Dosing and Monitoring: The recommended dose of IV lepirudin for HIT is 0.15 mg/kg/h with or with- out an initial bolus of 0.4 mg/kg. The anticoagulant effect of lepirudin in this setting is monitored by using the aPTT, and the dose is adjusted to achieve a target aPTT ratio of 1.5 to 2.5 times control (Linkins et al).32 When given for thromboprophylaxis after elective hip replacement surgery, desirudin is given subcutaneously at a dose of 15 mg twice daily with- out monitoring. The plasma half-life of the hirudins is 60 min after IV injection and 120 min after subcutaneous injec- tion.216 Hirudin is cleared via the kidneys, and the 2012 American College of Chest Physicians by Kimberly Henricks on February 10, 2012 chestjournal.chestpubs.org Downloaded from e36S Parenteral Anticoagulants Hemodialysis or hemoperfusion can remove bivalirudin or argatroban. Dialysis using high-flux dialysis membranes can clear hirudin. Acknowledgments Author Contributions: As Topic Editor, Dr Garcia oversaw the development of this article, including any analysis and subsequent development of the information contained herein. Dr Garcia: contributed as a Topic Editor. Dr Baglin: contributed as a panelist. Dr Weitz: contributed as a panelist. Dr Samama: contributed as a panelist. Financial/nonfinancial disclosures: In summary, the authors have reported to CHEST the following conflicts of interest: Drs Weitz and Garcia have served as consultants for Boehringer Ingelheim, Bristol-Myers Squibb, Pfizer, Daiichi-Sankyo, Bayer, and Johnson & Johnson. Dr Samama has received honoraria for lectures or consulting from Bayer Healthcare, Johnson & Johnson, Bristol- Myers Squibb, Boehringer Ingelheim, sanofi-aventis, and Rovi, and has served on a steering committee for Daiichi-Sankyo. Dr Baglin has reported that no potential conflicts of interest exist with any companies/organizations whose products or services may be dis- cussed in this article. Role of sponsors: The sponsors played no role in the development of these guidelines. 