Douglas County ambulances will continue to carry a synthetic blood substitute whose safety has been questioned in the national media.

The Wall Street Journal on Feb. 22 reported that Northfield Laboratories Inc., the Evanston, Ill.-based maker of PolyHeme, shut down an earlier trial after 10 of 81 patients who received the synthetic blood suffered heart attacks. Two of those patients died, the newspaper said.

“We’re still going to be participating in the PolyHeme study,” Jim Murray, a division chief for Lawrence-Douglas County Fire & Medical, said Wednesday.

The earlier trial apparently failed because medical officials were using too much of the synthetic blood, he said, overloading patients’ systems. Stricter controls are in place for this test, he said.

“We feel it’s safe to continue the study,” Murray said.

Just one person in the Kansas test area has received the synthetic blood, officials said this week.