Hemodilution

Research reports from J.R. Egan and co-authors provide new insights into thoracic and cardiovascular surgery

"Dystrophin and dysferlin are involved in membrane integrity, whereas aquaporins selectively transport water. These proteins were examined in a model of pediatric cardiac surgery, together with a trial of poloxamer 188, which may reduce membrane injury. Eight lambs were randomized to saline with or without poloxamer 188. Lambs underwent 2 hours of cardiopulmonary bypass and aortic crossclamping. After a further 9 hours of monitoring, the hearts were assessed for water content, capillary leak, and protein expression. Dystrophin expression was unaffected by ischemia/reperfusion, but dysferlin expression was reduced. Aquaporin 1 protein increased after ischemia/reperfusion. Poloxamer 188 administration was associated with supranormal levels of dystrophin, preservation of dysferlin expression, and normalization of aquaporin 1 expression. Poloxamer 188 was associated with less capillary leak, maintained colloid osmotic pressure, and less hemodilution. Poloxamer 188 was associated with an improved hemodynamic profile (higher blood pressure, higher venous saturation, and lower lactate), although the heart rate tended to be higher. Changes in protein expression within the myocardial membrane were found in a clinically relevant model of pediatric cardiac surgery. Indicators of reduced performance, such as lower blood pressure and lower oxygen delivery, were lessened in association with the administration of the membrane protecting poloxamer 188," wrote J.R. Egan and colleagues.

The researchers concluded: "Poloxamer 188 was also associated with potentially beneficial changes in membrane protein expression, reduced capillary leakage, and less hemodilution."

Egan and colleagues published their study in the Journal of Thoracic and Cardiovascular Surgery (Myocardial membrane injury in pediatric cardiac surgery: An animal model. Journal of Thoracic and Cardiovascular Surgery, 2009;137(5):1154-1162).

Additional information can be obtained by contacting D.S. Winlaw, Kids Heart Research, Locked Bag 4001, Westmead, NSW 2145, Australia.

The publisher of the Journal of Thoracic and Cardiovascular Surgery can be contacted at: Mosby-Elsevier, 360 Park Avenue South, New York, NY 10010-1710, USA.

Keywords: Australia, Westmead, Life Sciences, Blood Transfusion, Reperfusion, Medical Device, Transfusion Medicine, Pediatric, Low Cardiac Output, Ischemia, Cardiology, Cardiopulmonary Bypass, Cardiovascular, Cardiac Surgery, Perfusion, Thoracic and Cardiovascular Surgery.

This article was prepared by Medical Device Business Week editors from staff and other reports. Copyright 2009, Medical Device Business Week via NewsRx.com.