Table 2.

Studies assessing the correlation and agreement between the fluid balance and weight based methods of fluid overload estimation.

Study author	Conclusion
van Asperen et al. (13)	Fluid balance charts both over and under-estimate body weight change and are unreliable as a single measure of fluid status in neonates
Selewski et al. (15)	Both the methods were similar in predicting the degree of FO at CRRT initiation and mortality
Hazle et al. (16)	Both the methods could predict the significant association between positive fluid balance and associated poor outcomes in infants post-cardiac surgery
Benoit et al. (17)	>10% weight gain (p = 0.001) and fluid overload (0.075) predicted PICU admission in pediatric stem cell transplant recipients on univariate analysis but only >10% weight gain (0.018) remained an independent risk factor for PICU admission after adjustment
Bontant et al. (18)	- Correlations were strong between fluid input minus output/adjusted fluid input minus output and body weight change - Agreement between was poor between fluid input minus output/adjusted fluid input minus output and body weight change during the first 24 h after PICU admission - Since daily body weight is not particularly difficult to measure, fluid input minus output/adjusted fluid input minus output calculations may be reserved for the most severely ill patients in whom body weight measurement is strictly contraindicated
Perren et al. (19)	Correlation and Bland Altman agreement was poor between - body weight change and cumulative fluid balance in a cohort of ICU patients
Mank et al. (20)	- Body weight was deemed to be a more accurate, safe and reliable parameter for monitoring fluid retention in patients undergoing hyperhydration prior to chemotherapy - Correlation between body weight change and cumulative fluid balance was relatively low
Eastwood (21)	Body weight gain in post-cardiac surgery patients was falsely undermined by the fluid balance method
Kelm et al. (22)	Fluid balance did not correlate with clinical and radiological evidence of FO in a large cohort of septic patients but body weight did

FB method: $\%FO=\frac{(dailyfluidintake(L)-totaloutput(L))}{Baselinebodyweight(kg)}x\mathit{\text{100}}.$

Weight based methods: $\%FO=\frac{(CRRTinitiationweight(kg)-hosptialadmissionweight(kg))}{hosptialadmissionweight(kg)}x\mathit{\text{100}}.$

Or

$\%FO=\frac{(CRRTinitiationweight(kg)-ICUadmissionweight(kg))}{ICUadmissionweight(kg)}x\mathit{\text{100}}.$