Haemodynamic effect of a 20% albumin fluid bolus in post-cardiac surgery patients.

Objective: To study the cardiovascular effect over 30 minutes following the end of fluid bolus therapy (FBT) with 20% albumin in patients after cardiac surgery.
Design: Prospective observational study.
Setting: Intensive care unit of a tertiary university-affiliated hospital.
Participants: Twenty post-cardiac surgery mechanically ventilated patients with a clinical decision to administer FBT.
Intervention: FBT with a 100 mL bolus of 20% albumin.
Main Outcome Measures: Cardiac index (CI) response was defined by a ≥ 15% increase, while mean arterial pressure (MAP) response was defined by a ≥ 10% increase.
Results: The most common indication for FBT was hypotension (40%). Median duration of infusion was 7 minutes (interquartile range [IQR], 3-9 min). At the end of FBT, five patients (25%) showed a CI response, which increased to almost half in the following 30 minutes and dissipated in one patient. MAP response occurred in 11 patients (55%) and dissipated in five patients (45%) by a median of 6 minutes (IQR, 6-10 min). CI and MAP responses coexisted in four patients (20%). An intrabolus MAP response occurred in 17 patients (85%) but dissipated in 11 patients (65%) within a median of 7 minutes (IQR, 2-11 min). On regression analysis, faster fluid bolus administration predicted MAP increase at the end of the bolus.
Conclusion: In post-cardiac surgery patients, CI response to 20% albumin FBT was not congruous with MAP response over 30 minutes. Although hypotension was the main indication for FBT and a MAP response occurred in most of patients, such response was maximal during the bolus, dissipated in a few minutes, and was dissociated from the CI response.