Purpose: A balanced fluid replacement strategy appears to be promising for correcting hypovolemia. The benefits of a balanced fluid replacement regimen were studied in elderly cardiac surgery patients.
Methods: In a randomized clinical trial, 50 patients aged >75 years undergoing cardiac surgery received a balanced 6% HES 130/0.42 plus a balanced crystalloid solution (n = 25) or a non-balanced HES in saline plus saline solution (n = 25) to keep pulmonary capillary wedge pressure/central venous pressure between 12-14 mmHg. Acid-base status, inflammation, endothelial activation (soluble intercellular adhesion molecule-1, kidney integrity (kidney-specific proteins glutathione transferase-alpha; neutrophil gelatinase-associated lipocalin) were studied after induction of anesthesia, 5 h after surgery, 1 and 2 days thereafter. Serum creatinine (sCr) was measured approximately 60 days after discharge.
Results: A total of 2,750 +/- 640 mL of balanced and 2,820 +/- 550 mL of unbalanced HES were given until the second POD. Base excess (BE) was significantly reduced in the unbalanced (from +1.21 +/- 0.3 to -4.39 +/- 1.0 mmol L(-1) 5 h after surgery; P < 0.001) and remained unchanged in the balanced group (from 1.04 +/- 0.3 to -0.81 +/- 0.3 mmol L(-1) 5 h after surgery). Evolution of the BE was significantly different. Inflammatory response and endothelial activation were significantly less pronounced in the balanced than the unbalanced group. Concentrations of kidney-specific proteins after surgery indicated less alterations of kidney integrity in the balanced than in the unbalanced group.
Conclusions: A total balanced volume replacement strategy including a balanced HES and a balanced crystalloid solution resulted in moderate beneficial effects on acid-base status, inflammation, endothelial activation, and kidney integrity compared to a conventional unbalanced volume replacement regimen.