UNITED STATES - APRIL 29:  Robert L. Parkinson, chairman and chief executive officer of Baxter International Inc., pauses while testifying during a House Oversight and Investigations subcommittee hearing on deaths caused by severe allergic reactions to the blood thinner heparin in Washington, D.C., U.S., on Tuesday, April 29, 2008. Baxter International and its supplier of the main ingredient for heparin said that the drug appears to have been deliberately contaminated.  (Photo by Brendan Smialowski/Bloomberg via Getty Images)