Will There Be Blood?
Washington residents face a declining blood supply
STORY BY KEVIN KENNEY
photos by Evan Abell | infographic by Aiden Lee
Critical care nurse Sally McPherson has seen the necessity of a blood transfusion first hand.
“The patient said, ‘Something’s wrong, something’s wrong,’ then he stopped talking, and stopped breathing. As we were putting the breathing tube in, that’s when blood started coming out of his mouth,” McPherson says.
An ulcer had eroded the wall of his stomach and ruptured a major artery, McPherson says. He required an emergency transfusion.
Unlike a normal transfusion, where a simple IV will suffice, doctors plunged a large tube called a central line into a vein in his neck. They hooked the line to a machine called a rapid infuser. In an hour, the machine pumped nearly two gallons of blood into the patient. Afterwards they rushed him to surgery to fix the ruptured artery, McPherson says.
This patient is not alone. Every two seconds someone in the United States requires a blood transfusion, according to the American Red Cross.
The average amount of blood used in a transfusion is three units. A unit of whole blood is defined as 450 milliliters, about one pint. A major emergency such as a car accident can require over 100 units of blood, enough to fill the car’s gas tank, according to the American Red Cross.
In 2011, hospitals transfused 13.8 million units of blood according to the Department of Health and Human Services (HHS), which surveys blood centers every three years. That year 14.6 million units were available for transfusion, a 9.1 percent decrease from 2008, according to HHS.
The narrowing gap between numbers of donors and number of patients can be a problem says David Leitch, director of Volunteer and Donor Resources at Puget Sound Blood Center.
Every day, Puget Sound Blood Center collects blood and sends it by the truckload to hospitals throughout Western Washington and Oregon, Leitch says.
“We can only build up our supply so much in any given time period because blood only lasts so long. We can’t stockpile it,” Leitch says.
Maintaining the supply requires 900 to 1,000 donations every day, Leitch says. Certain times of the year impede this goal, he adds.
Brief shortages can cause serious consequences. In 2011, 10.3 percent of surveyed hospitals couldn’t meet non-surgical blood demands, according to HHS.
“If we don’t have enough blood we start asking hospitals to hold off on surgeries,” Leitch adds. “We also may limit the amount of blood we are able to ship them in order to conserve the supply.”
The blood center ensures hospitals have sufficient blood for critical patients, such as McPherson’s, but shortages may delay elective surgeries such as joint replacements.
In 2011, 3.3 percent of hospitals surveyed delayed surgeries. Delays lasted anywhere from one to 14 days, according to HHS.
KEEPING UP WITH THE KIDS
Puget Sound Blood Center offers incentives to keep donations flowing in, Leitch says.
“We manage it very closely, and try to focus our donors on the summer time. That time of the year the biggest challenge is just making sure we can get people to participate,” Leitch says.
Sometimes, the blood center issues an emergency appeal, which typically prompts the community to rally and fulfill the request, Leitch says.
“We still need 900 to 1,000 donors,” Leitch says. “The demand stays the same.”
PAY BY THE PINT
For Western economics Professor Hart Hodges, the problem of incentives is simple. Money talks.
“I don’t think there’s any doubt that if you pay for it you’d get more of it,” Hodges says. “One thing an economist would ask is why you see clinics paying for plasma but requesting blood on donation.”
The difference all lies in whose blood the centers want, he says.
“If I, and I’m going to be very politically incorrect here, see homeless people or drug addicts, they’re the ones who need money and they find selling plasma to be a worthwhile thing,” Hodges says. “But what about blood? I need a system where I’m not being attractive to people who are HIV positive or have hepatitis. One way to do this is by asking for volunteers to appeal to a different audience.”
This policy assumes we need an extra level of screening, Hodges says.
“The system of pre-screening by donation is decades and decades old, the situation’s probably changed,” Hodges says.
In 2011, 102,000 units of blood were discarded because of disease, according to the report from the Department of Health and Human Services.
All donated units were tested for HIV and hepatitis.
“If the cost of testing outweighs the amount of extra blood you’d get from buying it, we’d want to stick with the current system,” Hodges says. “If it’s cheaper and easier to screen blood now, it might make sense to start buying it. “
MAKING THEIR OWN
Ice-cold mist rolls out of a beaker of liquid nitrogen as Western senior Johann Sigurjonson drops a small plastic test tube in. The mist parts briefly, revealing the dark red liquid inside the tube.
Today this tube will travel, on dry ice, to be tested in a lab across the country. If the tests determine if the red compound is similar enough to hemoglobin — the oxygen-carrying molecule in red blood cells — years from now hospitals may transfuse it in place of whole blood.
Sigurjonson works in a Western biochemistry laboratory under Dr. Spencer Anthony-Cahill. The goal of the research is to create an artificial blood substitute.
Researchers around the world are working on blood substitutes. Most are oxygen-carrying molecules based on hemoglobin, Sigurjonson says.
Substitutes could last longer than whole blood, which can only be stored for 42 days. It could also be transfused to anyone, regardless of blood type.
However, researchers must design them carefully.
“Outside of the cell, hemoglobin is actually quite toxic to your body. It gets filtered out by your kidneys really fast, which can cause deposits that lead to kidney damage.” Sigurjonson says.
Scientists have discovered that larger forms of hemoglobin don’t cause toxic effects. Therefore, research has focused on building larger molecules, Sigurjonson says.
The most developed blood substitute is chemically cross-linked hemoglobin. Researchers create it by purifying hemoglobin and adding chemicals that bind it together into long strands. In 2001 the government of South Africa approved its use, but Sigurjonson hopes his group can do better.
“When researchers add these chemicals to hemoglobin, they make a solution with a wide range of sizes. There’s no way to control that. Some of those hemoglobins can be below the threshold for toxic effects,” Sigurjonson says. “Our method creates proteins from the ground up, so we get only one size of hemoglobin.”
Sigurjonson’s group harnesses the natural machinery of cells to create single-chain hemoglobin. Cells create proteins based on genes, or sequences of DNA. To make their protein, the group creates a gene made up of many sequences for hemoglobin. When they add this gene to bacterial cells, the cells grow a single protein made up of many units of hemoglobin, Sigurjonson says.
In the summer of 2013, the group successfully created the protein.
“We worked 70- to 80-hour weeks several weeks in a row. Finally we got enough to send out for testing, and we got really good data,” Sigurjonson says.
The next step is off-campus animal testing, but they have hit a snag.
“Research is all centered around funding; it’s all about the money. Our grant recently ran out, so we need to put out more papers to try to get a new one,” Sigurjonson says.
In his time at Western, Sigurjonson has stepped into the nationwide struggle to stretch our limited blood supply. Every day he and others work to give people like McPherson’s patient a fighting chance.
