate. Current antimicrobial dose recommendations will expose patients to underdosing and increase the risk for treatment failure and development of resistance. Dose recommendations are proposed for some major antibiotic and antifungal treatments in patients receiving at least 25 mL/kg/h CVVH.

The Effects of High-volume Hemofiltration by Different Ultrasound Directing on Extra Vascular Lung Water Index in Patients with Septic Shock.

BACKGROUND: We explored the effects of high-volume hemofiltration(HVHF) by different ultrasound directing on the plasma N-terminal pro-B-type natriuretic peptide(NT-Pro-BNP), extra vascular lung water index (EVLWI), liquid net balance quantity and prognosis in patients with septic shock. METHODS: Overall, 107 intensive patients with septic shock were enrolled by retrospective analysis from Department of Intensive Care Unit (ICU) of the Shandong Provincial Hospital affiliated to Shandong University from 2014-2017. According to HVHF by different ultrasound directing, all the patients were divided into two groups ((ultrasonic cardiac output monitor (USCOM), group A, n=51cases)) and ((critical bedside ultrasound (CBU), group B, n=56cases)). RESULTS: The value of CI in group A had a significant positive correlation with the value of PCCI by the PiCCO2 monitoring (P<0.05). The lung ultrasound water B lines in group B also had a significant positive correlation with the value of EVLWI by the PiCCO2 monitoring. The cumulative liquid net balance quantity in group B had a more significant elevation than group A after treatment 7th d. The level of EVLWI after treatment 48 h and 72 h, the level of plasma NT-Pro-BNP, the levels of P(A-a)DO2,OI and blood lactic after treatment 72 h, and the APACHE II scores and SOFA scores after treatment 7thd were reduced more significantly in group B than group A (P<0.001). The mortality at 28th day had a more significant decrease in group B than group A. CONCLUSION: It could decrease the level of NT-Pro-BNP, EVLWI, P(A-a)DO2, which then improves pulmonary oxygenation. Consequently, it decreased the APACHE II and SOFA scores and improved the 28th survival rate of patients.

The effects of early high-volume hemofiltration on prolonged cardiac arrest in rats with reperfusion by cardiopulmonary bypass: a randomized controlled animal study.

BACKGROUND: It is not yet clear whether hemofiltration can reduce blood cytokine levels sufficiently to benefit patients who suffer prolonged cardiac arrest (CA) treated with cardiopulmonary bypass (CPB). We sought to assess effects of high-volume and standard volume continuous veno-venous hemofiltration (CVVH) on blood cytokine levels and survival in a rat model of prolonged CA treated with CPB. METHODS: Sprague-Dawley male rats were subjected to 12 min of asphyxia to induce CA. CPB was initiated for resuscitation of animals and maintained for 30 min. Twenty-four rats were randomly assigned into three groups: without CVVH treatment (sham); standard volume CVVH at a filtration rate of 35-45 mL/kg/h; and high-volume hemofiltration (HVHF, 105-135 mL/kg/h). Hemofiltration was started simultaneously with CPB and maintained for 6 h. Plasma TNFα and IL-6 levels were measured at baseline, 0.5, 1, 2, 3, and 6 h after reperfusion. Survival time, neurological deficit score, and hemodynamic status were assessed. RESULTS: All animals survived over 6 h and died within 24 h. There were no significant differences in survival time (log-rank test, sham vs. CVVH; p = 0.49, sham vs. HVHF; p = 0.33) or neurological deficit scores (ANOVA, p = 0.14) between the groups. There were no significant differences in blood cytokine levels between the groups. Mean blood pressure in sham group animals increased to 1.5-fold higher than baseline levels at 30 min. HVHF significantly reduced blood pressure to 0.7-fold of sham group (p < 0.01). CONCLUSIONS: There was no improvement in mortality, neurological dysfunction, TNFα, or IL-6 levels in rats after prolonged CA with CPB on either hemofiltration group when compared to the sham group.

Effects of high-volume hemofiltration on alveolar-arterial oxygen exchange in patients with refractory septic shock.

BACKGROUND: High-volume hemofiltration (HVHF) is technically possible in severe acute pancreatitis (SAP) patients complicated with multiple organ dysfunction syndrome (MODS). Continuous HVHF is expected to become a beneficial adjunct therapy for SAP complicated with MODS. In this study, we aimed to explore the effects of fluid resuscitation and HVHF on alveolar-arterial oxygen exchange, the Acute Physiology and Chronic Health Evaluation II (APACHE II) score in patients with refractory septic shock. METHODS: A total of 89 refractory septic shock patients, who were admitted to ICU, the Provincial Hospital affiliated to Shandong University from August 2006 to December 2009, were enrolled in this retrospective study. The patients were randomly divided into two groups: fluid resuscitation (group A, n=41), and fluid resuscitation plus high-volume hemofiltration (group B, n=48). The levels of O2 content of central venous blood (CcvO2), arterial oxygen content (CaO2), alveolar-arterial oxygen pressure difference P(A-a)DO2, ratio of arterial oxygen pressure/alveolar oxygen pressure (PaO2/PaO2), respiratory index (RI) and oxygenation index (OI) were determined. The oxygen exchange levels of the two groups were examined based on the arterial blood gas analysis at different times (0, 24, 72 hours and 7 days of treatment) in the two groups. The APACHE II score was calculated before and after 7-day treatment in the two groups. RESULTS: The levels of CcvO2, CaO2 on day 7 in group A were significantly lower than those in group B (CcvO2: 0.60±0.24 vs. 0.72±0.28, P<0.05; CaO2: 0.84±0.43 vs. 0.94±0.46, P<0.05). The level of oxygen extraction rate (O2ER) in group A on the 7th day was significantly higher than that in group B (28.7±2.4 vs. 21.7±3.4, P<0.01). The levels of P(A-a)DO2 and RI in group B on the 7th day were significantly lower than those in group A. The levels of PaO2/PaO2 and OI in group B on 7th day were significantly higher than those in group A (P<0.05 or P<0.01). The APACHE II score in the two groups reduced gradually after 7-day treatment, and the APACHE II score on the 7th day in group B was significantly lower than that in group A (8.2±3.8 vs. 17.2±6.8, P<0.01). CONCLUSION: HVHF combined with fluid resuscitation can improve alveolar-arterial-oxygen exchange, decrease the APACHE II score in patients with refractory septic shock, and thus it increases the survival rate of patients.

Shock séptico en unidad de cuidados intensivos: Enfoque actual en el tratamiento / Septic shock in intensive care units: Current focus on treatment

Los pilares terapéuticos del niño con shock séptico se mantienen en el tiempo, sin embargo, se han incorporado nuevos conceptos, siendo importante que el pediatra y el intensivista tengan conocimiento a cabalidad de ellos. La reanimación con fluidos es una intervención fundamental, no obstante, aún no se ha establecido un tipo de fluido ideal, presentando cada uno limitaciones específicas, no existiendo evidencia sobre la superioridad de un tipo de fluido. Si a pesar de una adecuada resucitación con fluidos persiste el shock, el inicio de inótropos y/o vasopresores está indicado. En caso de refractariedad al uso de vasopresores, nuevos fármacos vasoactivos pueden ser empleados y el uso de hidrocortisona debe considerarse en niños con sospecha de insuficiencia suprarrenal. Existe controversia respecto a la transfusión de glóbulos rojos o el nivel óptimo de glucemia, no existiendo consenso en el valor umbral para el uso de estos hemocomponentes o el inicio de insulina, respectivamente. Asimismo, la utilización de la hemofiltración de alto volumen (HFAV)aún permanece controversial, requiriendo mayores estudios para su recomendación en forma rutinaria en el curso de un shock séptico refractario. El soporte nutricional es primordial, ya que la desnutrición es una grave complicación que debe ser prevenida y tratada adecuadamente. El objetivo de la presente revisión es entregar una actualización en los más recientes avances en tratamiento del shock séptico en la población pediátrica.

Essential therapeutic principles in children with septic shock persist over time, although some new concepts have been recently incorporated, and fully awareness of pediatricians and intensivists is essential. Fluid resuscitation is a fundamental intervention, but the kind of ideal fluid has not been established yet, as each of these interventions has specific limitations and there is no evidence supportive of the superiority of one type of fluid. Should septic shock persists despite adequate fluid resuscitation, the use of inotropic medication and/or vasopressors is indicated. New vasoactive drugs can be used in refractory septic shock caused by vasopressors, and the use of hydrocortisone should be considered in children with suspected adrenal insufficiency, as it reduces the need for vasopressors. The indications for red blood cells transfusion or the optimal level of glycemia are still controversial, with no consensus on the threshold value for the use of these blood products or the initiation of insulin administration, respectively. Likewise, the use of high-volume hemofiltration is a controversial issue and further study is needed on the routine recommendation in the course of septic shock. Nutritional support is crucial, as malnutrition is a serious complication that should be properly prevented and treated. The aim of this paper is to provide update on the most recent advances as concerns the treatment of septic shock in the pediatric population.