To determine the relative distribution of fluid within the extracellular fluid volume (ECFV) and the effect on oxygen delivery after infusing either normal saline or 5% albumin in cardiac surgical patients.
Prospective, randomized, unblinded, interventional study.
Cardiac surgical intensive care unit in a 450-bed teaching hospital.
Postoperative cardiac surgical patients (n = 40).
Infusion of either normal saline or 5% albumin to a hemodynamic end point determined by the patient’s clinician.
Plasma volume (PV), ECFV, cardiac index, and arterial oxygen content were measured immediately before (baseline) and after each fluid infusion. PV and ECFV were measured by dilution of 131I-albumin and [35S]sodium sulfate, respectively. Interstitial fluid volume (ISFV) was calculated as ECFV − PV. Baseline values for PV, ISFV, ECFV, and oxygen delivery index did not differ between treatment groups. Infusion of normal saline and 5% albumin increased PV by 9 ± 23% and 52 ± 84% of the volume infused, respectively (p < .05), whereas there was no significant difference between saline and albumin in the change in ISFV per volume infused. Only 5% albumin significantly increased cardiac index, although oxygen delivery did not change significantly after either infusion.
In postoperative cardiac surgical patients, infusion of 5% albumin is approximately five times as efficient as a PV expander but has comparable effects on changes in ISFV and oxygen delivery relative to normal saline.
From the Program in Critical Care Medicine, Center for Health Evaluation and Outcome Sciences, and Division of Nuclear Medicine, St. Paul’s Hospital and University of British Columbia, Vancouver, BC, Canada.
Supported, in part, by a Fellowship (to DE) from the Heart and Stroke Foundation of British Columbia and Yukon.
Address requests for reprints to: David Ernest, MBBS, Box Hill Hospital, Nelson Road, Box Hill, Victoria 3128, Australia. E-mail: firstname.lastname@example.org
We found that 5% albumin is approximately five times as efficient as a plasma volume expander, although it did not have a significantly different effect on the expansion of the interstitial fluid volume relative to normal saline.