Electronic ArticleElectronic bed weighing vs daily fluid balance changes after cardiac surgery☆
Section snippets
Background and rationale
Numerous studies have shown an association between fluid overload and increased mortality [1], [2], [3], [4], [5], [6]. However, assessing fluid status in critical illness remains difficult. For this purpose, most intensive care units (ICUs) record a daily fluid balance (FB), which is typically calculated based on the recording of inputs and outputs.
Despite its widespread utilization, such calculations are associated with multiple flaws. First, they do not account for fluids losses such as
Materials and methods
We designed an observational study of all consecutive patients admitted to ICU after cardiac surgery between December 2011 and August 2012. Patients were excluded if their weight was above 181.4 kg (400 lb: limit of scale validation), if they were undergoing minor cardiac procedures (such as pacemaker implantation), had an ICU stay less than 48 hours, or if the bed was not tared (calibrated with default beddings in place) before admission. We aimed to obtain data from a sample of more than 100
Patients' characteristics and compliance with protocol
During the study period, 112 patients were admitted in ICU after cardiac surgery. Of these, data were not collected in 2 patients (1.8%). Seven were excluded, as their ICU length of stay was less than 48 hours. Hence, 103 patients were included in this analysis. Their characteristics and outcomes are presented in Table 1.
Of the 548 possible weights, 414 (75.5%) were obtained (257 pairs). Of these, 8 (3.1%) were excluded because the change in BW was greater than 15 kg, and a typing error was
Summary of key findings
We performed a prospective observational study in more than 100 patients undergoing cardiac surgery to test the ability of weight-enabled beds to evaluate changes in fluid status under optimal clinical conditions. We observed good compliance with the protocol except for measurements on ICU admission. Nevertheless, weights obtained with clinical beds and regular scale had poor agreement. Similarly, changes in BW as measured by these beds were only poorly correlated with simultaneous FB. This
Acknowledgments
All authors stated that they had no conflicts of interest to declare.
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2019, Journal of Critical CareCitation Excerpt :To this end, it has not yet been established how best to accurately monitor cumulative fluid balance. Daily fluid balance can be calculated based on input and output volumes recorded on patient charts, and by body weight measured at defined timepoints; however, both have been criticized as non- robust, insensitive, and unreliable predictors of fluid overload in critically ill patients [42]. Bioelectrical impedance analysis (BIA) is an alternative tool that is used to measure body composition.
A comparison of compliance in the estimation of body fluid status using daily fluid balance charting and body weight changes during continuous renal replacement therapy
2019, Australian Critical CareCitation Excerpt :Although strict quality control measures were implemented during the study, it did not eliminate the uncertainty in 1 case (a daily weight change of 19.5 kg). This represented a 0.3% (1/286) error in the recording/documenting of daily bodyweight changes but lower than the 3.1% (8/257) reported elsewhere for uncertainty over changes in body weight greater than 15 kg.13 Our study confirms that a calculated fluid balance is not predictive of a similar change in body weight.
Components of Fluid Balance and Monitoring
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This study was funded by the Intensive Care and Anaesthesiology fund from the Austin Hospital.