Evaluation of Current Heparin Weight Based Protocol in Obese Patients

Purpose: To evaluate the difference in achieving goal activated partial thromboplastin time (aPTT) within 24 hours utilizing the institutional heparin weight based protocol between obese and non-obese patients. Methods: Retrospective, non-randomized, open label chart review in a community based hospital. Patients age 18 years or older receiving heparin therapy for greater than or equal to 24 hours identified. Patients were excluded if the protocol was utilized for acute coronary syndrome or interrupted within the initial 24 hours of therapy. Patients were also excluded if any deviations from the protocol were identified. The primary endpoint evaluated the difference in achieving goal aPTT within 24 hours between obese and non-obese patients. The secondary endpoint evaluated the difference in achieving goal aPTT within 24-48 hours and safety outcomes such as bleeds. Results: Of the 253 patients identified, 167 patients were included and 86 patients were excluded. Seventy-two (71.3%) of the nonobese and 48 (72.7%) of obese patients achieved goal aPTT within 24 hours (odd ratio [OR]: 0.98, 95 % confidence interval (CI): 0.6 to 1.58). Sixteen (15.8%) of nonobese and 13 (19.7%) of the obese patients achieved goal aPTT within 24 to 48 hours (OR: 0.77, 95 % CI: 0.3 to 1.95). Two (1.9 %) of the nonobese and 3 (4.5 %) of the obese patients had a documented major bleed (OR: 0.42 and 95 % CI: 0.69 to 2.61). Conclusion: Overall, there was no difference in achieving goal aPTT between nonobese and obese patients while utilizing our facility’s weight based heparin dosing. No major bleeding was documented that warranted discontinuation of therapy, and bleeding incidences between both groups were similar.