Objective: There is a growing body of evidence indicating that perioperative fluid management during cardiac surgery influences patient care and outcome. The choice of fluid therapy and the degree of systemic inflammatory response triggered during surgery control the effects of tissue edema formation and end-organ function. As such, "goal-directed" fluid resuscitation protocols that measure colloid osmotic pressure (COP) may promote improvements in patient morbidity and mortality.
Methods: Thirty patients scheduled for primary coronary artery bypass grafting were prospectively randomized for perioperative fluid treatment under COP guidance [albumin (ALB), n = 17] or conventional fluid protocols without COP support (control, n = 13). Whole-blood samples were drawn at four different time intervals including (A) anesthesia induction, (B) 10 minutes after the initiation of cardiopulmonary bypass, (C) at the completion of sternal skin approximation, and (D) 3 hours after admission to the cardiac intensive care unit. Interleukin 6 (IL-6) and IL-8 were measured by immunometric, enzyme-linked immunosorbent assays as well as C-reactive protein. Colloid osmotic pressure values were measured using a colloid osmometer.
Results: As compared with conventional fluid protocols, the patients treated in the intervention (ALB) group received significantly less total perioperative fluid [7893.6 (1874.5) vs 10,754.8 (2403.9), P = 0.001], and this relationship remained after controlling for age, sex, and The Society of Thoracic Surgeons risk score (β = -0.5, t = -3.1, P = 0.005). Colloid osmotic pressure values were significantly higher in the ALB group at time point D after surgery (P = 0.03). There were no significant differences in IL-6, IL-8, and C-reactive protein values between the groups at any of the time blood draw intervals. Perioperative outcomes were evaluated by treatment group. For both groups, the incidence of perioperative morbidity was low and did not differ by treatment group.
Conclusions: The use of COP-guided fluid resuscitation was associated with a significant reduction in perioperative fluid demand. However, patients prescribed to COP-guided fluid therapy did not experience a reduction in whole-body inflammation or improved surgical outcome as compared with conventional fluid management techniques.