Association between serum albumin levels at admission and clinical outcomes in pediatric intensive care units: a multi-center study

Abstract

Background: Albumin, a vital component in regulating human blood oncotic pressure, plays an important role in the prediction of prognosis in pediatric patients.Previous research identified significant differences in serum albumin levels of healthy and critically ill children.

Methods: The present study aims to investigate the correlation between albumin levels measured during pediatric intensive care unit(PICU) admission and clinical outcomes. In 2022, a comprehensive analysis of the records was conducted retrospectively in four tertiary hospital PICUs in different cities in the south-east region of Turkey. We then conducted a ROC analysis to predict mortality based on hypoalbuminemia.A cut-off value was determined, and the patients were divided into two groups: hypoalbuminemic and normoalbuminemic.Based on this cut-off level, we evaluated the association between admission serum albumin levels and mortality, length of stay, laboratories, need for mechanical ventilation, and extracorporeal treatments.

Results: A total of 1329 patients admitted to the PICUs between January 1, 2022 and January 1, 2023 were included. The mortality rate amounted to 16.2%.The mean albumin level was 4.03 ± 0.69 g/dl in the surviving and 3.35 ± 0.90 g/dl in the non-surviving group(p < 0.001).The average length of stay in the PICU amounted to 8.98 ± 17.07, while the mean length of hospital stay was 11.23 ± 18.81days.Patients with hypoalbuminemia had significantly longer stays in the PICU and hospital as compared to those with normal albumin levels(p = 0.025 and p < 0.001,respectively).We found robust evidence that albumin levels are a strong predictor of mortality, with a predictive rate of 84.5%(OR:0.322, 95% CI:0.263-0.395, p < 0.001).The cut-off value was 3.785(AUC:0.731, Sensitivity:68.3%, Specificity:67%). A negative correlation was identified between albumin levels and lactate, C- reactive protein (CRP), and Blood urea nitrogen (BUN) levels across all patients. Conversely, a positive correlation was observed between neutrophil, lymphocyte, platelet, hemoglobin, sodium, and glucose levels. However, in patients with a cut-off point of 3.785 for albumin levels, a negative correlation was observed between albumin and lactate, CRP, and creatine levels. Conversely, a positive correlation was found between bicarbonate, platelet, hemoglobin, and glucose levels. Based on these findings, we conclude that hypoalbuminemia is associated with a higher rate of inotrope therapy and mechanical ventilation support. Furthermore, the rates of plasmapheresis, continuous renal replacement therapy, and extracorporeal membrane oxygenation initiation were markedly reduced in patients with elevated albumin levels (p < 0.001).

Conclusion: The serum albumin, which is an excellent and cost-effective biomarker that can be readily and economically evaluated in any center worldwide, as evidenced by the findings of our study, is a highly efficacious indicator of admission albumin levels for the prediction of mortality and outcomes in PICUs. Furthermore, it predicts the selection of appropriate treatment and mechanical supports. It is straightforward to utilise, as it does not necessitate the use of scoring systems or tests that require lengthy and intricate analyses, and it is readily available.

Keywords: Albumin; Hypoalbuminemia; Mortality; Pediatric intensive care.

Fig. 1

The study confidently determined the sensitivity and specificity rates, as well as the cut-off value of albumin levels in predicting mortality, through ROC analysis. The albumin levels’ area under the curve (AUC) value was found to be 0.731, with a sensitivity rate of 68.30% and a specificity rate of 67.00%, using a cut-off value of 3.785