Protamine-associated hypotension in patients on hemodialysis: Retrospective study and prevalence of antiprotamine antibodies

Aims: Protamine, when administered to neutralize heparin in cardiovascular surgery, is associated with occasionally severe antigen-antibody reactions associated with substantial morbidity and mortality. The objective of this study is to investigate whether patients on hemodialysis are more susceptible to the protamine adverse effects. Method: First, a retrospective analysis of a protamine-associated hypotension episode (PAHE) in 239 patients undergoing coronary artery bypass grafting surgery was performed for the incidence study in the period of 1999 to 2005. Second, an ELISA determination of serum anti-protamine IgG antibody in 255 serum samples from individuals without previous surgical histories was conducted for prevalence survey. In both studies, patients on HD were matched for age with non HD patients. Results: The highest incidence (57%) of PAHE occurred in patients on hemodialysis using of M-insulin (a mixed type of insulin aspart 30%, insulin aspart protamine 70%) formulation, and this group also exhibited a high anti-protamine IgG antibody titer in serum (odds ratio: 18.31). Conclusions: A substantial proportion of patients on hemodialysis are at high risk of acquiring protamine adverse effects, but definite conclusion about the association between uremia and PAHE, however, still needs to be made with caution.