Hypoalbuminemia is associated with increased risk of acute kidney injury in hospitalized patients: A meta-analysis

Association between lactate/albumin ratio and prognosis in critically ill patients with acute kidney injury undergoing continuous renal replacement therapy

BACKGROUND

The primary objective was to examine the association between the lactate/albumin ratio (LAR) and the prognosis of patients with acute kidney injury (AKI) undergoing continuous renal replacement therapy (CRRT).

METHODS

Utilizing the Medical Information Mart for Intensive Care IV (MIMIC-IV, v2.0) database, we categorized 703 adult AKI patients undergoing CRRT into survival and non-survival groups based on 28-day mortality. Patients were further grouped by LAR tertiles: low (< 0.692), moderate (0.692-1.641), and high (> 1.641). Restricted cubic splines (RCS), Least Absolute Shrinkage and Selection Operator (LASSO) regression, inverse probability treatment weighting (IPTW), and Kaplan-Meier curves were employed.

RESULTS

In our study, the patients had a mortality rate of 50.07% within 28 days and 62.87% within 360 days. RCS analysis revealed a non-linear correlation between LAR and the risk of mortality at both 28 and 360 days. Cox regression analysis, which was adjusted for nine variables identified by LASSO, confirmed that a high LAR (>1.641) served as an independent predictor of mortality at these specific time points (p < 0.05) in AKI patients who were receiving CRRT. These findings remained consistent even after IPTW adjustment, thereby ensuring a reliable and robust outcome. Kaplan-Meier survival curves exhibited a gradual decline in cumulative survival rates at both 28 and 360 days as the LAR values increased (log-rank test, χ2 = 48.630, p < 0.001; χ2 = 33.530, p < 0.001).

CONCLUSION

A high LAR (>1.641) was found to be an autonomous predictor of mortality at both 28 and 360 days in critically ill patients with AKI undergoing CRRT.

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 prediction model utility in premature myocardial infarction

The incidence of premature myocardial infarction (PMI) has been rising and acute kidney injury (AKI) occurring in PMI patients severely impacts prognosis. This study aimed to develop and validate a prediction model for AKI specific to PMI patients. The MIMIC-Ⅲ-CV and MIMIC-Ⅳ databases were utilized for model derivation of PMI patients. Single-center data served for external validation. There were 571 and 182 AKI patients in the training set (n = 937) and external validation set (n = 292) cohorts, respectively. Finally, a 7-variable model consisting of: Sequential Organ Failure Assessment (SOFA) score, coronary artery bypass grafting (CABG), ICU stay time, loop diuretics, estimated glomerular filtration rate (eGFR) HCO3- and Albumin was developed, achieving an AUC of 0.85 (95% CI: 0.83-0.88) in the training set. External validation also confirmed model robustness. This model may assist clinicians in the early identification of patients at elevated risk for PMI. Further validation is warranted before clinical application.

Current Trends in Biohumoral Screening for the Risk of Sudden Cardiac Death: A Systematic Review

Background and Objectives: Sudden cardiac death (SCD) represents a challenge to health systems globally and is met with increased frequency in the population. Over time, multiple screening methods have been proposed, including the analysis of various plasma biomarkers. This article aims to analyze for illustrative purposes the specialized literature in terms of current biomarkers and testing trends, in the case of cardiovascular diseases and implicitly sudden cardiac death. Materials and Methods: In this regard, we searched the PubMed database from 2010 to the present time using the keywords "sudden cardiac death" and "biomarkers". The inclusion criteria were clinical trials that analyzed the effectiveness of screening methods in terms of biomarkers used in stratifying the risk of cardiac distress and/or sudden cardiac death. We excluded reviews, meta-analyses, and studies looking at the effectiveness of treatments. Results: An extended approach was found, through studies that brought to the forefront both classical markers analyzed by new, more performant methods, markers for other pathologies that also determined cardiovascular impact, non-specific molecules with effects on the cardiovascular system, and state-of-the-art markers, such as microRNA. Some molecules were analyzed simultaneously in certain groups of patients. Conclusion: The observed current trend revealed the tendency to define the clinical-biological particularities of the person to be screened.

Construction and validation of a risk assessment model for acute kidney injury in patients with acute pancreatitis in the intensive care unit

BACKGROUND

To construct and validate a risk assessment model for acute kidney injury (AKI) in patients with acute pancreatitis (AP) in the intensive care unit (ICU).

METHODS

A total of 963 patients diagnosed with acute pancreatitis (AP) from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database was included. These patients were randomly divided into training set (N = 674) and validation set (N = 289) at a ratio of 7:3. Clinical characteristics were utilized to establish a nomogram for the prediction of AKI during ICU stay. These variables were selected by the least absolute shrinkage and selection operation (LASSO) regression and included in multivariate logistic regression analysis. Variables with P-values less than 0.05 were included in the final model. A nomogram was constructed based on the final model. The predicted accuracy of the nomogram was assessed by calculating the receiver operating characteristic curve (ROC) and the area under the curve (AUC). Moreover, calibration curves and Hosmer-Lemeshow goodness-of-fit test (HL test) were performed to evaluate model performance. Decision curve analysis (DCA) evaluated the clinical net benefit of the model.

RESULTS

A multivariable model that included 6 variables: weight, SOFA score, white blood cell count, albumin, chronic heart failure, and sepsis. The C-index of the nomogram was 0.82, and the area under the receiver operating characteristic curve (AUC) of the training set and validation set were 0.82 (95% confidence interval:0.79-0.86) and 0.76 (95% confidence interval: 0.70-0.82), respectively. Calibration plots showed good consistency between predicted and observed outcomes in both the training and validation sets. DCA confirmed the clinical value of the model and its good impact on actual decision-making.

CONCLUSION

We identified risk factors associated with the development of AKI in patients with AP. A risk prediction model for AKI in ICU patients with AP was constructed, and improving the treatment strategy of relevant factors in the model can reduce the risk of AKI in AP patients.

Association of Preoperative Prognostic Nutritional Index with Risk of Postoperative Acute Kidney Injury: A Meta-Analysis of Observational Studies

This meta-analysis aimed to assess the clinical association of the preoperative prognostic nutritional index (pre-PNI) with the risk of postoperative acute kidney injury. Four databases (e.g., Medline) were searched from inception to December 2022 to investigate the association between pre-PNI (i.e., low vs. high) and PO-PNI as well as the correlation between pre-PNI and other postoperative prognostic indices. Overall, 13 observational studies, including 9185 patients, were eligible for analysis. A low PNI was related to increased risks of PO-AKI [odd ratio (OR) = 1.65, p = 0.001, 3811 patients], postoperative infection (OR = 2.1, p < 0.00001, 2291 patients), and mortality (OR = 1.93, p < 0.0001, 2159 patients). Albeit statistically nonsignificant, a trend was noted, linking a low PNI to higher risks of postoperative bleeding (OR = 2.5, p = 0.12, 1157 patients) and stroke (OR = 1.62, p = 0.07, 2036 patients). Pooled results revealed a prolonged intensive care unit (ICU) stay in patients with low PNIs compared to those with high PNIs (MD: 0.98 days, p = 0.02, 2209 patients) without a difference in hospital stay between the two groups (MD: 1.58 days, p = 0.35, 2249 patients). This meta-analysis demonstrated an inverse correlation between PNI and the risks of PO-AKI, postoperative infection, and mortality, as well as the length of ICU stay, which warrants further investigations for verification.

Prognostic implication of lactic dehydrogenase-to-albumin ratio in critically ill patients with acute kidney injury

BACKGROUND

No studies have been published on the correlation between lactic dehydrogenase-to-albumin ratio (LAR) and poor prognosis of acute kidney injury (AKI) patients, warranting further research. This analysis sought to investigate the prognostic implication of LAR in critically ill patients with AKI.

METHODS

The present study enrolled 11,046 and 5180 adults with AKI from the Medical Information Mart for Intensive Care III (MIMIC III) and MIMIC IV, respectively. Data from MIMIC IV were identified as the training cohort, and those from MIMIC III were identified as the validation cohort. We applied multivariate regression analysis to identify the link between LAR and all-cause mortality. Restricted cubic spline (RCS) was conducted to figure out the correlation between LAR and in-hospital mortality. Furthermore, we carried out stratification analyses to examine if the effects of LAR on in-hospital mortality were consistent across various subclasses.

RESULTS

The level of LAR was remarkably higher in the in-hospital non-survivor group (p < 0.001). Furthermore, the increased LAR group presented a remarkably higher rate of in-hospital mortality at AKI stages 1, 2, and 3 compared with the decreased LAR group (all p < 0.001). Multivariate regression analyses exhibited the independent prognostic significance of LAR for all-cause mortality (all p < 0.001). MIMIC III observed concordant results. RCS indicated a non-linear correlation between LAR and in-hospital death (P for non-linearity < 0.001). The relationship between LAR and in-hospital mortality was still significant in patients with various subclasses.

CONCLUSIONS

Elevated LAR at admission is a prognostic risk factor for critically ill patients with AKI.

[Risk factors for early acute kidney injury after cardiac arrest in children in the pediatric intensive care unit and a prognostic analysis]

OBJECTIVES

To investigate the risk factors for acute kidney injury (AKI) in children with cardiac arrest (CA) and the influencing factors for prognosis.

METHODS

A retrospective analysis was performed on the medical records of the children who developed CA in the pediatric intensive care unit (PICU) of Hunan Children's Hospital from June 2016 to June 2021. According to the presence or absence of AKI within 48 hours after return of spontaneous circulation (ROSC) for CA, the children were divided into two groups: AKI (n=50) and non-AKI (n=113). According to their prognosis on day 7 after ROSC, the AKI group was further divided into a survival group (n=21) and a death group (n=29). The multivariate logistic regression analysis was used to investigate the risk factors for early AKI in the children with CA and the influencing factors for prognosis.

RESULTS

The incidence rate of AKI after CA was 30.7% (50/163). The AKI group had a 7-day mortality rate of 58.0% (29/50) and a 28-day mortality rate of 78.0% (39/50), and the non-AKI group had a 7-day mortality rate of 31.9% (36/113) and a 28-day mortality rate of 58.4% (66/113). The multivariate logistic regression analysis showed that long duration of cardiopulmonary resuscitation (OR=1.164, 95%CI: 1.088-1.246, P<0.001), low baseline albumin (OR=0.879, 95%CI: 0.806-0.958, P=0.003), and adrenaline administration before CA (OR=2.791, 95%CI: 1.119-6.961, P=0.028) were closely associated with the development of AKI after CA, and that low baseline pediatric critical illness score (OR=0.761, 95%CI: 0.612-0.945, P=0.014), adrenaline administration before CA (OR=7.018, 95%CI: 1.196-41.188, P=0.031), and mechanical ventilation before CA (OR=7.875, 95%CI: 1.358-45.672, P=0.021) were closely associated with the death of the children with AKI after CA.

CONCLUSIONS

Albumin should be closely monitored for children with ROSC after CA, especially for those with long duration of cardiopulmonary resuscitation, low baseline pediatric critical illness score, adrenaline administration before CA, and mechanical ventilation before CA, and such children should be identified and intervened as early as possible to reduce the incidence of AKI and the mortality rate.

ISCCM Guidelines on Acute Kidney Injury and Renal Replacement Therapy

Acute kidney injury (AKI) is a complex syndrome with a high incidence and considerable morbidity in critically ill patients. Renal replacement therapy (RRT) remains the mainstay of treatment for AKI. There are at present multiple disparities in uniform definition, diagnosis, and prevention of AKI and timing of initiation, mode, optimal dose, and discontinuation of RRT that need to be addressed. The Indian Society of Critical Care Medicine (ISCCM) AKI and RRT guidelines aim to address the clinical issues pertaining to AKI and practices to be followed for RRT, which will aid the clinicians in their day-to-day management of ICU patients with AKI.

How to cite this article

Mishra RC, Sodhi K, Prakash KC, Tyagi N, Chanchalani G, Annigeri RA, et al. ISCCM Guidelines on Acute Kidney Injury and Renal Replacement Therapy. Indian J Crit Care Med 2022;26(S2):S13-S42.

Preoperative hypoalbuminemia in patients undergoing cardiac surgery: a meta-analysis

The preoperative serum albumin level has been shown to be associated with adverse postoperative complications, meaning that hypoalbuminemia may also be a risk factor. We performed a meta-analysis to evaluate the association of serum albumin levels with survival and complication rates after cardiac surgery. Relevant articles were identified through seven databases. Twenty studies with 22553 patients (hypoalbuminemia group, n = 9903; normal group, n = 12650) who underwent cardiac surgery met the inclusion criteria after screening. The primary outcomes were that hypoalbuminemia was significantly correlated with serious long-term all-cause mortality (hazard ratio [HR]: 1.95 [1.54-2.48]; P < 0.00001) and increased mortality (risk ratio [RR] = 1.91 [1.61-2.27], P < 0.00001). Hypoalbuminemic patients with cardiopathy were more likely to suffer postoperative complications (bleeding, infections, renal injury, and others) than those whose serum albumin levels were normal. Furthermore, hypoalbuminemia increased the time in the intensive-care unit (ICU) (mean difference [MD] = 1.18 [0.49-1.87], P = 0.0008), length of hospital stay (LOS) (MD = 3.34, 95% CI: 1.88-4.80, P < 0.00001), and cardiopulmonary bypass time (CPB) (MD = 12.40 [1.13-23.66], P = 0.03). Hypoalbuminemia in patients undergoing cardiac surgery appears to have a poor all-cause mortality or increased risk of complications. Adjusted perioperative serum albumin levels and treatment strategies for this high-risk population have the potential to improve the survival.

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

BACKGROUND

This study aimed to assess the association of hypoalbuminemia with mortality in critically ill patients requiring continuous renal replacement therapy (CRRT).

METHODS

This is a retrospective cohort study of critically ill patients receiving CRRT from December 2006 through November 2015 in a tertiary referral hospital in the United States. We used logistic regression to assess serum albumin at CRRT initiation as predictors for 90-day mortality.

RESULTS

A total of 911 patients requiring CRRT were included in this study. The mean serum albumin at CRRT initiation was 3.0 ± 0.7 g/dL. The 90-day mortality was 57%. Serum albumin levels of ≤2.4, 2.5-2.9, 3.0-3.4, and ≥ 3.5 g/dL were noted in 24%, 29%, 24%, and 23% of patients, respectively. In adjusted analysis, serum albumin ≤2.4 g/dL compared with serum albumin of ≥3.5 g/dL was significantly associated with higher 90-day mortality with OR of 1.57 (95% CI 1.02-2.42). Serum albumin 2.5-2.9 and 3.0-3.4 g/dL were not associated with higher mortality. Sensitivity analysis in patients requiring CRRT in the setting of acute kidney injury showed consistent results.

CONCLUSION

Approximately three out of four patients had hypoalbuminemia (<3.5 g/dL) at CRRT initiation. However, only severe hypoalbuminemia <2.5 g/dL was significantly associated with higher mortality.

[Use of albumin : State of the art]

The Saline versus Albumin Fluid Evaluation (SAFE) study has demonstrated that the use of albumin as an infusion solution in volume therapy can be regarded as safe. An exception is hypo-oncotic albumin in traumatic brain injury. While clear indications of albumin exist for some patients with liver cirrhosis, large studies that demonstrate a clinically relevant advantage beyond hemodynamic effects and would therefore justify wider use in many other areas are still lacking. In large-volume paracentesis, spontaneous bacterial peritonitis, but also in hepatorenal syndrome, use of albumin is recommended and established due to clinical benefit in randomized controlled trials. In septic shock, use of albumin may be considered, with two large studies addressing this issue in Germany and Italy being still in the recruitment phase. For volume therapy, albumin can be used primarily when other measures for hemodynamic stabilization have been exhausted. This applies to volume resuscitation in hypovolemia as well as in conservative fluid management in the so-called "de-resuscitation" phase. The extent to which the correction of severe hypoalbuminemia with exogenous albumin can improve the impaired outcome of these patients is also part of ongoing studies. On the way to a more individualized medicine, hypoalbuminemia may serve as a parameter in future decision making for or against the use of albumin in volume therapy.

Risk Factors, Clinical Characteristics, and Prognosis of Acute Kidney Injury in Hospitalized COVID-19 Patients: A Retrospective Cohort Study

Background: Acute kidney injury (AKI) is a serious complication of COVID-19. Methods: Records of hospitalized adult patients with confirmed SARS-CoV-2 infection from 1 March to 31 May 2020 were retrospectively reviewed. Results: Of 283 patients, AKI occurred in 40.6%. From multivariate analyses, the risk factors of AKI in COVID-19 can be divided into: (1) demographics/co-morbidities (male, increasing age, diabetes, chronic kidney disease); (2) other organ involvements (transaminitis, elevated troponin I, ST segment/T wave change on electrocardiography); (3) elevated biomarkers (ferritin, lactate dehydrogenase); (4) possible bacterial co-infection (leukocytosis, elevated procalcitonin); (5) need for advanced oxygen delivery (non-invasive positive pressure ventilation, mechanical ventilation); and (6) other critical features (ICU admission, need for vasopressors, acute respiratory distress syndrome). Most AKIs were due to pre-renal (70.4%) and intrinsic (34.8%) causes. Renal replacement therapy was more common in intrinsic AKI. Both pre-renal (HR 3.2; 95% CI 1.7–5.9) and intrinsic AKI (HR 7.7; 95% CI 3.6–16.3) were associated with higher mortality. Male, stage 3 AKI, higher baseline and peak serum creatinine and blood urea nitrogen were prevalent in intrinsic AKI. Urine analysis and the fractional excretion of sodium and urea were not helpful in distinguishing intrinsic AKI from other causes. Conclusions: AKI is very common in COVID-19 and is associated with higher mortality. Characterization of AKI is warranted due to its diverse nature and clinical outcome.