title: Focus on thrombin: alternative anticoagulants.
abstract: Unfractionated heparin and protamine have been integral to cardiopulmonary bypass since cardiac surgery was first undertaken. These drugs are inexpensive and well understood but are contraindicated in some individuals, and resistance to heparin can be problematic in others. The interplay between the endothelium, anticoagulants, the coagulation cascade, and the inflammatory response that characterizes cardiac surgery may contribute to some of the complications associated with cardiopulmonary bypass. Various alternative drugs and strategies have been used to manage patients unsuitable for heparin or protamine, but each has its own disadvantages. At present, direct thrombin inhibitors may offer the best available alternative to heparin in cardiac surgery, particularly the short-acting bivalirudin, but this class of anticoagulants is relatively expensive and has no reversal agent. Balanced anticoagulation using combinations of drugs that act at different stages in the coagulation system may improve the management of coagulation in cardiac surgery, but careful investigation of this concept is needed.
authors.affiliation: Department of Anaesthesiology, University of Auckland, Auckland, New Zealand. a.merry@auckland.ac.nz
authors.forename: Alan F
authors.initials: AF
authors.lastname: Merry
mesh_terms: D000925:Anticoagulants / Q000009:adverse effects / Q000191:economics / Q000494:pharmacology*; D001777:Blood Coagulation / Q000187:drug effects; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D006493:Heparin / Q000009:adverse effects; D006629:Hirudins / Q000009:adverse effects / Q000191:economics / Q000494:pharmacology; D006801:Humans; D010446:Peptide Fragments / Q000009:adverse effects / Q000191:economics / Q000494:pharmacology; D011479:Protamines / Q000009:adverse effects; D011994:Recombinant Proteins / Q000009:adverse effects / Q000191:economics / Q000494:pharmacology; D013917:Thrombin / Q000037:antagonists & inhibitors*
chemical_list: D000925:Anticoagulants; D006629:Hirudins; D010446:Peptide Fragments; D011479:Protamines; D011994:Recombinant Proteins; D006493:Heparin; D013917:Thrombin; C074619:bivalirudin