Preoperative Low Serum Albumin Levels Increase the Requirement of Renal Replacement Therapy after Cardiac Surgery

Contemporary association of preoperative malnutrition and outcomes of hiatal hernia repairs in the United States

BACKGROUND

Hypoalbuminemia has been used as a surrogate for malnutrition and is associated with worse postoperative outcomes across major operations. Because patients with hiatal hernia often have inadequate caloric intake, we examined the association of serum albumin levels with outcomes after hiatal hernia repair.

METHODS

Adults undergoing elective and non-elective hiatal hernia repair via any approach were tabulated from the 2012 to 2019 National Surgical Quality Improvement Program. Patients were stratified into the Hypoalbuminemia cohort if serum albumin <3.5 mg/dL using restricted cubic spline analysis. Major adverse events were defined as a composite of all-cause mortality and major complications per the American College of Surgeons National Surgical Quality Improvement Program risk calculator. Entropy balancing was used to adjust for intergroup differences. Multivariable regression models were then constructed to assess the association of preoperative albumin with major adverse events, postoperative length of stay, and 30-day readmission.

RESULTS

Of 23,103 patients, 11.7% comprised the Hypoalbuminemia cohort. The Hypoalbuminemia group was older, less commonly of White race, and less likely to have an independent functional status than others. They were also more likely to undergo inpatient, non-elective surgery via laparotomy. After entropy balancing and adjustment, hypoalbuminemia remained associated with increased odds of major adverse events and multiple complications and longer adjusted postoperative length of stay. There was no significant difference in adjusted odds of readmission.

CONCLUSION

We used a quantitative methodology to establish a serum albumin threshold of 3.5 mg/dL associated with increased adjusted odds of major adverse events, increased postoperative length of stay, and postoperative complications after hiatal hernia repair. These results may guide preoperative nutrition supplementation.

Low albumin levels are independently associated with neonatal acute kidney injury: a report from AWAKEN Study Group

BACKGROUND

Data from adult and pediatric literature have shown an association between albumin levels and AKI. Whether hypoalbuminemia and neonatal AKI are associated has not been studied.

METHODS

We evaluated the association of albumin with early (during the first postnatal week) and late (after the first postnatal week) AKI for 531 neonates from the Assessment of Worldwide AKI Epidemiology in Neonates (AWAKEN) database and for 3 gestational age (GA) subgroups: < 29, 29 to < 36, and ≥ 36 weeks GA.

RESULTS

Low albumin levels were associated with increased odds of neonatal AKI; for every 0.1 g/dL decrease in albumin, the odds of late AKI increased by 12% on continuous analysis. After adjustment for potential confounders, neonates with albumin values in the lowest quartiles (< 2.2 g/dL) had an increased odds of early [Adjusted Odd Ratio (AdjOR) 2.5, 95% CI = 1.1-5.3, p < 0.03] and late AKI [AdjOR 13.4, 95% CI = 3.6-49.9, p < 0.0001] compared to those with albumin in the highest quartile (> 3.1 g/dL). This held true for albumin levels 2.3 to 2.6 g/dL for early [AdjOR 2.5, 95% CI = 1.2-5.5, p < 0.02] and late AKI [AdjOR 6.4, 95% CI = 1.9-21.6, p < 0.01]. Albumin quartiles of (2.7 to 3.0 g/dL) were associated with increased odds of late AKI. Albumin levels of 2.6 g/dL and 2.4 g/dL best predicted early (AUC = 0.59) and late AKI (AUC = 0.64), respectively. Analysis of albumin association with AKI by GA is described.

CONCLUSIONS

Low albumin levels are independently associated with early and late neonatal AKI. Albumin could be a potential modifiable risk factor for neonatal AKI.

Linear Association Between Hypoalbuminemia and Increased Risk of Acute Respiratory Distress Syndrome in Critically Ill Adults

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We hypothesized that low serum albumin would contribute to pulmonary edema formation, thereby independently increasing the risk of developing acute respiratory distress syndrome in critically ill patients.

Hypoalbuminemia as Surrogate and Culprit of Infections

Hypoalbuminemia is associated with the acquisition and severity of infectious diseases, and intact innate and adaptive immune responses depend on albumin. Albumin oxidation and breakdown affect interactions with bioactive lipid mediators that play important roles in antimicrobial defense and repair. There is bio-mechanistic plausibility for a causal link between hypoalbuminemia and increased risks of primary and secondary infections. Serum albumin levels have prognostic value for complications in viral, bacterial and fungal infections, and for infectious complications of non-infective chronic conditions. Hypoalbuminemia predicts the development of healthcare-associated infections, particularly with Clostridium difficile. In coronavirus disease 2019, hypoalbuminemia correlates with viral load and degree of acute lung injury and organ dysfunction. Non-oncotic properties of albumin affect the pharmacokinetics and pharmacodynamics of antimicrobials. Low serum albumin is associated with inadequate antimicrobial treatment. Infusion of human albumin solution (HAS) supplements endogenous albumin in patients with cirrhosis of the liver and effectively supported antimicrobial therapy in randomized controlled trials (RCTs). Evidence of the beneficial effects of HAS on infections in hypoalbuminemic patients without cirrhosis is largely observational. Prospective RCTs are underway and, if hypotheses are confirmed, could lead to changes in clinical practice for the management of hypoalbuminemic patients with infections or at risk of infectious complications.

The prognostic nutritional index on postoperative day one is associated with one-year mortality after burn surgery in elderly patients

BACKGROUND

Burn injury in elderly patients can result in poor outcomes. Prognostic nutritional index (PNI) can predict the perioperative nutritional status and postoperative outcomes. We aim to evaluate the risk factors, including PNI, for one-year mortality after burn surgery in elderly patients.

METHODS

Burn patients aged ≥65 years were retrospectively included. PNI was calculated using the following equation: 10 × serum albumin level (g/dL) + 0.005 × total lymphocyte count (per mm³). Cox regression, receiver operating characteristic curve and Kaplan-Meier survival analyses were performed to evaluate the risk factors for postoperative one-year mortality.

RESULTS

Postoperative one-year mortality occurred in 71 (37.6%) of the 189 elderly burn patients. Risk factors for one-year mortality were PNI on postoperative day one (hazard ratio (HR) = 0.872; 95% CI = 0.812-0.936; p < 0.001), Sequential Organ Failure Assessment score (HR = 1.112; 95% CI = 1.005-1.230; p = 0.040), American Society of Anesthesiologists physical status (HR = 2.064; 95% CI = 1.211-3.517; p = 0.008), total body surface area burned (HR = 1.017; 95% CI = 1.003-1.032; p = 0.015) and preoperative serum creatinine level (HR = 1.386; 95% CI = 1.058-1.816; p = 0.018). The area under the curve of PNI for predicting one-year mortality after burn surgery was 0.774 (optimal cut-off value = 25.5). Patients with PNI ≤25.5 had a significantly lower one-year survival rate than those with PNI >25.5 (32.1% vs 75.9%, p < 0.001).

CONCLUSIONS

PNI on postoperative day one was associated with postoperative one-year mortality in elderly burn patients. The postoperative one-year survival rate was lower in patients with PNI ≤25.5 than in those with PNI >25.5. These findings indicate the importance of identifying elderly burn patients with low PNI, thereby reducing the mortality after burn surgery.

Phases of fluid management and the roles of human albumin solution in perioperative and critically ill patients

OBJECTIVE

Positive fluid balance is common among critically ill patients and leads to worse outcomes, particularly in sepsis, acute respiratory distress syndrome, and acute kidney injury. Restrictive fluid infusion and active removal of accumulated fluid are being studied as approaches to prevent and treat fluid overload. Use of human albumin solutions has been investigated in different phases of restrictive fluid resuscitation, and this narrative literature review was undertaken to evaluate hypoalbuminemia and the roles of human serum albumin with respect to hypovolemia and its management.

METHODS

PubMed/EMBASE search terms were: "resuscitation," "fluids," "fluid therapy," "fluid balance," "plasma volume," "colloids," "crystalloids," "albumin," "hypoalbuminemia," "starch," "saline," "balanced salt solution," "gelatin," "goal-directed therapy" (English-language, pre-January 2020). Additional papers were identified by manual searching of reference lists.

RESULTS

Restrictive fluid administration, plus early vasopressor use, may reduce fluid balance, but in some cases fluid overload cannot be entirely avoided. Deresuscitation, with fluid actively removed through diuretics or ultrafiltration, reduces duration of mechanical ventilation and intensive care unit stay. Combining hyperoncotic human albumin solution with diuretics increases hemodynamic stability and diuresis. Hyperoncotic albumin corrects hypoalbuminemia and raises colloid osmotic pressure, limiting edema formation and potentially improving endothelial function. Serum levels of albumin relative to C-reactive protein and lactate may predict which patients will benefit most from albumin therapy.

CONCLUSIONS

Hyperoncotic human albumin solution facilitates restrictive fluid therapy and the effectiveness of deresuscitative measures. Current evidence is mostly from observational studies, and more randomized trials are needed to better establish a personalized approach to fluid management.

The C-reactive protein/albumin ratio as a new predictor for postoperative atrial fibrillation after coronary artery bypass graft surgery

BACKGROUND

This study aimed to investigate the predictive significance of C-reactive protein/albumin ratio for postoperative atrial fibrillation occurrence in patients who were underwent coronary artery bypass graft surgery.

METHODS

Among 830 patients who underwent coronary artery bypass grafting with cardiopulmonary bypass between January 2016 and February 2020, 137 patients with no prior arrhythmia history were included in this cross sectional study.

RESULTS

One hundred and thirty-seven (16.5%) patients developed atrial fibrillation in postoperative period. Patients who experienced postoperative atrial fibrillation were more likely to be older but displayed similar rates of diabetes mellitus, hypertension, hypercholesterolemia, cerebrovascular disease, peripheral vascular disease and chronic obstructive pulmonary disease. For prediction of postoperative atrial fibrillation development, diagnostic odds ratio (OR) and positive likelihood ratio of C-reactive protein/albumin ratio value (OR: 1.854; confidence interval [CI]: 1.598-2.142; P < .001) was higher than serum C-reactive protein and albumin levels. (OR: 1.159; CI: 1.115-1.201; P < .001; OR: 0.438; CI: 0.258-0.865; P < .001, respectively). Which means that C-reactive protein/albumin ratio may detect postoperative atrial fibrillation development better C-reactive protein itself.

CONCLUSION

Based on our results, patients who developed postoperative atrial fibrillation after coronary artery bypass grafting had significantly higher preoperative C-reactive protein/albumin ratio levels than patients who remained in normal sinus rhythm in the postoperative period. Also, higher C-reactive protein/albumin ratio value was one of the independent predictive factors for postoperative atrial fibrillation. Therefore, we concluded that evaluating preoperative C-reactive protein/albumin ratio value might provide early identification of patients with high risk for postoperative atrial fibrillation.

Postoperative complications associated with coronary artery bypass graft surgery and their therapeutic interventions

Coronary artery disease is one of the commonest surgery demanding cardiovascular diseases. Coronary artery bypass graft surgery is practiced all over the world for the treatment of coronary artery disease. Systemic trauma during the surgery is associated with a wide range of complications, some of which are fatal. Preoperative risk factors such as age, previous illness and obesity are common predictors of these adverse events. Advances in therapeutic medicine have allowed timely treatment of these adverse events and co-morbidities. This review summarizes some of the most occurring complications associated with coronary artery bypass graft and corresponding treatment options.

Is Hypoalbuminemia a Predictor for Acute Kidney Injury after Coronary Bypass Grafting in Diabetes Mellitus Patients?

Objective

Acute kidney injury (AKI) is one of the most important complications after coronary artery bypass grafting (CABG) procedure. Serum albumin, which is an acute phase reactant, is suggested to be associated with AKI development subsequent to various surgical procedures. In this study, we research the relation between preoperative serum albumin levels and postoperative AKI development in diabetes mellitus (DM) patients undergoing isolated CABG.

Methods

We included a total of 634 diabetic patients undergoing CABG (60.5±9.1 years, 65.1% male) into this study, which was performed between September 2009 and January 2014 in a single center. The relation between preoperative serum albumin levels and postoperative AKI development was observed. AKI was evaluated and diagnosed using the Kidney Disease: Improving Global Outcomes (KDIGO) classification.

Results

AKI was diagnosed in 230 (36.3%) patients. Multiple logistic regression analysis was performed to determine the independent predictors of AKI development. Proteinuria (odds ratio [OR] and 95% confidence interval [CI], 1.066 [1.002-1.135]; P=0.043) and low preoperative serum albumin levels (OR and 95% CI, 0.453 [0.216-0.947]; P=0.035) were found to be independent predictors of AKI. According to the receiver operating characteristic curve analysis, albumin level <3mg/dL (area under the curve: 0.621 [0.572-0.669], P<0.001) had 83% sensitivity and 10% specificity on predicting the development of AKI.

Conclusion

We observed that a preoperative low serum albumin level was associated with postoperative AKI development in patients with DM who underwent isolated CABG procedure. We emphasize that this adjustable albumin level should be considered before the operation since it is an easy and clinically implementable management for the prevention of AKI development.

Can Serum Nutritional Related Biomarkers Predict Mortality Of Critically Ill Older Patients With Acute Kidney Injury?

Background

Critically ill older patients with acute kidney injury (AKI), also referred to as acute renal failure, are associated with high in-hospital mortalities. Preexisting malnutrition is highly prevalent among AKI patients and increases in-hospital mortality rate. This study is to evaluate the predictive power of some serum nutritional related biomarkers predicting the 90 days in-hospital mortality of critically ill older patients with AKI.

Methods

A prospective, observational study was conducted in a university teaching hospital. One hundred and five critically ill older patients with AKI aged 60-95 were enrolled and were divided into survival group (n=44) and non-survival group (n=61) in the light of their final outcomes. Receiver operating characteristic analyses (ROC) were performed to calculate the area under ROC curve (AUC). Sensitivity and specificity of in-hospital mortality prediction were calculated.

Results

Significant differences were found between the survival group and non-survival group of critically ill older patients with AKI. AUC of low density lipoprotein (LDL) and albumin were 0.686 and 0.595, respectively. The asymptotic 95% confidence intervals of LDL and albumin were 0.524-0.820 and 0.488-0.696, respectively. Sensitivity of the 90 days in-hospital mortality prediction of LDL and albumin were 68.71% and 69.09%, respectively. Specificity of 90 days in-hospital mortality prediction of LDL and albumin were 69.23% and 50.0%, respectively.

Conclusion

LDL and albumin did not have sufficient power to predict the 90 days in-hospital mortality of critically ill older patients with AKI. Further research on the association between malnutrition and poor prognosis of critically ill older patients with AKI is needed in the future.Trial registration: ClinicalTrials.gov identifier: NCT00953992.

Preoperative hypoalbuminemia was associated with acute kidney injury in high-risk patients following non-cardiac surgery: a retrospective cohort study

Background

Acute kidney injury (AKI) is a common complication following non-cardiac surgery with adverse short- and long- term morbidity and mortality. Evidence shows that hypoalbuminemia is associated with increased AKI risk in patients with infectious diseases and cancer and following cardiac surgery and transplant surgery. However, little evidence is available on non-cardiac surgery population. Thus, we investigated the association between preoperative hypoalbuminemia and AKI following non-cardiac surgery.

Methods

We retrospectively assessed perioperative risk factors and preoperative serum albumin concentration in 729 consecutive adult patients who underwent non-cardiac surgery from July 1, 2017, to June 30, 2018. Each patient was categorized according to maximal Kidney Disease Improving Global Outcomes criteria based on creatinine changes and urine output within the first week after surgery. Multivariate Logistic regression models were used to analyze the association between preoperative hypoalbuminemia and postoperative AKI.

Results

Of 729 patients, 188 (25.8%) developed AKI. AKI incidence was higher in patients with preoperative serum albumin < 37.5 g/L than in those with preoperative serum albumin ≥37.5 g/L [35.9% (98/273) vs. 19.7% (90/456), P < 0.001]. Multivariate logistic regression analysis showed that preoperative serum albumin < 37.5 g/L (odds ratio 1.892; 95% confidence interval 1.238–2.891; P = 0.003) was independently associated with postoperative AKI. Patients with preoperative serum albumin < 37.5 g/L tended to have a higher but not significant ratio in AKI stage 2 (2.6% vs 1.1%, P = 0.144) and much higher ratio in AKI stage 3 (4.8% vs 0.7%, P < 0.001) than those with preoperative serum albumin ≥37.5 g/L. AKI patients had a higher in-hospital mortality rate [6.9% (13/188) vs. 0.2% (1/541), P < 0.001]. Kaplan-Meier analysis revealed that the cumulative survival rate decreased with increasing AKI severity (P < 0.001). Postoperative AKI was also associated with other worse outcomes, such as prolonged mechanical ventilation [53.4 (33.0, 73.8) vs 14.7 (11.1, 18.3) hours, P < 0.001], intensive care unit stay [4.0 (3.1, 4.9) vs 2.0 (1.8, 2.3) days, P < 0.001], postoperative hospital stay [17.8 (14.8, 20.9) vs 12.3 (11.3, 13.3) days, P < 0.001], and higher total cost [13,453 (8538, 20,228) vs 11,306 (6277, 16,400) dollars, P < 0.001].

Conclusions

Preoperative hypoalbuminemia was independently associated with AKI after non-cardiac surgery, and postoperative AKI was associated with poor outcomes.

Electronic supplementary material

The online version of this article (10.1186/s12871-019-0842-3) contains supplementary material, which is available to authorized users.

The predictive value of the prognostic nutritional index for postoperative acute kidney injury in patients undergoing on-pump coronary bypass surgery

BACKGROUND

We aimed to investigate the predictive value of the prognostic nutritional index (PNI) regarding the development of acute kidney injury (AKI) after elective coronary artery bypass grafting (CABG).

METHODS

A total of 336 consecutive patients with normal serum creatinine levels undergoing CABG were enrolled in this retrospective study. AKI was defined as meeting Acute Kidney Injury Network (AKIN) criteria based on the occurrence of creatinine changes within the first 48 h after CABG surgery. The patients were grouped according to whether they developed AKI or not into an AKI (-) and an AKI (+) group.

RESULTS

AKI developed in 88 (26.2%) of all patients. The PNI was independently predictive of AKI (OR: 0.829, 95% CI: 0.783-0.877, p <  0.001). Moreover, C-reactive protein (CRP), a history of diabetes mellitus, and positive inotropric usage were independent risk factors for AKI in the multivariate logistic regression analysis. The area under the curve (AUC) of the multivariable model, including positive inotrope support, a history of diabetes mellitus, and CRP, was 0.693 (95% CI: 0.626-0.760, p <  0.001) in predicting AKIN. When the PNI was added to the multivariable model, the AUC was 0.819 (95% CI, 0.762-0.865, z = 3.777, difference p = 0.0002). Also, the addition of the PNI to the multivariable model was associated with a significant net reclassification improvement estimated at 88.2% (p <  0.001) and an integrated discrimination improvement of 0.22 (p <  0.001).

CONCLUSIONS

Our study demonstrated that decreasing the PNI could be associated with the development of AKI after coronary artery bypass surgery.

Fluids and Organ Dysfunction: A Narrative Review of the Literature and Discussion of 5 Controversial Topics

Evidence-based clinical decision making is at the forefront of modern cardiothoracic anesthesia practice. Therefore, as a field, cardiac anesthesiologist should strive to ensure that the available evidence is of the highest possible quality. In this narrative review, 5 important topics that the authors believe require additional investigation in cardiothoracic anesthesia and critical care related to fluid therapy and organ dysfunction are outlined briefly. In particular, the authors believe that the areas of pulmonary artery catheter use, restrictive versus liberal transfusion strategies, cardiopulmonary bypass prime composition, colloid use in resuscitation and its effects on acute kidney injury, and management of acute kidney injury after cardiac surgery hold many unanswered questions and opportunities for continued improvement in the specialty of cardiac anesthesia. This article accompanies a presentation at the 46th Association of Cardiac Anesthesiologists Annual Meeting on October 22, 2017.

Causal relationship between hypoalbuminemia and acute kidney injury

Our meta-analysis published in 2010 provided evidence that low levels of serum albumin (hypoalbuminemia) are a significant independent predictor of acute kidney injury (AKI) and death following AKI. Since then, a large volume of additional data from observational clinical studies has been published further evaluating the relationship between serum albumin and AKI occurrence. This is an updated review of the literature to re-evaluate the hypothesis that hypoalbuminemia is independently associated with increased AKI risk. Eligible studies published from September 2009 to December 2016 were sought in PubMed (MEDLINE) and forty-three were retained, the great majority being retrospective observational cohort studies. These included a total of about 68000 subjects across a diverse range of settings, predominantly cardiac surgery and acute coronary interventions, infectious diseases, transplant surgery, and cancer. Appraisal of this latest data set served to conclusively corroborate and confirm our earlier hypothesis that lower serum albumin is an independent predictor both of AKI and death after AKI, across a range of clinical scenarios. The body of evidence indicates that hypoalbuminemia may causally contribute to development of AKI. Furthermore, administration of human albumin solution has the potential to prevent AKI; a randomized, controlled study provides evidence that correcting hypoalbuminemia may be renal-protective. Therefore, measurement of serum albumin to diagnose hypoalbuminemia may help identify high-risk patients who may benefit from treatment with exogenous human albumin. Multi-center, prospective, randomized, interventional studies are warranted, along with basic research to define the mechanisms through which albumin affords nephroprotection.