Quality assurance of high-dose i.v. heparin treatment exemplified by patients implanted with coronary Palmaz-Schatz stents.
The need to standardize treatment with high-dose IV standard heparin by using activated partial thromboplastin time (APTT) reagents tested for their heparin sensitivity and by establishing a standard treatment schedule led to the development of the "Lainz concept" of heparin management. The determination of heparin sensitivity of the 2 APTT reagents used (APTT Micronized Silica and APTT Actin FSL), their good agreement (r = .9977; P = .000), and their therapeutic APTT ratio of 1.5-2.5 fold of baseline APTT (therapeutic range, forty-five to seventy-five seconds) equivalent to 0.3-0.7 antifactor Xa units are presented. The "Lainz concept" was tested in 29 patients receiving high-dose heparin after coronary artery stenting. A mean dose of 1,273 U of standard heparin/hour (15.7 U/kg body weight/hour) was shown to produce APTTs in the therapeutic range. From the introduction of the "Lainz concept" 81% of the APTTs were kept within the therapeutic range by using a defined heparin-monitoring schedule based on a guideline protocol for controlling heparin treatment. Only 19% of the APTTs were below the therapeutic range. Factors underlying subtherapeutic APTTs are discussed. The reduction in the rate of subtherapeutic APTTs to less than 3% seen after the introduction of the "Lainz concept" constitutes an important contribution toward quality assurance in high-dose heparin treatment.
Haushofer
A
A
Central Laboratory, Stadt Wien Lainz, Vienna, Austria.
Halbmayer
W M
WM
Prachar
H
H
Fischer
M
M
D000368:Aged; D003327:Coronary Disease / Q000628:therapy*; D003331:Coronary Vessels / Q000187:drug effects*; D005260:Female; D006083:Graft Occlusion, Vascular / Q000517:prevention & control*; D006493:Heparin / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010314:Partial Thromboplastin Time; D011785:Quality Assurance, Health Care; D015607:Stents
D006493:Heparin