Impact of nutritional status on the mortality and clinical outcomes of children admitted to the pediatric intensive care unit: A systematic review and meta-analysis

Abstract

Background and aims

Malnutrition has been associated with poor outcomes in hospitalized patients; however, previous studies reported variable results due to different periods, height and weight standards, interventions, and possible confounding factors. We aimed to evaluate the association of nutritional status with the clinical outcomes in children admitted to the Pediatric Intensive Care Unit (PICU).

Methods

We searched PubMed, Scopus, Web of Science, and Cochrane Library from inception to May 2024 using keywords and MeSH related to critically ill children, outcome, and nutritional status or malnutrition in different combinations. Studies reporting the association of undernutrition (UN), over-nutrition (ON), or both with outcomes of patients admitted to PICU aged 1 month to 18 years were included. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline was used to collect studies and extract relevant data. After removing duplicates, title, and abstract screening was done for 6560 studies, 121 full-text studies were reviewed, and 52 studies were finally included. The outcome measures were to assess risk difference (RD) and standardized mean difference (SMD) among UN, ON, and normal nutrition groups for mortality (primary), PICU length of stay (LOS), hospital LOS, duration, or need of mechanical ventilation (MV), and hospital-acquired infections (secondary). The protocol of this study is registered with the Open Science Framework (https://osf.io/ywmvz).

Results

We included 52 studies comprising 34,795 patients (4843 undernourished, 18,373 normally nourished, and 6552 overnourished). The male-to-female ratio was 1.13, with a mean age of 3.66 years. Meta-analysis showed a significantly increased risk of mortality in the UN group (RD = 0.02; 95%CI = 0.01–0.04, P < 0.0001) but not in the ON group (RD = 0.00; 95%CI = −0.01–0.01, P = 0.78). The need for MV (RD = 0.04; P = 0.0004) and duration of MV (SMD = 0.23; P < 0.00001) were significantly greater in the UN children but not in the ON group (P = 0.13, P = 0.43, respectively). UN significantly prolonged hospital LOS (SMD = 0.26; P < 0.00001) and PICU LOS (SMD = 0.27; P < 0.00001).

Conclusion

Undernutrition is independently associated with poor outcomes, including a higher risk of mortality, need for MV, longer MV duration, PICU, and hospital LOS. However, overnutrition did not show such associations with poor outcomes in critically ill children. Timely recognition of malnutrition is important for enhancing pediatric critical care and optimizing outcomes through planned nutritional interventions.