Impact of hypoalbuminemia on mortality in critically ill patients requiring continuous renal replacement therapy

Impact of Early Administration of Albumin on Mortality Among Severe COVID-19 Patients, China

Purpose

Hypoalbuminemia is commonly observed in patients with severe Coronavirus Disease 2019 (COVID-19) and is independently associated with adverse outcomes. However, the efficacy of albumin administration on the clinical prognosis of these patients remains uncertain.

Patients and Methods

This multicenter retrospective study enrolled 458 patients with severe COVID-19 in four medical centers from December 1, 2022, to June 1, 2024. Clinical features and laboratory variables were collected through electronic medical records. The cohorts were divided into two groups: albumin administration and non-albumin administration. Propensity score matching (PSM) was used for minimizing confounding effect. Statistical analyses were conducted to assess the relationship between early albumin administration and 28-day mortality.

Results

Four hundred and fifty-eight severe COVID-19 cases were included in the study, of which 167 (36.5%) received early albumin administration, while 291 (63.5%) did not. Among these patients, 140 experienced in-hospital mortality and 318 survived. Compared to survivors, non-survivors exhibited significantly lower serum albumin levels (29.1g/L vs.33.8g/L, p < 0.05). In comparison to patients with admission albumin levels ≥30 g/L, those with albumin levels <30 g/L had a significantly higher in-hospital mortality (48.4% vs 21.1%, p < 0.001). Prior to PSM, the albumin administration group demonstrated significantly higher 28-day and in-hospital cumulative survival rates compared to the non-albumin group (both p < 0.001). However, no significant differences were observed between the two groups following PSM (p = 0.21 and p = 0.41, respectively).

Conclusion

Hypoalbuminemia was correlated with adverse outcomes in severe COVID-19 patients. However, early albumin administration did not reduce 28-day mortality and in-hospital mortality in these patients, and more relative RCTs were required for validation.

High platelet-to-albumin ratio is associated with 30-day mortality in critically ill patients

BACKGROUND

The role of inflammation and hypoproteinemia in influencing outcomes of critically ill patients has been widely recognized. However, there is a paucity of research on the prognostic value of the platelet-to-albumin ratio (PAR) in critically ill patients. Therefore, the aim of this study is to assess the prognostic significance of PAR in this population.

METHODS

Patients diagnosed with critical illnesses from January 2020 to October 2022 were retrospectively enrolled in our study. Baseline demographic and clinical data were collected for each participant. Platelet counts and albumin levels were measured at baseline, and the PAR was calculated. The area under the receiver operating characteristic curve, Kaplan-Meier survival analysis, and multivariate Cox regression analysis were used to predict 30-day mortality.

RESULTS

Three hundred and seventy-eight patients diagnosed with critical illness were categorized into two groups: survivors (n = 299) and non-survivors (n = 79). Analysis of the 30-day outcome revealed that the area under the curve (AUC) for the PAR (AUC: 0.705; 95% CI 0.639-0.771; p < 0.001) was significantly higher than that for albumin (AUC: 0.673; 95% CI 0.609-0.736; p < 0.001), but slightly lower than that for the APACHE II score (AUC: 0.713; 95% CI 0.650-0.777; p < 0.001). In addition, the Kaplan-Meier survival analysis demonstrated a significantly higher 30-day mortality in the high-PAR group. Furthermore, Cox regression analysis identified albumin (HR: 0.936; 95% CI 0.895-0.978; p = 0.003), APACHE II score (HR: 1.225; 95% CI 1.149-1.305; p < 0.001), and high PAR (HR: 1.237; 95% CI 1.130-1.353; p < 0.001) as independent risk factors for the prognosis of critically ill patients.

CONCLUSIONS

The PAR has emerged as a significant prognostic indicator in critically ill patients, with an elevated ratio being associated with poorer clinical outcomes.

Construction and evaluation of a mortality prediction model for patients with acute kidney injury undergoing continuous renal replacement therapy based on machine learning algorithms

BACKGROUND

To construct and evaluate a predictive model for in-hospital mortality among critically ill patients with acute kidney injury (AKI) undergoing continuous renal replacement therapy (CRRT), based on nine machine learning (ML) algorithm.

METHODS

The study retrospectively included patients with AKI who underwent CRRT during their initial hospitalization in the United States using the medical information mart for intensive care (MIMIC) database IV (version 2.0), as well as in the intensive care unit (ICU) of Huzhou Central Hospital. Patients from the MIMIC database were used as the training cohort to construct the models (from 2008 to 2019, n = 1068). Patients from Huzhou Central Hospital were utilized as the external validation cohort to evaluate the models (from June 2019 to December 2022, n = 327). In the training cohort, least absolute shrinkage and selection operator (LASSO) regression with cross-validation was employed to select features for constructing the model and subsequently established nine ML predictive models. The performance of these nine models on the external validation cohort dataset was comprehensively evaluated based on the area under the receiver operating characteristic curve (AUROC) and the optimal model was selected. A static nomogram and a web-based dynamic nomogram were presented, with a comprehensive evaluation from the perspectives of discrimination (AUROC), calibration (calibration curve) and clinical practicability (DCA curves).

RESULTS

Finally, 1395 eligible patients were enrolled, including 1068 patients in the training cohort and 327 patients in the external validation cohort. In the training cohort, LASSO regression with cross-validation was employed to select features and nine models were individually constructed. Compared to the other eight models, the Lasso regularized logistic regression (Lasso-LR) model exhibited the highest AUROC (0.756) and the optimal calibration curve. The DCA curve suggested a certain clinical utility in predicting in-hospital mortality among critically ill patients with AKI undergoing CRRT. Consequently, the Lasso-LR model was the optimal model and it was visualized as a common nomogram (static nomogram) and a web-based dynamic nomogram (https://chsyh2006.shinyapps.io/dynnomapp/). Discrimination, calibration and DCA curves were employed to assess the performance of the nomogram. The AUROC for the training and external validation cohorts in the nomogram model was 0.771 (95%CI: 0.743, 0.799) and 0.756 (95%CI: 0.702, 0.809), respectively. The calibration slope and Brier score for the training cohort were 1.000 and 0.195, while for the external validation cohort, they were 0.849 and 0.197, respectively. The DCA indicated that the model had a certain clinical application value.

CONCLUSIONS

Our study selected the optimal model and visualized it as a static and dynamic nomogram integrating clinical predictors, so that clinicians can personalized predict the in-hospital outcome of critically ill patients with AKI undergoing CRRT upon ICU admission.

Short- and long-term outcomes in critically ill patients with primary glomerular disease: a case‒control study

INTRODUCTION

Glomerular diseases, encompassing primary and secondary forms, pose significant morbidity and mortality risks. Despite their impact, little is known about critically ill patients with primary glomerulopathy admitted to the intensive care unit (ICU).

METHODS

We conducted a case‒control study of patients with primary glomerulopathy using the Medical Information Mart for Intensive Care IV database. Demographic, clinical, and outcome data were collected. Logistic regression and mediation analysis were performed to identify predictors of hospital and long-term mortality.

RESULTS

Among 50,920 patients, 307 with primary glomerulopathy were included. Infectious and cardiovascular-related causes were the main reasons for ICU admission, with sepsis being diagnosed in more than half of the patients during their ICU stay. The hospital mortality rate was similar to that of the control group, with a long-term mortality rate of 29.0% three years post-ICU discharge. Reduced urine output and serum albumin were identified as independent predictors of hospital mortality, while serum albumin and the Charlson comorbidity index were significantly associated with long-term mortality. Notably, although acute kidney injury was frequent, it was not significantly associated with mortality. Additionally, reduced urine output mediates nearly 25% of the association between serum albumin and hospital mortality.

CONCLUSION

Critically ill patients with primary glomerulopathy exhibit unique characteristics and outcomes. Although hospital mortality was comparable to that of the control group, long-term mortality remained high. The serum albumin concentration and Charlson Comorbidity Index score emerged as robust predictors of long-term mortality, highlighting the importance of comprehensive risk assessment in this population. The lack of an association between acute kidney injury and mortality suggests the need for further research to understand the complex interplay of factors influencing outcomes in this patient population.

Hypoalbuminemia is a predictor of mortality in patients with cardiogenic shock requiring veno-arterial extracorporeal membrane oxygenation

INTRODUCTION

Hypoalbuminemia is predictive of mortality in critically ill patients, especially those with cardiac etiologies of illness. The objective of this study was to determine the association of albumin level pre-cannulation for veno-arterial (V-A) extracorporeal membrane oxygenation (ECMO) and important clinical hospital outcomes.

METHODS

This was a retrospective, observational cohort study of albumin levels in patients with cardiogenic shock requiring V-A ECMO between December 2015 and August 2021 in a single, high-volume ECMO center. The primary outcome was in-hospital mortality.

RESULTS

Of 434 patients assessed, 318 were included. The overall mean pre-ECMO albumin was 3 ± 0.8 g/dL and mean albumin at 72 hours post-cannulation was 2.7 ± 0.5 g/dL. For patients with pre-ECMO albumin ≤3 g/dL vs. >3 g/dL, in-hospital mortality was 44.9% vs. 27.5%, respectively (p = .002). In multivariable logistic regression analysis, higher albumin (per 1 g/dL increase) at time of V-A ECMO initiation was associated with decreased odds of in-hospital mortality (OR, 0.68; 95% CI, 0.48-0.96; p = .03). Patients with a pre-ECMO albumin ≤3 g/dL required significantly more platelet transfusions and had higher incidence of gastrointestinal bleeding during V-A ECMO support (both p < .05).

CONCLUSIONS

Hypoalbuminemia at time of cannulation is significantly associated with in-hospital mortality and ECMO-related complications including platelet transfusion and gastrointestinal bleeding. Albumin levels at the time of consideration of V-A ECMO may serve as a key prognostic indicator and may assist in effective decision-making regarding this invasive and costly resource.

Low-Dose Continuous Kidney Replacement Therapy and Mortality in Critically Ill Patients With Acute Kidney Injury: A Retrospective Cohort Study

RATIONALE & OBJECTIVE

Continuous kidney replacement therapy (CKRT) is preferred when available for hemodynamically unstable acute kidney injury (AKI) patients in the intensive care unit (ICU). The Kidney Disease: Improving Global Outcomes (KDIGO) guidelines recommend a delivered CKRT dose of 20-25mL/kg/h; however, in Japan the doses are typically below this recommendation due to government health insurance system restrictions. This study investigated the association between mortality and dose of CKRT.

STUDY DESIGN

Single-center retrospective cohort study.

SETTING & PARTICIPANTS

Critically ill patients with AKI treated with CKRT at a tertiary Japanese university hospital between January 1, 2012, and December 31, 2021.

EXPOSURE

Delivered CKRT doses below or above the median.

OUTCOME

90-day mortality after CKRT initiation.

ANALYTICAL APPROACH

Multivariable Cox regression analysis and Kaplan-Meier analysis.

RESULTS

The study population consisted of 494 patients. The median age was 72 years, and 309 patients (62.6%) were men. Acute tubular injury was the leading cause of AKI, accounting for 81.8%. The median delivered CKRT dose was 13.2mL/kg/h. Among the study participants, 456 (92.3%) received delivered CKRT doses below 20mL/kg/h, and 204 (41.3%) died within 90 days after CKRT initiation. Multivariable Cox regression analysis revealed increased mortality in the below-median group (HR, 1.73 [95% CI, 1.19-2.51], P=0.004). Additionally, a significant, inverse, nonlinear association between 90-day mortality and delivered CKRT dose was observed using delivered CKRT dose as a continuous variable.

LIMITATIONS

Single-center, retrospective, observational study.

CONCLUSIONS

A lower delivered CKRT dose was independently associated with higher 90-day mortality among critically ill patients who mostly received dosing below the current KDIGO recommendations.

PLAIN-LANGUAGE SUMMARY

The Kidney Disease: Improving Global Outcomes (KDIGO) guidelines recommend delivering a continuous kidney replacement therapy (CKRT) dose of 20-25mL/kg/h. However, it is not clear if it is safe to use delivered CKRT doses below this recommendation. In this study, over 90% of the patients received CKRT with a delivered dose below the KDIGO recommendation. We divided these patients into 2 groups based on the median delivered CKRT dose. Our findings show that a delivered CKRT dose below the median was associated with increased risk of death within 90 days. These findings show that a lower delivered CKRT dose was independently associated with higher 90-day mortality among critically ill patients who mostly received dosing below current KDIGO recommendations.

Association between the prognostic nutritional index (PNI) and all-cause mortality in patients with chronic kidney disease

BACKGROUND

Nutrition and immunity play an important role in many chronic diseases. The prognostic nutritional index (PNI) has been proposed as a comprehensive indicator of an individual's immune and nutritional status. However, there is a lack of evidence regarding the association between the PNI and mortality in patients with chronic kidney disease (CKD).

METHODS

We used National Health and Nutrition Examination Survey (NHANES) data from 2001-2014 for participants with CKD. Mortality data were obtained from the National Death Index and matched to NHANES participants. Cox proportional hazards models were used to estimate hazard ratios for all-cause mortality.Results: The patients were 72.5 ± 9.8 years old, and 47.57% were male. The median follow-up was 58 months, and the mortality rate in patients with CKD was 30.27%. A higher PNI protected against all-cause mortality in patients with CKD, with an adjusted hazard ratio (aHR) of 0.98 (95% confidence interval (CI): 0.97-0.99). After grouping according to PNI quartiles, statistically significant between-group differences were observed in survival probabilities. The aHR for the lowest PNI quartile compared to the highest PNI quartile was 1.64 (95% CI: 1.26-2.14). Sensitivity analysis further supported this association. Restricted cubic spline analysis revealed an L-shaped association between the PNI and all-cause mortality in patients with CKD, with a critical value of 50.5.

CONCLUSIONS

The PNI is a protective factor in patients with CKD, with an L-shaped decrease in all-cause mortality with an increasing PNI.

Association of hypochloremia with mortality among patients requiring continuous renal replacement therapy

BACKGROUND

Serum chloride derangement is common in critically ill patients requiring continuous renal replacement therapy (CRRT). We aimed to assess the association between serum chloride levels before and during CRRT with mortality.

METHODS

This is a retrospective cohort study of critically ill patients receiving CRRT for acute kidney injury from December 2006 through November 2015 in a tertiary referral hospital in the United States. We used logistic regression to assess serum chloride before and mean serum chloride during CRRT as predictors for 90 days mortality after CRRT initiation. The normal reference range for serum chloride was 99-108 mmol/L.

RESULTS

Of 1282 eligible patients, 25%, 50%, and 25% had hypochloremia, normochloremia, and hyperchloremia, respectively. The adjusted odds ratio for 90 days mortality in patients with hypochloremia before CRRT was 1.82 (95% CI 1.29-2.55). During CRRT, 4%, 70%, 26% of patients had mean serum chloride in the hypochloremia, normochloremia, and hyperchloremia range, respectively. The adjusted odds ratio for 90 days mortality in patients with mean serum chloride during CRRT in the hypochloremia range was 2.96 (95% CI 1.43-6.12). Hyperchloremia before and during CRRT was not associated with mortality. The greater serum chloride range during CRRT was associated with increased mortality (OR 1.29; 95% CI 1.13-1.47 per 5 mmol/L increase).

CONCLUSION

Hypochloremia before and during CRRT is associated with higher mortality.

Moderator Effect of Hypoalbuminemia in Volume Resuscitation and Plasma Expansion with Intravenous Albumin Solution

Intravenous administration of crystalloid or colloid solutions is the most common intervention for correcting hypovolemia in intensive care unit patients. In critical illness, especially sepsis and severe trauma, vascular wall permeability increases, and trans-endothelial escape of serum albumin, the major oncotic plasma constituent, contributes to the development of hypoalbuminemia and edema formation. The volume effects of intravenous human albumin solution exceed those of crystalloid solutions. If hypoalbuminemia is an effect moderator, the crystalloid-to-albumin ratio of fluid resuscitation volumes is not well characterized. Randomized controlled trials have confirmed that intravenous administration of human albumin solutions for volume resuscitation results in a lower net fluid balance compared with crystalloids, and smaller infusion volumes may be sufficient for hemodynamic stabilization when human albumin solutions are used. This narrative review summarizes the current evidence and conclusions drawn regarding the role of hypoalbuminemia in volume resuscitation. In the 'Saline versus Albumin Fluid Evaluation' study using 4% human albumin solution or saline, the saline-to-albumin ratio of study fluids was significantly higher in patients with baseline serum albumin concentrations of 25 g/L or less as compared to patients with baseline serum albumin concentrations of more than 25 g/L. In patients receiving renal replacement therapy, intravenous administration of 20-25% human albumin solution reduces intradialytic hypotension and improves fluid removal better than saline if serum albumin levels are similarly reduced. These data suggest that hypoalbuminemia acts as an effect moderator in volume resuscitation and plasma expansion with albumin solution. The volume effectiveness of intravenous human albumin solution in resuscitation appears to be greater when the serum albumin levels are low. In clinical situations, serum albumin concentrations per se may inform when and how to include intravenous albumin in fluid resuscitation if large amounts of crystalloids are needed, which requires further studies.

Worsening or improving hypoalbuminemia during continuous renal replacement therapy is predictive of patient outcome: a single-center retrospective study

Background

Hypoalbuminemia at the initiation of continuous renal replacement therapy (CRRT) is a risk factor for poor patient outcomes. However, it is unknown whether the patterns of changes in serum albumin levels during CRRT can be used to predict patient outcomes.

Methods

This retrospective study analyzed data that had been consecutively collected from January 2016 to December 2020 at the Third Affiliated Hospital. We included patients with acute kidney injury who received CRRT for ≥ 72 h. We divided the patients into four groups based on their serum albumin levels (albumin ≥ 3.0 g/dL or < 3.0 g/dL) at the initiation and termination of CRRT.

Results

The 793 patients in this study were categorized into the following albumin groups: persistently low, 299 patients (37.7%); increasing, 85 patients (10.4%); decreasing, 195 patients (24.6%); and persistently high, 214 patients (27.1%). In-hospital mortality rates were highest in the persistently low and decreasing groups, followed by the increasing and persistently high groups. The hazard ratio for in-hospital mortality was 0.481 (0.340–0.680) in the increasing group compared to the persistently low group; it was 1.911 (1.394–2.620) in the decreasing group compared to the persistently high group. The length of ICU stay was 3.55 days longer in the persistently low group than in the persistently high group.

Conclusions

Serum albumin levels changed during CRRT, and monitoring of patterns of change in serum albumin levels is useful for predicting in-hospital mortality and the length of ICU stay.

Association of Serum Potassium Derangements with Mortality among Patients Requiring Continuous Renal Replacement Therapy

BACKGROUND

We aimed to assess the association between serum potassium and mortality in patients receiving continuous renal replacement therapy (CRRT).

METHODS

We studied 1,279 acute kidney injury patients receiving CRRT in a tertiary referral hospital in the United States. We used logistic regression to assess the association of serum potassium before CRRT and mean serum potassium during CRRT with 90-day mortality after CRRT initiation, using serum potassium 4.0-4.4 mmol/L as reference group.

RESULTS

Before CRRT, there was a U-shaped association between serum potassium and 90-day mortality. There was a significant increase in mortality when serum potassium before CRRT was ≤3.4 and ≥4.5 mmol/L. During CRRT, progressively increased mortality was noted when mean serum potassium was ≥4.5 mmol/L. The odds ratio of 90-day mortality was significantly higher when mean serum potassium was ≥4.5 mmol/L.

CONCLUSION

Hypokalemia and hyperkalemia before CRRT and hyperkalemia during CRRT predicts 90-day mortality. This article is protected by copyright. All rights reserved.

Association of Serum Phosphate Derangement With Mortality in Patients on Continuous Renal Replacement Therapy

Background:

There is limited evidence on the association of serum phosphate with mortality in patients receiving continuous renal replacement therapy (CRRT).

Objective:

To assess the association of serum phosphate with mortality in critically ill patients requiring CRRT for acute kidney injury (AKI).

Design:

A cohort study.

Setting:

A tertiary referral hospital in the United States.

Patients:

Acute kidney injury patients receiving CRRT from 2006 through 2015 in intensive care units.

Measurements:

(1) Serum phosphate before CRRT and (2) mean serum phosphate during CRRT were categorized into 3 groups; ≤2.4 (hypophosphatemia), 2.5 to 4.5 (normal serum phosphate group), and ≥4.6 (hyperphosphatemia) mg/dL.

Methods:

Multivariable logistic regression was used to assess the association between serum phosphate and 90-day mortality.

Results:

A total of 1108 patients were included in this study. Of these, 55% died within 90 days after CRRT initiation. Before CRRT, 3%, 30%, and 66% had hypophosphatemia, normophosphatemia, and hyperphosphatemia, respectively. Before CRRT, both hypophosphatemia and hyperphosphatemia were significantly associated with higher 90-day mortality with the adjusted odds ratio (OR) of 2.22 (95% confidence interval [CI]: [1.03, 4.78]) and 1.62 (95% CI: [1.21, 2.18]), respectively. During CRRT, 3%, 85%, and 12% had mean serum phosphate in hypophosphatemia, normophosphatemia, and hyperphosphatemia range. During CRRT, hyperphosphatemia was significantly associated with higher 90-day mortality with adjusted OR of 2.22 (95% CI: [1.45, 3.38]).

Limitations:

Single center, observational design, lack of information regarding causes of serum phosphate derangement.

Conclusion:

Most CRRT patients had hyperphosphatemia before CRRT initiation but maintain normal serum phosphate during CRRT. Before CRRT, hypo- and hyperphosphatemia, and during CRRT, hyperphosphatemia predicted higher mortality.

Trial registration:

Not registered.