The ineffectiveness of a non-weight based heparin regimen in achieving therapeutic activated partial thromboplastin time (aPTT) in acute coronary syndrome.
Although low molecular weight heparin (LMWH) is increasingly being used in the treatment of acute coronary syndrome (ACS), unfractionated intravenous (IV) heparin infusion is still widely used in Australian hospitals for the treatment of ACS. This paper evaluates the effectiveness of a non-weight based heparin regimen in achieving a therapeutic activated partial thromboplastin time (aPTT) within 24 hours of IV heparin commencement. A sequential retrospective chart review of 99 medical records of ACS patients in a district hospital in south western Sydney, Australia, was performed. These patients were prescribed IV heparin and did not receive thrombolytic or warfarin therapy. Only 35 per cent reached a therapeutic aPTT level within 24 hours of commencement of IV heparin therapy. Comparison of therapeutic aPTT and non-therapeutic aPTT groups revealed that body weight was the only factor that was significantly different in the two groups. Patients who reached the therapeutic aPTT threshold within 24 hours weighed significantly less (mean body weight: 70.3 kg versus 80.3 kg) than those who did not reach the therapeutic threshold within 24 hours of heparin commencement (t = 3.80, d.f. = 86, p < 0.001). Given that a significant proportion of patients who require IV heparin therapy exceed the 70 kg body weight, the findings from this study suggest that a non-weight based heparin regimen is ineffective in the rapid achievement of therapeutic aPTT.
Salamonson
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Division of Nursing, Faculty of Health, University of Western Sydney, Campbelltown, NSW.
D000208:Acute Disease; D000368:Aged; D000789:Angina, Unstable / Q000097:blood / Q000188:drug therapy*; D000925:Anticoagulants / Q000627:therapeutic use*; D001835:Body Weight; D002985:Clinical Protocols / Q000592:standards; D016903:Drug Monitoring / Q000379:methods; D005260:Female; D019983:Guideline Adherence; D006493:Heparin / Q000627:therapeutic use*; D006801:Humans; D007262:Infusions, Intravenous; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000188:drug therapy*; D009517:New South Wales; D010314:Partial Thromboplastin Time / Q000379:methods / Q000592:standards; D017410:Practice Guidelines as Topic; D012189:Retrospective Studies; D013577:Syndrome; D013997:Time Factors; D017211:Treatment Failure
D000925:Anticoagulants; D006493:Heparin