• Colloids;
  • colloid osmotic pressure;
  • coronary artery bypass surgery;
  • crystalloid;
  • fluid balance;
  • lung functions

The effects on fluid balance, pulmonary tunctions and economics were evaluated in a randomized comparison of one colloid free and three colloid containing fluid regimens, for 48 hours during and after coronary artery-bypass (CAB) surgery.

A standard regimen for anaesthesia, extracorporeal circulation and monitoring was used. Only Ringer's acetate (RAc) was used as priming solution for extracorporeal circulation. Forty patients were randomized to receive either RAc, polygeline 35 mg-ml-1 (Haemaccel®), dextran 70 (Macrodex®) 60 mg ml-14, or albumin 40 mg-ml-1 in saline whenever fluid volume was needed to stabilize haemodynamics.

At the end of the operation, fluid retention was significantly lower in patients receiving polygeline and dextran 70, compared with patients receiving RAc. At 48 hours, however, there were no differences in cumulative fluid balance. Patients in the colloid groups postoperatively had a higher serum colloid osmotic pressure (s-COP), bui a higher net lung capillary filtration pressure (AP) only on the second postoperative day than the RAc group. However, this did not adversely atfect intrapulmonary venous admixture, arterial oxygen tension, or time on respirator in the RAc group compared with the colloid groups. The most expensive colloid fluid regimen (albumin) cost about 230 USS more per patient than the RAc fluid regimen.

We conclude that Ringer's acetate for volume replacement to stabilize haemodynamics during and after CAB surgery is associated with increased fluid retention only during the intraoperative period, compared with dextran 70 or polygeline, and with a lower serum colloid osmotic pressure and net lung capillary filtration pressure postoperatively, compared with all three colloid groups. This does not affect pulmonary functions adversely. Thus, the RAc regimen is clinically fully acceptable and economically more favourable than the polygeline, dextran 70, and albumin-containing fluid regimens.