Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Hemoglobin-Based Agent Reduces Need for Transfusion During Heart Surgery

13.12.2002


A Phase II clinical trial conducted at Duke University Medical Center and five other U.S. institutions has shown that an agent made of purified human hemoglobin appears safe and may be effective when used instead of transfused human blood to replace blood lost during heart surgery.



If the benefits of the agent, known as hemoglobin raffimer, are proven in subsequent Phase III clinical trials, physicians would not need to use as much donated blood during surgery, the researchers said. An estimated 20 percent of all human blood transfused in the U.S. is associated with heart surgery, so the Duke researchers believe that an efficient ?oxygen therapeutic? could play an important role in reducing the need for transfused blood.

The results of the trial were published today (Dec. 13, 2002) in the Journal of Cardiothoracic and Vascular Anesthesia.


The study also showed although hemoglobin raffimer -- like other oxygen therapeutics or blood substitutes tested to date -- produced elevated blood pressures during surgery, it was the only significant side effect and was manageable.

?Our data suggests that hemoglobin raffimer, when used during bypass surgery, is well tolerated and may be effective in reducing blood transfusions,? said Duke anesthesiologist Steven Hill, M.D. ?Although elevated blood pressure was more frequent in patients given hemoglobin raffimer when compared to controls, aggressive management kept blood pressures under control.

?If we had an agent that could temporarily sustain oxygen delivery to the body during surgery without having to use donated blood, that could have significant long-term potential for our patients,? he said.

Hill said the importance of developing an effective oxygen therapeutic is not only because of the decreasing donor pool for human blood and fears of disease transmission, but also because transfused blood may lead to worse outcomes after heart surgery. He cited the results of a recent study conducted at the Medical College of Ohio, which showed that five years after heart surgery, 15 percent of patients receiving blood transfusions had died, compared to a seven percent mortality rate for those who didn?t receive a transfusion.

?It may be that transfusion is not as safe as we think,? Hill said. ?So if we had a product that we could pull off the shelf at any time, and not have to worry about the possibilities of any infectious agents or immune responses, that could be a major step forward in improving outcomes.?

Hemoglobin raffimer is produced by removing hemoglobin, an oxygen-carrying molecule, from human red blood cells that have ?expired,? or passed their 42-day shelf life. After 42 days, Hill explained, stored red blood cells begin to break down and are no longer used in human transfusions.

?For hemoglobin raffimer, the hemoglobin is extracted and the other components of the red blood cells are discarded,? Hill said. ?The hemoglobin is then heat-treated and filtered, which eliminates risks of infectious agents.?

In bypass procedures, some of a patient?s own blood may be removed just prior to being placed on the heart-lung machine -- which takes over for the heart during surgery. The blood is replaced by a colloid solution. Then, the patients? own blood can be returned at a later point during the surgery, preferably after blood loss has ceased. This blood preservation strategy is frequently used to reduce the need for transfused blood.

?To avoid transfusion during cardiac surgery, however, we do have to remove a significant amount of the patients? own blood,? Hill said. ?A hemoglobin-based oxygen carrier would provide additional circulating hemoglobin to facilitate safe removal of the patient?s blood and support oxygen delivery to the body during the three to four hours of surgery.?

In the Duke study, 60 patients undergoing coronary artery bypass operations at six U.S. medical centers were randomized to receive either varying doses of hemoglobin raffimer or colloid during surgery. Of those receiving hemoglobin raffimer, 44 percent did not need a blood transfusion, while 18 percent of the control group avoided transfusion. Other than elevated blood pressures, the researchers found no other significant negative side effects from the agent.

There are two other ongoing trials of hemoglobin raffimer -- a Phase III trial being conducted in Canada and the United Kingdom, as well as a Phase II trial in the U.S., which is examining the effectiveness of the agent at higher doses.

The clinical trial was funded by Hemosol, Inc., Toronto, which developed hemoglobin raffimer. Hill has no financial interest in Hemosol.

Joining Hill in the study were Katherine Grichnik, M.D., from Duke and Lewis Gottschalk, M.D., University of Texas Medical School, Houston.

contact sources :
Steven Hill , (919) 681-6614
Hill0012@mc.duke.edu

Richard Merritt | dukemed news
Further information:
http://dukemednews.org/news/article.php?id=6189
http://www.mc.duke.edu/

More articles from Health and Medicine:

nachricht On track to heal leukaemia
18.01.2017 | Universitätsspital Bern

nachricht Penn vet research identifies new target for taming Ebola
12.01.2017 | University of Pennsylvania

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

A big nano boost for solar cells

18.01.2017 | Power and Electrical Engineering

Glass's off-kilter harmonies

18.01.2017 | Materials Sciences

Toward a 'smart' patch that automatically delivers insulin when needed

18.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>