Summary
Background: The application of a heparin dosing nomogram in the treatment of patients
with venous thromboembolism resulted in improvement of heparin therapy in clinical
research settings. In 1992 a heparin nomogram was introduced in our hospital, which
is a community hospital where anticoagulant therapy is supervised by the attending
physicians. We studied whether comparable improvements were achieved in such a non-surveyed
clinical setting. Methods: Patients were identified from computerized discharge records,
and classified into a pre-nomogram (discharged in 1990 or 1991) and a nomogram patient
group (discharged in 1993 or 1994). The use of the nomogram was encouraged but the
application remained on a voluntary basis. Since the definition of the target APTT
range was different in the pre-nomogram period as compared to the nomogram period,
a formal analysis of pre- and post-nomogram results was not considered justified.
Results: The APTT ratio, six hours after the start of heparin treatment, was below
the predefined lower limit in 72% of 127 patients in the pre-nomogram group and in
13% of 127 patients in the nomogram group. During 1043 days heparin therapy in the
nomogram group the morning APTT ratio was subtherapeutic in 8%. In 58% of all APTT
results the physician responded according to the nomogram. The subsequent APTT was
in the target range in 64% of the cases compared to 31% if the adjustement was not
performed according to the nomogram (P<.0001). Major bleeding episodes occurred in
3.1% in the pre-nomo-gram period and in 0.7% in the nomogram period.
Conclusion: The present study shows that the introduction of a heparin dosing nomogram
in a non-research clinical setting results in more adequate heparin anticoagulation
with low risks of bleeding.
