We prospectively studied transport of a group of 100 surgery/trauma patients and a matched control group in the ICU. APACHE II scores for the two groups were 23 +/- 6 and 20 +/- 8. During transport both groups had ECG, heart rate, blood pressure, and oxygen saturation continuously monitored. We also determined the cost and results of transport for those patients requiring diagnostic testing. There were six diagnostic tests performed: CT scan of the abdomen (39%), CT scan of the head (31%), CT scan of the chest (8%), CT scan of the cervical spine (4%), angiography (14%), and tomography (4%). Average transport time was 74 +/- 16 minutes with a range of 20-225 minutes. Physiologic changes defined as a BP +/- 20 mm Hg, heart rate +/- 20 beats/min, respiratory rate +/- 5 breaths/min, or oxygen saturation +/- 5% for 5 minutes duration occurred in 66% of transported patients and 60% of ICU patients. There were no differences in arterial blood gas levels before and during transport. In 39% of transports, the results of diagnostic testing produced a change in patient management within 48 hours. Abdominal CT scanning and angiography were associated with the highest percentage of tests leading to a management change (51% and 57%). The average charge to the patient was $612.00 and the average cost to the hospital $452.00. Our results suggest that while physiologic changes are frequent during transport, they are also frequent in ICU patients as a consequence of the severity of illness.(ABSTRACT TRUNCATED AT 250 WORDS)