Association between fluid intake and extubation failure in intensive care unit patients with negative fluid balance: a retrospective observational study

Background: Negative fluid balance (NFB) is associated with reduced extubation failure. However, whether achieving more NFB can further improve extubation outcome has not been investigated. This study aimed to investigate whether more NFB and restricted fluid intake were associated with extubation success.

Methods: We performed a retrospective study of adult patients with mechanical ventilation (MV) admitted to Medical Information Mart for Intensive Care (MIMIC-III) from 2001 to 2012. Patients with duration of MV over 24 hours and NFB within 24 hours before extubation were included for analysis. The primary outcome was extubation failure, defined as reintubation within 72 hours after extubation. Association between fluid balance or fluid intake and extubation outcome were investigated with multivariable logistic models.

Results: A total of 3433 extubation events were recorded. 1803 with NFB were included for the final analysis, of which 201(11.1%) were extubation failure. Compared with slight NFB (- 20 to 0 ml/kg), more NFB were not associated improved extubation outcome. Compared with moderate fluid intake (30 to 60 ml/kg), lower (< 30 ml/kg, OR 0.75, 95% CI [0.54, 1.05], p = 0.088) or higher (> 60 ml/kg, OR 1.63, 95% CI [0.73, 3.35], p = 0.206) fluid intake was not associated with extubation outcome. Duration of MV, chronic obstructive pulmonary disease (COPD), hypercapnia, use of diuretics, and SAPSIIscore were associated with extubation failure.

Conclusions: More NFB or restricted fluid intake were not associated with reduced extubation failure in patients with NFB. However, for COPD patients, restricted fluid intake was associated with extubation success.