The albumin controversy

Associations of Preoperative Nutritional Status and Sarcopenia With Mortality in Patients With Abdominal Aortic Aneurysm After Open and Endovascular Abdominal Aortic Aneurysm Repair: A Retrospective Study

OBJECTIVE

The effect of preoperative malnutrition and sarcopenia on outcomes in patients with abdominal aortic aneurysm (AAA) after open surgical repair (OSR) and endovascular abdominal aortic aneurysm repair is undefined. The authors conducted the study to address this issue in this population.

DESIGN

A retrospective observational study.

SETTING

A large tertiary hospital.

PARTICIPANTS

Patients with AAA who underwent OSR and endovascular aneurysm repair (EVAR).

INTERVENTIONS

Evaluation of nutritional status (Nutritional Risk Screening 2002 [NRS 2002] and the Controlling Nutritional Status [CONUT] scores), muscle size (skeletal muscle index), and postoperative parameters.

MEASUREMENTS AND MAIN RESULTS

A total of 199 patients were reviewed from January 2020 to December 2022. Patients weew categorized into group A (CONUT <4) and group B (CONUT ≥4) based on whether their CONUT scores were less than 4. The mortality (p = 0.004) and the incidence of Clavien-Dindo class III complications (p = 0.007) in group B were higher than those in group A. CONUT score was an independent risk factor for midterm mortality (hazard ratio 1.329; 95% CI, 1.104-1.697; p = 0.002) and Clavien-Dindo class III complications (odds ratio 1.225; 95% CI, 1.012-1.482; p = 0.037) according to univariate and multivariate analyses, whereas NRS 2002 score and sarcopenia were not. Kaplan-Meier curves showed a lower midterm survival rate in group B (log-rank p < 0.001).

CONCLUSION

In patients with AAA undergoing OSR or EVAR, a CONUT score ≥4 was associated with increased Clavien-Dindo class III complications and mortality. Preoperative nutritional status should be evaluated and optimized in this high-risk population.

Fluid Homeostasis and Diuretic Therapy in the Neonate

Understanding physiologic water balance and homeostasis mechanisms in the neonate is critical for clinicians in the NICU as pathologic fluid accumulation increases the risk for morbidity and mortality. In addition, once this process occurs, treatment is limited. In this review, we will cover fluid homeostasis in the neonate, explain the implications of prematurity on this process, discuss the complexity of fluid accumulation and the development of fluid overload, identify mitigation strategies, and review treatment options.

Management of Acute Kidney Injury in Extremely Low Birth Weight Infants

Acute kidney injury (AKI) is a common problem in the neonatal intensive care unit (NICU). Neonates born at <1,000 g (extremely low birth weight, ELBW) are at an increased risk of secondary associated comorbidities such as intrauterine growth restriction, prematurity, volume restriction, ischaemic injury, among others. Studies estimate up to 50% ELBW infants experience at least one episode of AKI during their NICU stay. Although no curative treatment for AKI currently exists, recognition is vital to reduce potential ongoing injury and mitigate long-term consequences of AKI. However, the definition of AKI is imperfect in this population and presents clinical challenges to correct identification, thus contributing to under recognition and reporting. Additionally, the absence of guidelines for the management of AKI in ELBW infants has led to variations in practice. This review summarizes AKI in the ELBW infant and includes suggestions such as close observation of daily fluid balance, review of medications to reduce nephrotoxic exposure, management of electrolytes, maximizing nutrition, and the use of diuretics and/or dialysis when appropriate.

The autophagy marker LC3 strongly predicts immediate mortality after surgical resection for hepatocellular carcinoma

The remnant liver's ability to regenerate may affect post-hepatectomy immediate mortality. The promotion of autophagy post-hepatectomy could enhance liver regeneration and reduce mortality. This study aimed to identify predictive factors of immediate mortality after surgical resection for hepatocellular carcinoma (HCC). A total of 535 consecutive HCC patients who had undergone their first surgical resection in Taiwan were enrolled between 2010 and 2014. Clinicopathological data and immediate mortality, defined as all cause-mortality within three months after surgery, were analyzed. The expression of autophagy proteins (LC3, Beclin-1, and p62) in adjacent non-tumor tissues was scored by immunohistochemical staining. Approximately 5% of patients had immediate mortality after surgery. The absence of LC3, hypoalbuminemia (<3.5 g/dl), high alanine aminotransferase, and major liver surgery were significantly associated with immediate mortality in univariate analyses. Multivariate logistic regression demonstrated that absence of LC3 (hazard ratio/95% confidence interval: 40.8/5.14-325) and hypoalbuminemia (2.88/1.11-7.52) were significantly associated with immediate mortality. The 3-month cumulative incidence of mortality was 12.1%, 13.0%, 21.4% and 0.4%, respectively, among patients with absence of LC3 expression, hypoalbuminemia, both, or neither of the two. In conclusion, the absence of LC3 expression in adjacent non-tumor tissues and hypoalbuminemia were strongly predictive of immediate mortality after resection for HCC.

Hypoalbuminemia is a predictor of mortality and rebleeding in peptic ulcer bleeding under proton pump inhibitor use

BACKGROUND/PURPOSE

Peptic ulcer bleeding remains a deadly disease, and a simple indicator of long-term outcomes is crucial. This study validated whether hypoalbuminemia and its related factors in patients with peptic ulcer bleeding can indicate long-term mortality and rebleeding under proton pump inhibitor use.

METHODS

The prospective cohort study enrolled 426 patients with peptic ulcer bleeding who had high risk stigmata at endoscopy and had received endoscopic hemostasis. They were divided into 79 patients in the hypoalbuminemia group (Hypo-AG, serum albumin <28 g/L), 135 in the marginal hypoalbuminemia group (Margin-AG, serum albumin 28-34.9 g/L), and 212 in the normal albuminemia group (Normal-AG, serum albumin ≥35 g/L). Each subject received 72-h of intravenous infusion and then the oral form of proton pump inhibitors and were monitored for 84 days to assess all-cause mortality and recurrent bleeding.

RESULTS

The primary outcome of all-cause mortality rates were increased in a stepwise fashion in a trend from Normal-AG, Margin-AG, to Hypo-AG (0-28th day: 1.9%, 2.2%, 12.8%, p < 0.001; 29th-84th day: 2.5%, 8.0%, 10.6%, p < 0.01). The secondary outcome of recurrent bleeding rates were also increased in the same fashion (0-28th day: 6.4%, 15.4%, 24.6%, p < 0.001; 29th-84th day: 0%, 3.0%, 4.2%, p = 0.01). Abnormal albuminemia was <30 g/L related to hemoglobin levels <70 g/L, nosocomial bleeding, cirrhosis, age ≥70 years, shock, and ulcer size ≥1.0 cm independently (p < 0.05).

CONCLUSION

Hypoalbuminemia in patients with peptic ulcer bleeding can be an alarm indicator of all-cause mortality and recurrent bleeding in a long-term follow-up situation under proton pump inhibitor use (NCT01591083).

Impacts of albumin synergized with hydroxyethyl starch on early microvascular albumin leakage after major abdominal surgery in rabbits

PURPOSE

To investigate the impacts of albumin synergized with hydroxyethyl starch (HES) on early microvascular albumin leakage after major abdominal surgery in rabbits.

METHODS

Forty male Japanese rabbits were randomly divided into four groups: the control group, the saline group, the albumin group, and the Syn group (hydroxyethyl starch+albumin). The latter three groups were performed gastrectomy plus resection of pancreatic body and tail and splenectomy. The serum albumin concentration was detected before and 48h after surgery, and the conditions of mesenteric microvascular leakage in these 4 groups were observed under microscope 48 h after surgery to calculate the leakage rate.

RESULTS

Compared with the saline group, the albumin group and the Syn group exhibited significantly increased serum albumin concentrations 48h after surgery (P<0.05). The albumin leakage rate was the most obvious in the albumin group, followed by the saline group, while that in the Syn group was the minimal, and there existed significant differences among these groups (P<0.05) .

CONCLUSION

Simple administration of albumin in the early stage after major abdominal surgery could increase the albumin leakage, while the synergization of albumin and hydroxyethyl starch could reduce the albumin leakage.

Bilirubin-Induced Neurotoxicity in the Preterm Neonate

Bilirubin-induced neurotoxicity in preterm neonates remains a clinical concern. Multiple cellular and molecular cascades likely underlie bilirubin-induced neuronal injury, including plasma membrane perturbations, excitotoxicity, neuroinflammation, oxidative stress, and cell cycle arrest. Preterm newborns are particularly vulnerable secondary to central nervous system immaturity and concurrent adverse clinical conditions that may potentiate bilirubin toxicity. Acute bilirubin encephalopathy in preterm neonates may be subtle and manifest primarily as recurrent symptomatic apneic events. Low-bilirubin kernicterus continues to be reported in preterm neonates, and although multifactorial in nature, is often associated with marked hypoalbuminemia.

The Role of Ischemia Modified Albumin as a Biomarker in Patients with Chronic Liver Disease

INTRODUCTION

Chronic Liver Disease (CLD) is characterised by gradual destruction of liver tissue over time. Ischemia Modified Albumin (IMA) is an upcoming biomarker shown to be elevated in conditions associated with ischemia and oxidative stress. Albumin levels are greatly reduced in patients with CLD and studying its alterations will provide essential information regarding the molecular changes occurring to it.

AIM

The study aims to estimate IMA and IMA/Albumin ratio in patients with CLD and to correlate it with parameters assessing liver function and the Model for End Stage Liver Disease (MELD) score.

MATERIALS AND METHODS

The study consisted of 43 CLD patients as test subjects and 28 apparently healthy individuals as controls. Multiple parameters assessing liver function like albumin, bilirubin, aspartate transaminase (AST), alanine transaminase (ALT), Gamma Glutamyl Transpeptidase (GGT), alkaline phosphatase (ALP), Prothrombin Time (PT) INR and creatinine were estimated and the MELD score calculated. Serum IMA expressed as Absorbance Units (ABSU) was estimated using the Albumin Cobalt Binding test (ABT). Student's t-test and correlation coefficient was used for statistical analysis.

RESULTS

Serum IMA was significantly higher in CLD patients (0.5320 ± 0.1677) as compared to the control group (0.3203 ± 0.1257) with a p-value of <0.0001. The IMA/Albumin ratio was also significantly higher (0.2035 ± 0.0970) in patients with CLD compared to control group (0.0714 ± 0.0283) with a p-value of <0.0001. IMA has a negative correlation with albumin. The IMA/Albumin ratio shows positive correlation with MELD score, bilirubin and ALP. There was no correlation with ALT, AST, GGT and PT INR.

CONCLUSION

Decreased serum albumin correlates with increase in IMA in CLD could indicate a qualitative change and not merely a quantitative reduction of albumin. IMA can serve as a biomarker to assess the disease severity and prognosis of CLD patients.

Albumin synthesis in very low birth weight infants is enhanced by early parenteral lipid and high-dose amino acid administration

BACKGROUND & AIMS

Albumin is one of the most important plasma proteins and plays a key role in many physiologic processes, such as preserving colloid osmotic pressure, scavenging radicals, and binding and transporting bilirubin, hormones, and drugs. However, albumin concentrations are often low in preterm infants during the first days of life. We hypothesized that early parenteral lipid and high-dose amino acid (AA) administration to very low birth weight (VLBW) infants from birth onwards increases hepatic albumin synthesis rates.

METHODS

Inborn VLBW infants were randomized to receive from birth onwards either 2.4 g amino acids/(kg(·)d) (control group), 2.4 g amino acids/(kg(·)d) plus 2 g lipids/(kg(·)d) (AA + lipid group), or 3.6 g amino acids/(kg(·)d) plus 2 g lipids/(kg(·)d) (high AA + lipid group). On postnatal day 2, infants received a primed continuous infusion of [U-(13)C6,(15)N]leucine. Mass spectrometry was used to determine the fractional and absolute albumin synthesis rates (FSR and ASR, respectively).

RESULTS

In total, 28 infants (median gestational age 27 weeks (IQR 25-28), median birth weight 810 g (IQR 679-998) were studied. The median FSR was 6.5%/d in the control group, 10.6%/d in the AA group, and 12.3%/d in the high AA + lipid group, while the median was 84 mg/(kg(·)d) in the control group, 138 mg/(kg(·)d) in the AA group, and 160 mg/(kg(·)d) in the high AA + lipid group.

CONCLUSION

A group of VLBW infants given parenteral nutrition containing lipids and high-dose amino acids showed a higher rate of albumin synthesis compared to infants receiving no lipids and standard amounts of amino acids during the first two days of life.

Temporal changes in blood product usage in preterm neonates born at less than 30 weeks' gestation in Canada

BACKGROUND

Knowledge of neonatal transfusion practices remains limited to local cohorts or survey-based studies. This study evaluated the pattern and temporal changes in the types and frequency of blood product use among preterm neonates born at less than 30 weeks' gestation in Canada.

STUDY DESIGN AND METHODS

A retrospective cohort study of preterm neonates born at less than 30 weeks' gestation and admitted to participating neonatal intensive care units in the Canadian Neonatal Network from 2004 to 2012 was conducted to evaluate blood product usage. The temporal change in red blood cell (RBC) use was evaluated by dividing the study period into three epochs: 2004 to 2006, 2007 to 2009, and 2010 to 2012.

RESULTS

Of 14,868 eligible neonates admitted to participating units in Canada during the overall study period, 8252 (56%) received RBCs, 2151 (15%) platelets, 1556 (11%) fresh-frozen plasma, 915 (6%) albumin, and 302 (2%) cryoprecipitate. Temporal evaluation over three epochs revealed a trend toward fewer RBC transfusions among neonates born at 26 to 29 weeks' gestation (p = <0.01-0.04) but use remained unchanged or increased for neonates born at 23 to 25 weeks' gestation (p = 0.02-0.54).

CONCLUSION

Blood product use remains at a very high frequency in preterm neonates born at less than 30 weeks' gestation. Evolutionary practice changes and relative high tolerance for anemia may be associated with a reduction in RBC usage in recent years in neonates born at at least 26 weeks' gestation. This contrasts with the ongoing higher usage of blood products observed at extremely low gestational ages.

Diagnostic and predictive performance and standardized threshold of traditional biomarkers for drug-induced liver injury in rats

Traditional biomarkers such as alanine and aspartate aminotransferase (ALT, AST) and total bilirubin (TBIL) have been widely used for detecting drug-induced liver injury (DILI). Although the Food and Drug Administration (FDA) proposed standardized thresholds for human as Hy's law, those for animals have not been determined, and predictability of these biomarkers for future onset of hepatic lesions remains unclear. In this study, we investigated these diagnostic and predictive performance of 10 traditional biomarkers for liver injury by receiver-operating characteristic (ROC) curve, using a free-access database where 142 hepatotoxic or non-hepatotoxic compounds were administrated to male rats (n=5253). Standardization of each biomarker value was achieved by calculating the ratio to control mean value, and the thresholds were determined under the condition of permitting 5% false positive. Of these 10 biomarkers, AST showed the best diagnostic performance. Furthermore, ALT and TBIL also showed high performance under the situation of hepatocellular necrosis and bile duct injury, respectively. Additionally, the availability of the diagnostic thresholds in difference testing facility was confirmed by the application of these thresholds to in-house prepared dataset. Meanwhile, incorrect diagnosis by the thresholds was also observed. Regarding prediction, all 10 biomarkers showed insufficient performance for future onset of hepatic lesions. In conclusion, the standardized diagnostic thresholds enable consistent evaluation of traditional biomarkers among different facilities, whereas it was suggested that novel biomarker is required for more accurate diagnosis and prediction of DILI.

Perioperative nutritional support and fluid therapy in patients with liver diseases

The prevalence of liver dysfunction and malnutrition is common among patients with obstructive jaundice or cirrhosis, the poor nutrition status in patients with indications for hepatic resection increases the risk of postoperative complications and/or mortality. Hepatic surgery significantly affects body's metabolism and environment. Therefore, it is very important for patients with liver diseases undergoing hepatic surgery to receive essential nutritional support and fluid therapy during perioperative period. There are several principles in nutritional support and fluid therapy that surgeons need to pay attention to, for example, time, nutritional approach, fluid volume, choice of fat emulsions and amino acids. Some issues, such as albumin and plasma application, choice of crystalloid and colloid, liver protective therapy, also need further attention.

Intravenous albumin shortens the duration of hospitalization for patients with hypoalbuminemia and bleeding peptic ulcers: a pilot study

BACKGROUND

Patients with hypoalbuminemia have an increased risk of ulcer rebleeding and longer length of hospitalization.

AIMS

This study aimed to test whether intravenous albumin can decrease the incidence of rebleeding or shorten the duration of hospitalization in patients with bleeding peptic ulcers and hypoalbuminemia.

METHODS

Sixty-two patients with bleeding peptic ulcers and Rockall scores ≥ 6 were prospectively enrolled after having received endoscopic therapy. The enrolled patients were divided into a normal albumin group (serum albumin ≥ 3 g/dL, n = 39) or an intervention group (<3 g/dL, n = 23) to receive a 3-day course of omeprazole infusion and 25-day oral esomeprazole. Patients (n = 29) with bleeding ulcers and hypoalbuminemia who received the same dose of intravenous and oral omeprazole but did not receive albumin therapy were enrolled from a previous study as the control group. In the intervention group, patients received albumin infusion (10 g q8h) for 1 day (serum albumin levels 2.5-2.9 g/dL) and 2 days (<2.5 g/dL), respectively.

RESULTS

The 28-day cumulative rebleeding rates were similar between the intervention group and the control group (39.1 vs. 42.3 %, p = 0.99). The intervention group had a shorter duration of hospitalization (9 vs. 15 days, p = 0.02) than cohort controls. The risk of rebleeding developed after discharge were similar (normal albumin group vs. intervention group vs. control group, 1/5 [20 %] vs. 2/9 [22.2 %] vs. 1/11 [9.1 %], p = 0.7).

CONCLUSIONS

Albumin administration shortens the duration of hospitalization for patients with peptic ulcer bleeding and hypoalbuminemia, but does not decrease the incidence of rebleeding.

[Testosterone-deficiency as a risk factor for hip fracture in eldery men]

OBJECTIVES

Progressive loss of bone mineral density weakens the bones and increases the probability of osteoporotic fractures. It is well known that sex steroids play a role in the maintenance of bone density. This fact makes us think there might be a correlation between sex steroid levels and osteoporotic hip fractures.

MATERIAL AND METHODS

A case-control study was performed. The cases were 54 men who suffered from hip fracture. They were compared with 54 age-matched male control subjects. Levels of total testosterone, sex hormone binding globuline, albumin and oestradiol were measured in all subjects in order to calculate free testosterone and bio-testosterone levels.

RESULTS

Men who suffered from hip fracture had lower serum total testosterone (8.74 nmol/L versus 11.16 nmol/L; p=0.116) and lower free testostenone (155.1pmol/L versus 204.4pmol/L; p=0.02) than control subjects. Bio-testosterone levels were lower in patients with hip fracture (2.69 nmol/L versus 3.89 nmol/L; p=0.002), being the latter the best fracture predictor (OR: 1.58).

CONCLUSIONS

In our study population, men with hip fractures had significantly lower levels of calculated free testosterone and bio-testosterone. These findings suggest that free testosterone and bio-testosterone levels are independent predictors for osteoporotic hip fracture in eldery men.

Hypoproteinemia on the first day of life and adverse outcome in very preterm infants admitted to the neonatal intensive care unit

OBJECTIVE

We aimed to investigate the relationship between day-1 hypoproteinemia and severe adverse outcome (SAO) in very preterm infants admitted to the neonatal intensive care unit (NICU).

STUDY DESIGN

Retrospective study of all patients born from 24 to 31 weeks gestation and cared for in our NICU over an 8-year period. Infants were excluded if the serum protein value on the first day of life was not available.

RESULT

A total of 913 patients were included. In all, 14.6% presented with SAO (death or severe neurological injury on cranial ultrasound). Hypoproteinemia (total protein level <40 g l(-1)) on day 1 of life occurred in 19.5 % of all patients. The rate of SAO was 33.7% in patients with hypoproteinemia and 9.9% in those with normoproteinemia (P<0.0001). Logistic and multiple regression analysis confirmed that the association hypoproteinemia-SAO remained significant after adjustment for the other major predictors of outcome present at baseline (odds ratio 3.4; 95% confidence interval 2.1-5.4; P<0.0001).

CONCLUSION

Hypoproteinemia was highly associated with SAO in this cohort of critically ill preterm infants. We are unable to explain the link between hypoproteinemia and adverse outcome in our population. This investigation serves as a hypothesis-generating report of a large preterm infants sample, and suggests the need to assess the predictive accuracy for adverse outcome of hypoproteinemia in future prospective studies.

Acute endotoxemia in mice induces downregulation of megalin and cubilin in the kidney

Severe sepsis is often accompanied by acute renal failure with renal tubular dysfunction. Albuminuria is a common finding in septic patients and we studied whether it was due to an impairment of proximal tubular endocytosis of filtered albumin. We studied the regulation of megalin and cubilin, the two critical multiligand receptors responsible for albumin absorption, during severe experimental endotoxemia. Lipopolysaccharide (LPS) caused a time- and dose-dependent suppression of megalin and cubilin expression that was paralleled by a decrease in plasma albumin levels and an increase in the urine concentration of albumin in mice. Incubation of rat renal cortical slices with LPS also reduced the mRNA expression of megalin and cubilin. Further, LPS suppressed megalin and cubilin mRNA expression in murine primary proximal tubule cells and decreased the uptake of FITC albumin in these cells. In addition, the increase in urine levels of albumin in response to ischemia/reperfusion-induced acute renal failure was paralleled by a decrease in the expression of megalin and cubilin. Thus, our data indicate that the expression of megalin and cubilin is decreased during experimental endotoxemia and in response to renal ischemia/reperfusion injury. This downregulation may contribute, in part, to an increase in urine levels of albumin during acute renal failure.

Does administering albumin to postoperative gastroschisis patients improve outcome?

OBJECTIVES

Newborns who undergo surgery for gastroschisis correction may present with oliguria, anasarca, prolonged postoperative ileus, and infection. New postoperative therapeutic procedures were tested with the objective of improving postoperative outcome.

PATIENTS AND METHODS

One hundred thirty-six newborns participated in one of two phases. Newborns in the first phase received infusions of large volumes of crystalloid solution and integral enteral formula, and newborns in the second phase received crystalloid solutions in smaller volumes, with albumin solution infusion when necessary and the late introduction of a semi-elemental diet. The studied variables were serum sodium and albumin levels, the need for albumin solution expansion, the occurrence of anasarca, the length of time on parenteral nutrition, the length of time before initiating an enteral diet and reaching a full enteral diet, orotracheal intubation time, length of hospitalization, and survival rates.

RESULTS

Serum sodium levels were higher in newborns in the second phase. There was a correlation between low serum sodium levels and orotracheal intubation time; additionally, low serum albumin levels correlated with the length of time before the initiation of an oral diet and the time until a full enteral diet was reached. However, the discharge weights of newborns in the second phase were higher than in the first phase. The other studied variables, including survival rates (83.4% and 92.0%, respectively), were similar for both phases.

CONCLUSIONS

The administration of an albumin solution to newborns in the early postoperative period following gastroschisis repair increased their low serum sodium levels but did not improve the final outcome. The introduction of a semi-elemental diet promoted an increase in body weight at the time of discharge.

Human serum albumin: from bench to bedside

Human serum albumin (HSA), the most abundant protein in plasma, is a monomeric multi-domain macromolecule, representing the main determinant of plasma oncotic pressure and the main modulator of fluid distribution between body compartments. HSA displays an extraordinary ligand binding capacity, providing a depot and carrier for many endogenous and exogenous compounds. Indeed, HSA represents the main carrier for fatty acids, affects pharmacokinetics of many drugs, provides the metabolic modification of some ligands, renders potential toxins harmless, accounts for most of the anti-oxidant capacity of human plasma, and displays (pseudo-)enzymatic properties. HSA is a valuable biomarker of many diseases, including cancer, rheumatoid arthritis, ischemia, post-menopausal obesity, severe acute graft-versus-host disease, and diseases that need monitoring of the glycemic control. Moreover, HSA is widely used clinically to treat several diseases, including hypovolemia, shock, burns, surgical blood loss, trauma, hemorrhage, cardiopulmonary bypass, acute respiratory distress syndrome, hemodialysis, acute liver failure, chronic liver disease, nutrition support, resuscitation, and hypoalbuminemia. Recently, biotechnological applications of HSA, including implantable biomaterials, surgical adhesives and sealants, biochromatography, ligand trapping, and fusion proteins, have been reported. Here, genetic, biochemical, biomedical, and biotechnological aspects of HSA are reviewed.

Rationale for albumin infusions

PURPOSE OF REVIEW

To describe the metabolism and function of albumin, and to scrutinize the evidence that infusion of albumin may be beneficial in disease. To explain why albumin infusion does not improve clinical outcome in most disease states, studied.

RECENT FINDINGS

Albumin acts as a binding protein and an oncotic agent. However, albumin may also act as an extracellular scavenger, which leads to oxidation of albumin. It is likely that this compromises its function and it is possible that this drives its degradation. In disease, these useful processes are accelerated leading to rapid ageing of the molecule.Albumin infusion does not improve clinical outcome despite increasing oncotic pressure in chronic disease. It is not superior to nonprotein colloids or electrolyte solutions in acute hypovolemia with one or two exceptions (liver failure, possibly cerebral infarction). One potential explanation is that pharmaceutical albumin does not have the oxidative qualities that freshly synthesized albumin has.

SUMMARY

Albumin infusion has not proven to achieve clinical benefit in many acute and chronic disease states with a few exceptions in acute hypovolemia (e.g. postparacentesis). Future studies should reveal whether infusion of freshly synthesized nonoxidized albumin is of greater clinical benefit.

Nutritional therapy for burns in children and adults

Burns are a serious injury that requires optimal nutritional support. This review discusses the nutritional care for adults and children with major burns. A burned patient's metabolism is greatly accelerated with increased requirements for energy, carbohydrates, proteins, fats, vitamins, minerals, and antioxidants. Early nutrition by parenteral and enteral feedings is vital. Careful assessment of the nutritional state of the burn patient is also important to reduce infection, recovery time, and long-term sequelae.

Cardiovascular distribution of the calcium sensing receptor before and after burns

Due to up-regulation of the parathyroid gland calcium-sensing receptor (CaR), burned children have hypocalcemic hypoparathyroidism, and decreased myocardial contractility. Our aim was to localize the CaR in the heart and measure receptor density changes due to burns. Heart and aorta samples from sheep subjected to 40% burn or sham conditions were probed for CaR via fluorescence microscopy. CaR was localized to endocardial endothelium, myocardial microvasculature, and fibroblasts and vessels of the aortic adventitia. CaR was not found in cardiomyocytes or smooth muscle cells. No differences in density of CaR or beta-adrenergic receptors were noted. No differences in CaR distribution were seen in the myocardium or aorta, in contrast to the parathyroid where burn injury up-regulates CaR. We suggest that CaR has a local, tissue-specific role, and functions in vascular calcium sensing for intravascular calcium deposition or regulation of other calcium channels after trauma or burn.

Albumin synthesis in premature neonates is stimulated by parenterally administered amino acids during the first days of life

BACKGROUND

We recently showed that parenteral administration of amino acids to premature infants immediately after birth is safe and results in a positive nitrogen balance and increased whole-body protein synthesis. However, we did not determine organ-specific effects; albumin, produced by the liver, is an important protein, but its concentration is often low in premature neonates during the first few days after birth.

OBJECTIVE

The objective of the study was to test the hypothesis that the fractional and absolute albumin synthesis rates would increase with the administration of amino acids after birth, even at low nonprotein energy intake.

DESIGN

Premature infants (<1500 g birth weight), who were on ventilation, received from birth onward either glucose only (control group, n = 7) or glucose and 2.4 g amino acid kg(-1) d(-1) (intervention group, n = 8). On postnatal day 2, all infants received a primed continuous infusion of [1-(13)C]leucine, and mass spectrometry techniques were used to determine the incorporation of the leucine into albumin. Results are expressed as medians and 25th and 75th percentiles.

RESULTS

Albumin fractional synthesis rates in the intervention group were significantly higher than those in the control group [22.9% (17.6-28.0%)/d and 12.6% (11.0-19.4%)/d, respectively; P = 0.029]. Likewise, the albumin absolute synthesis rates in the intervention group were significantly higher than those in the control group [228 (187-289) mg kg(-1) d(-1) and 168 (118-203) mg kg(-1) d(-1), respectively; P = 0.030].

CONCLUSION

Amino acid administration increases albumin synthesis rates in premature neonates even at a low energy intake.

Albumin reduces blood-brain barrier permeability but does not alter infarct size in a rat model of neonatal stroke

Human serum albumin therapy confers neurobehavioral and histopathologic neuroprotection in adult stroke models. We investigated whether albumin might also be neuroprotective in ischemic brain injury using a transient filament middle cerebral artery occlusion (tfMCAO) model in 10-d-old rat pups treated with 0.25% albumin or saline 1 h after reperfusion. We performed serial neurobehavioral and magnetic resonance imaging (MRI) assessments immediately after tfMCAO (day 0) and on 1, 3, 7, 14, and 28 d. IgG staining to assess blood-brain barrier (BBB) integrity and standard histology was obtained on 1, 3, and 28 d. Hemispheric infarct volumes from MRI were similar in saline and albumin groups (0 h: 39% and 44%; d 1: 46% and 55%; and d 28:10% and 24%) as were neurobehavioral assessments. IgG staining at 3 d post-ischemia showed loss of BBB integrity that was significantly reduced after albumin. Elevated T2 values suggesting vasogenic edema was seen in albumin compared with saline-treated animals, as was increased water mobility (i.e. increased apparent diffusion coefficient (ADC) reflecting cytotoxic edema. The reasons why albumin was not neuroprotective in neonatal stroke compared with adults remain uncertain. Effective strategies in adult models need to be reassessed in the neonate.

Management of acute renal failure in the newborn

Acute renal failure is common in the neonatal period. It is usually manifest by abnormal biochemistry and decreased urine output (<1 ml/kg/h), but non-oliguric renal failure is also common. A detailed understanding of the common pathophysiological mechanisms is rarely needed but an understanding of the common aetiologies (pre-renal, renal and post-renal) will enable the clinician to approach the problem in a logical manner. A standard approach to fluid and electrolyte management is described, along with a practical approach to the investigation and management of renal failure. A working understanding of the principles of peritoneal dialysis is important and a brief overview of the role of haemodialysis in neonatal renal failure is provided.

Albumin therapy in clinical practice

Albumin is the predominant product of hepatic protein synthesis and one of the more abundant plasma proteins. Among its multiple physiologic roles, it plays an essential part in the generation of colloid-oncotic pressure. In the United States, the indications for which albumin therapy are considered include hypovolemia or shock, burns, hypoalbuminemia, surgery or trauma, cardiopulmonary bypass, acute respiratory distress syndrome, hemodialysis, and sequestration of protein-rich fluids. The use of this relatively expensive therapy accounts for up to 30% of the total pharmacy budget in certain hospitals. The use of albumin therapy in different clinical situations and its influence in morbidity and mortality have been reviewed in multiple randomized controlled trials and meta-analyses. Despite frequent reviews, the use of albumin remains controversial in several clinical situations. At the same time, these valuable reviews seem to have documented the advantages of albumin therapy in the management of ascites and clarified the use of albumin in volume resuscitation. More studies have been recommended to investigate the use of albumin in different doses and its role in hypoalbuminemia. This article will provide an overview of albumin metabolism, use of albumin for volume expansion, the potential therapeutic role of albumin in liver disease, and the role of albumin therapy in nutrition.

Albumin infusion for low serum albumin in preterm newborn infants

BACKGROUND

Intravenous albumin infusion to treat hypoalbuminaemia is used in intensive care nurseries. Hypoalbuminaemia occurs in a number of clinical situations including prematurity, the acutely unwell infant, respiratory distress syndrome (RDS), chronic lung disease (CLD), necrotising enterocolitis (NEC), intracranial haemorrhage, hydrops fetalis and oedema. Fluid overload is a potential side effect of albumin administration. Albumin is a blood product and therefore carries the potential risk of infection and adverse reactions. Albumin is also a scarce and expensive resource.

OBJECTIVES

The primary objective was to assess whether albumin infusions, in preterm neonates with low serum albumin, reduces mortality and morbidity. A secondary objective was to assess whether albumin infusion is associated with significant side effects.

SEARCH STRATEGY

Searches were made of MEDLINE from 1966 to April 2004, CINAHL from 1982 to April 2004 and the current Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library issue 1, 2004). Previous reviews (including cross references) and abstracts were also searched.

SELECTION CRITERIA

All randomised controlled trials in which individual patients were allocated to albumin infusion versus control were included. Cross-over studies were excluded. Quasi randomised trials were excluded. Participants were preterm infants who had hypoalbuminaemia. Types of interventions included albumin infusion versus placebo (e.g. crystalloid) or no treatment.

DATA COLLECTION AND ANALYSIS

The reviewers worked independently to search for trials for inclusion and to assess methodological quality. Studies were assessed using the following key criteria: blinding of randomisation, blinding of intervention, completeness of follow up and blinding of outcome measurement.

MAIN RESULTS

Only two small studies were found for inclusion in this review and only one reported clinically relevant outcomes - it found no significant differences for our primary outcome measure of death (RR 1.5 [95% confidence interval 0.3 - 7.43]) or secondary outcome measures of intraventricular haemorrhage, patent ductus arteriosus, necrotising enterocolitis, bronchopulmonary dysplasia, duration of mechanical ventilation and duration of oxygen therapy.

REVIEWERS' CONCLUSIONS

There is a lack of evidence from randomised trials to determine whether the routine use of albumin infusion, in preterm neonates with low serum albumin, reduces mortality or morbidity, and no evidence to assess whether albumin infusion is associated with significant side effects. There is a need for good quality, double-blind randomised controlled trials to assess the safety and efficacy of albumin infusions in preterm neonates with low serum albumin.