"It's a site where every couple of days, somebody inserts a needle to extract blood from the body," Fowler said. "There is this constant mild or minor trauma from these needles. Normally, these sites will last several years without a problem."
But if the vessel breaks down, the consequences can be fatal, especially if a patient is alone.
"The patients would be found with a good amount of blood around them," Vincenti said.
The two most common types of access sites are fistulas and grafts, both of which lie below the skin and are punctured during each dialysis treatment. A fistula is the joining of an artery to a vein, while a graft is a synthetic or natural vessel that is joined to a vein.
FOR THE RECORD - An article in yesterday's editions incorrectly reported that almost 12,000 people on dialysis die annually in Maryland. In fact, that figure represents deaths between Jan. 1, 2000, and Aug. 8, 2006, according to the Mid-Atlantic Renal Coalition.
THE SUN REGRETS THE ERROR
A third type is a venous catheter, a plastic tube that's inserted into a blood vessel but protrudes above the skin surface.
The deaths were not linked to one type. Seven of the people who bled to death had fistulas, while 10 had grafts, Vincenti said. Most of the 17 hemorrhaged after the veins had gradually eroded from repeated use.
Four patients had venous catheters that became dislodged. There was incomplete data on the remaining three.
"Right now, what we want to do is increase the amount of education that's going on. ... When you have someone in a hemodialysis chair, you have a captive audience," Vincenti said. "It may be a good time to re-educate them, review some warning signs."
Dr. Jeffrey Fink, the former chairman of the Maryland Kidney Commission, said hemorrhaging is a known risk of dialysis - but it's uncommon and hasn't, to his knowledge, been extensively researched.
"It does happen, it's unfortunate, but it's never hit a point on the radar screen as something that's epidemic," said Fink, a nephrologist at the University of Maryland Medical Center.
Fink said he favored issuing the advisories, but doesn't necessarily agree that some of the deaths could have been prevented. He said he would need further information from the medical examiner's office to make that judgment.
Fink said he's never had a patient bleed to death though one recently woke up in time to get help.
"The patient had a hemorrhage and happened to wake up wet," he said. "Everybody I talked to has a few cases where this has happened."