Alcohol is to blame in many accidents that cause major head injuries, but it also might help people survive after they get hurt, researchers said.

Researchers examined data on 1,158 patients treated at a Toronto hospital for severe brain injury due to blunt trauma from 1988 and 2003.

Those with blood-alcohol levels up to 0.23 percent -- nearly three times the common legal limit of 0.08 percent -- were 24 percent more likely to survive their injuries than patients entering the hospital with no alcohol in their bloodstream, the study found.

But patients with even higher alcohol levels in their blood were 73 percent more likely to die than those with none, the study also found.

Dr. Homer Tien of Sunnybrook Health Sciences Center and the University of Toronto, who led the study, emphasized that these findings should not be interpreted as endorsing irresponsible actions like driving after drinking.

Rather, Tien said, they point to the possibility of developing a drug to give to brain trauma patients after injury to improve their odds of surviving.

"We don't have anything that we can give to head-injured patients as a drug. So this raises an interesting possibility," Tien said in a telephone interview. "Perhaps alcohol has some beneficial effects for head injury -- after injury."

"But by no means are we advocating that there's any advantage to drinking and then driving or drinking and doing anything that may get you into an accident because your chances of getting into a fatal accident are much higher," Tien added.

The findings were published in the journal Archives of Surgery.

The researchers suggested that alcohol at low or moderate levels in the bloodstream may protect against secondary brain injury that happens when traumatized brain cells remain starved of oxygen, exacerbating the damage inflicted by the original trauma.

Most of the patients who had alcohol in their bloodstream had been involved in vehicle accidents.

About 28 percent of them who arrived at the hospital with a blood alcohol concentration of up to 0.23 percent died, while 36 percent of those with no alcohol died, the study found.

By way of comparison, the study also looked at 528 patients with severe torso injuries but no or insignificant head injuries, and found that blood alcohol levels were unrelated to their survival rates.

The researchers noted that drinking alcohol, by impairing motor skills, reaction time and judgment, is the most important personal risk factor for fatal injuries, contributing to about a third of all deaths from injury in vehicle crashes, falls and other circumstances.