A University of Missouri researcher is developing a portable monitoring device that first-response medical teams can use to save the lives of accident victims on the scene by replacing lost blood with plasma expanders rather than donor blood.
The device uses a novel method to quickly measure changes in a patient's blood plasma viscosity, a key factor in survival.
"Recent studies have shown that blood loss not only reduces the oxygen carried by blood, but also reduces the blood viscosity," said Mark A. Haidekker, assistant professor of biological engineering.
"Low viscosity leads to the collapse of capillary blood vessels and to oxygen deficiency in the tissue. The crucial step to prevent hemorrhagic shock is to get viscosity back up," he said
As viscosity is shown to decrease, medical rescue teams can inject high-viscosity plasma expanders consisting of saline and starch, rather than whole blood, buying critical time for patients to reach a hospital.
"Conventional medicine says that if you lose 25% of your blood you need full blood replacement with all the associated problems, which include getting and typing the blood. This is particularly bad today with a scarcity and potential infection of blood," he said.
But experiments indicate that accident victims can lose as much as 80% of their blood--four of their five liters of blood--and live when high-viscosity expanders are used to maintain oxygen supply through the capillaries, he said.
Haidekker's device uses fluorescent rotor molecules to monitor changes in a patient's blood plasma viscosity.
Rotor molecules sense the viscosity of their environment because their rotational movement is restricted by high viscosity.
A decrease in the patient's blood viscosity intensifies the rotor molecule's fluorescence. While standard mechanical viscometers usually take minutes for an accurate readout, fluorescence can be measured within seconds.
With this device a patient's blood can be constantly monitored and plasma expander injections adjusted to maintain 4.5 centipoises, the normal viscosity of full blood, he said.
Haidekker envisions a prototype a little larger than a VCR. Such a device and a supply of standard plasma expanders can easily fit in any paramedic's van, he said.
Haidekker joined the MU faculty from the University of California, San Diego, where he was an assistant research scientist.
The MU Biological Engineering program, now in its fifth year, combines engineering and biological sciences in one curriculum. Study areas include designing systems for medical and pharmaceutical applications, developing new food products and biological treatment of environmental pollutants.