Search Results (25)

Background: Human serum albumin (HSA), the most abundant plasma protein, is essential for oncotic pressure, endothelial protection, drug binding, and immune modulation. Despite its widespread clinical use since the 1940s, its therapeutic benefit in critically ill patients remains debated. This narrative review summarizes current evidence on HSA use in common intensive care scenarios. Clinical Applications: In hepatorenal syndrome (HRS), albumin combined with vasoconstrictors like terlipressin improves renal function and survival. In spontaneous bacterial peritonitis (SBP), albumin lowers the risk of acute kidney injury and mortality, particularly in high-risk cirrhotic patients. Post-paracentesis albumin reduces circulatory dysfunction and may enhance survival in cirrhosis. For septic shock, trials show no overall mortality benefit over crystalloids, though albumin may offer hemodynamic advantages in specific subgroups. In acute respiratory distress syndrome (ARDS), albumin improves oxygenation in hypoalbuminemic patients, without survival benefits. During major cardiac or abdominal surgery, albumin reduces fluid needs and postoperative complications, especially in hypoalbuminemic individuals. In acute brain injury, albumin’s role is controversial: it may aid recovery after cerebral hemorrhage, but can worsen outcomes in traumatic brain injury. In trauma and ECMO patients, albumin may stabilize hemodynamics and improve outcomes in selected cases. Conclusions: Inappropriate albumin use remains common, and evidence on its optimal concentration, dose, timing, and patient selection is limited. HSA is safe and beneficial in specific situations. Routine use should follow evidence-based guidelines. Future research must identify patients who are most likely to benefit and clarify optimal dosing strategies, concentrations, and therapeutic goals. Full article

Purpose: This review consolidates current evidence on how chronic kidney disease (CKD)-especially end-stage kidney disease (ESKD) and its treatments-alters choroidal and retinal vascular permeability, leading to changes in intraocular fluid homeostasis. Methods: A literature search of Medical Literature Analysis and Retrieval System Online (MEDLINE), reference lists, and key ophthalmology-nephrology texts was performed for studies published between 1980 and 2025. One-hundred-forty-four articles (clinical trials, observational cohorts, and case reports) met the inclusion criteria. Data were abstracted on choroidal thickness changes, blood-retinal barrier integrity, incidence of Central Serous Chororioretinopathy (CSCR) and Serous Retinal Detachment (SRD) in dialysis and transplant populations, and systemic variables such as oncotic pressure, hypertension, and corticosteroid exposure, with special attention to retinal pigment epithelium (RPE) pump function. Findings were synthesized qualitatively and tabulated where appropriate. Results: ESKD induces a triad of lowered plasma oncotic pressure, fluctuating hydrostatic forces, and impaired RPE pump function that collectively drive subretinal fluid accumulation. Hemodialysis acutely reduces sub-foveal choroidal thickness by a mean of ≈15–25 µm yet shows inconsistent effects on retinal thickness. Large population data demonstrate a three- to four-fold higher SRD risk and ~1.5-fold higher CSCR risk in dialysis patients versus controls, with peritoneal dialysis conferring the greatest hazard. After kidney transplantation, CSCR prevalence approaches 6%, driven by combined stresses of surgery, hypertension, and long-term corticosteroid or calcineurin-inhibitor therapy. Most reported SRDs resolve as systemic parameters normalize, underscoring the importance of promptly identifying systemic drivers. Conclusions: Systemic fluid-pressure imbalances and treatment-related factors in CKD significantly perturb the outer blood-retinal barrier. Regular ophthalmic surveillance, early visual-symptom screening (e.g., Amsler grid), and close nephrologist-ophthalmologist collaboration are essential for timely detection and management. Future research should quantify the relative contribution of hypoalbuminemia, hypertension, and immunosuppression to ocular permeability changes, and evaluate preventive strategies tailored to high-risk CKD subgroups. Full article

Basic physiology and molecular mechanisms accounting for the maldistribution of fluid that is characteristic of the “third fluid space” (V_t2) have been known for several decades but have been poorly integrated into the clinical literature. Today, the maldistribution can be quantified and simulated in living humans by using volume kinetic mathematics, which introduces possibilities to validate interventions designed to mitigate the pathophysiology. Fluid accumulation in V_t2 occurs both in fluid overload and inflammation, and both are largely influenced by interstitial fluid pressure. This is normally slightly sub-atmospheric but increases during volume loading to eventually exceed the ambient air pressure, whereby the loss of vacuum allows pools of fluid to appear in the interstitial gel. Opening of V_t2 due to fluid overload can be delayed/minimized by lowering the infusion rate, hemorrhage, and the use of hyper-oncotic fluid. Accumulation of fluid in V_t2 during acute inflammation and tissue injury can be explained by disruption of the cell–matrix interactions that actively regulate the interstitial pressure. Inflammatory mediators, mostly tissue cytokines, cause release of tensile forces that disrupt integrin-dependent adhesion between interstitial fibroblasts and collagen fibers. This disruption causes the interstitial space to expand, which results in a deep negative (suction) pressure. These events can be modulated by α-trinositol and insulin. Full article

Background/Objectives: Idiopathic edema (IE) in women is characterized by swelling of hands and face followed by increasing abdominal and truncal girth, bloating, edema, >1.4 kg weight gain when in upright posture, and nocturia that eliminates the retained fluid. A capillary leak is the primary pathophysiologic abnormality that induces different clinical presentations that were considered untreatable. Methods: We utilized different aspects of Starling forces of edema formation and treated four uncomplicated cases of IE by reducing salt intake with or without diuretics and two cases of life-threatening cases due to seizures and coma induced by acute hyponatremia in one and postural dizziness, fainting, and fractures and dislocations of joints in another. Results: All four uncomplicated cases of IE were treated by reducing salt intake with or without diuretics that eliminated the weight gain and nocturia. The patient with hyponatremia never developed hyponatremia by reducing water intake and signs and symptoms of IE by salt restriction and diuretic therapy and eliminated the postural hypotension, falls, and fainting by use of support hose that increased interstitial hydrostatic pressure to eliminate fluid shifting from intravascular to interstitial spaces. Conclusions: A leaky capillary induces pathophysiologic changes that activate different metabolic pathways. IE is now a treatable condition, following: 1. Salt restriction with or without diuretics for the cyclical weight gain, and 2. Water restriction for hyponatremia, hyponatremic seizures, and coma and 3. support hose for postural hypotension, postural dizziness, and fainting. IE is unrecognized and probably more common than it is perceived. Full article

Albumin is the most abundant protein synthesized exclusively by the hepatocytes in the liver. Once secreted into plasma, it helps in the maintenance of osmotic pressure, as well as the exertion of defensive roles such as anti-oxidative and anti-inflammatory functions. Dysregulation in the synthesis and clearance of albumin is observed in various hepatic and extra-hepatic diseases. Abnormal levels of albumin could be either a cause or an effect of various pathological ailments, including hepatic, cardiac, renal, neurological, etc. Owing to its long half-life and multiple binding sites in its heart-shaped structure, it interacts with various internal agents, such as hormones, or external substances like drugs, which is why transportation can be one of its many functions. Additionally, albumin’s drug interactions, as well as displacement of albumin–drug binding, could have serious clinical consequences, and careful considerations should be made in determining an appropriate drug regimen to achieve a desired therapeutic outcome with minimal side effects. Moreover, albumin also undergoes several post-translational modifications that can influence its physiological roles, including drug binding and antioxidant functions. Furthermore, it has a complicated role in physiology, where it can help in maintaining plasma oncotic pressure and prevent endothelial cell apoptosis but can have adverse effects on the lungs and kidneys. These adverse effects are mainly attributed to ER stress and inflammasome activation. This narrative review provides an overview of the general biology of albumin and its effects in physiology, with a focus on its beneficial and adverse effects and the underlying molecular mechanisms. Full article

Low-frequency oscillations of blood components have been observed when the plasma is diluted by crystalloid fluid. The present study explores whether oscillations also occur during the infusion of hyper-oncotic albumin 20%. For this purpose, the hemoglobin-derived plasma dilution, plasma colloid osmotic pressure, and plasma albumin concentration were measured on 15 occasions over 5 h in 72 volunteers. All of them received 3 mL/kg of albumin 20% over 30 min in various clinical settings. Quality checks excluded 35% of the concentration–time curves, leaving 137 for analysis. Fourier transforms applied to the residuals after curve-fitting showed that the dominating frequency was 144 ± 42 min (mean ± SD), corresponding to 0.007 Hz and a wave amplitude of 1.8 ± 0.9%. The highest percentile of the amplitudes corresponded to a “peak-to-peak” variation in the plasma volume by 6%, which corresponds to a fluctuation of 180 mL, or 45% of the maximum volume expansion following the infusion of albumin 20%. Differences between settings (volunteers, surgery, postoperative, and post-burn) were small. In conclusion, oscillations with very low frequency occurred after infusion of albumin 20%. They varied the plasma volume by 3.6% and by up to 6% in the percentile with the highest amplitudes. The oscillations are large enough to affect measurements of cardiovascular function. Full article

Background/Objectives: Cardiopulmonary bypass can lead to hemodilution, causing a fluid shift to the interstitial space. Albumin helps counteract the intravascular fluid movement to the extravascular space and reduces the risk of complications associated with fluid imbalance. Our main objective was to evaluate the effectiveness of albumin addition in the cardiopulmonary bypass priming solution compared to standard priming, focusing on its role in reducing pleural effusion development. Methods: This was a single-center randomized controlled trial conducted at a tertiary care hospital specializing in cardiology and cardiac surgery. It involved 70 individuals scheduled for elective open-heart surgery. All cases were randomly assigned into two groups of 35 patients. The study group replaced 100 mL of standard CPB priming solution with 100 mL of 20% human albumin. We measured serum albumin levels before and after the surgery, 6 and 12 h after, and calculated colloid oncotic pressure. Thorax CT scans were performed on the first postoperative day to measure and calculate pleural effusion volume. Results: Albumin addition to cardiopulmonary bypass priming solution led to a significant reduction in pleural effusion development after CPB. An albumin level <35 g/L after the surgery showed a significant increase in pleural effusion development, and 100 mL of 20% albumin was sufficient to maintain serum albumin levels > 35 g/L. Conclusions: Our study suggests a link between postoperative hypoalbuminemia and the early development of pleural effusion after CPB, as well as the possible benefits of adding 100 mL of 20% albumin compared to standard crystalloid CPB priming to minimize postoperative pleural effusion development. Full article

Background: Lung transplantation is the most effective treatment for end-stage respiratory diseases, but its application is limited by the shortage of organs. Ex vivo lung perfusion (EVLP) has emerged as a promising technique to evaluate and recondition donor lungs previously deemed unsuitable for transplantation. However, limitations such as lung contusions, air leaks, and perfusate extravasation, especially in portable EVLP systems, hinder the procedure. Despite prolonged perfusions that can result in blood pooling at the lung bases due to fixed lung positioning and diminished oncotic pressure, in some cases, extending perfusion time beyond the typical 5–6 h could benefit extended-criteria lungs, addressing factors such as edema or logistical complications. Methods: We present an innovative protocol involving prolonged EVLP, pronation of the graft, and the addition of anti-edematous drugs to the perfusate. Results: This novel approach, previously tested in animal models, enhances lung reconditioning and expands the donor pool. Conclusions: Our findings suggest that this strategy overcomes key limitations of standard EVLP, offering a valuable solution for improving the availability of transplantable lungs. Full article

Serum albumin (ALB), one of the most important proteins in human physiology, has the main functions of maintaining plasma oncotic pressure and plasma volume, transporting hormones, vitamins, oligominerals and drugs, and exerting a powerful antioxidant-anti-inflammatory role. Its prognostic value in liver and malabsorption syndromes is well known. In this narrative review, an analysis of the most important studies evaluating the prognostic significance of low serum ALB levels in hospitalized patients was performed. Specifically, the risk in emergency medicine, cardiovascular diseases, Coronavirus Disease 19 (COVID-19) infection, nephrology, oncology, and autoimmune rheumatic diseases has been examined to fully explore its clinical value. ALB is a negative acute-phase reactant and the reduction in its serum levels represents a threatening parameter for long-term survival in several clinical settings, and a strong biomarker for a poor prognosis in most diseases. Therefore, clinicians should consider serum ALB as a valuable tool to assess the efficacy of specific therapies, both in hospitalized patients and in chronic follow-up. Full article

The main factors in the COVID-19 pathology, which can initiate extensive structural changes at the cellular and molecular levels, are the generation of free radicals in abnormal amounts, and oxidative stress. Under “oxidative shock” conditions, the proteins undergo various modifications that affect their function and activity, and as a result distribute malfunctioning protein derivatives in the body. Human serum albumin is a small globular protein characterized by a high overall binding capacity for neutral lipophilic and acidic dosage forms. The albumin concentration is crucial for the maintenance of plasma oncotic pressure, the transport of nutrients, amino acids, and drugs, the effectiveness of drug therapy, and the prevention of drug toxicity. Hypoalbuminemia and structural defects molecule in the protein suggest a risk of changed metabolism and increased plasma concentration of unbound drugs. Therefore, the albumin structural and functional changes accompanied by low protein levels can be a serious prerequisite for ineffective therapy, frequent complications, and high mortality in patients with SARS-CoV-2 infection. The current opinion aims the research community the application of Site-Directed Spin Labeling Electron Paramagnetic Resonance spectroscopy (SDSL-EPR) and 3-Maleimido-PROXYL radical in determining abnormalities of the albumin dynamics and protein concentrations in COVID-19 critical patients. Full article

Albumin is a natural biomaterial that is abundantly available in blood and body fluids. It is clinically used as a plasma expander, thereby increasing the plasma thiol concentration due to its cysteine residues. Albumin is a regulator of intervascular oncotic pressure, serves as an anti-inflammatory modulator, and it has a buffering role due to its histidine imidazole residues. Because of its unique biological and physical properties, albumin has also emerged as a suitable biomaterial for coating implantable devices, for cell and drug delivery, and as a scaffold for tissue engineering and regenerative medicine. As a biomaterial, albumin can be used as surface-modifying film or processed either as cross-linked protein gels or as electrospun fibers. Herein we have discussed how albumin protein can be utilized in regenerative medicine as a hydrogel and as a fibrous mat for a diverse role in successfully delivering drugs, genes, and cells to targeted tissues and organs. The review of prior studies indicated that albumin is a tunable biomaterial from which different types of scaffolds with mechanical properties adjustable for various biomedical applications can be fabricated. Based on the progress made to date, we concluded that albumin-based device coatings, delivery of drugs, genes, and cells are promising strategies in regenerative and personalized medicine. Full article

A significant proportion of patients with a severe traumatic brain injury (TBI) have hypoalbuminemia and require fluid resuscitation. Intravenous fluids can have both favorable and unfavorable consequences because of the risk of hyperhydration and hypo- or hyperosmolar conditions, which may affect the outcome of a TBI. Fluid resuscitation with human albumin solution (HAS) corrects low serum albumin levels and aids in preserving euvolemia in non-brain-injured intensive care units and in perioperative patients. However, the use of HAS for TBI remains controversial. In patients with TBI, the infusion of hypooncotic (4%) HAS was associated with adverse outcomes. The side effects of 4% HAS and the safety and efficacy of hyperoncotic (20–25%) HAS used in the Lund concept of TBI treatment need further investigation. A nonsystematic review, including a meta-analysis of controlled clinical trials, was performed to evaluate hyperoncotic HAS in TBI treatment. For the meta-analysis, the MEDLINE and EMBASE Library databases, as well as journal contents and reference lists, were searched for pertinent articles up to March 2021. Four controlled clinical studies involving 320 patients were included. The first was a randomized trial. Among 165 patients treated with hyperoncotic HAS, according to the Lund concept, 24 (14.5%) died vs. 59 out of 155 control patients (38.1%). A Lund concept intervention using hyperoncotic HAS was associated with a significantly reduced mortality (p = 0.002). Evidence of the beneficial effects of fluid management with hyperoncotic HAS on mortality in patients with TBI is at a high risk of bias. Prospective randomized controlled trials are required, which could lead to changes in clinical practice recommendations for fluid management in patients with TBI. Full article

Vascular permeability is a selective mechanism that maintains the exchange between vessels, tissues, and organs. The regulation was mostly studied during the nineteenth century by physiologists who defined physical laws and equations, taking blood, tissue interstitial, and oncotic pressure into account. During the last decades, a better knowledge of vascular cell functions and blood-vessel interactions opens a new area of vascular biology. Endothelial cell receptors vascular cell adhesion molecule (VCAM), intercellular cell adhesion molecule (ICAM), vascular endothelial growth factor receptor (VEGFR-2), receptor for advanced glycation end products (RAGE), and mediators were identified and their role in homeostasis and pathological situations was described. The molecular differences of endothelial cell junctions (tight, gap, and adherens junctions) and their role in vascular permeability were characterized in different organs. The main mediators of vasomotricity and permeability, such as prostaglandins, nitric oxide (NO), prostacyclin, vascular growth factor (VEGF), and cytokines, have been demonstrated to possess major functions in steady state and pathological situations. Leukocytes were shown to adhere to endothelium and migrate during inflammatory situations and infectious diseases. Increased vascular permeability is linked to endothelium integrity. Glycocalyx, when intact, may limit cancer cell metastasis. Biological modifications of blood and tissue constituents occurring in diabetes mellitus were responsible for increased permeability and, consequently, ocular and renal complications. Vascular pressure and fluidity are major determinants of pulmonary and cerebral edema. Beside the treatment of the infectious disease, of the blood circulation dysfunction and inflammatory condition, drugs (cyclooxygenase inhibitors) and specific antibodies anti-cytokine (anti-VEGF) have been demonstrated to reduce the severity and the mortality in diseases that exhibited enhanced vascular permeability. Full article

Reliable mathematical models are important tools for design/optimization of haemo-filtration modules. For a specific module, such a model requires knowledge of fluid- mechanical and mass transfer parameters, which have to be determined through experimental data representative of the usual countercurrent operation. Attempting to determine all these parameters, through measured/external flow-rates and pressures, combined with the inherent inaccuracies of pressure measurements, creates an ill-posed problem (as recently shown). The novel systematic methodology followed herein, demonstrated for Newtonian fluids, involves specially designed experiments, allowing first the independent reliable determination of fluid-mechanical parameters. In this paper, the method is further developed, to determine the complete mass transfer module-characteristics; i.e., the mass transfer problem is modelled/solved, employing the already fully-described flow field. Furthermore, the model is validated using new/detailed experimental data on concentration profiles of a typical solute (urea) in counter-current flow. A single intrinsic-parameter value (i.e., the unknown effective solute-diffusivity in the membrane) satisfactorily fits all data. Significant insights are also obtained regarding the relative contributions of convective and diffusive mass-transfer. This study completes the method for reliable module simulation in Newtonian-liquid flow and provides the basis for extension to plasma/blood haemofiltration, where account should be also taken of oncotic-pressure and membrane-fouling effects. Full article