Bugeja A, Harris S, McCormick B, et al. - In this retrospective cohort study, the safety and efficacy of 2 doses of tinzaparin among in-center extended duration nocturnal hemodialysis (INHD) patients receiving 6–8 h hemodialysis, 3 times per week, were determined. Researchers assessed antifactor Xa levels at time 0, 2 h, 4 h mid-hemodialysis (mid-HD), 6 h, and at end of each INHD session for 4 weeks and investigated extracorporeal dialysis circuit clotting and bleeding events after switching from unfractionated heparin to tinzaparin, using a standard protocol of tinzaparin delivery at the initiation and midpoint of HD. Conversion to tinzaparin was done in 16 patients in the Ottawa Hospital INHD program; follow-up of these patients for 177 INHD sessions was done. Outcomes support the safety and efficacy of tinzaparin for most INHD patients without accumulation or bleeding. They identified a necessity for an increased tinzaparin dose for 31% of INHD patients for conversion from unfractionated heparin to tinzaparin.