The conventional wisdom that helicopters are the best way to transport all stroke patients treated with clot-busting drugs may not be correct, a small study at one medical center suggests.

People suffering a stroke caused by a blood clot - which most strokes are - can be treated with a medication called tissue plasminogen activator (tPA). As long as the drug is given within three hours of the first stroke symptoms, it can break up the blood clot and help limit brain damage from the stroke.

Often, patients are treated with tPA at their local ER, then transferred to a larger medical center for admission. And the standard thinking has been that a helicopter, rather than a ground ambulance, is the better way to do that.

That is true in some cases, according to Dr. Alejandro Rabinstein of the Mayo Clinic in Rochester, Minnesota, one of the researchers on the new study.

But the assumption that helicopters are better for all patients has not actually been put to the test - which, given the expense, is an important gap.

“It’s been presumed that getting to the stroke center from your local center faster (by helicopter) is going to improve outcomes,” Rabinstein told Reuters Health. “But the reality is that no one has examined that.”

So Rabinstein and his colleagues looked at records for 122 stroke patients who’d been transferred to their center from a “spoke” hospital - mostly rural hospitals within a 120-mile radius of the Mayo Clinic.

Of those patients, 94 were transported by helicopter and 28 by ground - usually because a helicopter was requested, but not available.

Overall, the study found, helicopters were faster, taking an average of 54 minutes, versus 69 minutes by ambulance.

But there was no difference in patient complications, like bleeding from the tPA treatment, en route to the stroke center. And there were no clear differences in how patients fared longer-term - including their length of stay in the hospital, and their risk of dying within 30 days.

One-quarter of patients transported by ambulance died, compared with 17 percent of helicopter-transported patients - a statistically insignificant difference.

Still, Rabinstein said, there are some tPA-treated patients who should be transferred by helicopter - namely, those who need an additional, “endovascular rescue therapy” to treat the clot (if the tPA doesn’t work, for instance).

For those patients, “minutes can be important,” Rabinstein said.

“I wouldn’t want this to be interpreted as saying that stroke patients shouldn’t get an air ambulance,” Rabinstein said.

But, he added, the majority of tPA patients would either not need or not be candidates for those additional treatments. “For them, the only justification (for helicopter transport) would be to reduce complications, which we didn’t find,” Rabinstein said.

Of course, this study looked only at a small number of patients transported to one medical center. Rabinstein said he does not know if the findings would hold true for other stroke centers and their smaller “spoke” hospitals.

“I can only say that it applies to our experience,” he said.

Hopefully, Rabinstein said, the results will prompt other medical centers to examine their own patient outcomes.

SOURCE: Stroke, online December 8, 2011.