Too much heparin: Possible source of error in blood gas analysis

Abstract

Sodium heparin solution is widely used as an anticoagulant in blood gas analysis. Although alterations in blood gas measurements may occur when small sample volumes are diluted by heparin, such errors are generally thought to be of theoretical rather than practical importance. We report on three patients in whom major alterations in blood gas measurements resulted from the use of excess heparin solution in the sampling syringe and discuss the clinical implications of diluting samples with heparin.