title: Plasma heparin levels after low dose subcutaneous heparin in patients undergoing hip replacement.
abstract: Plasma heparin levels were measured at 2 and 8 h after 5000 iu of heparin subcutaneously in 43 patients awaiting total hip replacement. At 2 h, 37 patients had plasma levels between 0.05 and 0.15 iu/ml, three patients had more than 0.2 iu/ml, and three had only trace levels. At 8 h, most patients had less than 0.1 iu/ml, and six patients had no detectable plasma heparin. There were no correlations between plasma heparin levels and age, sex, body weight or use of analgesics. Patients with high 2 h plasma heparin levels may bleed at operation, whereas those with very low plasma heparin concentrations may be at risk of post-operative venous thrombosis; it may therefore sometimes be necessary to monitor plasma heparin levels in order to determine the optimal regime in individual cases.
mesh_terms: D000328:Adult; D000368:Aged; D000700:Analgesics / Q000494:pharmacology; D001835:Body Weight; D004305:Dose-Response Relationship, Drug; D005260:Female; D006493:Heparin / Q000008:administration & dosage / Q000097:blood*; D006615:Hip / Q000601:surgery*; D006801:Humans; D007279:Injections, Subcutaneous; D008297:Male; D008875:Middle Aged; D013997:Time Factors
chemical_list: D000700:Analgesics; D006493:Heparin