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Biphasic Activated Partial Thromboplastin Time Waveform and Adverse Events in Non–Intensive Care Unit Patients

Eve Y. Smith, Linda A. Charles PhD, Elizabeth M. Van Cott MD
DOI: http://dx.doi.org/10.1309/W4F7892WJE6Y1W7Y 138-141 First published online: 1 January 2004


The purpose of the present study was to determine whether the presence of a biphasic activated partial thromboplastin time (aPTT) waveform (BPW) is associated with adverse clinical outcomes among patients not in an intensive care unit (ICU). Consecutive patients from the emergency department or non-ICU inpatient floors with a BPW (n = 24) were enrolled prospectively, along with 24 matched control subjects with a normal aPTT waveform. Patients with a BPW had a significantly longer hospital stay (mean [median], 16.9 [11] vs 4.9 [2.5] days; P = .011), were more likely to have a positive microbial culture (16/24 [67%] vs 3/24 [13%]; P <.001), were transferred more often to an ICU (6/24 [25%] vs 0/24 [0%]; P = .010), and were more likely to receive an RBC transfusion (11/24 [46%] vs 5/24 [21%]; P = .047) or a fresh frozen plasma transfusion (5/24 [21%] vs 0/24 [0%]; P = .025). Emergency department patients with a BPW were more likely to be admitted (11/11 vs 5/11; P = .018). These results suggest that the BPW is associated with an increased rate of adverse events among non-ICU patients. Further study in this population is warranted.

Key Words:
  • Biphasic aPTT waveform
  • DIC
  • Disseminated intravascular coagulation
  • Activated partial thromboplastin time
  • aPTT