Bringing back the (weighing) balance in the PICU--for good measure

Bio-impedance spectroscopy for total body water assessment in pediatric surgical patients: A single center pilot cohort study

BACKGROUND

Excess peri‑operative fluid administration is associated with higher morbidity and mortality. We aimed to examine the feasibility of bio-impedance spectroscopy (BIS) to record serial peri‑operative fluid volumes in the pediatric surgical population.

METHODS

Children who underwent major elective general surgery from March 2019 to March 2020 were included. Total body water (TBW) assessment by BIS was recorded prior to surgery and on subsequent post-operative days (POD). We recorded the duration, tolerance and completion of each BIS assessment. We used Spearman coefficient and Bland Altman analysis to examine correlation and agreement between fluid balance (FB) in ml/kg calculated from intake/output (IO) recording and measured by BIS.

RESULTS

20 (87%) of 23 consented patients, median age 2.5 (1-17) years and 13 (65%) male, completed pre-operative and post-operative measurements, and were included in the analysis. Median time required for BIS assessments was 10 (5-15) minutes, and there were no recorded side effects or intolerance. The correlation coefficient for fluid balance measurements on POD 1 between BIS and IO methods was 0.59 (p = 0.01); mean bias (limits) of agreement was 26 (111 to 163) mL/kg. The trend in TBW measured by BIS declined from POD 1-3, while the recorded FB increased.

CONCLUSION

Bedside BIS is feasible and well-tolerated. Despite moderate correlation between fluid balance assessment by BIS and IO on POD 1, the wide limits of agreement between values from these methods preclude their use interchangeably. The role of BIS in assessment of fluid status in the pediatric surgical population should be further examined.

LEVEL OF EVIDENCE

Level III.

Serum Albumin Is an Independent Predictor of Clinical Outcomes in Critically Ill Children

OBJECTIVES

Serum albumin is a strong biomarker of disease severity and prognosis in adult patients. In contrast, its value as predictor of outcome in critically ill children has not been established. We aimed to determine whether admission hypoalbuminemia is associated with outcome in a general pediatric population of critically ill patients, taking into account the inflammatory response, disease severity, and nutritional status of the patient.

DESIGN

Analysis of prospectively collected database.

SETTING

PICU of a teaching hospital.

PATIENTS

Two hundred seventy-one patients consecutively admitted. Neonates, patients with chronic liver or kidney disease, inborn errors of metabolism, those who received prior administration of albumin solution, and readmissions were excluded.

MEASUREMENTS AND MAIN RESULTS

Outcome variables were 60-day mortality, probability of ICU discharge at 60 days, and ventilator-free days. Potential exposure variables for the outcome were sex, age, nutritional status, albumin, C-reactive protein and serum lactate at admission, and Pediatric Index of Mortality 2 score. Admission hypoalbuminemia was present in 64.2% of patients. After adjustment for confounding factors, only serum lactate, Pediatric Index of Mortality 2 score, and serum albumin were associated with higher mortality: the increase of 1.0 g/dL in serum albumin at admission resulted in a 73% reduction in the hazard of death (hazard ratio, 0.27; 95% CI, 0.14-0.51; p < 0.001). The increase of 1 g/dL in serum albumin was also independently associated with a 33% rise in the probability of ICU discharge (subhazard ratio, 1.33; 95% CI, 1.07-1.64; p = 0.008) and increased ventilator-free-days (odds ratio, 1.86; 95% CI, 0.56-3.16; p = 0.005).

CONCLUSIONS

Hypoalbuminemia at admission to a PICU is associated with higher 60-day mortality, longer duration of mechanical ventilation, and lower probability of ICU discharge. These associations are independent of the magnitude of inflammatory response, clinical severity, and nutritional status.