Albumin administration is associated with acute kidney injury in cardiac surgery: a propensity score analysis

Reduce intraoperative albumin utilisation in cardiac surgical patients: a quality improvement initiative

BACKGROUND

Albumin continues to be used routinely by cardiac anaesthesiologists perioperatively despite lack of evidence for improved outcomes. The Multicenter Perioperative Outcomes Group (MPOG) data ranked our institution as one of the highest intraoperative albumin users during cardiac surgery. Therefore, we designed a quality improvement project (QIP) to introduce a bundle of interventions to reduce intraoperative albumin use in cardiac surgical patients.

METHODS

Our institutional MPOG data were used to analyse the FLUID-01-C measure that provides the number of adult cardiac surgery cases where albumin was administered intraoperatively by anaesthesiologists from 1 July 2019 to 30 June 2022. The QIP involved introduction of the following interventions: (1) education about appropriate albumin use and indications (January 2021), (2) email communications reinforced with OR teaching (March 2021), (3) removal of albumin from the standard pharmacy intraoperative medication trays (April 2021), (4) grand rounds presentation discussing the QIP and highlighting the interventions (May 2021) and (5) quarterly provider feedback (starting July 2021). Multivariable segmented regression models were used to assess the changes from preintervention to postintervention time period in albumin utilisation, and its total monthly cost.

RESULTS

Among the 5767 cardiac surgery cases that met inclusion criteria over the 3-year study period, 16% of patients received albumin intraoperatively. The total number of cases that passed the metric (albumin administration was avoided), gradually increased as our interventions went into effect. Intraoperative albumin utilisation (beta=-101.1, 95% CI -145 to -56.7) and total monthly cost of albumin (beta=-7678, 95% CI -10712 to -4640) demonstrated significant decrease after starting the interventions.

CONCLUSIONS

At a single academic cardiac surgery programme, implementation of a bundle of simple and low-cost interventions as part of a coordinated QIP were effective in significantly decreasing intraoperative use of albumin, which translated into considerable costs savings.

High Serum Albumin Levels were Associated with Acute Kidney Injury in Pediatric Surgical Intensive Care Units

INTRODUCTION

There are limited studies revealing the association between serum albumin concentrations and acute kidney injury (AKI) in critically ill children.

METHODS

This was a multicenter retrospective study. Children consecutively admitted to four pediatric surgical intensive care units (PSICUs) between January 2016 and December 2020 were screened for analysis. Patients without recorded albumin values during the PSICU stay were excluded. Data were extracted from the electronic medical records systems of the hospitals. AKI was defined according to the Kidney Disease Improving Global Outcome (KDIGO) guidelines. The associations between serum albumin levels and AKI were assessed by using logistic regression models.

RESULTS

A total of 7802 children were included in the analysis. The median age of the children was 1.0 (interquartile range (IQR), 0.0-4.0) years. There were 3214 (41.2 %) children who developed AKI. In the univariate logistic regression model, serum albumin levels were associated with AKI (odds ratio (OR) = 1.04, 95 % confidence interval (CI) 1.04-1.05). After adjusting for covariates, serum albumin showed an independent association with AKI (OR = 1.04, 95 % CI 1.03-1.05). Albumin levels above 39.43 g/L (OR = 1.036, 95 % CI 1.002-1.070) were associated with AKI in the unadjusted cubic spline. In the adjusted cubic spline, albumin levels above 40.41 g/L (OR = 1.061, 95 % CI 1.003-1.122) were associated with AKI.

CONCLUSION

High serum albumin was associated with AKI in critically ill children in the PSICU. Further studies are needed to validate our findings.

TYPE OF STUDY

Prognostic Study.

LEVEL OF EVIDENCE

LEVEL II.

Acute kidney injury after cardiac surgery

PURPOSE OF REVIEW

Patients undergoing cardiac surgery are at high risk to develop cardiac surgery-associated acute kidney injury (CS-AKI) postoperatively. CS-AKI is associated with an increased risk for persistent renal dysfunction, morbidity and mortality. This review summarizes the epidemiology and pathophysiology of CS-AKI, as well as current treatment and prevention strategies.

RECENT FINDINGS

As AKI is a syndrome with complex pathophysiology, no causative treatment strategies exist. Recent advances in the field of AKI biomarkers offer new perspectives on the issue and the implementation of biomarker-guided preventive strategies may reduce rates of CS-AKI. Finally, nephroprotective treatments and angiotensin II as a novel vasopressor may offer new opportunities for high-risk patients undergoing cardiac surgery.

SUMMARY

Based on the described novel approaches for early detection, prevention and management of CS-AKI, a precision-medicine approach should be implemented in order to prevent the development of AKI in patients undergoing cardiac surgery.

Acute kidney injury associated with nephrotoxic drugs in critically ill patients: a multicenter cohort study using electronic health record data

Background

Nephrotoxic drugs frequently cause acute kidney injury (AKI) in adult intensive care unit (ICU) patients. However, there is a lack of large pharmaco-epidemiological studies investigating the associations between drugs and AKI. Importantly, AKI risk factors may also be indications or contraindications for drugs and thereby confound the associations. Here, we aimed to estimate the associations between commonly administered (potentially) nephrotoxic drug groups and AKI in adult ICU patients whilst adjusting for confounding.

Methods

In this multicenter retrospective observational study, we included adult ICU admissions to 13 Dutch ICUs. We measured exposure to 44 predefined (potentially) nephrotoxic drug groups. The outcome was AKI during ICU admission. The association between each drug group and AKI was estimated using etiological cause-specific Cox proportional hazard models and adjusted for confounding. To facilitate an (independent) informed assessment of residual confounding, we manually identified drug group-specific confounders using a large drug knowledge database and existing literature.

Results

We included 92 616 ICU admissions, of which 13 492 developed AKI (15%). We found 14 drug groups to be associated with a higher hazard of AKI after adjustment for confounding. These groups included established (e.g. aminoglycosides), less well established (e.g. opioids) and controversial (e.g. sympathomimetics with α- and β-effect) drugs.

Conclusions

The results confirm existing insights and provide new ones regarding drug associated AKI in adult ICU patients. These insights warrant caution and extra monitoring when prescribing nephrotoxic drugs in the ICU and indicate which drug groups require further investigation.

Intraoperative Use of Albumin in Major Noncardiac Surgery: Incidence, Variability, and Association With Outcomes

BACKGROUND

The impact of albumin use during major surgery is unknown, and a dearth of evidence governing its use in major noncardiac surgery has long precluded its standardization in clinical guidelines.

OBJECTIVE

In this study, we investigate institutional variation in albumin use among medical centers in the United States during major noncardiac surgery and explore the association of intraoperative albumin administration with important postoperative outcomes.

METHODS

The study is an observational retrospective cohort analysis performed among 54 U.S. hospitals in the Multicenter Perioperative Outcomes Group and includes adult patients who underwent major noncardiac surgery under general anesthesia between January 2014 and June 2020. The primary endpoint was the incidence of albumin administration. Secondary endpoints are acute kidney injury (AKI), net-positive fluid balance, pulmonary complications, and 30-day mortality. Albumin-exposed and albumin-unexposed cases were compared within a propensity score-matched cohort to evaluate associations of albumin use with outcomes.

RESULTS

Among 614,215 major surgeries, predominantly iso-oncotic albumin was administered in 15.3% of cases and featured significant inter-institutional variability in use patterns. Cases receiving intraoperative albumin involved patients of higher American Society of Anesthesiologists physical status and featured larger infused crystalloid volumes, greater blood loss, and vasopressor use. Overall, albumin was most often administered at high-volume surgery centers with academic affiliation, and within a propensity score-matched cohort (n=153,218), the use of albumin was associated with AKI (aOR 1.24, 95% CI 1.20-1.28, P <0.001), severe AKI (aOR 1.45, 95% CI 1.34-1.56, P <0.001), net-positive fluid balance (aOR 1.18, 95% CI 1.16-1.20, P <0.001), pulmonary complications (aOR 1.56, 95% CI 1.30-1.86, P <0.001), and 30-day all-cause mortality (aOR 1.37, 95% CI 1.26-1.49, P <0.001).

CONCLUSIONS

Intravenous albumin is commonly administered among noncardiac surgeries with significant inter-institutional variability in use in the United States. Albumin administration was associated with an increased risk of postoperative complications.

Effect of albumin usage during cardiopulmonary bypass on postoperative acute kidney injury in cardiac surgery patients: A historical cohort study

Introduction

Acute kidney injury (AKI) after cardiac surgery is a common and serious postoperative complication and is associated with an increased risk of mortality, morbidity, length of hospital stay, and costs. We evaluated the effect of albumin usage on postoperative AKI in patients who underwent on-pump Coronary Artery Bypass Graft Surgery (CABG).

Methods

This non-randomized cohort study was conducted on data from adult patients who underwent elective CABG, from March of 2015 to March of 2019. We assessed two groups of patients including the albumin (who received 50cc albumin 20% in priming solution) and the non-albumin groups. We recorded demographic data, medical history, and preoperative laboratory data. We compared postoperative changes in serum creatinine (Cr), blood urea nitrogen (BUN), and Glomerular Filtration Rate (GFR) up to 72 hours after surgery with preoperative ones. Also, the stage of kidney dysfunction was assessed according to the AKIN classification. The statistical analysis of the data was processed by SPSS 24 program.

Results

Overall, we reviewed 506 patients chart [260 (51.4%) in albumin and 246 (48.6%) in non-albumin group]. In both groups, serum Cr, BUN, and GFR increased in 72 hours postoperatively compared with preoperative levels. This increase was greater in the non-albumin group than in the albumin group. However, the difference was not statistically significant between the two groups (p > 0.05). None of the patients developed renal failure or required dialysis.

Conclusion

We concluded that the use of albumin in prime solution did not have a statistically significant effect on postoperative renal dysfunction after CABG.

Retrospective analysis of the use of canine-specific albumin in 125 critically ill dogs

OBJECTIVE

To describe the clinical use of canine-specific albumin (CSA) in critically ill dogs, report adverse events, and evaluate measurable clinical effects of CSA administration.

DESIGN

Retrospective case series from 2019 to 2020.

SETTING

Large, urban, private-practice referral and emergency center.

ANIMALS

Consecutive sample of 125 client-owned dogs administered CSA transfusions.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The conditions most commonly associated with the use of CSA were surgical (32/125) and nonsurgical (20/125) gastrointestinal disease. Both serum albumin and total plasma protein concentrations were significantly increased posttransfusion (P < 0.001), and 16% albumin transfusions produced the greatest magnitude increase in serum albumin (P = 0.0015). Concurrent crystalloid administration did not affect change in albumin. While there was no significant improvement in blood pressure seen in those patients that received albumin, a significant improvement in shock index was identified (P = 0.02). Adverse events were uncommon; however, 8 critically ill dogs died during CSA administration.

CONCLUSIONS

CSA appears to be a relatively safe alternative to synthetic colloids and complementary to crystalloids in critically ill patients. More concentrated solutions may be more effective in raising serum albumin concentration. Further investigation into the indications for and efficacy of CSA will continue to improve our knowledge of this blood product.

Perioperative Fluid Management and Volume Assessment

Fluid therapy is an integral component of perioperative care and helps maintain or restore effective circulating blood volume. The principal goal of fluid management is to optimize cardiac preload, maximize stroke volume, and maintain adequate organ perfusion. Accurate assessment of volume status and volume responsiveness is necessary for appropriate and judicious utilization of fluid therapy. To accomplish this, static and dynamic indicators of fluid responsiveness have been widely studied. This review discusses the overarching goals of perioperative fluid management, reviews the physiology and parameters used to assess fluid responsiveness, and provides evidence-based recommendations on intraoperative fluid management.

Association between 20% Albumin Use and Acute Kidney Injury in Major Abdominal Surgery with Transfusion

Red blood cell (RBC) transfusion and albumin administration can affect kidney function. We aimed to evaluate the association between intraoperative 20% albumin administration and acute kidney injury (AKI), along with the duration of hospitalization and 30-day mortality in patients undergoing major abdominal surgery with RBC transfusion. This retrospective study included 2408 patients who received transfusions during major abdominal surgery. Patients were categorized into albumin (n = 842) or no-albumin (n = 1566) groups. We applied inverse probability of treatment weighting (IPTW), propensity score (PS) matching (PSM), and PS covariate adjustment to assess the effect of albumin administration on the outcomes. In the unadjusted cohort, albumin administration was significantly associated with increased risk of AKI, prolonged hospitalization, and higher 30-day mortality. However, there was no significant association between albumin administration and AKI after adjustment (OR 1.26, 95% CI 0.90-1.76 for the IPTW; OR 1.03, 95% CI 0.72-1.48 for the PSM; and OR 1.04, 95% CI 0.76-1.43 for the PS covariate adjustment methods). While albumin exposure remained associated with prolonged hospitalization after adjustment, it did not affect 30-day mortality. Our findings suggest that hyper-oncotic albumin can be safely administered to patients who are at risk of developing AKI due to RBC transfusion.

Drug-induced kidney injury in Chinese critically ill pediatric patients

Background: Drug-induced acute kidney injury (DIKI) is a common adverse drug reaction event but is less known in pediatric patients. The study explored the DIKI in Chinese pediatric patients using the Pediatric Intensive Care database (PIC).

Method: We screened pediatric patients with acute kidney injury (AKI) using the KDIGO criteria from the PIC and then assessed the relationship between their drugs and DIKI using the Naranjo scale. For the fifteen frequently used DIKI-suspected drugs, we divided patients into drug-exposed and non-exposed groups, using the outcome of whether DIKI was presented or not. Propensity score matching (PSM) was used to control for the effects of four confounders, age, gender, length of hospital stay, and major diagnosis. Unconditional logistic regression was used to identify statistically significant differences between the two groups.

Results: A total of 238 drugs were used 1,863 times by the 81 patients with DIKI during their hospital stay. After screening the Naranjo scale to identify the top 15 suspected DIKI drugs with a high frequency of use, we found that furosemide injection (p = 0.001), midazolam injection (p = 0.001), 20% albumin prepared from human plasma injection (p = 0.004), fentanyl citrate injection (p = 0.001), compound glycyrrhizin injection (p = 0.026), vancomycin hydrochloride for intravenous (p = 0.010), and milrinone lactate injection (p = 0.009) were associated with DIKI.

Conclusion: In critically ill pediatric patients, DIKI is more likely to occur after using furosemide injection, midazolam injection, 20% albumin prepared from human plasma injection, fentanyl citrate injection, compound glycyrrhizin injection, vancomycin hydrochloride for intravenous, milrinone lactate injection.

Survival and recovery modeling of acute kidney injury in critically ill adults

Objectives:

Acute kidney injury is common among the critically ill. However, the incidence, medication use, and outcomes of acute kidney injury have been variably described. We conducted a single-center, retrospective cohort study to examine the risk factors and correlates associated with acute kidney injury in critically ill adults with a particular focus on medication class usage.

Methods:

We reviewed the electronic medical records of all adult patients admitted to an intensive care unit between 1 February and 30 August 2020. Acute kidney injury was defined by the 2012 Kidney Disease: Improving Global Outcomes guidelines. Data included were demographics, comorbidities, symptoms, laboratory parameters, interventions, and outcomes. The primary outcome was acute kidney injury incidence. A Least Absolute Shrinkage and Selection Operator regression model was used to determine risk factors associated with acute kidney injury. Secondary outcomes including acute kidney injury recovery and intensive care unit mortality were analyzed using a Cox regression model.

Results:

Among 226 admitted patients, 108 (47.8%) experienced acute kidney injury. 37 (34.3%), 39 (36.1%), and 32 patients (29.6%) were classified as acute kidney injury stages I–III, respectively. Among the recovery and mortality cohorts, analgesics/sedatives, anti-infectives, and intravenous fluids were significant (p-value < 0.05). The medication classes IV-fluid electrolytes nutrition (96.7%), gastrointestinal (90.2%), and anti-infectives (81.5%) were associated with an increased odds of developing acute kidney injury, odd ratios: 1.27, 1.71, and 1.70, respectively. Cox regression analyses revealed a significantly increased time-varying mortality risk for acute kidney injury-stage III, hazard ratio: 4.72 (95% confidence interval: 1–22.33). In the recovery cohort, time to acute kidney injury recovery was significantly faster in stage I, hazard ratio: 9.14 (95% confidence interval: 2.14–39.06) cohort when compared to the stage III cohort.

Conclusion:

Evaluation of vital signs, laboratory, and medication use data may be useful to determine acute kidney injury risk stratification. The influence of particular medication classes further impacts the risk of developing acute kidney injury, necessitating the importance of examining pharmacotherapeutic regimens for early recognition of renal impairment and prevention.

Blood Urea Nitrogen-to-Albumin Ratio in Predicting Long-Term Mortality in Patients Following Coronary Artery Bypass Grafting: An Analysis of the MIMIC-III Database

Background

This study examined the role of blood urea nitrogen-to-albumin ratio (BAR) in predicting long-term mortality in patients undergoing coronary artery bypass grafting (CABG).

Methods

In this retrospective cohort study, patients undergoing CABG were enrolled from the Medical Information Mart for Intensive Care III (MIMIC III) database. Patients were divided into the three groups according to the optimal cutoff values of BAR determined by X-tile software. The survival curve was constructed by the Kaplan–Meier method and multivariate Cox regression analysis was performed to explore the independent prognostic factors of 1- and 4-year mortality after CABG. The receiver operating characteristic (ROC) curves and the areas under the ROC curves (AUCs) were calculated to estimate the accuracy of BAR in predicting the outcomes. Subgroup analyses were also carried out.

Results

A total of 1,462 patients at 4-year follow-up were included, of which 933, 293, and 236 patients were categorized into the group 1 (≤ 6.45 mg/g), group 2 (>6.45 and ≤ 10.23 mg/g), and group 3 (>10.23 mg/g), respectively. Non-survivors showed an increased level of BAR at both 1- (p < 0.001) and 4-year (p < 0.001) follow-up compared with the survivors. The patients with a higher BAR had a higher risk of 1- and 4-year mortality following CABG (33.05 vs. 14.33 vs. 5.14%, p < 0.001 and 52.97 vs. 30.72 vs. 13.08%, p < 0.001, respectively). Cox proportional hazards regression model suggested a higher BAR as an independent risk factor of 1-year mortality (HR 3.904; 95% CI 2.559–5.956; P < 0.001) and 4-year mortality (HR 2.895; 95% CI 2.138–3.921; P < 0.001) after adjusting for confounders. Besides, the receiver operating characteristic (ROC) curves showed the better predictive ability of BAR compared to other grading scores at both 1- (0.7383, 95% CI: 0.6966–0.7800) and 4-year mortality (0.7189, 95% CI: 0.6872–0.7506). Subgroup analysis demonstrated no heterogeneous results of BAR in 4-year mortality in particular groups of patient.

Conclusion

This report provided evidence of an independent association between 1- and 4-year mortality after CABG and BAR. A higher BAR was associated with a higher risk of long-term mortality and could serve as a prognostic predictor in patients following CABG.

Renal injury in cardiorenal syndrome type 1 is mediated by albumin

Cardiorenal syndrome type 1 (CRS‐1) acute kidney injury (AKI) is a critical complication of acute cardiovascular disease but is poorly understood. AKI induces acute albuminuria. As chronic albuminuria is associated with worsening kidney disease and albumin has been implicated in tubular epithelial injury, we investigated whether albumin participates in CRS‐1, and whether CRS‐1 alters renal albumin handling. We report the role of albumin in in vivo and in vitro CRS‐1 models. An established translational model, cardiac arrest and cardiopulmonary resuscitation (CA/CPR) induced severe acute albuminuria which correlated with tubular epithelial cell death. In vivo microscopy demonstrated CA/CPR‐induced glomerular filtration of exogenous albumin, while administration of exogenous albumin after CA/CPR worsened AKI compared to iso‐oncotic control. Increased albumin signal was observed in the proximal tubules of CA/CPR mice compared to sham. Comparison of albumin flux from tubular lumen to epithelial cells revealed saturated albumin transport within minutes of albumin injection after CA/CPR. In vitro, HK2 cells (human kidney tubular epithelial cells), exposed to oxygen‐glucose deprivation were injured by albumin in a dose dependent fashion. This interference was unchanged by the tubular endocytic receptor megalin. In conclusion, CRS‐1 alters albumin filtration and tubular uptake, leading to increased tubular exposure to albumin, which is injurious to tubular epithelial cells, worsening AKI. Our findings shed light on the pathophysiology of renal albumin and may guide interventions such as albumin resuscitation to improve CRS‐1 outcomes. This investigation may have important translational relevance for patients that receive exogenous albumin as part of their CRS‐1 treatment regimen.

Effect Of Snakehead Fish Extract On Kidney Function In Patients Undergoing Radiotherapy

Background — Most malignancy patients that undergo radiotherapy with or without chemotherapy, especially those with malignancy of the pelvic region, are accompanied by hypoalbuminemia and kidney injury. Human albumin has been shown to have nephroprotective effects. Snakehead fish extract, a consumable source of albumin, can be an effective and cheap alternative to reduce the risk of kidney injury in malignancy patients. Objective — Analyze the effect of snakehead fish extract on urea, creatinine, and albumin serum levels in radiotherapy patients. Material and Methods — This study was conducted on patients undergoing radiotherapy. They were divided into two groups, each consisting of 15 patients; the control group was given a placebo and the experimental group was given snakehead fish extract. Albumin, urea, and creatinine serum levels were determined respectively by the bromocresol green method, urease method, and jaffe method, both before and after treatment. All data were analyzed using SPSS 22.0. Results — The serum albumin level decreased in both groups. While it dropped further in the treatment group than in the control group, the difference was not significant. Urea and creatinine serum levels decreased in the experimental group and increased in the control group. Once more, however, this difference was not statistically significant. Conclusion — The administration of snakehead fish extract had no significant effect on albumin, urea, or creatinine serum levels in patients undergoing radiotherapy.

To RAP or Not to RAP: A Retrospective Comparison of the Effects of Retrograde Autologous Priming

Retrograde autologous priming (RAP) is a process used to reduce hemodilution associated with the initiation of cardiopulmonary bypass (CPB). Previous studies have reported potential benefits to RAP; however, many of these studies do not evaluate the benefits of RAP with limited preoperative fluid administration combined with a condensed CPB circuit. We examined clinical metrics of patients who underwent RAP versus those who did not undergo RAP prior to the initiation of CPB. This was a retrospective data review of 1,303 patients who underwent CPB in the setting of open-heart surgery for a 2-year period. RAP was used on all patients between June 1, 2017 and June 30, 2018 (n = 519) and not used on patients between July 1, 2018 and June 30, 2019 (n = 784). Both groups were subjected to a low-prime CPB circuit volume of 800-900 mL. We compared the clinical metrics for packed red blood cell (PRBC) transfusion, oxygen delivery, postoperative acute kidney injury (AKI), Albumin utilization, ventilator time, Intensive Care Unit length of stay (ICU LOS), and 30-day mortality between the two groups. Our data analysis showed there were no statistically significantly differences between the two groups on the incidence of postoperative AKI, PRBC administration, ventilator time, ICU LOS or 30-day mortality. In the RAP group, there was a statistically significant lower oxygen delivery and a statistically significant increased volume of Albumin administered postoperatively, although those differences were so small, they were potentially not clinically significant. Our analysis revealed no significant benefit to performing RAP with limited preoperative fluid administration and minimized CPB circuit prime volume. We formalized a process that included limiting preoperative fluid administration and minimizing the CPB circuit volume so that we were not required to RAP and did not simultaneously sacrifice patient outcomes in other areas.

Serum Albumin Before CRRT Was Associated With the 28- and 90-Day Mortality of Critically Ill Patients With Acute Kidney Injury and Treated With Continuous Renal Replacement Therapy

Introduction: Although low serum albumin (ALB) may worsen acute kidney injury (AKI), additional study is needed to establish the connection between ALB and the prognosis of critically ill patients with AKI and treated with continuous renal replacement therapy (CRRT). Methods:A secondary analysis of a bi-center, retrospective, and observational study, such as critically ill patients with AKI and treated with CRRT from January 2009 to September 2016. The univariate analysis, multi-factor regression analysis, sensitivity analysis, and curve-fitting analysis were applied to explore the association of ALB with the 28 and 90 days mortality of critically ill patients with AKI and treated with CRRT, and the removal efficiency of serum phosphorus. Results: From January 2009 to September 2016, 1,132 cases with AKI and treated with CRRT met the inclusion criteria and enrolled in this study. We found that the higher ALB before CRRT, the lower the 28- and 90-day mortality of patients with AKI and treated with CRRT, the higher removal efficiency of serum phosphorus, the adjusted hazard ratio (HR) value for 28-day mortality in the four models were separately 0.92 (0.90, 0.95), 0.91 (0.89, 0.94), 0.92 (0.89, 0.95), and 0.92 (0.89, 0.95); the adjusted HR value for 90 day mortality in the four models were 0.91 (0.89, 0.94), 0.92 (0.89, 0.95), 0.92 (0.89, 0.95), and 0.92 (0.89, 0.96); the adjusted OR value for the removal efficiency of serum phosphorus in the four models were separately -0.04 (-0.07, -0.01), -0.05 (-0.08, -0.01), -0.04 (-0.08, -0.01), and -0.04 (-0.08, -0.01). The sensitivity analysis and curve-fitting analysis also showed that ALB before CRRT was correlated with the 28 and 90 days mortality of critically ill patients with AKI and treated with CRRT and the removal efficiency of serum phosphorus. Conclusion: The higher the serum ALB before CRRT, the lower the mortality of critically ill patients with AKI and treated with CRRT, and the higher the clearance efficiency of serum phosphorus.

Albumin in adult cardiac surgery: a narrative review

PURPOSE

Intravascular fluids are a necessary and universal component of cardiac surgical patient care. Both crystalloids and colloids are used to maintain or restore circulating plasma volume and ensure adequate organ perfusion. In Canada, human albumin solution (5% or 25% concentration) is a colloid commonly used for this purpose. In this narrative review, we discuss albumin supply in Canada, explore the perceived advantages of albumin, and describe the clinical literature supporting and refuting albumin use over other fluids in the adult cardiac surgical population.

SOURCE

We conducted a targeted search of PubMed, Embase, Medline, Web of Science, ProQuest Dissertations and Theses Global, the Cochrane Central Register of Controlled trials, and the Cochrane Database of Systematic Reviews. Search terms included albumin, colloid, cardiac surgery, bleeding, hemorrhage, transfusion, and cardiopulmonary bypass.

PRINCIPAL FINDINGS

Albumin is produced from fractionated human plasma and imported into Canada from international suppliers at a cost of approximately $21 million CAD per annum. While it is widely used in cardiac surgical patients across the country, it is approximately 30-times more expensive than equivalent doses of balanced crystalloid solutions, with wide inter-institutional variability in use and no clear association with improved outcomes. There is a general lack of high-quality evidence for the superiority of albumin over crystalloids in this patient population, and conflicting evidence regarding safety.

CONCLUSIONS

In cardiac surgical patients, albumin is widely utilized despite a lack of high- quality evidence supporting its efficacy or safety. A well-designed randomized controlled trial is needed to clarify the role of albumin in cardiac surgical patients.

Albumin use in bleeding cardiac surgical patients and associated patient outcomes

PURPOSE

Albumin solution is a colloid used for resuscitation in cardiac surgical patients, but it is unclear if it offers advantages over crystalloids. We examined current clinical practice across 11 cardiac surgical centres and the association of albumin with outcomes in a cohort of bleeding cardiac surgical patients.

METHODS

This was a post hoc analysis of data from the Effect of Fibrinogen Concentrate vs Cryoprecipitate on Blood Component Transfusion After Cardiac Surgery (FIBRES) trial. Multivariable regression models adjusted for demographic and surgical characteristics were used to examine predictors of early albumin administration (within the initial 24 perioperative hours), late albumin administration (from 24 hr to seven days after cardiopulmonary bypass), and the association of albumin use with 28-day acute kidney injury, mortality, and length of hospital and intensive care unit (ICU) stay.

RESULTS

Of the 735 patients included, 525 (71%) received albumin, ranging from 4.8% to 97.4% of patients across institutions, with 475 (64.6%) receiving albumin early (5% or 25% solution). In the adjusted models, female sex and preoperative hospital admission were associated with early use, while heart failure, female sex, bleeding severity, older age, and prior albumin use were predictors of later administration. Early albumin use was not associated with differences in acute kidney injury (adjusted odds ratio [aOR] 1.77; 95% confidence interval [CI], 0.96 to 3.27; P = 0.07), mortality (aOR 1.66; 95% CI, 0.99 to 2.78; P = 0.05), or length of ICU stay (P = 0.11) or hospital stay (P = 0.67).

CONCLUSIONS

Albumin use is common but highly variable within and across sites. Albumin use was not associated with improved outcomes. High quality randomized controlled trials should clarify its role in cardiac surgical patients.

Intravenous Albumin for Mitigating Hypotension and Augmenting Ultrafiltration during Kidney Replacement Therapy

Among its many functions, owing to its oversized effect on colloid oncotic pressure, intravascular albumin helps preserve the effective circulatory volume. Hypoalbuminemia is common in hospitalized patients and is found especially frequently in patients who require KRT either for AKI or as maintenance hemodialysis. In such patients, hypoalbuminemia is strongly associated with morbidity, intradialytic hypotension, and mortality. Intravenous albumin may be administered in an effort to prevent or treat hypotension or to augment fluid removal, but this practice is controversial. Theoretically, intravenous albumin administration might prevent or treat hypotension by promoting plasma refilling in response to ultrafiltration. However, clinical trials have demonstrated that albumin administration is not nearly as effective a volume expander as might be assumed according to its oncotic properties. Although intravenous albumin is generally considered to be safe, it is also very expensive. In addition, there are potential risks to using it to prevent or treat intradialytic hypotension. Some recent studies have suggested that hyperoncotic albumin solutions may precipitate or worsen AKI in patients with sepsis or shock; however, the overall evidence supporting this effect is weak. In this review, we explore the theoretical benefits and risks of using intravenous albumin to mitigate intradialytic hypotension and/or enhance ultrafiltration and summarize the current evidence relating to this practice. This includes studies relevant to its use in patients on maintenance hemodialysis and critically ill patients with AKI who require KRT in the intensive care unit. Despite evidence of its frequent use and high costs, at present, there are minimal data that support the routine use of intravenous albumin during KRT. As such, adequately powered trials to evaluate the efficacy of intravenous albumin in this setting are clearly needed.

New Trends in the Utilization of Intravenous Fluids

Intravenous fluids (IVFs) are the most commonly used drugs in hospitalized patients. Knowledge of the indications and pharmacokinetics of IVFs is critical for all medical disciplines. Isotonic saline (normal saline, 0.9% NS) is the most utilized intravenous solution. Isotonic saline effectively expands the intravascular compartment, as one-quarter of the infusate goes intravascularly, while the remaining three-quarters go into the interstitial space. The proper use of IVFs in different clinical scenarios is paramount. IVFs differ with regard to their half-life, intravascular volume expansion, preparation, and cost. Crystalloids are more commonly utilized due to their relatively low cost and availability. Colloids are very advantageous in cases of shock or hemorrhage, as they remain in the intravascular space, thus facilitating an increase in blood pressure (BP) prior to blood administration. Colloids are also advantageous in cases of burns and severe hypoglobulinemia. Human albumin (5%, 20%, and 25%) is the most used colloid solution. It remains intravascularly provided and there is no capillary leak as in systematic inflammation. The goal in hospitalized patients is timely and adequate intravenous fluid resuscitation. Utilization of a large volume of isotonic saline may lead to hypervolemia, hypernatremia, hyperchloremia, metabolic acidosis, and hypokalemia. The use of balanced intravenous solutions has been advocated to avoid these complications.

Oxidized Albumin as a Mediator of Kidney Disease

Renal diseases are a global health concern, and nearly 24% of kidney disease patients are overweight or obese. Particularly, increased body mass index has been correlated with oxidative stress and urinary albumin excretion in kidney disease patients, also contributing to increased cardiovascular risk. Albumin is the main plasma protein and is able to partially cross the glomerular filtration barrier, being reabsorbed mainly by the proximal tubule through different mechanisms. However, it has been demonstrated that albumin suffers different posttranslational modifications, including oxidation, which appears to be tightly linked to kidney damage progression and is increased in obese patients. Plasma-oxidized albumin levels correlate with a decrease in estimated glomerular filtration rate and an increase in blood urea nitrogen in patients with chronic kidney disease. Moreover, oxidized albumin in kidney disease patients is independently correlated with higher plasma levels of transforming growth factor beta (TGF-β1), tumor necrosis factor (TNF-α), and interleukin (IL)-1β and IL-6. In addition, oxidized albumin exerts a direct effect on neutrophils by augmenting the levels of neutrophil gelatinase-associated lipocalin, a well-accepted biomarker for renal damage in patients and in different experimental settings. Moreover, it has been suggested that albumin oxidation occurs at early stages of chronic kidney disease, accelerating the patient requirements for dialytic treatment during disease progression. In this review, we summarize the evidence supporting the role of overweight- and obesity-induced oxidative stress as a critical factor for the progression of renal disease and cardiovascular morbimortality through albumin oxidation.

Intraoperative Data Enhance the Detection of High-Risk Acute Kidney Injury Patients When Added to a Baseline Prediction Model

BACKGROUND

Aspects of intraoperative management (eg, hypotension) are associated with acute kidney injury (AKI) in noncardiac surgery patients. However, it is unclear if and how the addition of intraoperative data affects a baseline risk prediction model for postoperative AKI.

METHODS

With institutional review board (IRB) approval, an institutional cohort (2005-2015) of inpatient intra-abdominal surgery patients without preoperative AKI was identified. Data from the American College of Surgeons National Surgical Quality Improvement Program (preoperative and procedure data), Anesthesia Information Management System (intraoperative data), and electronic health record (postoperative laboratory data) were linked. The sample was split into derivation/validation (70%/30%) cohorts. AKI was defined as an increase in serum creatinine ≥0.3 mg/dL within 48 hours or >50% within 7 days of surgery. Forward logistic regression fit a baseline model incorporating preoperative variables and surgical procedure. Forward logistic regression fit a second model incorporating the previously selected baseline variables, as well as additional intraoperative variables. Intraoperative variables reflected the following aspects of intraoperative management: anesthetics, beta-blockers, blood pressure, diuretics, fluids, operative time, opioids, and vasopressors. The baseline and intraoperative models were evaluated based on statistical significance and discriminative ability (c-statistic). The risk threshold equalizing sensitivity and specificity in the intraoperative model was identified.

RESULTS

Of 2691 patients in the derivation cohort, 234 (8.7%) developed AKI. The baseline model had c-statistic 0.77 (95% confidence interval [CI], 0.74-0.80). The additional variables added to the intraoperative model were significantly associated with AKI (P < .0001) and the intraoperative model had c-statistic 0.81 (95% CI, 0.78-0.83). Sensitivity and specificity were equalized at a risk threshold of 9.0% in the intraoperative model. At this threshold, the baseline model had sensitivity and specificity of 71% (95% CI, 65-76) and 69% (95% CI, 67-70), respectively, and the intraoperative model had sensitivity and specificity of 74% (95% CI, 69-80) and 74% (95% CI, 73-76), respectively. The high-risk group had an AKI risk of 18% (95% CI, 15-20) in the baseline model and 22% (95% CI, 19-25) in the intraoperative model.

CONCLUSIONS

Intraoperative data, when added to a baseline risk prediction model for postoperative AKI in intra-abdominal surgery patients, improves the performance of the model.

Effects of 5% Albumin Plus Saline Versus Saline Alone on Outcomes From Large-Volume Resuscitation in Critically Ill Patients

OBJECTIVES

To compare 5% albumin with 0.9% saline for large-volume resuscitation (> 60 mL/Kg within 24 hr), on mortality and development of acute kidney injury.

DESIGN

Retrospective cohort study.

SETTING

Patients admitted to ICUs in 13 hospitals across Western Pennsylvania. We analyzed two independent cohorts, the High-Density Intensive Care databases: High-Density Intensive Care-08 (July 2000 to October 2008, H08) and High-Density Intensive Care-15 (October 2008 to December 2014, H15).

PATIENTS

Total of 18,629 critically ill patients requiring large-volume resuscitation.

INTERVENTIONS

Five percent of albumin in addition to saline versus 0.9% saline.

MEASUREMENTS AND MAIN RESULTS

After excluding patients with acute kidney injury prior to large-volume resuscitation, 673 of 2,428 patients (27.7%) and 1,814 of 16,201 patients (11.2%) received 5% albumin in H08 and H15, respectively. Use of 5% albumin was associated with decreased 30-day mortality by multivariate regression in H08 (odds ratio 0.65; 95% CI 0.49-0.85; p = 0.002) and in H15 (0.52; 95% CI 0.44-0.62; p < 0.0001) but was associated with increased acute kidney injury in H08 (odds ratio 1.98; 95% CI 1.56-2.51; p < 0.001) and in H15 (odds ratio 1.75; 95% CI 1.58-1.95; p < 0.001). However, 5% albumin was not associated with persistent acute kidney injury and resulted in decreased major adverse kidney event at 30, 90, and 365 days. Propensity matched analysis confirmed similar associations with mortality and acute kidney injury.

CONCLUSIONS

During large-volume resuscitation, 5% albumin was associated with reduced mortality and major adverse kidney event at 30, 90, and 365 days. However, a higher rate of acute kidney injury of any stage was observed that did not translate into persistent renal dysfunction.

Decreased albumin is associated with elevated N-terminal pro-brain natriuretic peptide and poor long-term prognosis in patients with chronic heart failure

At present, the association between albumin, N-terminal pro-brain natriuretic peptide (NT-proBNP) and long-term prognosis in patients with chronic heart failure (CHF) is unclear. Therefore, the purpose of this study is to explore the relationship between albumin, NT-proBNP and all-cause mortality in CHF patients.Three hundred fifty two CHF patients were recruited in our study, and patients were divided into 2 groups according to the mean (37.16 g/L) of albumin concentration [low group (albumin < 37.16 g/L) and high group (albumin≥37.16 g/L)]. Differences between groups was compared by odds ratio (OR) and 95% confidence interval (CI).NT-proBNP in the high group was significantly lower than that in the low group at baseline [1811.50 (698.75-4037.00) vs 3479.50 (1538.50-7824.25), P < .001]. Spearman correlation analysis showed that there was a negative correlation between albumin and NT-pro BNP log10 transform (ρ= -0.217, P < .001). Furthermore, curve fitting further confirmed that albumin was negatively correlated with NT-proBNP. After a median follow-up of 1726 days, 90 patients in the high group occur all-cause mortality, and 98 patients in the low group occur all-cause mortality (46.88% vs 61.25%, OR = 0.29, 95% CI: 0.08-0.50). After adjusting for the selected confounding covariates by multivariate regression analysis, decreased albumin was still associated with increased all-cause mortality (high group vs low group: OR = 0.62, 95% CI: 0.39-0.97).Decreased albumin is associated with elevated NT-ProBNP and poor long-term prognosis in CHF patients. Clinicians need to pay enough attention to the nutritional status of CHF patients.

Postoperative renal morbidity and mortality after volume replacement with hydroxyethyl starch 130/0.4 or albumin during surgery: a propensity score-matched study

PURPOSE

We aimed to compare retrospectively the rates of renal morbidity and mortality in surgical patients receiving 6% HES 130/0.4 to those receiving albumin.

METHODS

From a Japanese nationwide medical database between 2014 and 2016, we identified adults who received HES 130/0.4 (HES group) or albumin (albumin group) as a single colloid solution on the day of surgery. After propensity score matching, the two groups were analyzed with χ2 or Mann Whitney U test. The primary outcome was the incidence of acute kidney injury (AKI). Secondary outcomes included the incidence of renal-replacement therapy, hospital length of stay, in-hospital 30-day mortality, the use of vasoactive agents, and the fluid requirement on the day of surgery.

RESULTS

Of 76,048 patients in the database, propensity score matching identified 289 matched pairs. There was no statistically significant difference in the incidence of AKI between the HES and the albumin group (15.2% vs. 20.8%, respectively: P = 0.08). The secondary outcomes did not differ between groups except the following. Median hospital stay was 5 days shorter in the HES group (18 vs. 23 days; P < 0.001), and the median net fluid requirement on the day of surgery was 15 mL/kg lower in the HES group (140 vs. 155 mL/kg, respectively; P = 0.01).

CONCLUSIONS

Postoperative renal morbidity and mortality did not differ between patients receiving HES 130/0.4 and those receiving albumin. HES 130/0.4 was associated with shorter hospital stay and less fluid requirement compared to albumin. These findings support the use of 6% HES 130/0.4 for perioperative volume replacement as an alternative to albumin.

TRIAL REGISTRATION

UMIN000027896 and the date of registration was June 30, 2017 at https://www.umin.ac.jp/ctr/index-j.html .

Which risk predictors are more likely to indicate severe AKI in hospitalized patients?

OBJECTIVES

Acute kidney injury (AKI) is a sudden episode of kidney failure or damage and the risk of AKI is determined by the complex interactions of patient factors. In this study, we aimed to find out which risk factors in hospitalized patients are more likely to indicate severe AKI.

METHODS

We constructed a retrospective cohort of adult patients from all inpatient units of a tertiary care academic hospital between November 2007 and December 2016. AKI predictors included demographic information, admission and discharge dates, medications, laboratory values, past medical diagnoses and admission diagnosis. We developed a machine learning-based knowledge mining model and a screening framework to analyze which risk predictors are more likely to imply severe AKI in hospitalized populations.

RESULTS

Among the final analysis cohort of 76,957 hospital admissions, AKI occurred in 7,259 (9.43 %) with 6,396 (8.31 %) at stage 1, 678 (0.88 %) at stage 2, and 185 (0.24 %) at stage 3. We compared the non-AKI (without AKI) vs any AKI (stages 1-3), and mild AKI (stage 1) vs severe AKI (stages 2 and 3), where the best cross-validated area under the receiver operator characteristic curve (AUC) were 0.81 (95 % CI, 0.79-0.82) and 0.66 (95 % CI, 0.62-0.71), respectively. Using the developed knowledge mining model and screening framework, we identified 33 risk predictors indicating that severe AKI may occur.

CONCLUSIONS

This study screened out 33 risk predictors that are more likely to indicate severe AKI in hospitalized patients, which would help strengthen the early care and prevention of patients.

Impact of 6% balanced hydroxyethyl starch following cardiopulmonary bypass on renal function: a retrospective study

Background

We aimed to evaluate the effect of limited volume of hydroxyethyl starch (HES) administration on postoperative renal function in patients undergoing cardiac surgery under cardiopulmonary bypass (CPB).

Methods

One thousand six hundred fifty-seven patients undergoing cardiac surgery under CPB over two years were included. The patients were divided according to the amount of HES administrated during the first 2 days post-surgery; moderate dose HES (≥20 ml/kg) versus low dose HES (< 20 ml/kg). Outcomes were compared by using inverse probability weighting.

Results

Incidence of acute kidney injury (AKI) was higher in the moderate HES group (p = .02). However, new renal replacement therapy (RRT) (P = .30) and early mortality (p = .97) was similar between the groups. When adjusted, the moderate HES use was associated with AKI (OR, 1.66; 95% CI, 1.12–2.44; p = .01), but did not increase the risk of new RRT (OR, 1.27; 95% CI, 0.71–2.18; p = .40) or early mortality (HR, 0.73; 95% CI, 0.29–1.81; p = .50).

Conclusions

The moderate dose administration of HES (≥20 ml/kg) in the postoperative period following cardiac surgery might be associated with the risk of AKI. However, it was not associated with serious adverse outcomes such as new RRT or mortality. Further randomized controlled studies are needed to validate study results.

Mannitol Is Associated with Less Postoperative Delirium after Aortic Valve Surgery in Patients Treated with Bretschneider Cardioplegia

Background  Heart surgery with extracorporeal circulation (ECC) often leads to postoperative delirium (POD). This is associated with increased morbidity resulting in longer hospital stay and associated costs. The purpose of our study was to analyze the effect of intraoperative mannitol application on POD in patients undergoing elective aortic valve replacement (AVR).

Materials and Method s In our retrospective single-center study, 259 patients underwent elective AVR, using Bretschneider cardioplegic solution for cardiac arrest, between 2014 and 2017. Patients were divided in mannitol ( n  = 188) and nonmannitol ( n  = 71) groups. POD was assessed using the confusion assessment method for the intensive care unit (ICU). Statistical significance was assumed at p  < 0.05.

Results  Baseline patient characteristics did not differ between the groups. Incidence of POD was significantly higher in the nonmannitol group (33.8 vs. 13.8%; p  = 0.001). These patients required longer ventilation time (24.1 vs. 17.1 hours; p  = 0.021), higher reintubation rate (11.3 vs. 2.7%; p  = 0.009), ICU readmission (12.7 vs. 4.8%; p  = 0.026), prolonged ICU (112 vs. 70 hours; p  = 0.040), and hospital stay (17.8 vs. 12.6 days; p  < 0.001), leading to higher expenses (19,349 € vs. 16,606 €, p  < 0.001). A 30-day mortality was not affected, but nonmannitol group showed higher Simplified Acute Physiology Score II score (32.2 vs. 28.7; p  < 0.001). Mannitol substitution was independently associated with lower incidence of POD (odds ratio: 0.40; 95% confidence interval: 0.18–0.89; p  = 0.02).

Conclusion  Treatment with mannitol during ECC was associated with decreased incidence of POD. This was accompanied by shorter ventilation time, ICU and hospital stay, and lower treatment expenses.

Risk factors for acute kidney injury in an enhanced recovery pathway for colorectal surgery

PURPOSES

Enhanced recovery pathways (ERPs) have been disseminated worldwide to improve the perioperative patient outcomes while lowering direct healthcare costs. Recent evidence has revealed a potential association between ERPs for colorectal surgery and acute kidney injury (AKI). We, therefore, sought to identify the risk factors associated with postoperative AKI among patients in an ERP for colorectal surgery.

METHODS

We analyzed the data resulting from a large multicenter, prospective cohort study of patients in an ERP for colorectal surgery. A multivariable analysis was performed to identify factors independently associated with postoperative AKI. The receiver operating characteristic (ROC) curves and contour representations were plotted for the diagnostic prediction analysis.

RESULTS

Among those patients included in the analysis (n = 1652), the overall incidence of postoperative AKI was 7.7% (95% CI 6.5-9.1%). After adjustment, the independent risk factors for AKI included age > 60 (OR 1.03, 95% CI 1.01-1.05), male gender (OR 2.33, 95% CI 1.36-4.02), ASA III-IV (OR 2.43, 95% CI 1.39-4.26), CKD (OR 2.45, 95% CI 1.42-4.23), open surgical approach (OR 2.62, 95% CI 1.63-4.21) and serum albumin < 3.5 g/dL (OR 1.68, 95% CI 1.02-2.79). An ROC analysis revealed that the composite of albumin, creatinine and age was a strong predictor of postoperative AKI [area under the curve (AUC) 0.756; 95% CI 0.705-0.808].

CONCLUSION

Postoperative AKI is common in the setting of ERPs for colorectal surgery and it is associated with a poor clinical outcome. Of those characteristics associated with postoperative AKI, one modifiable factor is a low preoperative albumin level. Screening for malnourished patients or optimizing the nutritional status may be a useful preoperative intervention to prevent postoperative AKI and associated complications.

Intravenous fluid therapy in the perioperative and critical care setting: Executive summary of the International Fluid Academy (IFA)

Intravenous fluid administration should be considered as any other pharmacological prescription. There are three main indications: resuscitation, replacement, and maintenance. Moreover, the impact of fluid administration as drug diluent or to preserve catheter patency, i.e., fluid creep, should also be considered. As for antibiotics, intravenous fluid administration should follow the four Ds: drug, dosing, duration, de-escalation. Among crystalloids, balanced solutions limit acid–base alterations and chloride load and should be preferred, as this likely prevents renal dysfunction. Among colloids, albumin, the only available natural colloid, may have beneficial effects. The last decade has seen growing interest in the potential harms related to fluid overloading. In the perioperative setting, appropriate fluid management that maintains adequate organ perfusion while limiting fluid administration should represent the standard of care. Protocols including a restrictive continuous fluid administration alongside bolus administration to achieve hemodynamic targets have been proposed. A similar approach should be considered also for critically ill patients, in whom increased endothelial permeability makes this strategy more relevant. Active de-escalation protocols may be necessary in a later phase. The R.O.S.E. conceptual model (Resuscitation, Optimization, Stabilization, Evacuation) summarizes accurately a dynamic approach to fluid therapy, maximizing benefits and minimizing harms. Even in specific categories of critically ill patients, i.e., with trauma or burns, fluid therapy should be carefully applied, considering the importance of their specific aims; maintaining peripheral oxygen delivery, while avoiding the consequences of fluid overload.

Effect and safety of 4% albumin in the treatment of cardiac surgery patients: study protocol for the randomized, double-blind, clinical ALBICS (ALBumin In Cardiac Surgery) trial

Background

In cardiac surgery with cardiopulmonary bypass (CPB), large amounts of fluids are administered. CPB priming with crystalloid solution causes marked hemodilution and fluid extravasation. Colloid solutions may reduce fluid overload because they have a better volume expansion effect than crystalloids. The European Medicines Agency does not recommend the use of hydroxyethyl starch solutions (HES) due to harmful renal effects. Albumin solution does not impair blood coagulation but the findings on kidney function are conflicting. On the other hand, albumin may reduce endothelial glycocalyx destruction and decrease platelet count during CPB. No large randomized, double-blind, clinical trials have compared albumin solution to crystalloid solution in cardiac surgery.

Methods/design

In this single-center, double-blind, randomized controlled trial comprising 1386 adult cardiac surgery patients, 4% albumin solution will be compared to Ringer’s acetate solution in CPB priming and volume replacement up to 3200 mL during surgery and the first 24 h of intensive care unit stay. The primary efficacy outcome is the number of patients with at least one major adverse event (MAE) during 90 postoperative days (all-cause death, acute myocardial injury, acute heart failure or low output syndrome, resternotomy, stroke, major arrhythmia, major bleeding, infection compromising post-procedural rehabilitation, acute kidney injury). Secondary outcomes are total number of MAEs, incidence of major adverse cardiac events (MACE; cardiac death, acute myocardial injury, acute heart failure, arrhythmia), amount of each type of blood product transfused (red blood cells, fresh frozen plasma, platelets), total fluid balance at the end of the intervention period, total measured blood loss, development of acute kidney injury, days alive without mechanical ventilation in 90 days, days alive outside intensive care unit at 90 days, days alive at home at 90 days, and 90-day mortality.

Discussion

The findings of this study will provide new evidence regarding efficacy and safety of albumin solution in adult patients undergoing cardiac surgery with CPB.

Trial registration

EudraCT (clinicaltrialsregister.eu) 2015–002556-27 Registered 11 Nov 2016 and ClinicalTrials.gov NCT02560519. Registered 25 Sept 2015.

Preventing Perioperative Acute Kidney Injury

How to cite this article: Bhosale SJ, Kulkarni AP. Preventing Perioperative Acute Kidney Injury. Indian J Crit Care Med 2020;24(Suppl 3):S126–S128.

Colloids and the Microcirculation

Colloid solutions have been advocated for use in treating hypovolemia due to their expected effect on improving intravascular retention compared with crystalloid solutions. Because the ultimate desired effect of fluid resuscitation is the improvement of microcirculatory perfusion and tissue oxygenation, it is of interest to study the effects of colloids and crystalloids at the level of microcirculation under conditions of shock and fluid resuscitation, and to explore the potential benefits of using colloids in terms of recruiting the microcirculation under conditions of hypovolemia. This article reviews the physiochemical properties of the various types of colloid solutions (eg, gelatin, dextrans, hydroxyethyl starches, and albumin) and the effects that they have under various conditions of hypovolemia in experimental and clinical scenarios.

Effects of crystalloid, hyper-oncotic albumin, and iso-oncotic albumin on lung and kidney damage in experimental acute lung injury

BACKGROUND

Conflicting data have reported beneficial effects of crystalloids, hyper-oncotic albumin (20%ALB), and iso-oncotic albumin (5%ALB) in critically ill patients. Although hyper-oncotic albumin may minimize lung injury, recent studies have shown that human albumin may lead to kidney damage proportional to albumin concentration. In this context, we compared the effects of Ringer's lactate (RL), 20%ALB, and 5%ALB, all titrated according to similar hemodynamic goals, on pulmonary function, lung and kidney histology, and molecular biology in experimental acute lung injury (ALI).

METHODS

Male Wistar rats received Escherichia coli lipopolysaccharide intratracheally (n = 24) to induce ALI. After 24 h, animals were anesthetized and randomly assigned to receive RL, 20%ALB, or 5%ALB (n = 6/group) to maintain hemodynamic stability (distensibility index of inferior vena cava < 25%, mean arterial pressure > 65 mmHg). Rats were then mechanically ventilated for 6 h. Six animals, which received neither ventilation nor fluids (NV), were used for molecular biology analyses.

RESULTS

The total fluid volume infused was higher in RL compared to 5%ALB and 20%ALB (median [interquartile range], 10.8[8.2-33.2] vs. 4.8[3.6-7.7] and 4.3[3.9-6.6] mL, respectively; p = 0.02 and p = 0.003). B-line counts on lung ultrasound (p < 0.0001 and p = 0.0002) and serum lactate levels (p = 0.01 and p = 0.01) were higher in RL than 5%ALB and 20%ALB. Diffuse alveolar damage score was lower in 5%ALB (10.5[8.5-12]) and 20%ALB (10.5[8.5-14]) than RL (16.5[12.5-20.5]) (p < 0.05 and p = 0.03, respectively), while acute kidney injury score was lower in 5%ALB (9.5[6.5-10]) than 20%ALB (18[15-28.5], p = 0.0006) and RL (16 [15-19], p = 0.04). In lung tissue, mRNA expression of interleukin (IL)-6 was higher in RL (59.1[10.4-129.3]) than in 5%ALB (27.0[7.8-49.7], p = 0.04) or 20%ALB (3.7[7.8-49.7], p = 0.03), and IL-6 protein levels were higher in RL than 5%ALB and 20%ALB (p = 0.026 and p = 0.021, respectively). In kidney tissue, mRNA expression and protein levels of kidney injury molecule (KIM)-1 were lower in 5%ALB than RL and 20%ALB, while nephronectin expression increased (p = 0.01 and p = 0.01), respectively.

CONCLUSIONS

In a rat model of ALI, both iso-oncotic and hyper-oncotic albumin solutions were associated with less lung injury compared to Ringer's lactate. However, hyper-oncotic albumin resulted in greater kidney damage than iso-oncotic albumin. This experimental study is a step towards future clinical designs.

Management of Sepsis in Patients With Cirrhosis: Current Evidence and Practical Approach

Sepsis in patients with cirrhosis is associated with high mortality. An impaired immune response accounts for the increased infection risk observed in these patients. Hemodynamic and systemic changes suggestive of sepsis may be observed in patients with cirrhosis in the absence of infection; therefore, diagnosis and treatment of sepsis may be delayed. The optimal management of the critically ill patient with sepsis and cirrhosis has not been well established and is generally extrapolated from consensus guidelines and expert recommendations made for management of patients without cirrhosis with sepsis. Despite the lack of strong evidence, we propose a contemporary pragmatic approach to sepsis management in patients with cirrhosis, including the choice of fluids, vasopressors, and antibiotics.

Acute kidney injury from sepsis: current concepts, epidemiology, pathophysiology, prevention and treatment

Sepsis-associated acute kidney injury (S-AKI) is a frequent complication of the critically ill patient and is associated with unacceptable morbidity and mortality. Prevention of S-AKI is difficult because by the time patients seek medical attention, most have already developed acute kidney injury. Thus, early recognition is crucial to provide supportive treatment and limit further insults. Current diagnostic criteria for acute kidney injury has limited early detection; however, novel biomarkers of kidney stress and damage have been recently validated for risk prediction and early diagnosis of acute kidney injury in the setting of sepsis. Recent evidence shows that microvascular dysfunction, inflammation, and metabolic reprogramming are 3 fundamental mechanisms that may play a role in the development of S-AKI. However, more mechanistic studies are needed to better understand the convoluted pathophysiology of S-AKI and to translate these findings into potential treatment strategies and add to the promising pharmacologic approaches being developed and tested in clinical trials.

Fluid Management Practices After Surgery for Congenital Heart Disease: A Worldwide Survey

OBJECTIVES

To determine common practice for fluid management after cardiac surgery for congenital heart disease among pediatric cardiac intensivists.

DESIGN

A survey consisting of 17 questions about fluid management practices after pediatric cardiac surgery. Distribution was done by email, social media, World Federation of Pediatric Intensive and Critical Care Societies website, and World Federation of Pediatric Intensive and Critical Care Societies newsletter using the electronic survey distribution and collection system Research Electronic Data Capture.

SETTING

PICUs around the world.

SUBJECTS

Pediatric intensivists managing children after surgery for congenital heart disease.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

One-hundred eight responses from 18 countries and six continents were received. The most common prescribed fluids for IV maintenance are isotonic solutions, mainly NaCl 0.9% (42%); followed by hypotonic fluids (33%) and balanced crystalloids solutions (14%). The majority of the respondents limit total fluid intake to 50% during the first 24 hours after cardiac surgery. The most frequently used fluid as first choice for resuscitation is NaCl 0.9% (44%), the second most frequent choice are colloids (27%). Furthermore, 64% of respondents switch to a second fluid for ongoing resuscitation, 76% of these choose a colloid. Albumin 5% is the most commonly used colloid (61%). Almost all respondents (96%) agree there is a need for research on this topic.

CONCLUSIONS

Our survey demonstrates great variation in fluid management practices, not only for maintenance fluids but also for volume resuscitation. Despite the lack of evidence, colloids are frequently administered. The results highlight the need for further research and evidence-based guidelines on this topic.

Trends and Updates on Cardiopulmonary Bypass Setup in Pediatric Cardiac Surgery

Perfusion strategies for cardiopulmonary bypass have direct consequences on pediatric cardiac surgery outcomes. However, inconsistent study results and a lack of uniform evidence-based guidelines for pediatric cardiopulmonary bypass management have led to considerable variability in perfusion practices among, and even within, institutions. Important aspects of cardiopulmonary bypass that can be optimized to improve clinical outcomes of pediatric patients undergoing cardiac surgery include extracorporeal circuit components, priming solutions, and additives. This review summarizes the current literature on circuit components and priming solution composition with an emphasis on crystalloid, colloid, and blood-based primes, as well as mannitol, bicarbonate, and calcium.

Acute kidney injury in postoperative shock: is hyperoncotic albumin administration an unrecognized resuscitation risk factor?

BACKGROUND

The use of hyperoncotic albumin (HA) for shock resuscitation is controversial given concerns about its cost, effectiveness, and potential for nephrotoxicity. We evaluated the association between early exposure to hyperoncotic albumin (within the first 48 h of onset of shock) and acute organ dysfunction in post-surgical patients with shock.

METHODS

This retrospective, cohort study included 11,512 perioperative patients with shock from 2009 to 2012. Shock was defined as requirement for vasopressors to maintain adequate mean arterial pressure and/or elevated lactate (> 2.2 mmol/L). Subsets of 3600 were selected after propensity score and exact matching on demographics, comorbidities, and treatment variables (> 30). There was a preponderance of cardiac surgery patients. Proportional odds logistic regression, multivariable logistic regression or Cox proportional hazard regression models measured association between hyperoncotic albumin and acute kidney injury (AKI), hepatic injury, ICU days, and mortality.

RESULTS

Hyperoncotic albumin-exposed patients showed greater risk of acute kidney injury compared to controls (OR 1.10, 95% CI 1.04, 1.17. P = 0.002), after adjusting for imbalanced co-variables. Within matched patients, 20.3%, 2.9%, and 4.4% of HA patients experienced KDIGO stages 1-3 AKI, versus 19.6%, 2.5%, and 3.0% of controls. There was no difference in hepatic injury (OR 1.16; 98.3% CI 0.85, 1.58); ICU days, (HR 1.05; 98.3% CI 1.00, 1.11); or mortality, (OR 0.88; 98.3% CI 0.64, 1.20).

CONCLUSIONS

Early exposure to hyperoncotic albumin in postoperative shock appeared to be associated with acute kidney injury. There did not appear to be any association with hepatic injury, mortality, or ICU days. The clinical and economic implications of this finding warrant further investigation.

Comparison of acute kidney injury between open and laparoscopic pylorus-preserving pancreaticoduodenectomy: Propensity score analysis

Laparoscopic pylorus-preserving pancreaticoduodenectomy is being performed more frequently because of improved surgical techniques. Although several studies have demonstrated safety and favourable outcomes of laparoscopic pylorus-preserving pancreaticoduodenectomy compared to open pylorus-preserving pancreaticoduodenectomy, few studies have focused on the development of postoperative acute kidney injury. This retrospective study compared the prevalence and risk factors of acute kidney injury following laparoscopic and open pylorus-preserving pancreaticoduodenectomy. Data from 809 patients who underwent pylorus-preserving pancreaticoduodenectomy between February 2012 and September 2016 were analysed. Patients were divided into two groups according to the surgical procedure (open pylorus-preserving pancreaticoduodenectomy [n = 632] vs laparoscopic pylorus-preserving pancreaticoduodenectomy [n = 177]). The Kidney Disease: Improving Global Outcomes criteria were used to define postoperative acute kidney injury and risk factors were investigated using multivariable logistic regression analysis with propensity score matching analysis and standardized mortality ratio weighting to compare outcomes. No significant differences were found in the occurrence of postoperative acute kidney injury and incidence of postoperative ICU admission between open and laparoscopic pylorus-preserving pancreaticoduodenectomy groups after propensity score matching (p = 1.000, p = 0.999, respectivelyand standardized mortality ratio weighted analysis (p = 0.619, p = 0.982, respectively). Hospital stay was significantly shorter in the laparoscopic pylorus-preserving pancreaticoduodenectomy group (propensity matched set, mean [SD], 16.7 [10.0] vs. 18.7 [9.6] days, p = 0.004; standardized mortality ratio, 16.6 [9.9] vs. 18.1 [8.8] days, p = 0.001). There was no significant difference in postoperative acute kidney injury incidence between both groups. Laparoscopic pylorus-preserving pancreaticoduodenectomy is promising with comparable postoperative outcomes to open pylorus-preserving pancreaticoduodenectomy and has the advantage of shorter hospital stay.