Hypoalbuminemia and acute kidney injury: a meta-analysis of observational clinical studies

Verification of serum albumin elevating effect of cell-free and concentrated ascites reinfusion therapy for ascites patients: a retrospective controlled cohort study

Cell-free and concentrated ascites reinfusion therapy (CART) is frequently used to treat refractory ascites in Japan. However, its efficacy remains unclear. This controlled cohort study verified the serum albumin elevating effect of CART by comparisons with simple paracentesis. Ascites patients receiving CART (N = 88) or paracentesis (N = 108) at our hospital were assessed for the primary outcome of change in serum albumin level within 3 days before and after treatment. A significantly larger volume of ascites was drained in the CART group. The change in serum albumin level was +0.08 ± 0.25 g/dL in the CART group and −0.10 ± 0.30 g/dL in the paracentesis group (P < 0.001). The CART – paracentesis difference was +0.26 g/dL (95%CI +0.18 to +0.33, P < 0.001) after adjusting for potential confounders by multivariate analysis. The adjusted difference increased with drainage volume. In the CART group, serum total protein, dietary intake, and urine volume were significantly increased, while hemoglobin and body weight was significantly decreased, versus paracentesis. More frequent adverse events, particularly fever, were recorded for CART, although the period until re-drainage was significantly longer. This study is the first demonstrating that CART can significantly increase serum albumin level as compared with simple paracentesis. CART represents a useful strategy to manage patients requiring ascites drainage.

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.

Sepsis associated acute kidney injury

Sepsis is defined as organ dysfunction resulting from the host's deleterious response to infection. One of the most common organs affected is the kidneys, resulting in sepsis associated acute kidney injury (SA-AKI) that contributes to the morbidity and mortality of sepsis. A growing body of knowledge has illuminated the clinical risk factors, pathobiology, response to treatment, and elements of renal recovery that have advanced our ability to prevent, detect, and treat SA-AKI. Despite these advances, SA-AKI remains an important concern and clinical burden, and further study is needed to reduce the acute and chronic consequences. This review summarizes the relevant evidence, with a focus on the risk factors, early recognition and diagnosis, treatment, and long term consequences of SA-AKI. In addition to literature pertaining to SA-AKI specifically, pertinent sepsis and acute kidney injury literature relevant to SA-AKI was included.

Risk of renal events during tenofovir disoproxil fumarate and entecavir antiviral prophylaxis in HBsAg-positive cancer patients undergoing chemotherapy

The risk of renal events in HBsAg-positive cancer patients receiving tenofovir disoproxil fumarate (TDF) or entecavir (ETV) antiviral prophylaxis during chemotherapy has not been evaluated. This study aimed to evaluate the renal safety of TDF and ETV during chemotherapy. Consecutive, 219 HBsAg-positive cancer patients treated with TDF (n = 106) or ETV (n = 113) for antiviral prophylaxis during chemotherapy with baseline serum creatinine (SCr) <1.2 mg/dL were retrospectively enrolled. Serial SCr levels and estimated glomerular filtration rate (eGFR) were monitored. The incidence of acute kidney injury (AKI) during antiviral prophylaxis was 33% and 38.9% in TDF and ETV groups, respectively (P = 0.441), while the incidence of sustained kidney injury was 11.3% and 11.5%, respectively (P = 1.000). By multivariate analysis, diuretics use (hazard ratio (HR) = 2.011, P = 0.042) and serum albumin levels (HR = 0.441, P = 0.001) were independent predictors of AKI; serum albumin levels (HR = 0.252, P = 0.002) was the only factor associated with sustained kidney injury; age (HR = 2.752, P < 0.001), baseline SCr levels (HR = 3.386, P < 0.001), and serum albumin levels (HR = 0.437, P = 0.001) were factors associated with a new eGFR <60 mL/min. 34.9% of patients in TDF group and 35.4% in ETV group had deteriorated chronic kidney disease (CKD) stage at the end of follow-up, respectively. There were no significant differences in the risk of renal events or CKD stage migration between TDF and ETV groups. Renal events may develop in about one-third of HBsAg-positive cancer patients undergoing chemotherapy. The risk of renal function impairment was comparable between patients treated with TDF and ETV antiviral prophylaxis.

Feature Ranking in Predictive Models for Hospital-Acquired Acute Kidney Injury

Acute Kidney Injury (AKI) is a common complication encountered among hospitalized patients, imposing significantly increased cost, morbidity, and mortality. Early prediction of AKI has profound clinical implications because currently no treatment exists for AKI once it develops. Feature selection (FS) is an essential process for building accurate and interpretable prediction models, but to our best knowledge no study has investigated the robustness and applicability of such selection process for AKI. In this study, we compared eight widely-applied FS methods for AKI prediction using nine-years of electronic medical records (EMR) and examined heterogeneity in feature rankings produced by the methods. FS methods were compared in terms of stability with respect to data sampling variation, similarity between selection results, and AKI prediction performance. Prediction accuracy did not intrinsically guarantee the feature ranking stability. Across different FS methods, the prediction performance did not change significantly, while the importance rankings of features were quite different. A positive correlation was observed between the complexity of suitable FS method and sample size. This study provides several practical implications, including recognizing the importance of feature stability as it is desirable for model reproducibility, identifying important AKI risk factors for further investigation, and facilitating early prediction of AKI.

Diagnostic Performance of Initial Serum Albumin Level for Predicting In-Hospital Mortality among Necrotizing Fasciitis Patients

Background: Hypoalbuminemia is known to be associated with adverse outcomes in critical illness. In this study, we attempted to identify whether hypoalbuminemia on emergency department (ED) arrival is a reliable predictor for in-hospital mortality in necrotizing fasciitis (NF). patients. Method: A retrospective cohort study of hospitalized adult patients with NF was conducted in a tertiary teaching hospital in Taiwan between March 2010 and March 2018. Blood samples were collected in the ED upon arrival, and serum albumin levels were determined. We evaluated the predictive value of serum albumin level at ED presentation for in-hospital mortality. All collected data were statistically analyzed. Result: Of the 707 NF patients, 40 (5.66%) died in the hospital. The mean serum albumin level was 3.1 ± 0.9 g/dL and serum albumin levels were significantly lower in the non-survivor group than in the survivor group (2.8 ± 0.7 g/dL vs. 3.5 ± 0.8 g/dL). In the multivariable logistic regression model, albumin was significantly associated with in-hospital mortality (odds ratio (OR) 0.92, 95% confidence interval (CI) 0.88–0.96, p < 0.001). The area under-the-receiver-operating-characteristic curve (AUC) for in-hospital survival was 0.77 (95% CI 0.72–0.82) and corresponding sensitivity, specificity, positive predictive value, negative predictive value, and positive and negative likelihood ratio were 66%, 74%, 33%, 88%, 2.25, and 0.48, respectively. High sensitivity (96%) for survival was shown at albumin level of 4.0 g/dL and high specificity (91%) for mortality was shown at a level of 2.5 g/dL. Conclusion: Initial serum albumin levels strongly predicted in-hospital mortality among patients with necrotizing fasciitis. NF patients with hypoalbuminemia on ED arrival should be closely monitored for signs of deterioration and early and aggressive intervention should be considered to prevent mortality.

Impact of the serum albumin level on acute kidney injury after cerebral artery aneurysm clipping

Background

Although hypoalbuminemia is a known risk factor for acute kidney injury (AKI) following surgery, little is known about its effects following aneurysm clipping surgery. We aimed to investigate the predictors of AKI and overall mortality and assessed the relationship between preoperative albumin and postoperative outcomes after aneurysm clipping surgery.

Methods

This study included 2,339 patients who underwent aneurysm clipping surgery. According to the criteria updated by the Kidney Disease: Improving Global Outcomes (KDIGO), patients were classified into AKI and no AKI group. Independent AKI predictors were analyzed by multivariate methods, and the influence of AKI on the outcome variables was assessed with by propensity score matching analysis. Survival in relation to AKI was analyzed using the Kaplan–Meier method.

Results

The total proportion of patients who developed AKI was 1.9%. The cutoff value of preoperative albumin for predicting AKI was 3.9 g/dL. Multivariate analyses showed that preoperative albumin≤ 3.9 g/dL, aneurysmal subarachnoid hemorrhage, male sex, phenylephrine use, and hemoglobin were associated with postoperative AKI development. In multivariate analysis, mortality was increased in AKI patients (p< 0.01). After propensity score matching, preoperative albumin≤ 3.9 g/dL was significantly related to AKI and overall mortality.

Conclusion

Preoperative albumin≤ 3.9 g/dL is associated with postoperative AKI and mortality.

Risk factors of acute kidney injury in children after cardiac surgery

BACKGROUND

The objective of this retrospective study was to determine the risk factors for acute kidney injury (AKI), including albumin, in children who underwent cardiac surgery. In addition, we evaluated the association between preoperative serum albumin level and postoperative AKI in these patients.

METHODS

This retrospective study included 505 pediatric patients who underwent congenital cardiac surgery. Preoperative and perioperative risk factors for AKI, including serum albumin level, were assessed. AKI incidence within 7 postoperative days was determined using the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Multivariable logistic regression analysis was performed to evaluate the association between possible risk factors and postoperative AKI.

RESULTS

Of 505 pediatric patients, 185 (36.6%) developed postoperative AKI. The preoperative serum albumin level was associated with postoperative AKI (odds ratio [OR] 0.506, 95% confidence interval [CI] 0.325-0.788; P = 0.003). Other independent factors associated with AKI were age <12 months (OR 1.911, 95% CI 1.166-3.132; P = 0.007), preoperative pulmonary hypertension (OR 1.853, 95% CI 1.182-2.907; P = 0.01), and cardiopulmonary bypass (CPB) duration (OR 1.006, 95% CI 1.003-1.009; P = 0.002). Patients with AKI had higher incidence of postoperative complications, longer mechanical ventilation times, and more prolonged intensive care unit and hospital stays than patients without AKI.

CONCLUSIONS

Preoperative serum albumin level, age <12 months, preoperative pulmonary hypertension, and CPB duration were associated with risk for postoperative AKI in children who underwent congenital cardiac surgery.

Relationship between perioperative thyroid function and acute kidney injury after thyroidectomy

Thyroid dysfunction may alter kidney function via direct renal effects and systemic haemodynamic effects, but information on the effect of thyroid function on postoperative acute kidney injury (AKI) following thyroidectomy remains scarce. We reviewed the medical records of 486 patients who underwent thyroidectomy between January 2010 and December 2014. Thyroid function was evaluated based on the free thyroxine or thyroid stimulating hormone levels. The presence of postoperative AKI was determined using the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. AKI developed in 24 (4.9%) patients after thyroidectomy. There was no association between preoperative thyroid function and postoperative AKI. Patients with postoperative hypothyroidism showed a higher incidence of AKI than patients with normal thyroid function or hyperthyroidism (19.4%, 6.7%, and 0%, respectively; P = 0.044). Multivariable logistic regression analysis showed that male sex (OR, 4.45; 95% CI, 1.80-11.82; P = 0.002), preoperative use of beta-blockers (OR, 4.81; 95% CI, 1.24-16.50; P = 0.016), low preoperative serum albumin levels (OR, 0.29; 95% CI, 0.11-0.76; P = 0.011), and colloid administration (OR, 5.18; 95% CI, 1.42-18.15; P = 0.011) were associated with postoperative AKI. Our results showed that postoperative hypothyroidism might increase the incidence of AKI after thyroidectomy.

Hypoalbuminemia as a predictor of acute kidney injury during colistin treatment

This study aimed to assess the predictors of acute kidney injury (AKI) during colistin therapy in a cohort of patients with bloodstream infections (BSI) due to colistin-susceptible Gram-negative bacteria, focusing on the role of serum albumin levels. The study consisted of two parts: (1) a multicentre retrospective clinical study to assess the predictors of AKI during colistin therapy, defined according to the Kidney Disease: Improving Global Outcomes (KDIGO) criteria; and (2) bioinformatic and biochemical characterization of the possible interaction between human serum albumin and colistin. Among the 170 patients included in the study, 71 (42%), 35 (21%), and 11 (6%) developed KDIGO stage 1 (K1-AKI), KDIGO stage 2 (K2-AKI), and KDIGO stage 3 (K3-AKI), respectively. In multivariable analyses, serum albumin <2.5 g/dL was independently associated with K1-AKI (subdistribution hazard ratio [sHR] 1.85, 95% confidence interval [CI] 1.17-2.93, p = 0.009) and K2-AKI (sHR 2.37, 95% CI 1.15-4.87, p = 0.019). Bioinformatic and biochemical analyses provided additional information nurturing the discussion on how hypoalbuminemia favors development of AKI during colistin therapy. In conclusion, severe hypoalbuminemia independently predicted AKI during colistin therapy in a large cohort of patients with BSI due to colistin-susceptible Gram-negative bacteria. Further study is needed to clarify the underlying causal pathways.

Assessing the influence of acute kidney injury on the mortality in patients with acute myocardial infarction: a clinical trail

Objectives: Acute kidney injury (AKI) increases the risk of death following acute myocardial infarction (AMI). In this current study, we tried to understand the role of newly KDIGO defined AKI in AMI-induced early and late mortality.

Methods: We retrospectively analyzed the clinical data of AMI patients (totaling 1371 cases) from the hospital’s computer database. And AKI was defined based on the KDIGO criteria but GFR or urinary output assessment was not used. Subsequently, we compared the association of AKI with 30-day and 30-day to 5-year all-cause mortality, using multivariate COX regression analysis with two models.

Results: We observed the development of AKI in 410 (29.9%) patients during the hospital stay. The 30-day and 30-day to 5-year mortality rates were 5.6% and 11.3%, respectively, in 1371 AMI patients. Further, adjusted Cox regression analysis based on model 1 revealed that AKI severity was an independent risk factor of 30-day mortality, while AKI Stage 3 was an independent predictor of 30-day to 5-year mortality. Adjusted Cox regression analysis based on model 2 revealed that normal baseline renal function with AKI and impaired renal function with AKI were independent risk factors of 30-day mortality, while normal baseline renal function with AKI and impaired renal function with AKI were identified to be independent predictors of 30-day to 5-year mortality.

Conclusions: Whether the baseline renal function decreased or not, AKI strongly correlated with short- and long-term all-cause mortality in patients with AMI. Specifically, the short-term mortality of AMI patients increased with more severe AKI.

Does fluid management affect the occurrence of acute kidney injury?

PURPOSE OF REVIEW

To describe the potential impact of different fluid management strategies on renal outcomes in critically ill and postoperative patients.

RECENT FINDINGS

Uncritical fluid administration may induce renal compartment syndrome and renal venous congestion, which contribute to kidney dysfunction. In more than 5000 randomized surgical or septic patients, goal-directed therapy did not reduce fluid accumulation, acute kidney injury (AKI) development or need for renal replacement therapy. In contrast to synthetic colloids, which increase the risk of AKI, albumin solutions and balanced crystalloids appear well tolerated from a renal standpoint in medical and surgical patients requiring intensive care. However, any clinical benefits compared with 0.9% sodium chloride have not yet been demonstrated.

SUMMARY

Although synthetic colloids should be avoided in patients with or at risk of AKI, the renal efficacy of using albumin solutions and/or balanced crystalloids as alternatives to 0.9% sodium chloride in high-risk patients is yet to be confirmed or refuted. Improved goal-directed protocols, which minimize unnecessary fluid administration and reduce potentially harmful effects of fluid overload, need to be developed and tested.

Early postoperative hypoalbuminemia is a risk factor for postoperative acute kidney injury following hip fracture surgery

INTRODUCTION

Acute kidney injury (AKI) is a common and serious complication after hip fracture surgery in older adults. Hypoalbuminemia is a known independent risk factor for AKI. However, few studies have investigated the relationship between early postoperative hypoalbuminemia and AKI after hip fracture surgery. Therefore, we sought to determine the incidence of and risk factors for AKI and the effects of early postoperative hypoalbuminemia on AKI incidence after surgery for hip fractures, especially intertrochanteric fractures of the proximal femur.

PATIENTS AND METHODS

In this retrospective cohort study from a single center, we reviewed the medical records of 481 consecutive patients (>60 years) who underwent surgery for intertrochanteric fracture of the proximal femur. Multiple logistic regression was performed to identify independent risk factors for AKI. After determining the cut-off value of the minimal level of postoperative serum albumin during the first two postoperative days, we divided the patients into two groups: group 1 included 251 patients whose minimal early postoperative serum albumin level was <2.9 g/dL during the first two postoperative days; and group 2 included 230 patients whose minimal early postoperative serum albumin level was ≥2.9 g/dL. The incidence of AKI was analyzed using inverse probability of treatment weighting (IPTW), propensity score matching (PSM), and propensity score matching weighting (PSMW) analyses.

RESULTS

The incidence of AKI, defined based on the Kidney Disease Improving Global Outcomes criteria, was 11.8% (n = 57). Chronic kidney disease and the minimal early postoperative serum albumin level <2.9 g/dL at any point during the first two postoperative days were independent risk factors for AKI. The IPTW, PSM, and PSMW analyses comparing the incidence of AKI between the two groups revealed that the minimal early postoperative serum albumin level <2.9 g/dL was significantly associated with AKI development (P < 0.001, P = 0.025, and P = 0.011, respectively).

CONCLUSION

The incidence of postoperative AKI was 11.8%. Our findings demonstrate that early postoperative hypoalbuminemia is an independent risk factor for AKI in patients undergoing surgery for intertrochanteric fracture of the proximal femur.

Awareness of acute kidney injury risk factors and perspectives on its practice guidelines

OBJECTIVES

Identifying and assessing risk factors for acute kidney injury (AKI) are crucial for its early detection and possible intervention to prevent AKI and associated adverse outcomes. This study aimed to investigate AKI risk factor awareness and risk assessment by healthcare professionals and to evaluate perspectives on the Kidney Disease Improving Global Outcomes AKI guidelines.

METHODS

This cross-sectional survey-based study was conducted among healthcare professionals (physicians and pharmacists) at XXX from December 2016 to February 2017.

RESULTS

Among the respondents (117 physicians and 135 pharmacists), 78% were aged ≤38 years, 57% were men, and 70% had <9 years of experience. Respondents varied in their knowledge of the 25 risk factors for AKI and 15 nephrotoxic drugs: 96% were aware of nephrotoxic medication, whereas 20% acknowledged female sex as an AKI risk factor, and 92% agreed with aminoglycoside, while 47% agreed with ciprofloxacin as nephrotoxic drugs. A significantly higher percentage of physicians identified individual AKI risk factors than pharmacists; however, a significantly higher percentage of pharmacists identified individual AKI-causing drugs than physicians. Although 77% of respondents encountered AKI cases in their practice, only half of them performed AKI risk assessment, and 42% stratified patients' AKI risk according to their presenting risk factors or documented AKI in previous medical history. Seventy-one percent of respondents agreed that practice guidelines improve patient outcome, and 69% thought these guidelines help standardize care and ensure that patients are treated in consistently.

CONCLUSION

While the majority of the respondents had a positive perspective toward AKI guidelines, a large variation in their knowledge of AKI risk factors, risk assessment, and nephrotoxic drugs was found. Educational efforts are needed to raise awareness and thereby reduce this variation.

U-shape association of serum albumin level and acute kidney injury risk in hospitalized patients

Background

While an association between hypoalbuminemia and increased risk of acute kidney injury (AKI) is well-established, the risk of AKI development and its severity among patients with elevated serum albumin is unclear. The aim of this study was to evaluate the risk of AKI in hospitalized patients stratified by various admission serum albumin levels.

Methods

This single-center retrospective study was conducted at a tertiary referral hospital. All adult hospitalized patients who had admission albumin levels available between January 2009 and December 2013 were enrolled. Admission albumin was categorized based on its distribution into six groups (≤2.4, 2.5–2.9, 3.0–3.4, 3.5–3.9, 4.0–4.4, and ≥4.5 mg/dL). The primary outcome was the incidence of hospital-acquired AKI (HAKI). Logistic regression analysis was performed to obtain the odds ratio of AKI for various admission albumin strata using the albumin 3.5 to 3.9 mg/dL (lowest incidence of AKI) as the reference group.

Results

Of the total 9,552 studied patients, HAKI occurred in 1,556 (16.3%) patients. The incidence of HAKI among patients with admission albumin ≤2.4, 2.5–2.9, 3.0–3.4, 3.5–3.9, 4.0–4.4, and ≥4.5 mg/dL was 18.3%, 14.3%, 15.5%, 14.2%, 16.7%, and 26.0%, respectively. After adjusting for potential confounders, admission serum albumin levels ≤2.4 and ≥4.5 mg/dL were associated with an increased risk of HAKI with odds ratios of 1.52 (95% CI 1.18–1.94) and 2.16 (95% CI 1.74–2.69), respectively. While stage 1 HAKI was significantly more frequent among patients with admission albumin ≥4.5 mg/dL (23.0% vs. 11.6%, P<0.001), incidence of stage 3 HAKI was higher in those with albumin ≤2.4 mg/dL (2.8% vs 0.3%, P<0.001).

Conclusion

Admission serum albumin levels ≤2.4 and ≥4.5 mg/dL were associated with an increased risk for HAKI. Patients with admission albumin ≥4.5 mg/dL had HAKI with a lower intensity when compared with those who had admission albumin levels ≤2.4 mg/dL.

AKI in the very elderly patients without preexisting chronic kidney disease: a comparison of 48-hour window and 7-day window for diagnosing AKI using the KDIGO criteria

Objectives

To compare the differences between the Kidney Disease Improving Global Outcomes (KDIGO) criteria of the 48-hour window and the 7-day window in the diagnosis of acute kidney injury (AKI) in very elderly patients, as well as the relationship between the 48-hour and 7-day windows for diagnosis and 90-day mortality.

Patients and methods

We retrospectively enrolled very elderly patients (≥75 years old) from the geriatrics department of the Chinese PLA General Hospital between January 2007 and December 2015. AKI patients were divided into 48-hour and 7-day groups by their diagnosis criteria. AKI patients were divided into survivor and nonsurvivor groups by their outcomes within 90 days after diagnosis of AKI.

Results

In total, 652 patients were included in the final analysis. The median age of the cohort was 87 (84–91) years, the majority (623, 95.6%) of whom were male. Of the 652 AKI patients, 334 cases (51.2%) were diagnosed with AKI by the 48-hour window for diagnosis, while 318 cases (48.8%) were by the 7-day window for diagnosis. The 90-day mortality was 42.5% in patients with 48-hour window AKI and 24.2% in patients with 7-day window AKI. Kaplan–Meier curves showed that 90-day mortality was lower in the 7-day window AKI group than in the 48-hour window AKI group (log rank: P<0.001). Multivariate analysis by the Cox model revealed that 48-hour window for diagnosis hazard ratio (HR=1.818; 95% CI: 1.256–2.631; P=0.002) was associated with higher 90-day mortality.

Conclusion

The 90-day mortality was higher in 48-hour window AKI than in 7-day window AKI in very elderly patients. The 48-hour KDIGO window definition may be less sensitive. The 48-hour KDIGO window definition is significantly better correlated with subsequent mortality and is, therefore, still appropriate for clinical use. Finding early, sensitive biomarkers of kidney damage is a future direction of research.

[Association of hypoalbuminemia with acute kidney injury in children after cardiac surgery]

OBJECTIVE

To study whether hypoalbuminemia after pediatric cardiopulmonary bypass (CPB) for cardiac surgery is a risk factor for postoperative acute kidney injury (AKI).

METHODS

A retrospective analysis was performed on the clinical data of 1 110 children who underwent CPB surgery between 2012 and 2016. According to the minimum serum albumin within 48 hours postoperatively, these patients were divided into hypoalbuminemia group (≤35 g/L) and normal albumin group (>35 g/L). The two groups were compared in terms of perioperative data and the incidence of AKI. Furthermore, the incidence of AKI was compared again after propensity score matching for the unbalanced factors during the perioperative period. The perioperative risk factors for postoperative AKI were analyzed by logistic regression.

RESULTS

The overall incidence rate of postoperative AKI was 13.78% (153/1 110), and the mortality rate was 2.52% (28/1 110). The mortality rate of children with AKI was 13.1% (20/153). The patients with hypoalbuminemia after surgery (≤35 g/L) accounted for 44.50% (494/1 110). Before and after propensity score matching, the hypoalbuminemia group had a significantly higher incidence of AKI than the normal albumin group (P<0.05). The children with AKI had a significantly lower serum albumin level after surgery than those without AKI (P<0.05). The multivariate logistic regression analysis showed albumin ≤35 g/L was one of the independent risk factors for postoperative AKI.

CONCLUSIONS

Albumin ≤35 g/L within 48 hours postoperatively is an independent risk factor for postoperative AKI in children after CPB surgery.

[Association of hypoalbuminemia with acute kidney injury in children after cardiac surgery]

OBJECTIVE

To study whether hypoalbuminemia after pediatric cardiopulmonary bypass (CPB) for cardiac surgery is a risk factor for postoperative acute kidney injury (AKI).

METHODS

A retrospective analysis was performed on the clinical data of 1 110 children who underwent CPB surgery between 2012 and 2016. According to the minimum serum albumin within 48 hours postoperatively, these patients were divided into hypoalbuminemia group (≤35 g/L) and normal albumin group (>35 g/L). The two groups were compared in terms of perioperative data and the incidence of AKI. Furthermore, the incidence of AKI was compared again after propensity score matching for the unbalanced factors during the perioperative period. The perioperative risk factors for postoperative AKI were analyzed by logistic regression.

RESULTS

The overall incidence rate of postoperative AKI was 13.78% (153/1 110), and the mortality rate was 2.52% (28/1 110). The mortality rate of children with AKI was 13.1% (20/153). The patients with hypoalbuminemia after surgery (≤35 g/L) accounted for 44.50% (494/1 110). Before and after propensity score matching, the hypoalbuminemia group had a significantly higher incidence of AKI than the normal albumin group (P<0.05). The children with AKI had a significantly lower serum albumin level after surgery than those without AKI (P<0.05). The multivariate logistic regression analysis showed albumin ≤35 g/L was one of the independent risk factors for postoperative AKI.

CONCLUSIONS

Albumin ≤35 g/L within 48 hours postoperatively is an independent risk factor for postoperative AKI in children after CPB surgery.

Vancomycin-induced acute kidney injury in elderly Chinese patients: a single-centre cross-sectional study

AIMS

The objective of the present study was to investigate the current situation concerning, and risk factors for, vancomycin (VAN)-induced acute kidney injury (VI-AKI) in elderly Chinese patients, to assess outcomes and risk factors in patients who have developed VI-AKI, in order to provide suggestions for improving the prevention and treatment of this condition in these patients.

METHOD

We retrospectively identified elderly older inpatients who had received four or more doses of VAN treatment. We compared patients with VI-AKI with those who received VAN treatment and had not developed AKI (NO-AKI). We defined VI-AKI as developing AKI during VAN therapy or within 3 days after withdrawal of VAN.

RESULTS

A total of 647 out of 862 elderly inpatients were included in the study. Among those excluded, in 89.3% of cases (192/215) this was because of lack of data on serum creatinine (SCr). Among included patients, 32.5% (210/647) of patients received therapeutic drug monitoring (TDM) during VAN therapy. In 66.9% of cases (424/634), there was insufficient TDM, and in 3.9% (25/634) this was appropriate. A total of 102 patients had confirmed VI-AKI, with an incidence of 15.8% (102/647). Multiple logistic regression analysis revealed that hyperuricaemia [odds ratio (OR) = 3.045; P = 0.000)], mechanical ventilation (OR = 1.906; P = 0.022) and concomitant vasopressor therapy (OR = 1.919; P = 0.027) were independent risk factors for VI-AKI; higher serum albumin (OR = 0.885; P = 0.000) was determined to be an independent protective factor for VI-AKI.

CONCLUSIONS

For the elderly Chinese patients treated with VAN, there was insufficient monitoring of SCr, too little use of VAN TDM, and lower rate of patients whose VAN though serum concentrations were not obtained at the correct time. We recommend that hospital managers increase investment in clinical pharmacists, to strengthen professional management. Patients with concomitant hyperuricaemia and on mechanical ventilation and vasopressor therapy should be paid more attention, and a higher serum albumin was determined to be an independent protective factor for VI-AKI.

Association of prealbumin levels with contrast-induced acute kidney injury in elderly patients with elective percutaneous coronary intervention

Purpose

Inflammatory factors play a critical role in contrast-induced acute kidney injury (CI-AKI). Prealbumin, a nutritional and inflammatory indicator, is a well-established predictor of short- and long-term outcomes in numerous clinical conditions. The current study investigated the association of pre-procedural prealbumin levels with CI-AKI and long-term outcomes in geriatric patients after elective percutaneous coronary intervention (PCI).

Patients and methods

A total of 558 patients aged≥75 years, who underwent elective PCI between January 2012 and December 2015, were selected for the current study. Pre-procedural prealbumin levels were measured before PCI. Multivariable logistic regression and Cox proportional hazard regression analyses were performed to identify the independent risk factors for CI-AKI and long-term mortality.

Results

Out of 558 patients, 54 developed CI-AKI. The optimal cutoff value of prealbumin for detecting CI-AKI was 185.5 mg/L with 62.7% sensitivity and 70.4% specificity based on the receiver operating characteristic analysis (C-statistic=0.710; 95% confidence interval [CI] 0.673–0.751). Multivariable analysis demonstrated that prealbumin≤185.5 mg/L was significantly associated with CI-AKI (odds ratio [OR] 0.397; 95% CI 0.195–0.808; P=0.011). Cox regression analysis demonstrated that prealbumin≤185.5 mg/L was associated with long-term mortality (adjusted hazard ratio [HR] 0.525; 95% CI 0.289–0.952; P=0.034) during the follow-up.

Conclusion

Pre-procedural levels of prealbumin were independently associated with an increased risk of CI-AKI and long-term mortality in elderly patients undergoing elective PCI.

PREOPERATIVE RISK FACTORS FOR ACUTE KIDNEY INJURY AFTER LIVER TRANSPLANTATION: RESULTS FROM A CROSS-SECTIONAL STUDY IN NORTHEAST OF BRAZIL

BACKGROUND

Acute kidney injury (AKI) is a common complication in the immediate postoperative period of patients undergoing liver transplantation.

OBJECTIVE

The aim of this study was to evaluate preoperative risk factors for AKI after liver transplantation.

METHODS

A cross-sectional study was conducted with adults submitted to orthotopic liver transplantation at a reference hospital in Fortaleza, Northeast of Brazil, from January to December 2016. Preoperative risk factors were evaluated for AKI development in the immediate postoperative period. AKI was defined according to the Kidney Disease: Improving Global Outcomes (KDIGO) criteria.

RESULTS

A total of 40 patients were included in the study. AKI was found in 85% of patients in the first 24 hours after transplantation, most of them (40%) classified in KDIGO stage 1. Preoperative data indicate that serum albumin levels were lower in the KDIGO stage 3 group compared to the non-AKI group, as well as the hematocrit levels. Direct bilirubin (DB) was higher in the KDIGO stage 3 group compared to the group without AKI, as well as alkaline phosphatase (AP) and gamma-glutamiltransferase (GGT). In a logistic regression analysis independent risk factors for AKI were increase levels of AP, GGT and DB and decrease level of serum albumin.

CONCLUSION

Low levels of serum albumin, and elevated levels of DB, AP and GGT in the preoperative period are risk factors for AKI development after liver transplantation.

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.

Development and Validation of a Risk Prediction Model for Acute Kidney Injury After the First Course of Cisplatin

Purpose Cisplatin-associated acute kidney injury (C-AKI) is common. We sought to develop and validate a predictive model for C-AKI after the first course of cisplatin. Methods Clinical and demographic data were collected on patients who received cisplatin between 2000 and 2016 at two cancer centers. C-AKI was defined as a 0.3 mg/dL rise in serum creatinine within 14 days of receiving cisplatin. Using multivariable logistic regression models with C-AKI as the primary outcome, we created a scoring model from the development cohort (DC) and tested it in the validation cohort (VC). Results C-AKI occurred in 13.6% of 2,118 patients in the DC and in 11.6% of 2,363 patients in the VC. Factors significantly associated with C-AKI included age 61 to 70 years (odds ratio [OR], 1.64 [95% CI, 1.21 to 2.23]; P = .001) and 71 to 90 years (OR, 2.97 [95% CI, 2.06 to 4.28]; P < .001) compared with ≤ 60 years; cisplatin dose 101 to 150 mg (OR, 1.58 [95% CI, 1.14 to 2.19]; P = .007) and > 150 mg (OR, 3.73 [95% CI, 2.68 to 5.20]; P < .001) compared with ≤ 100 mg; a history of hypertension (OR, 2.10 [95% CI, 1.54 to 2.72]; P < .001) compared with no hypertension; and serum albumin 2.0 to 3.5 g/dL (OR, 2.21 [95% CI, 1.62 to 3.03]; P < .001) compared with > 3.5 g/dL. The baseline estimated glomerular filtration rate was not significantly associated with the risk of C-AKI. The c-statistics of the score-based model in the DC and the VC were 0.72 (95% CI, 0.69 to 0.75) and 0.70 (95% CI, 0.67 to 0.73), respectively. Scores of 0, 3.5, and 8.5 were associated with a probability of C-AKI of 0.03 (95% CI, 0.03 to 0.05), 0.12 (95% CI, 0.11 to 0.14), and 0.51 (95% CI, 0.43 to 0.60), respectively. Conclusion A score-based model created by using the patient's age, cisplatin dose, hypertension, and serum albumin is predictive of C-AKI.

Hypoalbuminemia at admission predicts the development of acute kidney injury in hospitalized patients: A retrospective cohort study

Background

Development of acute kidney injury (AKI) is common and is associated with poor outcomes. We aimed to determine whether hypoalbuminemia (HA) at admission could be a risk factor for the development of AKI and mortality in hospitalized patients.

Methods

We enrolled patients who were admitted to Seoul National University Bundang Hospital from January 2013 to December 2013. HA at admission was defined as a serum albumin level < 3.4 mg/dL measured within two days after admission. AKI was defined as an increase in the serum creatinine level by ≥0.3 mg/dL or ≥1.5 times of the baseline value during the hospital stay.

Results

A total of 19,472 patients were enrolled and divided into HA and normoalbuminemia (NA) groups at admission. The incidence of AKI was 10.7% (340/3179) in the HA group and 4.1% (662/16293) in the NA group (adjusted odds ratio [OR], 1.243; 95% confidence interval [CI], 1.069–1.445; P = 0.005). The hazard ratios for the 30-day, 90-day, and 1-year mortality were 1.873 (95% CI, 1.383–2.537; P < 0.001), 1.710 (95% CI, 1.410–2.072; P < 0.001), and 1.372 (95% CI, 1.214–1.551; P < 0.001), compared to the NA group. In patients with AKI, albumin replacement improved renal recovery (OR, 2.605; 95% CI, 1.450–4.681; P = 0.001). The mortality rate was not different according to albumin replacement.

Conclusions

HA is associated with the development of AKI and high mortality in hospitalized patients. Replacement of albumin after the development of AKI may contribute to renal recovery. Further clinical trials are warranted.

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.

Are There Modifiable Risk Factors to Improve AKI?

Acute kidney injury (AKI) is a common critical syndrome, with high morbidity and mortality. Patients with AKI typically have an adverse prognosis, from incident chronic kidney disease (CKD), progression to end-stage renal disease (ESRD), subsequent cardiovascular disease, and ultimately death. However, there is currently no effective therapy for AKI. Early detection of risk factors for AKI may offer a good approach to prevention or early intervention. Traditional risk factors include extreme age, many common comorbid diseases, such as preexisting CKD, some specific exposures, such as sepsis, and exposure to some nephrotoxic agents. Recently, several novel risk factors for AKI, such as hyperuricemia, hypoalbuminemia, obesity, anemia, and hyperglycemia, have been identified. The underlying mechanisms between these nontraditional risk factors and AKI and whether their correction can reduce AKI occurrence remain to be clarified. This review describes the current epidemiology of AKI, summarizes its outcome, outlines the traditional risk profile, and finally highlights some recently identified novel risk factors.

Diagnostic performance of initial serum albumin level for predicting in-hospital mortality among aspiration pneumonia patients

PURPOSE

The predictive value of serum albumin in adult aspiration pneumonia patients remains unknown.

METHODS

Using data collected during a 3-year retrospective cohort of hospitalized adult patients with aspiration pneumonia, we evaluated the predictive value of serum albumin level at ED presentation for in-hospital mortality.

RESULTS

248 Patients were enrolled; of these, 51 cases died (20.6%). The mean serum albumin level was 3.4±0.7g/dL and serum albumin levels were significantly lower in the non-survivor group than in the survivor group (3.0±0.6g/dL vs. 3.5±0.6g/dL). In the multivariable logistic regression model, albumin was associated with in-hospital mortality significantly (adjusted odds ratio 0.30, 95% confidential interval (CI) 0.16-0.57). The area under the receiver operating characteristics (AUROC) for in-hospital survival was 0.72 (95% CI 0.64-0.80). The Youden index was 3.2g/dL and corresponding sensitivity, specificity, positive predictive value, negative predictive value, positive and negative likelihood ratio were 68.6%, 66.5%, 34.7%, 89.1%, 2.05 and 0.47, respectively. High sensitivity (98.0%) was shown at albumin level of 4.0g/dL and high specificity (94.9%) was shown at level of 2.5g/dL.

CONCLUSION

Initial serum albumin levels were independently associated with in-hospital mortality among adult patients hospitalized with aspiration pneumonia and demonstrated fair discriminative performance in the prediction of in-hospital mortality.

Prognostic value of hypoalbuminemia for adverse outcomes in patients with rheumatic heart disease undergoing valve replacement surgery

High-risk patients with rheumatic heart disease (RHD) who were undergoing valve replacement surgery (VRS) were not identified entirely. This study included 1782 consecutive patients with RHD who were undergoing VRS to explore the relationship between hypoalbuminemia and adverse outcomes and to confirm whether hypoalbuminemia plays a role in risk evaluation. A total of 27.3% of the RHD patients had hypoalbuminemia. In-hospital deaths were significantly higher in the hypoalbuminemic group than in the non-hypoalbuminemic group (6.6% vs 3.1%, P = 0.001). Hypoalbuminemia was an independent predictor of in-hospital death (OR = 1.89, P = 0.014), even after adjusting for the Euro score. The addition of hypoalbuminemia to Euro score enhanced net reclassification improvement (0.346 for in-hospital death, P = 0.004; 0.306 for 1-year death, p = 0.005). A Kaplan-Meier curve analysis revealed that the cumulative rate of 1-year mortality after the operation was higher in patients with a new Euro score ≥6. These findings indicated that hypoalbuminemia was an independent risk factor for in-hospital and 1-year mortality after VRS in patients with RHD, which might have additive prognostic value to Euro score.

Association of preoperative hypoalbuminemia with postoperative acute kidney injury in patients undergoing brain tumor surgery: a retrospective study

OBJECTIVE Hypoalbuminemia is known to be independently associated with postoperative acute kidney injury (AKI). However, little is known about the association between the preoperative serum albumin level and postoperative AKI in patients undergoing brain tumor surgery. The authors investigated the incidence of AKI, impact of preoperative serum albumin level on postoperative AKI, and death in patients undergoing brain tumor surgery. METHODS The authors retrospectively reviewed the electronic medical records and laboratory results of 2363 patients who underwent brain tumor surgery between January 2008 and December 2014. Postoperative AKI was defined according to Kidney Disease: Improving Global Outcomes Definition and Staging (KDIGO). Multivariate logistic regression analysis was used to identify demographic, preoperative laboratory, and intraoperative factors associated with AKI development. Cox proportional hazards models were used to investigate the adjusted odds ratio and hazard ratio for the association between preoperative serum albumin level and outcome variables. RESULTS The incidence of AKI was 1.8% (n = 43) using KDIGO criteria. The incidence of AKI was higher in patients with a preoperative serum albumin level < 3.8 g/dl (3.5%) than in those with a preoperative serum albumin level ≥ 3.8 g/dl (1.2%, p < 0.001). The overall mortality was also higher in the former than in the latter group (5.0% vs 1.8%, p < 0.001). After inverse probability of treatment-weighting adjustment, a preoperative serum albumin level < 3.8 g/dl was also found to be associated with postoperative AKI (OR 1.981, 95% CI 1.022-3.841; p = 0.043) and death (HR 2.726, 95% CI 1.522-4.880; p = 0.001). CONCLUSIONS The authors' results demonstrated that a preoperative serum albumin level of < 3.8 g/dl was independently associated with AKI and mortality in patients undergoing brain tumor surgery.

Structural and functional integrity of human serum albumin: Analytical approaches and clinical relevance in patients with liver cirrhosis

Human serum albumin (HSA) is the most abundant circulating plasma protein. Besides a significant contribution to the osmotic pressure, it is also involved in the fine regulation of many other physiological processes, including the balance of the redox state, the inflammatory and/or immunological responses, and the pharmacokinetic and pharmacodynamics of many drugs. Growing evidence suggests that HSA undergoes structural and functional damage in diseases characterized by an enhanced systemic inflammatory response and oxidative stress, as it occurs in chronic liver disease. Based on their clinical relevance, this review provides a summary of the most common post-translational modifications affecting HSA structural integrity and functions and their clinical relevance in the field of liver disease. The review also provides a critical description of the analytical approaches employed for the investigation of conformational alterations and the identification/quantitation of specific post-translational modifications affecting HSA. Finally, the analytical methods available for the assessment of two of the most clinically relevant non-oncotic properties of HSA, namely the binding capacity and the antioxidant activity, are critically reviewed. Among the available techniques particular attention is given to those proposed for the in vitro and in vivo investigation of structurally modified albumin.

Acute kidney injury after liver transplantation: Recent insights and future perspectives

Acute kidney injury (AKI) is a common postoperative complication after liver transplantation (LT). The occurrence of postoperative AKI after LT (Post-LT AKI) is associated with inferior patient and graft outcomes. Post-LT AKI is multifactorial in origin and has been related to the severity of liver disease, pre-LT renal dysfunction, graft quality, perioperative events and toxicity of immunosuppressive therapy. Furthermore it is thought that hepatic ischaemia reperfusion injury might be a driving force in the aetiology of post-LT AKI. Novel biomarkers for AKI are emerging and can be useful for early identification and characterization of AKI. There is a clear need for strategies aimed at preventing or treating post-LT AKI. Several pharmacological and non-pharmacological interventions have been studied, but so far failed to show any benefit in the prevention of post-LT AKI. Further studies are needed to develop and evaluate new interventions aimed at preventing post-LT AKI and improve patient outcomes.

Urinary cadmium levels predict mortality of patients with acute heart failure

BACKGROUND

Acute heart failure (AHF) is a serious condition that is associated with increased mortality in critically ill patients. Previous studies indicated that environmental exposure to cadmium increases mortality of general populations. However, the relationship of cadmium exposure and mortality is unclear for AHF patients.

MATERIALS AND METHODS

A total of 153 patients with AHF in intensive care units (ICUs) met the inclusion criteria and were followed up for 6 months. Demographic data, AHF etiology, hematological and biochemical data, and hospital mortality were recorded. The scores of two predictive systems (Sequential Organ Failure Assessment [SOFA], Acute Physiology and Chronic Health Evaluation II [APACHE II]) for mortality in critically ill patients were calculated, and urinary cadmium levels were recorded.

RESULTS

At the end of the follow-up period, the mortality rate was 24.8%. The survivors (n=115) had higher urinary cadmium levels on day 1 (D1UCd) of ICU admission than non-survivors (n=38). A multiple linear regression analysis revealed a positive correlation between D1UCd and acute kidney injury, but a negative correlation between D1UCd and the level of serum albumin. A multivariate Cox analysis indicated that D1UCd was an independent predictor of mortality in AHF patients. For each increment of 1 μg of D1UCd, the hazard ratio for ICU mortality was 1.20 (95% confidence interval [CI]: 1.09-1.32, P<0.001). The area under the receiver operating characteristic curve for D1UCd was 0.84 (95% CI: 0.78-0.91), better than the values for the SOFA and APACHE II systems.

CONCLUSION

The D1UCd may serve as a single predictor of hospital mortality for AHF patients in the ICU. Because of the high mortality and smaller sample size, more investigations are required to confirm these observations and elucidate the underlying mechanisms.

Acute kidney injury and mortality 1 year after major non-cardiac surgery

Background

Even mild and transient acute kidney injury (AKI), defined by increases in serum creatinine level, has been associated with adverse outcomes after major surgery. However, characteristic decreases in creatinine concentration during major illness could confound accurate assessment of postoperative AKI.

Methods

In a single-hospital, retrospective cohort study of non-cardiac surgery, the association between postoperative AKI, defined using the Kidney Disease: Improving Global Outcomes criteria, and 1-year survival was modelled using a multivariable Cox proportional hazards analysis. Factors associated with development of AKI were examined by means of multivariable logistic regression. Temporal changes in serum creatinine during and after the surgical admission in patients with and without AKI were compared.

Results

Some 1869 patients were included in the study, of whom 128 (6·8 per cent) sustained AKI (101 stage 1, 27 stage 2–3). Seventeen of the 128 patients with AKI (13·3 per cent) died in hospital compared with 16 of 1741 (0·9 per cent) without AKI (P &lt; 0·001). By 1 year, 34 patients with AKI (26·6 per cent) had died compared with 106 (6·1 per cent) without AKI (P &lt; 0·001). Over the 8–365 days after surgery, AKI was associated with an adjusted hazard ratio for death of 2·96 (95 per cent c.i. 1·86 to 4·71; P &lt; 0·001). Among hospital survivors without AKI, the creatinine level fell consistently (median difference at discharge versus baseline –7 (i.q.r. –15 to 0) µmol/l), but not in those with AKI (0 (–16 to 26) µmol/l) (P &lt; 0·001).

Conclusion

Although the majority of postoperative AKI was mild, there was a strong association with risk of death in the year after surgery. Underlying decreases in serum creatinine concentration after major surgery could lead to underestimation of AKI severity and overestimation of recovery.

Impact of decreased serum albumin levels on acute kidney injury in patients with acute decompensated heart failure: a potential association of atrial natriuretic peptide

Although hypoalbuminemia at admission is a risk for acute kidney injury (AKI) and mortality in patients with acute decompensated heart failure (ADHF), the clinical significance of decreased serum albumin levels (DAL) during ADHF therapy has not been elucidated. This study aimed to evaluate whether DAL was associated with AKI, and whether intravenous atrial natriuretic peptide (ANP) administration, which provides an effective treatment for ADHF but promotes albumin extravasation, was associated with DAL and AKI. A total of 231 consecutive patients with ADHF were enrolled. AKI was defined as ≥0.3 mg/dl absolute or 1.5-fold increase in serum creatinine levels within 48 h. AKI occurred in 73 (32%) of the 231 patients during ADHF therapy. The median value of decreases in serum albumin levels was 0.3 g/dl at 7 days after admission. When DAL was defined as ≥0.3 g/dl decrease in serum albumin levels, DAL occurred in 113 patients, and was independently associated with AKI. Of the 231 patients, 73 (32%) were treated with intravenous ANP. DAL occurred more frequently in patients receiving ANP than in those not receiving ANP (77 vs. 36%, p < 0.001), and ANP was independently associated with DAL. The incidence of AKI was higher in patients receiving ANP than in those not receiving ANP (48 vs. 24%, p < 0.001). ANP was independently associated with AKI. In conclusion, DAL is associated with AKI. Intravenous ANP administration may be one of the promoting factors of DAL, which leads to AKI, indicating a possible novel mechanism of AKI.

Serum prealbumin and its changes over time are associated with mortality in acute kidney injury

Serum prealbumin is a clinically relevant indicator of nutritional status and inflammation in patients with acute kidney injury (AKI). This study aimed to determine whether serum prealbumin and its longitudinal changes over a week could improve the prediction of 90-day mortality in AKI patients. This prospective cohort study included 340 adults with AKI between 2014 and 2015. There were 94 (27.6%) patient deaths within 90 days. Serum prealbumin level <10 mg/dL at the time of AKI diagnosis was associated with a 155% increased death risk ratio (adjusted hazard ratio [HR], 2.55; 95% confidence interval [CI], 1.18 to 5.49; P = 0.02). Serum prealbumin fall >4 mg/dL was also associated with 90-day mortality in adjusted Cox regression models (HR, 1.79; 95% CI, 1.06 to 3.03; P = 0.03). Compared to serum albumin, mortality-predictability of serum prealbumin (P = 0.01) and its changes (P = 0.01) were both increased. Adding prealbumin and its changes on the conventional covariates improved the prediction of progression to 90-day mortality (NRI 0.29, P = 0.04; aIDI 0.08; P = 0.03). In conclusion, serum prealbumin, and its changes were independent predictors of worse prognosis in AKI, and could be potential surrogates to better predict 90-day mortality.

Early postoperative albumin level following total knee arthroplasty is associated with acute kidney injury: A retrospective analysis of 1309 consecutive patients based on kidney disease improving global outcomes criteria

Hypoalbuminemia has been reported to be an independent risk factor for acute kidney injury (AKI). However, little is known about the relationship between the albumin level and the incidence of AKI in patients undergoing total knee arthroplasty (TKA). The aim of our study was to assess incidence and risk factors for AKI and to evaluate the relationship between albumin level and AKI following TKA.The study included a retrospective review of medical records of 1309 consecutive patients who underwent TKA between January 2008 and December 2014. The patients were divided into 2 groups according to the lowest serum albumin level within 2 postoperative days (POD2_alb level < 3.0 g/dL vs ≥3.0 g/dL). Multivariate logistic regression analysis was used to assess risk factors for AKI. A comparison of incidence of AKI, hospital stay, and overall mortality in the 2 groups was performed using propensity score analysis.Of 1309 patients, 57 (4.4%) developed AKI based on Kidney Disease Improving Global Outcomes criteria. Factors associated with AKI included age (odds ratio [OR] 1.05; 95% confidence interval [CI] 1.01-1.09; P = 0.030), diabetes (OR 3.12; 95% CI 1.65-5.89; P < 0.001), uric acid (OR 1.51; 95% CI 1.26-1.82; P < 0.001), beta blocker use (OR 2.65; 95% CI 1.48-4.73; P = 0.001), diuretics (OR 16.42; 95% CI 3.08-87.68; P = 0.001), and POD2_alb level < 3.0 g/dL (OR 1.92; 95% CI 1.09-3.37; P = 0.023). After propensity score analysis, POD2_alb level<3.0 g/dL was associated with AKI occurrence (OR 1.82; 95% CI 1.03-3.24, P = 0.041) and longer hospital stay (P = 0.001).In this study, we demonstrated that POD2_alb level<3.0 g/dL was an independent risk factor for AKI and lengthened hospital stay in patients undergoing TKA.

Probiotic pre-administration reduces mortality in a mouse model of cecal ligation and puncture-induced sepsis

A number of clinical trials have demonstrated that the use of probiotics has the potential to prevent nosocomial infections. However, the mechanism underlying probiotic-induced anti-infection and sepsis remains to be investigated. In the present study, 200 µl/day of Lactobacillus rhamnosus GG (LGG) or normal saline (control) was orally administrated to 4-week-old C57BL6 mice 4 weeks prior to cecal ligation and puncture (CLP). A number of mice were sacrificed 24 h after CLP, and the remaining mice were used for survival studies. Ileum tissues were collected to evaluate the injury on the intestine. Blood samples were also obtained to investigate the changed metabolic pattern in mice that underwent different treatments using ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS). In the survival studies, the mortality of CLP-induced septic mice pretreated with LGG was significantly lower compared with untreated mice (P=0.029). Ileum mucosal damage was evident in the control septic mice. Based on the data of UPLC-QTOF-MS, phosphatidylcholines were increased and lysophosphatidylcholines (LPCs) that contained polyunsaturated fatty acids were decreased in septic mice, whereas saturated fatty acid LPCs reveal no significant difference between septic and sham mice. In addition, the metabolic profile in the septic mice pretreated with LGG was much closer to that of sham mice compared with control septic mice. The results of the present study suggest that probiotic pre-administration reduces the mortality in septic mice by decreasing ileum mucosal damage, increasing the gut barrier integrity and altering global serum metabolic profiles.

RIFLE classification in geriatric patients with acute kidney injury in the intensive care unit

BACKGROUND

The RIFLE classification is widely used to assess the severity of acute kidney injury (AKI), but its application to geriatric AKI patients complicated by medical problems has not been reported.

METHODS

We investigated 256 geriatric patients (≥65 years old; mean age, 74.4 ± 6.3 years) who developed AKI in the intensive care unit (ICU) according to the RIFLE classification. Etiologic, clinical, and prognostic variables were analyzed.

RESULTS

They were categorized into RIFLE-R (n = 53), RIFLE-I (n = 102), and RIFLE-F (n = 101) groups. The overall in-hospital mortality was 39.8 %. There were no significant differences in RIFLE category between survivors and non-survivors. Survivors had significantly less needs for a ventilator and vasopressor, and lower number of failing organs. Survivors had higher systolic blood pressure, hemoglobin level, and serum albumin levels. We performed a logistic regression analysis to identify the independent predictors of in-hospital mortality. In a univariate analysis, hypertension, chronic kidney disease, RIFLE classification, number of failing organs, need for a ventilator and vasopressor, systolic blood pressure, hemoglobin level, and serum albumin levels were identified as prognostic factors of in-hospital mortality. However, in a multivariate analysis, hypertension, chronic kidney disease, number of failing organs, and serum albumin levels were independent risk factors, with no significant difference for in-hospital mortality with the RIFLE classification.

CONCLUSION

The RIFLE classification might not be associated with mortality in geriatric AKI patients in the ICU. In geriatric patients with AKI, various factors besides severity of AKI should be considered to predict mortality.

Effect of Exogenous Albumin on the Incidence of Postoperative Acute Kidney Injury in Patients Undergoing Off-pump Coronary Artery Bypass Surgery with a Preoperative Albumin Level of Less Than 4.0 g/dl

Background

Hypoalbuminemia may increase the risk of acute kidney injury (AKI). The authors investigated whether the immediate preoperative administration of 20% albumin solution affects the incidence of AKI after off-pump coronary artery bypass surgery.

Methods

In this prospective, single-center, randomized, parallel-arm double-blind trial, 220 patients with preoperative serum albumin levels less than 4.0 g/dl were administered 100, 200, or 300 ml of 20% human albumin according to the preoperative serum albumin level (3.5 to 3.9, 3.0 to 3.4, or less than 3.0 g/dl, respectively) or with an equal volume of saline before surgery. The primary outcome measure was AKI incidence after surgery. Postoperative AKI was defined by maximal AKI Network criteria based on creatinine changes.

Results

Patient characteristics and perioperative data except urine output during surgery were similar between the two groups studied, the albumin group and the control group. Urine output (median [interquartile range]) during surgery was higher in the albumin group (550 ml [315 to 980]) than in the control group (370 ml [230 to 670]; P = 0.006). The incidence of postoperative AKI in the albumin group was lower than that in the control group (14 [13.7%] vs. 26 [25.7%]; P = 0.048). There were no significant between-group differences in severe AKI, including renal replacement therapy, 30-day mortality, and other clinical outcomes. There were no significant adverse events.

Conclusion

Administration of 20% exogenous albumin immediately before surgery increases urine output during surgery and reduces the risk of AKI after off-pump coronary artery bypass surgery in patients with a preoperative serum albumin level of less than 4.0 g/dl.

Risk Stratification for Acute Kidney Injury: Are Biomarkers Enough?

Acute kidney injury (AKI) is a common and serious complication that is associated with several adverse outcomes in hospitalized patients. AKI significantly increases the risk of mortality, need for renal replacement therapy, and intensive care admission, and it also has serious economic ramifications. Effective risk stratification to identify patients at risk for severe AKI is essential for targeting our health care and research resources to tackle this important public health issue. The overwhelming majority of research in earlier diagnosis and risk stratification of AKI over the past 10 years has focused on novel biomarker development. The purpose of this review is to provide an update on other novel risk stratification tools than can be used in the prognostication of AKI. We discuss the utility of the furosemide stress test in predicting the severity of AKI and the renal angina index in predicting the occurrence of AKI. We also discuss NephroCheck, a prognostic test that measures tissue inhibitor of metalloproteinase-2 and insulin-like growth factor binding protein 7 for the early detection of severe AKI.

Fluid management in sepsis: The potential beneficial effects of albumin

Fluid administration is a key intervention in hemodynamic resuscitation. Timely expansion (or restoration) of plasma volume may prevent tissue hypoxia and help to preserve organ function. In septic shock in particular, delaying fluid resuscitation may be associated with mitochondrial dysfunction and may promote inflammation. Ideally, infused fluids should remain in the plasma for a prolonged period. Colloids remain in the intravascular space for longer periods than do crystalloids, although their hemodynamic effect is affected by the usual metabolism of colloid substances; leakage through the endothelium in conditions with increased permeability, such as sepsis; and/or external losses, such as with hemorrhage and burns. Albumin has pleiotropic physiological activities including antioxidant effects and positive effects on vessel wall integrity. Its administration facilitates achievement of a negative fluid balance in hypoalbuminemia and in conditions associated with edema. Fluid resuscitation with human albumin is less likely to cause nephrotoxicity than with artificial colloids, and albumin infusion has the potential to preserve renal function in critically ill patients. These properties may be of clinical relevance in circulatory shock, capillary leak, liver cirrhosis, and de-escalation after volume resuscitation. Sepsis is a candidate condition in which human albumin infusion to preserve renal function should be substantiated.

Simple blood and urinary parameters measured at ICU admission may sign for AKI development in the early postoperative period: a retrospective, exploratory study

Recent studies have suggested that some blood physicochemical and urinary biochemical parameters have a standardized behavior during acute kidney injury (AKI) development. The changes in these parameters frequently begin to occur before significant rises in serum creatinine (sCr) and may help in identifying patients with more subtle decreases in glomerular filtration rate (GFR). Surgical patients have an increased risk of AKI but renal impairment is usually not evident at ICU admission. We hypothesized that the surgical patients who have AKI diagnosed in the early postoperative period have an impaired GFR since ICU admission, indirectly inferred by alterations in these blood physicochemical and urinary biochemical parameters even in the presence of a still normal sCr. We retrospectively evaluated 112 surgical patients who were categorized according to AKI development during the first 3 ICU days. Twenty-eight patients developed AKI, most of them in the first day (D1) after ICU admission (D0). AKI patients had, at D0, lower serum pH and albumin, higher C - reactive protein (CRP), lower urine sodium (NaU) and fractional excretion of urea (FEUr). Fractional excretion of potassium (FEK) was high in both groups at D0 but remained high in the subsequent days only in AKI patients. Very low CRP and high serum albumin, high NaU and FEUr values at ICU admission had a significant negative predictive value for AKI. We concluded that some easily assessed parameters in blood and urine may help to identify patients with indirect signs of increased inflammatory response and decreased GFR at ICU admission, which could help to predict the risk of postoperative AKI development.

Hypoalbuminemia Within Two Postoperative Days Is an Independent Risk Factor for Acute Kidney Injury Following Living Donor Liver Transplantation: A Propensity Score Analysis of 998 Consecutive Patients

OBJECTIVE

Acute kidney injury is a known major complication of liver transplantation. Previous reports have shown that hypoalbuminemia is associated with an increased risk of acute kidney injury. However, little is known about the relationship between the early postoperative albumin level and acute kidney injury after living donor liver transplantation. The aim of this study was to identify the influence of the postoperative albumin level on acute kidney injury prevalence after living donor liver transplantation.

DESIGN

A retrospective analysis.

SETTING

A tertiary care university hospital.

PATIENTS

Nine hundred and ninety-eighty patients underwent living donor liver transplantation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We divided the enrolled patients into two groups: group 1 included patients whose postoperative albumin level was less than 3.0 g/dL (n = 522), and group 2 included patients with an albumin level greater than or equal to 3.0 g/dL (n = 476). The prevalence of acute kidney injury, major adverse cardiac events, hospital stay, ICU stay, 30-day mortality, and overall mortality was analyzed using inverse probability of treatment weighting and propensity-score matching (n = 249 pairs) analysis. The prevalence of acute kidney injury was higher in group 1 defined by both Acute Kidney Injury Network (after adjusting for inverse probability of treatment weighting [n = 364; 69.7%] and propensity-score matching [n = 152; 61.0%]) and Risk, Injury, Failure, Loss, and End-stage kidney disease criteria (after adjusting for inverse probability of treatment weighting [n = 419; 80.3%] and propensity-score matching [n = 190; 76.3%]). The overall mortality was higher in group 1 after adjusting for inverse probability of treatment weighting (n = 61; 11.7%) and propensity-score matching (n = 23; 9.2%). The hospital (p < 0.001) and ICU (p = 0.006) stays were significantly prolonged in group 1. Acute kidney injury was associated with ICU stay by the Acute Kidney Injury Network criteria (p = 0.034), and overall mortality was correlated with acute kidney injury by the Risk, Injury, Failure, Loss, and End-stage kidney disease criteria (p = 0.014).

CONCLUSIONS

Early postoperative hypoalbuminemia is an independent risk factor for acute kidney injury, and postoperative acute kidney injury is related to postoperative ICU stay and overall mortality after living donor liver transplantation.

Serum Albumin and Cerebro-cardiovascular Mortality During a 15-year Study in a Community-based Cohort in Tanushimaru, a Cohort of the Seven Countries Study

Objective There is little long-term data on the association between the serum albumin levels and mortality in community-based populations. We aimed to determine whether the serum albumin level is an independent risk factor for all-cause and cause-specific death in a community-based cohort study in Japan. Methods In 1999, we performed a periodic epidemiological survey over a 15-year period in a population of 1,905 healthy subjects (783 males, 1,122 females) who were older than 40 years of age and who resided in Tanushimaru, a rural community, in Japan. Over the course of the study, we periodically examined the blood chemistry of the study subjects, including their serum albumin levels. Their baseline serum albumin levels were categorized into quartiles. Results The baseline albumin levels were significantly associated with age (inversely), body mass index (BMI), diastolic blood pressure, lipid profiles [high density lipoprotein-cholesterol (HDL-c), low-density lipoprotein-cholesterol (LDL-c) and triglycerides] and estimated glomerular filtration rate (eGFR). After adjusting for confounders, a Cox proportional hazards regression analysis demonstrated that a low serum albumin level was an independent predictor of all-cause death [hazard ratio (HR): 0.39, 95% confidence interval (CI): 0.24-0.65], cancer death (HR: 0.43, 95% CI: 0.18-0.99), death from infection (HR: 0.21, 95% CI: 0.06-0.73) and cerebro-cardiovascular death (HR: 0.19, 95% CI: 0.06-0.63). The HRs for all-cause and cerebro-cardiovascular death in the highest quartile vs. the lowest quartile of albumin after adjusting for confounders were 0.59 (95%CI:0.39-0.88) and 0.15 (95%CI: 0.03-0.66), respectively. Conclusion The serum albumin level was thus found to be a predictor of all-cause and cerebro-cardiovascular death in a general population.