Weaning readiness and fluid balance in older critically ill surgical patients

Few studies address predictors for successful weaning of older adults from mechanical ventilation.

To develop a clinical profile of older patients who are successfully weaned from long-term mechanical ventilation.

Forty patients in the trauma and surgical intensive care unit who were at least 60 years old were enrolled in the study after 3 days of active weaning and were monitored daily until successfully weaned or until the end of the 14-day study. Hemodynamic and gas exchange variables, fluid balance, oxygen cost of breathing, and scores on the Burns Weaning Assessment Program were analyzed.

Compared with patients who were not weaned, successfully weaned patients required mechanical ventilation for 5.3 days, started active weaning earlier (mean 10.7 vs 14.5 days, P = .04), had lower mean negative daily fluid balances in the beginning (-0.394 vs 1.107 L, P = .004), and had lower mean net cumulative fluid balances (6.856 vs 16.212 L) at the time of enrollment. They also maintained both a lower mean net cumulative fluid balance (10.753 vs 25.049 L, P= .02) and a negative daily fluid balance (-0.389 vs 1.904 L, P = .03) throughout. Their mean central venous pressure decreased over time and was significantly lower (P<.001).

Persistent positive fluid balance in older surgical patients is associated with prolonged mechanical ventilation. Estimates of fluid balance might be useful in weaning older patients from long-term mechanical ventilation.