Fluid Overload and Risk of Mortality in Critically Ill Patients

Prospective Cohort Study on Cumulative Fluid Balance and Outcome in Critically Ill Children Using a Restrictive Fluid Protocol

OBJECTIVE

To study the association of cumulative fluid balance and clinical outcomes in a pediatric intensive care unit (PICU) practicing restrictive fluid protocol.

METHODS

In this prospective cohort study, children aged less than 13 y admitted for more than 48 h were screened. Children with unstable hemodynamics throughout the stay were excluded. Fluid balance was calculated by percentage fluid overload (%FO) for the first 7 d. Patients were divided into positive fluid and negative fluid balance groups. The primary outcome was all-cause 28-d mortality.

RESULTS

A total of 888 patients (positive fluid balance group = 531, negative fluid balance group = 357) were analyzed. Mean (SD) cumulative %FO was 1.52 (0.67) vs. -1.18 (0.71), p = < 0.001, and minimum and maximum cumulative %FO were -3.0% and 3.1%, respectively. There was no significant difference in all-cause 28-d mortality between the two groups (n = 104/531, 19.6% vs. n = 60/357, 16.8%, RR = 1.17, 95% CI 0.87 to 1.55; p = 0.29). There was no difference in organ dysfunction [mean (SD) sequential organ failure assessment (SOFA) score 3.3 (0.7) vs. 3.3 (0.6)], acute kidney injury (65% vs. 63.6%), need for renal replacement therapy (14% vs. 13%), and duration of ventilation (median, IQR 4, 2-6 vs. 4, 2-6 d). Longer stay in PICU (5, 3-9 vs. 4, 3-7 d; p = 0.014) and in hospital (8, 5-11 vs. 7, 4-10 d; p = 0.007) were noted in the positive fluid balance group.

CONCLUSION

Cumulative fluid balance within 3% using restrictive fluid protocol was not associated with a significant difference in PICU mortality and morbidity.

Proenkephalin as a new biomarker for pediatric acute kidney injury - reference values and performance in children under one year of age

Objectives Acute kidney injury (AKI) is common in critically ill children, but current biomarkers are suboptimal. Proenkephalin A 119-159 (PENK) is a promising new biomarker for AKI in adults, but pediatric data is lacking. We determined PENK reference intervals for healthy children, crucial for clinical implementation, and explored concentrations in critically ill infants aged under 1 year. Methods Observational cohort study in healthy infants and critically ill children aged 0-1 years. Reference values were determined using generalized additive models. Plasma PENK concentrations between healthy children and critically ill children with and without AKI, were compared using linear mixed modelling. The performance of PENK as AKI biomarker was compared to cystatin C (CysC) and β-trace protein (BTP) using receiver-operating-characteristic (ROC) analysis. Results PENK concentrations in 100 healthy infants were stable during the first year of life (median 517.3 pmol/L). Median PENK concentrations in 91 critically ill children, were significantly higher in those with AKI (n=40) (KDIGO Stage 1 507.9 pmol/L, Stage 2 704.0 pmol/L, Stage 3 930.5 pmol/L) than non-AKI patients (n=51, 432.2 pmol/L) (p < 0.001). PENK appeared to relate better to AKI diagnosis than CysC and BTP (AUROC PENK 0.858, CysC 0.770 and BTP 0.711) in the first 24 h after recruitment. Conclusions PENK reference values are much higher in young infants than adults, but clearly discriminate between children with and without AKI, with comparable or better performance than CysC and BTP. Our results illustrate the importance of establishing age-normalized reference values and indicate PENK as a promising pediatric AKI biomarker.

Fluid overload is associated with increased 90-day mortality in AML patients undergoing induction chemotherapy

Treatment‐related complications contribute substantially to morbidity and mortality in acute myeloid leukemia (AML) patients undergoing induction chemotherapy. Although AML patients are susceptible to fluid overload (FO) (e.g., in the context of chemotherapy protocols, during sepsis treatment or to prevent tumor lysis syndrome), little attention has been paid to its role in AML patients undergoing induction chemotherapy. AML patients receiving induction chemotherapy between 2014 and 2019 were included in this study. FO was defined as ≥5% weight gain on day 7 of induction chemotherapy compared to baseline weight determined on the day of admission. We found FO in 23 (12%) of 187 AML patients undergoing induction chemotherapy. Application of >100 ml crystalloid fluids/kg body weight until day 7 of induction chemotherapy was identified as an independent risk factor for FO. AML patients with FO suffered from a significantly increased 90-day mortality rate and FO was demonstrated as an independent risk factor for 90-day mortality. Our data suggests an individualized, weight-adjusted calculation of crystalloid fluids in order to prevent FO-related morbidity and mortality in AML patients during induction chemotherapy. Prospective trials are required to determine the adequate fluid management in this patient population.

Fluid Overload

Fluid overload (FO) is characterized by hypervolemia, edema, or both. In clinical practice it is usually suspected when a patient shows evidence of pulmonary edema, peripheral edema, or body cavity effusion. FO may be a consequence of spontaneous disease, or may be a complication of intravenous fluid therapy. Most clinical studies of the association of FO with fluid therapy and risk of harm define it in terms of an increase in body weight of at least 5–10%, or a positive fluid balance of the same magnitude when fluid intake and urine output are measured. Numerous observational clinical studies in humans have demonstrated an association between FO, adverse events, and mortality, as have two retrospective observational studies in dogs and cats. The risk of FO may be minimized by limiting resuscitation fluid to the smallest amount needed to optimize cardiac output and then limiting maintenance fluid to the amount needed to replace ongoing normal and pathological losses of water and sodium.