Background: Persistent wound drainage and venous thromboembolism (VTE) are potential complications of total joint arthroplasty, and these risks can be challenging to balance in clinical practice. Anecdotal observation has suggested that following joint arthroplasty, persistent wound drainage occurs more frequently with higher body weight and higher doses of tinzaparin when compared with lower body weight and lower doses of tinzaparin. Objective: The overall purpose of this study was to describe the impact of a tinzaparin weight-band dosing table for VTE prophylaxis on wound healing, thrombosis, and bleeding outcomes in patients undergoing total joint arthroplasty. Methods: This retrospective chart review included patients who underwent total hip or knee arthroplasty and received tinzaparin for thromboprophylaxis per their weight-banding category. The primary outcome was the incidence of persistent wound drainage. Secondary outcomes include the occurrence of VTE and clinically important bleeding during hospital admission. Results: A total of 231 patients were included in the analysis. There was no significant difference in persistent wound drainage between the 3 weight categories, and there were no differences in rates of VTE or clinically important bleeding. Concurrent use of low-dose acetylsalicylic acid was associated with a 3-fold increased risk of persistent wound drainage (risk ratio = 3.35; 95% CI = 2.14-5.24; P = 0.00003). Conclusion and Relevance: In joint arthroplasty patients, we observed no significant difference in rates of persistent wound drainage between various weight categories receiving different weight-banded doses of tinzaparin. Our results do not suggest that the current weight-band dosing table for tinzaparin needs to be adjusted to optimize patient outcomes.

Thirteen volunteers received an iv dose of theophylline followed by blood sampling for 8 h to calculate pharmacokinetic parameters. Ten patients with asthma undergoing chronic dosing with slow release aminophylline underwent 12 h of blood sampling to calculate theophylline clearance. Both groups completed an Eysenck Personality Inventory (EPI) from which was derived scores for neuroticism (N) and extroversion (E). Using multiple regression analysis no independent effect of either N or E score on theophylline clearance or half-life could be demonstrated.