Albumin resuscitation increases cardiomyocyte contractility and decreases nitric oxide synthase II expression in rat endotoxemia

Pharmacological Interventions for Cirrhotic Ascites: From Challenges to Emerging Therapeutic Horizons

Ascites is the most common complication in patients with decompensated cirrhosis. This condition results in a severely impaired quality of life, excessive healthcare use, recurrent hospitalizations and significant morbidity and mortality. While loop diuretics and mineralocorticoid receptor antagonists are commonly employed for symptom relief, our understanding of their impact on survival remains limited. A comprehensive understanding of the underlying pathophysiological mechanism of ascites is crucial for its optimal management. The renin-angiotensin-aldosterone system (RAAS) is increasingly believed to play a pivotal role in the formation of cirrhotic ascites, as RAAS overactivation leads to a reduction in urine sodium excretion then a decrease in the ability of the kidneys to excrete water. In this review, the authors provide an overview of the pathogenesis of cirrhotic ascites, the challenges associated with current pharmacologic treatments, and the previous attempts to modulate the RAAS, followed by a description of some emerging targeted RAAS agents with the potential to be used to treat ascites.

Early Mortality Stratification with Serum Albumin and the Sequential Organ Failure Assessment Score at Emergency Department Admission in Septic Shock Patients

Background: Early risk stratification is crucial due to septic patients' heterogeneity. Serum albumin level may reflect the severity of sepsis and host status. This study aimed to evaluate the prognostic ability of the initial sequential organ failure assessment (SOFA) score alone and combined with serum albumin levels for predicting 28-day mortality in patients with septic shock. Methods: We conducted an observational study using a prospective, multicenter registry of septic shock patients between October 2015 and May 2022 from 12 emergency departments in the Korean Shock Society and the results were validated by examining those from the septic shock cohort in Asan Medical Center. The primary outcome was 28-day mortality. The area under the receiver operating characteristic (ROC) curve was used to compare the predictive values of SOFA score alone and SOFA score combined with serum albumin level. Results: Among 5805 septic shock patients, 1529 (26.3%) died within 28 days. Mortality increased stepwise with decreasing serum albumin levels (13.6% in albumin ≥3.5, 20.7% in 3.5-3.0, 29.7% in 3.0-2.5, 44.0% in 2.5-2.0, 56.4% in <2.0). The albumin SOFA score was calculated by adding the initial SOFA score to the 4 points assigned for albumin levels. ROC analysis for predicting 28-day mortality showed that the area under the curve for the albumin SOFA score was 0.71 (95% CI 0.70-0.73), which was significantly higher than that of the initial SOFA score alone (0.68, 95% CI: 0.67-0.69). Conclusions: The combination of the initial SOFA score with albumin can improve prognostic accuracy for patients with septic shock, suggesting the albumin SOFA score may be used as an early mortality stratification tool.

Serum albumin levels and risk of atrial fibrillation: a Mendelian randomization study

Objective

Although several observational studies have linked serum albumin to cardiovascular disease and considered it as an important biomarker, little is known about whether increasing or maintaining serum albumin levels can effectively improve the prognosis of patients with atrial fibrillation. Therefore, this study aims to further explore the causal relationship between serum albumin and atrial fibrillation and its potential mechanism.

Method

Using data from large-scale genome-wide association studies, we conducted a two-sample Mendelian randomization (MR) analysis and a mediation MR analysis, using serum albumin as the exposure variable and atrial fibrillation as the outcome variable. We included 486 serum metabolites as potential mediating factors. To increase the robustness of the analysis, we applied five statistical methods, including inverse variance weighted, weighted median, MR-Egger, simple mode, and weighted mode. Validate the MR results using Bayesian weighted Mendelian randomization method.

Result

The results of the MR analysis indicate a significant inverse association between genetically predicted serum albumin concentration (g/L) and the risk of atrial fibrillation (Beta = -0.172, OR = 0.842, 95% CI: 0.753-0.941, p = 0.002). Further mediation MR analysis revealed that serum albumin may mediate the causal relationship with atrial fibrillation by affecting two serum metabolites, docosatrienoate and oleate/vaccenate, and the mediating effect was significant. In addition, all our instrumental variables showed no heterogeneity and level-multiplicity in the MR analysis. To verify the stability of the results, we also conducted a sensitivity analysis using the leave-one-out method, and the results further confirmed that our findings were robust and reliable. Finally, we conducted a validation using the Bayesian weighted Mendelian randomization method, which demonstrated the reliability of our causal inference results.

Conclusion

This study strongly demonstrates the causal relationship between serum albumin and reduced risk of atrial fibrillation through genetic methods, and reveals the key mediating role of two serum metabolites in this relationship. These findings not only provide a new perspective for our understanding of the role of serum albumin in atrial fibrillation, but also provide new ideas for the prevention and treatment strategies of atrial fibrillation.

Albumin Infusion Reduces Fluid Loading for Postresuscitation Syndrome in a Pig Model of Refractory Cardiac Arrest Resuscitated With Venoarterial Extra Corporeal Membrane Oxygenation

Hemodynamic instability in postresuscitation syndrome worsens survival and neurological outcomes. Venoarterial extracorporeal membrane oxygenation (VA ECMO) for refractory cardiac arrest might improve outcomes. Hemodynamical support under VA ECMO relies on norepinephrine and crystalloids. The present work aims to assess the effects of albumin (ALB) infusion in a swine model of ischemic refractory cardiac arrest implanted by VA ECMO. Cardiac arrest was performed in 18 pigs and VA ECMO was initiated after 30 minutes cardiopulmonary resuscitation (CPR). Pigs were randomly assigned to standard care (norepinephrine + crystalloids) versus ALB group (ALB + standard care). Hemodynamical assessments were performed over 6 hours. Severe hypoalbuminemia was observed in the control group and could be reversed with ALB infusion. Total crystalloid load was significantly reduced with ALB infusion (1,000 [1,000-2,278] ml vs. 17,000 [10,000-19,000] ml, ALB versus control group, respectively, p < 0.001). There was no significant impact with regard to lactate clearance (29.16% [12.5-39.32] and 10.09% [6.78-29.36] for control versus ALB groups, respectively, p = 0.185), sublingual capillary microvascular parameters, or cerebral near-infrared spectrometer (NIRS) values. Compared to standard care, ALB infusion was highly effective in reducing fluid loading in a porcine model of postresuscitation syndrome after refractory cardiac arrest treated with VA ECMO.

Influence of Fibrinogen/Albumin Ratio and Fibrinogen/Pre-Albumin Ratio on Cardiac Autonomic Neuropathy in Type 2 Diabetes

Purpose

Subclinical inflammation may be involved in the pathogenesis of diabetic cardiac autonomic neuropathy (DCAN). The purpose of the study is to explore the relationship between novel inflammation biomarkers fibrinogen-albumin ratio (FAR), fibrinogen-prealbumin ratio (FPR), and DCAN in type 2 diabetes mellitus (T2DM).

Patients and Methods

A total of 715 T2DM patients were enrolled in this retrospective study, divided into non-DCAN (n=565) and DCAN (n=150) groups by Ewing's test. Serum fibrinogen, albumin, prealbumin, routine inflammatory and other biochemical markers were measured.

Results

Patients with versus without DCAN had higher FAR (10.29 ± 4.83 vs 7.22 ± 2.56 g/g, P < 0.001) and FPR (2.19 ± 1.85 vs 1.43 ± 0.93 g/mg, P < 0.001). As FAR and FPR quartiles increased, the incidence of DCAN increased (Quartile 1 vs Quartile 4: 8.4 vs 42.7%, 9.6 vs 39.2%, respectively, P < 0.001), heart rate variability parameters decreased (P < 0.001); the incidence of diabetic nephropathy, retinopathy and peripheral neuropathy tended to be higher and inflammation factors were more active (P < 0.01). FAR (OR, 95% CI: 1.16, 1.08-1.25, P < 0.001) and FPR (OR, 95% CI: 1.22, 1.03-1.44, P = 0.021) were independent determinants of DCAN; the risk of DCAN increased by approximately 65% and 27% with each increase in the standard deviation (SD) of FAR (OR per SD, 95% CI: 1.65, 1.29-2.11, P < 0.001) and FPR (OR per SD, 95% CI: 1.27, 1.04-1.56, P = 0.021).

Conclusion

FAR and FPR are independent risk factors and may influence DCAN development through inflammation.

Clinical features of patients with MOG-IgG associated disorders and analysis of the relationship between fibrinogen-to-albumin ratio and the severity at disease onset

Objective

The study aimed to investigate the differences in clinical features between pediatric and adult patients with first-episode MOG-IgG associated disorders (MOGAD) and evaluate the relationship between the fibrinogen-to-albumin ratio (FAR) and the severity of neurological deficits at disease onset.

Methods

We retrospectively collected and analyzed biochemical test results, imaging characteristics, clinical manifestations, expanded disability status scale (EDSS) score, and FAR. The Spearman correlation analysis and logistic regression models were used to examine the association between FAR and severity. Receiver operating characteristic (ROC) curve analysis was to analyze the predictive ability of FAR for the severity of neurological deficits.

Results

Fever (50.0%), headache (36.1%), and blurred vision (27.8%) were the most common clinical manifestations in the pediatric group (<18 years old). However, in the adult group (≥18 years old), the most common symptoms were blurred vision (45.7%), paralysis (37.0%), and paresthesia (32.6%). Fever was more common in the pediatric group, while paresthesia was more common in the adult patients, with all differences statistically significant (P < 0.05). The most frequent clinical phenotype in the pediatric group was acute disseminated encephalomyelitis (ADEM; 41.7%), whereas optic neuritis (ON; 32.6%) and transverse myelitis (TM; 26.1%) were more common in the adult group. The differences in clinical phenotype between the two groups were statistically significant (P < 0.05). In both pediatric and adult patients, cortical/subcortical and brainstem lesions were the most common lesions on cranial magnetic resonance imaging (MRI), whereas, for spinal MRI, cervical and thoracic spinal cord lesions were the most commonly observed. According to binary logistic regression analysis, FAR was an independent risk factor for the severity of neurological deficits (odds ratio = 1.717; 95% confidence interval = 1.191-2.477; P = 0.004). FAR (r = 0.359, P = 0.001) was positively correlated with the initial EDSS score. The area under the ROC curve was 0.749.

Conclusion

The current study found age-dependent phenotypes in MOGAD patients as ADEM was more commonly observed in patients < 18 years old, while ON and TM were more frequently found in patients ≥18 years old. A high FAR level was an independent indicator for more severe neurological deficits at disease onset in patients with a first episode of MOGAD.

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.

Randomized controlled multicentre study of albumin replacement therapy in septic shock (ARISS): protocol for a randomized controlled trial

BACKGROUND

Albumin is a key regulator of fluid distribution within the extracellular space and has several properties beyond its oncotic activity. The accumulating evidence suggests that supplementation of albumin may provide survival advantages only when the insult is severe as in patients with septic shock.

METHODS/DESIGN

The randomized controlled multicentre study of albumin replacement therapy in septic shock (ARISS) investigates whether the replacement with albumin and the maintenance of its serum levels of at least 30 g/l for 28 days improve survival in patients with septic shock compared to resuscitation and volume maintenance without albumin. Adult patients (≥ 18 years) with septic shock are randomly assigned within a maximum of 24 h after the onset of septic shock after obtaining informed consents to treatment or control groups. Patients assigned to the treatment group receive a 60-g loading dose of human albumin 20% over 2-3 h. Serum albumin levels are maintained at least at 30 g/l in the ICU for a maximum of 28 days following randomization using 40-80 g human albumin 20% infusion. The control group is treated according to the usual practice with crystalloids as the first choice for the resuscitation and maintenance phase of septic shock. The primary endpoint is 90 days mortality and secondary endpoints include 28-day, 60-day, ICU, and in-hospital mortality, organ dysfunction/failure, total amount of fluid administration and total fluid balance in the ICU, and lengths of ICU and hospital stay. In total, 1412 patients need to be analysed, 706 per group. For the sample size estimation, a 15% reduction in 90-day mortality is assumed, i.e. an absolute reduction of 7.5% points to 42.5% (relative risk 1.18). Assuming a dropout rate of 15%, a total of 1662 patients need to be allocated.

DISCUSSION

The results of the clinical trial may influence the treatment of patients with septic shock. The expected improvement in patient survival may result in a reduction in the resources currently used in the treatment of these patients and in the socioeconomic burden of this disease.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03869385 . Registration on 18 July 2019. Protocol version: Final 3.0.

[Does hypoalbuminemia contribute to the worsening of heart failure?]

BACKGROUND

Hypoalbuminemia has now emerged as a powerful prognosticator in heart failure regardless of age, clinical presentation, left ventricular ejection fraction and usual prognostic markers. Growing evidence is that this prognostic value persists after adjusting for causative factors for hypoalbuminemia such as malnutrition, inflammation and liver dysfunction.

OBJECTIVE

To address the prognostic relevance of hypoalbuminemia in frail elderly patients with well-characterized cardiogenic pulmonary edema at high risk for adverse outcome, beyond causative factors for low serum albumin levels. Serum albumin was measured after clinical stabilization to avoid hypervolemia.

RESULTS

In all, 67 patients with a mean age of 86 years were included. Hospital mortality was 30%. Patients who died and who survived were similar in age, ejection fraction, BNP concentration, serum creatinine, serum hemoglobin, total bilirubin and prealbumin. Patients who died had lower serum albumin levels (P<0.001), higher blood urea nitrogen (P=0.03) and higher C-reactive protein (P=0.02). In multivariate analysis, serum albumin was the sole independent predictor of hospital death (P<0.01), after adjusting for malnutrition (prealbumin P=ns), inflammation (C-reactive protein P=ns) and liver dysfunction (total bilirubin P=ns).

CONCLUSION

Serum albumin is a powerful prognosticator in frail elderly patients with acute cardiogenic pulmonary edema even after adjusting for main causative factors. These results suggest that hypoalbuminemia may contribute to the worsening of heart failure given the physiological properties of serum albumin that includes antioxidant activity and plasma colloid osmotic pressure action. Further studies are critically needed to address the relevance of prevention and correction of hypoalbuminemia in heart failure.

Serum albumin and cardiovascular disease: State-of-the-art review

Cardiovascular disease is the leading cause of death worldwide. Conceptually, endothelial dysfunction, inflammatory conditions and oxidative stress are at the forefront of the onset and development of most cardiovascular diseases, particularly coronary artery disease and heart failure. Serum albumin has many physiological properties, including in particular antioxidant, anti-inflammatory, anticoagulant and anti-platelet aggregation activity. It also plays an essential role in the exchange of fluids across the capillary membrane. Hypoalbuminemia is a powerful prognostic marker in the general population as well as in many disease states. In the more specific context of cardiovascular disease, low serum albumin is independently associated with the development of various deleterious conditions such as coronary artery disease, heart failure, atrial fibrillation, stroke and venous thromboembolism. Low serum albumin has also emerged as a potent prognostic parameter in patients with cardiovascular disease regardless of usual prognostic markers. Remarkably, its potent prognostic value persists after adjusting for causative confounders such as malnutrition and inflammation. This prognostic value probably refers primarily to the syndrome of malnutrition-inflammation and the severity of comorbidities. Nevertheless, several recent meta-analyses strongly support the hypothesis that hypoalbuminemia may act as an unrecognized, potentially modifiable risk factor contributing to the emergence and progression of cardiovascular disease, primarily by exacerbating oxidative stress, inflammation and platelet aggregation, and by favouring peripheral congestion and pulmonary edema. Currently, it is unknown whether prevention and correction of low serum albumin offers a benefit to patients with or at risk for cardiovascular disease, and further studies are critically needed in this setting.

Non-oncotic properties of albumin. A multidisciplinary vision about the implications for critically ill patients

INTRODUCTION

Effective resuscitation with human albumin solutions is achieved with less fluid than with crystalloid solutions. However, the role of albumin in today's critical care unit is also linked to its multiple pharmacological effects. Areas covered: The potential clinical benefits of albumin in select populations of critically ill patients like sepsis seem related to immunomodulatory and anti-inflammatory effects, antibiotic transportation and endothelial stabilization. Albumin transports many drugs used in critically ill patients. Such binding to albumin is frequently lessened in critically ill patients with hypoalbuminemia. These changes could result in sub-optimal treatment. Albumin has immunomodulatory capacity by binding several bacterial products. Albumin also influences vascular integrity, contributing to the maintenance of the normal capillary permeability. Moreover, the albumin molecule encompasses several antioxidant properties, thereby significantly reducing re-oxygenation injury, which is especially important in sepsis. In fact, most studies of albumin administration are a combination of a degree of resuscitation with a degree of maintenance or supplementation of albumin. Expert commentary: The potential clinical benefits of the use of albumin in selected critically ill patients such as sepsis seem related to its immunomodulatory and anti-inflammatory effects, antioxidant properties, antibiotic transportation and endothelial stabilization. Additional studies are warranted to further elucidate the underlying physiologic and molecular rationale.

Low serum albumin concentrations are associated with disease severity in patients with myasthenia gravis

Serum albumin (S-Alb) is a widely used biomarker of nutritional status and disease severity in patients with autoimmune diseases. We investigated the correlation between S-Alb and the severity of myasthenia gravis (MG).A total number of 166 subjects were recruited in the study. Subjects were divided into 3 groups (T1 to T3) by S-Alb levels: T1: 21.1 to 38.4 g/L, T2: 38.5 to 41.5 g/L, T3: 41.6 to 48.9 g/L. Regression analysis was performed to determine the correlation of initial albumin concentrations and the severity of disease of MG.Lower levels of S-Alb were observed in subjects with increased disease severity than those with slight disease severity, meanwhile, incidence of myasthenia crisis increased in the lower albumin tertiles (P < 0.001). The disease severity assessment was performed according to the criteria established by the Myasthenia Gravis Foundation of America. After adjusting for age, sex, body mass index (BMI), and duration of disease, it showed that higher S-Alb concentrations were associated with lower disease severity. Odds ratios (ORs) of T2 to T3 were 0.241 (95% CI: 0.103-0.566, P < 0.001), 0.140 (95% CI: 0.054-0.367, P < 0.001) when compared with subjects in the T1, respectively. When subjects were stratified into hypoalbuminemia and normal albumin groups, we found that the association between S-Alb and MG remained significant in the hypoalbuminemia group only (OR: 0.693, 95% CI: 0.550-0.874, P = 0.002) after further adjustment for age, sex, BMI, and duration of disease.This is the first study to demonstrate that S-Alb was independently associated with MG severity. In patients with low S-Alb, S-Alb concentration could be a potential biomarker for MG disability.

Serum albumin is associated with peripheral nerve function in patients with type 2 diabetes

The aim of this study is to investigate the association between serum albumin concentrations and nerve conduction (NC) parameters in Chinese patients with type 2 diabetes (T2DM). A total of 409 T2DM patients were enrolled between October 2010 and April 2014. All participants underwent nerve conduction studies. The composite Z scores for NC parameters including conduction velocity (CV), amplitude, and latency were calculated as well. Serum albumin was measured by Bromcresol Green dye-binding method. The composite Z scores of CV and amplitude increased with the increasing albumin tertiles (test for trend, both P < 0.001), while the composite Z score of latency decreased with increasing albumin tertiles (test for trend, P < 0.001). After adjusting for age, sex, duration, and HbA1c, higher serum albumin concentrations were associated with higher composite Z scores of CV (β = 0.314, P < 0.001), amplitude (β = 0.279, P < 0.001), and lower composite Z score of latency (β = -0.279, P < 0.001). When participants were stratified into albuminuria and normoalbuminuria group, we found the associations of serum albumin with composite Z scores of NC parameters remained significant only in the albuminuria group (CV Z score: β = 0.253, P = 0.002; amplitude Z score: β = 0.233, P = 0.006; latency Z score: β = -0.217 P = 0.013) after further adjustment for urinary albumin to creatinine ratio. The optimal cutoff point of serum albumin to indicate abnormal peripheral nerve function was 36.75 g/L in T2DM patients with albuminuria, with a sensitivity of 65.6 % and a specificity of 78.0 %. Serum albumin was independently associated with peripheral nerve function in T2DM patients, especially in those with albuminuria. Serum albumin could be a potential biomarker for diabetic peripheral neuropathy.

Persistent hypoalbuminemia is a predictor of outcome in cervical spinal cord injury

BACKGROUND CONTEXT

Hypoalbuminemia is associated with increased morbidity and mortality in various clinical settings and several major diseases. Albumin has multiple physiologic properties that could be beneficial in central nervous system injury.

PURPOSE

We sought to determine if albumin is associated with patient outcome after cervical spinal cord injury by conducting a retrospective analysis.

STUDY DESIGN/SETTING

A retrospective study of cervical spinal cord injury (CSCI) patients was conducted to investigate if serum albumin levels and other characteristics influence outcome (mechanical ventilation and death).

PATIENT SAMPLE

A total of 178 consecutive patients were included in the present study.

OUTCOME MEASURES

Demographic data were recorded, including age, gender, smoking history, time from injury to admission, severity of neurologic injury, neurologic level of lesion, mechanism of neurologic injury, Glasgow Coma Score, vitals in the Orthopedic Department, the occurrence of early surgical intervention (48 hours after injury), and daily serum albumin levels.

METHODS

No funds were received in support of this work. No specific conflicts of interest were involved in this article. Serum albumin levels and other characteristics known to influence outcome were included in univariate statistical analyses and the multiple logistic regression model to analyze the relationship with mechanical ventilation and death after cervical injury.

RESULTS

Approximately 41.0% (73/178) of patients had complete spinal cord injury (ASIA A), 36.5% (65/178) of patients required mechanical ventilation, and 8.4% (15/178) of patients died within the first month after injury. Albumin remained lower than 30 g/L for a period of time (≥5 days) in patients with an unfavorable outcome (patients requiring mechanical ventilation or who had died). Multiple logistic regression analysis identified age (>50 years), persistent hypoalbuminemia (<30 g/L and ≥5 days), C5 and above neurologic injury, and ASIA A as predictors for mechanical ventilation. In addition, persistent hypoalbuminemia, ASIA A, and C4 and above neurologic injury were significantly associated with death.

CONCLUSION

Similar to the ASIA scale and neurologic level, persistent hypoalbuminemia seems to be an independent predictor of outcome in patients with CSCI. Thus, a randomized trial assessing albumin in the treatment of cervical spinal cord injury is warranted.

Differentiated control of deranged nitric oxide metabolism: a therapeutic option in sepsis?

Derangement of nitric oxide (NO) metabolism represents one of the key mechanisms contributing to macro- and microcirculatory failure in sepsis. Sepsis-related therapy combining fluid resuscitation with administration of vasopressor and inotropic agents, however, does not guarantee correction of maldistributed nutritive perfusion between and within organs. Therefore, the differentiated and selective pharmacologic modulation of NO-mediated vascular function could play a useful role in hemodynamic management of patients with sepsis. This viewpoint carefully evaluates the potential role of intentionally using partially opposing effects of NO donors and NO synthase inhibitors to complement current therapy of hemodynamic stabilization in patients with sepsis.

Resuscitation fluids and endotoxin-induced myocardial dysfunction: is selection a load-independent differential issue?

Along with redistributive shock, myocardial dysfunction is now recognized as highly prevalent in early severe sepsis. Indeed, aside from their distinct loading potency, resuscitation fluids have been poorly investigated as to their specific molecular impact on myocardial dysfunction. The objective of this study was to evaluate the load-independent biological impact of different resuscitation fluids on endotoxin-induced myocardial dysfunction. Adult rats implanted with a central venous catheter were given an intraperitoneal injection of endotoxin (lipopolysaccharides [LPSs], Escherichia coli, 10 mg/kg) or normal saline (sham) and subsequently infused or not with similar "fluid potency" loading resuscitation fluid (normal saline, albumin [Alb], or hypertonic saline solution) for 6 to 24 h, followed by echocardiographic and hemodynamic monitoring together with biochemical and histopathologic evaluation. Intervention was to assess the selective influence of load-independent fluid infusion on the aforementioned parameters in groups of animals challenged or not with LPS. At comparative plasma volumes, Alb improved myocardial homeostasis after LPS challenge by (i) reducing left ventricular relative wall diastolic thickness, interstitial space enlargement, and endogenous Alb content; (ii) limiting cardiac apoptosis and sustaining extracellular signal-regulated mitogen-activated protein kinase activation; and (iii) enhancing the expression pattern of heme-oxygenase 1/inducible nitric oxide synthase. Hypertonic saline solution was also cardioprotective by early prevention of myocardial dysfunction and by reducing cardiac apoptosis. Fluid infusions have distinct load-independent structural/biological impacts on endotoxin-induced myocardial dysfunction. Albumin and hypertonic saline solution are the most pleiotropic fluids in protecting the heart after a "sepsis" hit.

Hyperoncotic albumin attenuates lung and intestine injuries caused by peritonitis-induced sepsis in rats

BACKGROUND

Hyperoncotic albumin may be a therapeutic option to improve tissue perfusion and organ injury in sepsis. To clarify the hypothesis and its mechanism, hyperoncotic albumin was administered to the rats in a polymicrobial sepsis-peritonitis model.

MATERIALS AND METHODS

Peritonitis was induced by a surgery of cecal ligation and puncture (CLP) in 27 male Wistar rats. For control purposes, sham operations without ligating and puncturing the cecum were performed in 20 rats. Three hours later, rats were randomized to receive intravenously 3 mL/kg of 5% albumin, 25% albumin, or normal saline. All the hemodynamic and biochemical parameters were measured during the 18-h observation.

RESULTS

In septic rats, 25% albumin attenuated hypotension, vascular hyporeactivity to norepinephrine, and the elevated serum levels of lactate dehydrogenase and blood urea nitrogen. However, these improvements were not noted in CLP rats after 5% albumin treatment. In addition, 25% albumin decreased metabolic acidosis and improved the CLP-induced hypoperfusion in the intestine and kidney. Superoxide levels in the aorta and lung and the protein expression of inducible nitric oxide synthase in the lung were also attenuated by 25% albumin in CLP rats. Microscopic findings confirmed that 25% albumin attenuated the substantial swelling and cell infiltration in the intestine and lung caused by CLP.

CONCLUSIONS

In this sepsis rat model, 25% albumin reduced macro- and microhemodynamic changes and attenuated intestine and lung injuries in peritonitis-induced sepsis.

Beneficial effects of hyperoncotic albumin on liver injury and survival in peritonitis-induced sepsis rats

Liver injury/dysfunction developing in patients with sepsis may lead to an increased risk of death. Small-volume resuscitation with hyperoncotic albumin (HA) has been proposed to restore physiologic hemodynamics in hemorrhagic and septic shock. We evaluated whether HA resuscitation could alleviate the development of liver injury/dysfunction in rats with polymicrobial sepsis induced by cecal ligation and puncture (CLP). The male Wistar rats received 0.9% saline or HA (25%, 3 mL/kg intravenously) at 3 h after CLP or sham operation. All hemodynamic and biochemical variables were measured during the 18-h observation. After 18 h of CLP, the septic rats developed circulatory failure (i.e., hypotension, tachycardia, and poor tissue perfusion), liver injury (examined by biochemical variables and histologic studies), and a higher mortality. Hyperoncotic albumin not only ameliorated the deterioration of hemodynamic changes but also attenuated neutrophil infiltration and cell death in the liver of septic animals. The septic rats treated with HA had a higher survival when compared with those with 0.9% saline treatment. Moreover, the increased plasma IL-1β, plasma IL-6, plasma nitrite/nitrate concentrations, liver iNOS expression, and liver superoxide levels in CLP rats were attenuated after administration of HA. Thus, HA may be regarded as a potential therapeutic agent in the early treatment of septic shock to prevent or reduce subsequent liver failure.

Update on transfusion solutions during surgery: review of hydroxyethyl starches 130/0.4

OBJECTIVES

Restoration of circulation is crucial in the surgical patient management. Colloids and crystalloids are widely used for blood volume therapy. We reviewed recent trials to evaluate efficacy and safety of hydroxyethyl starch (HES) 130/0.4 during surgery.

MATERIAL AND METHODS

A subjective, not systematic, review of literature was performed. Papers were searched to answer questions about efficacy of HES, its impact on coagulation and inflammation and its effects on pulmonary mechanics and renal function.

CONCLUSIONS

HES 130/0.4 is effective for volume therapy and is less expensive than human albumin. Its effects on coagulation and renal function are manageable; it may ameliorate pulmonary permeability and reduce inflammation.

[Burn: An inflammatory process]

Thermal injury induce a two-phase inflammatory response: first, a pro-inflammatory status, resulting in a systemic inflammatory response syndrome, then an anti-inflammatory phase characterized by a profound defect in cellular-mediated immunity. This inflammatory reaction proceeds from complex phenomenons in whom many cellular elements are involved (macrophage is the central one) and very complex molecular products interact (especially cytokines). These phenomenons promote significant physiopathologic consequences, especially on cardiovascular homeostasis and endothelial permeability, that lower the prognosis. The inflammatory reaction can be modified, enhanced or maintained by adverse events (i.e. infection) resulting in degradation of clinical situation. Despite a better comprehension of the phenomenons underlying this inflammatory process, diagnosis or therapeutic applications are at that time disappointing.

Effects of a predominantly hydroxyethyl starch (HES)-based and a predominantly non HES-based fluid therapy on renal function in surgical ICU patients

PURPOSE

To compare the effects of predominantly hydroxyethyl starch (HES 6% 130/0.4)-based with predominantly gelatin 4%-based fluid therapy on renal function in surgical intensive care unit (ICU) patients.

METHODS

Before-after, retrospective, study of surgical ICU patients. All patients admitted from January to June 2005 formed the HES group, with HES 130/0.4 as the standard colloid of choice. All patients admitted from January to June 2006 formed the GEL group, with gelatin 4% as the primary colloid. Acute renal failure (ARF) was defined as new need for renal replacement therapy (RRT) or at least a two-fold increase in baseline creatinine.

RESULTS

There were 1383 patients in the HES group and 1528 in the GEL group; 118 and 87, in each group respectively, had severe sepsis. The incidence of ARF and ICU and hospital mortality rates were similar in the two groups. In a post-hoc multivariable analysis, cumulative doses >33 ml/kg of either HES (OR = 1.85, 95% CI: 1.01-3.41, p < 0.001) or gelatin (OR = 1.99, 95% CI: 1.05-3.79, p = 0.035) were associated with a higher risk of ARF.

CONCLUSIONS

The incidence of ARF was similar in patients who received predominantly HES (6% 130/.04) fluid therapy and in those who received predominantly gelatin 4%. Moderate cumulative doses of modern HES or gelatin solutions may be associated with a higher risk of ARF.

Human serum albumin improves arterial dysfunction during early resuscitation in mouse endotoxic model via reduced oxidative and nitrosative stresses

Human serum albumin (HSA) is used as a resuscitation fluid in sepsis. This study investigated the potential protective properties of HSA on vascular function in a mouse endotoxic model in terms of oxidative and nitrosative stresses. Swiss mice were treated with either lipopolysaccharide (LPS) (50 mg/kg i.p.) or vehicle. One and five hours later, mice were infused with HSA (4%, 10 ml/kg), normal saline (0.9% NaCl, 30 ml/kg), or no fluid. Six hours after treatment, vascular reactivity was assessed on aortae and small mesenteric arteries. Measurements of NO and superoxide anion (O2(-)) by spin trapping and nuclear factor (NF)-kappaB, inducible NO synthase (iNOS), and peroxynitrite by Western blotting and immunohistochemical studies were conducted. HSA partially prevented the reduction of blood pressure induced by LPS and completely prevented both vascular hyporeactivity to phenylephrine and myogenic tone as well as endothelial dysfunction induced by the endotoxin. This was associated with a decreased up-regulation of NF-kappa B, iNOS, and peroxynitrite in the vascular wall. LPS-induced tissue increases in both NO and O2(-) production was decreased by HSA. These data demonstrate the protective effect of HSA treatment in experimental endotoxic shock by reducing the inflammatory process leading to oxidative and nitrosative stresses and vascular hyporeactivity.

Albumin resuscitation improves ventricular contractility and myocardial tissue oxygenation in rat endotoxemia

OBJECTIVE

Fluid resuscitation to improve delivery of oxygen to vital organs is a principal clinical intervention for septic patients. We previously reported that albumin resuscitation in rat endotoxemia improved contractility in isolated cardiomyocytes, but whether this effect occurs in vivo is unknown. We hypothesized that albumin resuscitation would improve decreased ventricular contractility and myocardial tissue oxygenation in vivo.

DESIGN

Randomized, controlled, prospective animal study.

SETTING

University animal laboratory.

SUBJECTS

Male Sprague-Dawley rats (250-350 g).

INTERVENTIONS

Rats were randomized into three groups: control with no lipopolysaccharide (n = 8), lipopolysaccharide (10 mg/kg) without albumin resuscitation (n = 8), and lipopolysaccharide with albumin resuscitation (n = 6). Five hours after lipopolysaccharide injection, animals were resuscitated with 10 mL/kg 5% rat albumin in 0.9% saline. Six hours after 10 mL/kg lipopolysaccharide, a pressure-volume conductance catheter (MIKRO-Tip 2.0-Fr, Millar Instruments, Houston, TX) was inserted into the left ventricle to quantify maximum elastance as an index of contractility. Myocardial tissue Po2 was measured using a fiberoptic oxygen probe.

MEASUREMENTS AND MAIN RESULTS

Maximum elastance decreased after lipopolysaccharide relative to control (47%, from 5.9 +/- 0.8 to 3.1 +/- 0.4 mm Hg/microL, p < .05). Albumin resuscitation prevented the lipopolysaccharide-induced decrease in maximum elastance (7.0 +/- 1.2 mm Hg/microL, p < .05 vs. lipopolysaccharide). Myocardial tissue Po2 was reduced in endotoxemia compared with control (53%, from 10.1 +/- 0.9 to 4.7 +/- 0.6 mm Hg, p < .05), and albumin resuscitation improved the lipopolysaccharide-induced tissue hypoxia toward the control value (9.0 +/- 1.4 mm Hg, p < .05).

CONCLUSIONS

Albumin resuscitation improved decreased ventricular contractility and myocardial oxygenation in endotoxemic rats. This result suggests that albumin resuscitation may improve ventricular dysfunction by improving myocardial hypoxia.

Can albumin administration relieve lung injury in trauma/hemorrhagic shock?

AIM: To study the effect of albumin administration on lung injury in trauma/hemorrhagic shock (T/HS).

METHODS: Sixty experimental animals were randomly divided into three groups: rats undergoing laparotomy without shock (T/SS); rats with T/HS and resuscitation with blood plus twice the volume of shed blood as Ringer’s lactate (RL), and rats with T/HS and resuscitation with blood plus additional 3 mL of 50 g/L human albumin. Expression of polymorphonuclear neutrophil (PMN) CD11b/CD18, intercellular adhesion molecule-1 (ICAM-1) of jugular vein blood and the severity of lung injuries [determined mainly by measuring activity of lung tissue myeloperoxidase (MPO) and lung injury score (LIS)] were measured after a 3-h recovery period.

RESULTS: All three groups showed a significant difference in the expressions of CD11b/CD18, ICAM-1, and severity of lung injury. The expressions of CD11b/CD18 in T/SS group, T/HS + RL group, T/HS + albumin group were 17.76% ± 2.11%, 31.25% ± 3.48%, 20.36% ± 3.21%, respectively (F = 6.25, P < 0.05). The expressions of ICAM-1 (U/mL) in T/SS group, T/HS + RL group, T/HS + albumin group were 258.76 ± 98.23, 356.23 ± 65.6, 301.01 ± 63.21, respectively (F = 5.86, P < 0.05). The expressions of MPO (U/g) in T/SS group, T/HS + RL group, T/HS + albumin group were 2.53 ± 0.11, 4.63 ± 1.31, 4.26 ± 1.12, respectively (F = 6.26, P < 0.05). Moreover, LIS in T/HS + RL group, T/HS + albumin group was 2.62 ± 0.23, 1.25 ± 0.24, respectively. The expressions of CD11b/CD18, ICAM-1 and MPO in T/HS + RL group were significantly increased compared to T/SS group (P = 0.025, P = 0.036, P = 0.028, respectively). However, administration of 3 mL of 50 g/L albumin significantly down-regulated the expressions of CD11b/CD18, ICAM-1 and lung injury index (MPO and LIS) when compared with the T/HS + RL rats (P = 0.035, P = 0.046, P = 0.038, P = 0.012, respectively).

CONCLUSION: The infusion of albumin during resuscitation period can protect lung from injury and decrease the expressions of CD11b/CD18, ICAM-1 in T/HS rats.

Albumin administration improves organ function in critically ill hypoalbuminemic patients: A prospective, randomized, controlled, pilot study

OBJECTIVE

To test the hypothesis that administration of albumin to correct hypoalbuminemia might have beneficial effects on organ function in a mixed population of critically ill patients.

DESIGN

: Prospective, controlled, randomized study.

SETTING

Thirty-one-bed, mixed medicosurgical department of intensive care.

PATIENTS

All adult patients with a serum albumin concentration < or =30 g/L were assessed for eligibility. Principal exclusion criteria were expected length of stay <72 hrs, life expectancy <3 months or a do-not-resuscitate order, albumin administration in the preceding 24 hrs, or evidence of fluid overload.

INTERVENTIONS

The 100 patients were randomized to receive 300 mL of 20% albumin solution on the first day, then 200 mL/day provided their serum albumin concentration was <31 g/dL (albumin group), or to receive no albumin (control group).

MEASUREMENTS AND MAIN RESULTS

The primary outcome was the effect of albumin administration on organ function as assessed by a delta Sequential Organ Failure Assessment score from day 1 to day 7 (or the day of intensive care discharge or death, whichever came first). The two groups of 50 patients were comparable at baseline for age, gender, albumin concentration, and Acute Physiology and Chronic Health Evaluation II score. Albumin concentration did not change over time in the control group but increased consistently in the albumin group (p < .001). Organ function improved more in the albumin than in the control group (p = .026), mainly due to a difference in respiratory, cardiovascular, and central nervous system components of the Sequential Organ Failure Assessment score. Diuretic use was identical in both groups, but mean fluid gain was almost three times higher in the control group (1679 +/- 1156 vs. 658 +/- 1101 mL, p = .04). Median daily calorie intake was higher in the albumin than in the control group (1122 [935-1158] vs. 760 [571-1077] kcal, p = .05).

CONCLUSIONS

Albumin administration may improve organ function in hypoalbuminemic critically ill patients. It results in a less positive fluid balance and a better tolerance to enteral feeding.

Endotoxin-induced heart dysfunction in rats: assessment of myocardial perfusion and permeability and the role of fluid resuscitation

OBJECTIVE

The pathophysiology of sepsis-induced myocardial dysfunction is still controversial. Whether microcirculatory hypoperfusion together with capillary leakage can occur in the heart wall also remains a matter of debate. The objective was to evaluate the impact of fluid resuscitation on endotoxin-induced myocardial dysfunction.

DESIGN

Adult rats were given intraperitoneal injection of endotoxin (lipopolysaccharide, Escherichia coli, 10 mg/kg) or phosphate-buffered solution, followed up by echocardiography and acetate micro-positron emission tomography scan imaging, together with final hemodynamic, biochemical, and pathologic evaluations up to 48 hrs.

SETTING

University laboratory.

SUBJECTS

Pathogen-free male Wistar rats (350 g).

INTERVENTIONS

Influence of isovolumic fluid infusion type (saline vs. pentastarch) on these variables was assessed in 11 groups of six animals including an unchallenged control one.

MEASUREMENTS AND MAIN RESULTS

Endotoxin injection induced a) myocardial dysfunction (decrease of approximately 15-20% in left ventricular ejection fraction); b) ventricular enlargement (approximately 1.5- to 1.7-fold increase in left ventricular systolic volume); c) cardiac output increase (10-15%); d) myocardial hypoperfusion ( approximately 1.5- to 2-fold decrease in acetate k1 constant rate); e) increased oxygen consumption (k2); and f) interstitial wall increase. Endotoxin injection also enhanced levels of arterial lactates and troponin I. Colloid (pentastarch) over crystalloid (saline) fluid resuscitation significantly reversed echocardiographic changes, some positron emission tomography imaging alterations, and lactate and troponin I levels without further enhancing interstitial spaces.

CONCLUSION

Endotoxin can induce reversible myocardial alterations with evidence of coronary hypoperfusion and heart wall enlargement/damage, some of which can be prevented by fluid resuscitation. The use of crystalloids is less beneficial than pentastarch.

Microvascular effects following treatment with polyethylene glycol-albumin in lipopolysaccharide-induced endotoxemia

OBJECTIVE

To determine whether resuscitation with polyethylene glycol conjugated bovine serum albumin (2.5% weight/volume) infused at 16 mL/kg/hr (PEG-BSA-16) or at 24 mL/kg/hr (PEG-BSA-24) for 1 hr improves microcirculatory conditions in endotoxemia compared with dextran 70 (6% weight/volume) infused at 24 mL/kg/hr (Dex).

DESIGN

Prospective study.

SETTING

University research laboratory.

SUBJECTS

Male Golden Syrian hamsters.

INTERVENTIONS

Hamsters implemented with a skinfold window chamber were given an intravenous injection of lipopolysaccharide and resuscitated within 10 mins with Dex, PEG-BSA-16, or PEG-BSA-24.

MEASUREMENTS AND MAIN RESULTS

Hamsters were observed during 24 hrs after lipopolysaccharide injection. Systemic variables measured included mean arterial pressure, heart rate, and systemic arterial blood gas. Microvascular function was characterized by measuring vessel diameter; red blood cell velocity; functional capillary density (FCD); P(O2) in arterioles, venules, and tissue; and perivascular nitric oxide concentration 6 hrs after lipopolysaccharide injection. At 6 hrs, animals with no treatment had the lowest FCD (6.7 +/- 5.7% of baseline). PEG-BSA provided significantly improved microvascular conditions as shown by restoration of FCD. Recovery of FCD was related to improved microvascular flow and perivascular and tissue P(O2), normalization of shear rate, and decreased perivascular nitric oxide concentration. These effects were related to improved fluid retention using PEG-BSA-24 as evidenced by the significantly lower hematocrit at 24 hrs after resuscitation. Nitric oxide at 6 hrs after induction of sepsis achieved perivascular millimolar concentrations, which were reduced to normal values by PEG-BSA-24 treatment. At 6 hrs there were significant differences in FCD, tissue P(O2), and perivascular nitric oxide concentration following PEG-BSA treatment by comparison with Dex treatment, although there were no differences in systemic variables between Dex and PEG-BSA groups.

CONCLUSIONS

PEG-BSA produces improved microcirculatory conditions in the treatment of endotoxemia when compared with dextran 70.

Microvascular resuscitation as a therapeutic goal in severe sepsis

Sepsis causes microvascular dysfunction. Increased heterogeneity of capillary blood flow results in local tissue hypoxia, which can cause local tissue inflammation, impaired oxygen extraction, and, ultimately, organ dysfunction. Microvascular dysfunction is clinically relevant because it is a marker for mortality: it improves rapidly in survivors of sepsis but fails to improve in nonsurvivors. This, along with the fact that resuscitation of mean arterial pressure and cardiac output alone fails to improve microvascular function, means that microvascular resuscitation is therefore a therapeutic goal. In animal studies of sepsis, volume resuscitation improves microvascular permeability and tissue oxygenation, and leads to improved organ function, including a reduction in myocardial dysfunction. Microvascular resuscitation strategies include hemodynamic resuscitation using the linked combination of volume resuscitation, judicious vasopressor use, and inotropes and vasodilators. Alternative vasoactive agents, such as vasopressin, may improve microcirculatory function to a greater degree than conventional vasopressors. Successful modulation of inflammation has a positive impact on endothelial function. Finally, targeted treatment of the endothelium, using activated protein C, also improves microvascular function and ultimately increases survival. Thus, attention must be paid to the microcirculation in patients with sepsis, and therapeutic strategies should be employed to resuscitate the microcirculation in order to avoid organ dysfunction and to reduce mortality.