Acute renal failure in the late phase after severe trauma is particularly dangerous, since it is resistant to therapy and contributes to the development of post-traumatic multiple organ failure. We have studied different treatment regimes in order to establish whether late renal failure can be prevented (study A: colloidal and crystalloid solutions; study B greater than: crystalloid solutions and dopamine; continuous infusion 3 micrograms/kg body weight). Renal function was assessed by means of the score by Goris as well as by creatinine clearance over a period of 14 days. Haemodynamics and cardiac function were determined on a daily basis. The demographic parameters were comparable in both groups. In group A 37 of 61 patients died (60.6%), and in group B 17 of 38 patients (44.7%) (P less than 0.05). The incidence of impairment of renal function was comparable; in group A there was significantly more severe damage (18%) compared to group B (2.6%). This coincided with significantly higher mortality in group A (group A: 60.65%; group B: 44.7%). In group A a lesser volume was given during the preclinical and clinical course, even after correcting for the volume-saving effect of colloidal solutions. In addition, cardiac index was higher in group B (day 9: 5.9 +/- 0.61 l/min) than in group A (day 9: 4.4 +/- 0.5 l/min) and pulmonary capillary wedge pressure (PCWP) was lower and systemic vascular resistance (SVR) higher over the whole period. Also, the arterio-venous oxygen difference (AvDO2) was higher following day 9 in patients in group A, but creatinine clearance was better in group B patients.(ABSTRACT TRUNCATED AT 250 WORDS)