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Cumulative fluid intake minus output is not associated with ventilator weaning duration or extubation outcomes in
Adrienne G Randolph1, Peter W Forbes, Rainer G Gedeit
1Department of Anesthesia, Children's Hospital, Boston, MA, USA.
Insights
Cumulative fluid balance, measured as intake minus output (I-O), did not predict respiratory outcomes in critically ill children managed with a mechanical ventilator protocol. This common clinical indicator lacks utility when patients are systematically assessed for ventilation weaning.
Area of Science:
- Pediatric Critical Care Medicine
- Respiratory Physiology
- Fluid Balance Management
Background:
- The impact of fluid balance on respiratory outcomes in pediatric intensive care is understudied.
- Cumulative fluid intake minus output (I-O) is a routinely recorded metric for fluid balance in pediatric intensive care units.
- This study investigated the predictive value of cumulative I-O for weaning duration and extubation failure in critically ill children.
Discussion:
- Cumulative I-O at the initiation of weaning did not correlate with the duration of mechanical ventilation weaning.
- Cumulative I-O at extubation did not predict the success of extubation.
- An association was observed between cumulative I-O at extubation and weaning duration in patients not managed under a strict protocol.
Key Insights:
- Routine fluid balance monitoring (cumulative I-O) may not be clinically useful for predicting respiratory outcomes in mechanically ventilated children managed with a standardized protocol.
- Systematic assessment of tidal volume and oxygenation at minimal ventilator support levels appears to supersede the predictive value of fluid balance.
- The findings suggest that current fluid balance monitoring practices may require re-evaluation in the context of protocolized ventilator management.
Outlook:
- Further research could explore alternative or adjunctive fluid balance assessment methods in pediatric critical care.
- Investigating the role of fluid balance in non-protocolized ventilator management may reveal specific patient subgroups where it holds predictive value.
- Developing and validating novel biomarkers for fluid status and respiratory outcomes in critically ill children is warranted.
Objective:
The effect of fluid balance on respiratory outcomes for critically ill children has not been evaluated. The only indicator of fluid balance routinely recorded across our intensive care units was estimated fluid intake and output. We sought to determine whether cumulative intake minus output (I-O) at the start of weaning predicted weaning duration and whether cumulative I-O at extubation predicted extubation failure.
Design:
Prospective observational study.
Setting:
Ten pediatric intensive care units.
Patients:
Cumulative I-O was recorded daily for 301 mechanically ventilated children (<18 yrs of age) from November 1999 through April 2001.
Interventions:
Cumulative I-O was recorded during a study of weaning strategies and extubation failure in which mechanical ventilation of the majority of patients during weaning and extubation was managed according to a protocol that did not include fluid balance indicators. Outcomes were the time to successful removal of ventilatory support and the rate of initial extubation failure.
Measurements And Main Results:
Relationships between cumulative I-O and outcomes were assessed by means of proportional hazards and logistic regression. The mean cumulative I-O per kilogram of ideal body weight at the start of weaning was 101 mL (sd, 180). Cumulative I-O at the time weaning was initiated did not predict duration of mechanical ventilator weaning. The mean cumulative I-O per kilogram of ideal body weight at extubation was 136 mL (sd, 237). Cumulative I-O at extubation did not predict extubation outcome. There was an association between cumulative I-O at extubation and the duration of weaning in cases not managed by a protocol.
Conclusion:
Although routinely recorded, cumulative fluid I-O does not appear to have clinical utility in cases managed according to a mechanical ventilator protocol in which tidal volume and oxygenation on minimal levels of ventilator support are systematically tested.
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