Haemodynamic and biochemical responses to fluid bolus therapy with human albumin solution, 4% versus 20%, in critically ill adults.

BACKGROUND: Fluid bolus therapy (FBT) is common in critically ill patients. With the exception of use in patients with traumatic brain injury, FBT with human albumin solution (HAS) appears safe and perhaps superior in severe sepsis.
OBJECTIVE: To determine the physiological effects of FBT with 4% v 20% HAS. DESIGN, SETTING AND PARTICIPANTS: A retrospective observational study of 202 critically ill patients receiving FBT with HAS in a tertiary intensive care unit between April 2012 and March 2013.
METHODS: FBT was instituted with 4% or 20% HAS, according to clinician preference. MAIN OUTCOME MEASURES: We compared biochemical and haemodynamic data between groups at baseline and at 1, 2 and 4 hours after FBT.
RESULTS: Patients who had received 20% HAS had more liver disease, a greater need for renal replacement therapy and higher Acute Physiology and Chronic Health Evaluation III scores on admission. Patients who had received 4% HAS received a median volume of 500 mL (interquartile range [IQR], 350-500 mL), compared with 100mL (IQR, 100- 200 mL) in the 20% HAS group (P < 0.0001); a median of 70 mmol v 10 mmol of sodium (P < 0.0001); and a median of 64 mmol v 2 mmol of chloride (P < 0.0001). There was a trend toward higher mean arterial pressures in the 20% group after FBT (78.2 mmHg v 76.4 mmHg, P = 0.03). There were no significant differences in the absolute or percentage change for any haemodynamic parameters. Serum biochemical test results were comparable with a non-significant signal of higher serum chloride and more negative base excess in patients receiving 4% HAS.
CONCLUSIONS: Haemodynamically, FBT with 100mL of 20% HAS performs in an equivalent way to 500 mL of 4% HAS but delivers much less fluid, sodium and chloride.