Prognostic value of ADAMTS13 in patients with severe sepsis and septic shock Abstract Purpose: ADAMTS13 level was evaluated as a predictor of mortality in patients with severe sepsis and septic shock, and compared with Acute Physiology and Chronic Health Evaluation II (APACHE II) scores.Methods: This prospective observational study was conducted in the Medical and Surgical Intensive Care Units of King Khalid University Hospital. Detailed clinical evaluations were performed on 84 patients (56.08±18.18 years of age) with severe sepsis and septic shock. ADAMTS13 levels were determined (three blood samples at 24 hours intervals) and APACHE II scores, hematological profiles, indices of organ hypo-perfusion, renal functions and coagulation profiles were recorded. Primary outcome was 30 days ICU mortality and secondary outcomes were its comparison with APACHE II score, length of ICU stay and use of vasopressor agents.Results: Hypertension (53.6%) and diabetic mellitus (45.2%) were the commonest comorbidities. The median ADAMTS13 levels were 336.65, 339.35 and 313.9, respectively. ROC analysis showed maximum area under the curve for second ADAMTS13 (AUC=0.760) compared with first (AUC=0.660) and third samples (AUC=0.707) and APACHE II scores (AUC=0.662). Patients were divided into low and high ADAMTS13 groups according to the best cut-off point. Mortality was high in the low ADAMTS13 level group [OR=4.5]and was significantly associated with age, DBP, ADAMTS13, APACHE II score, DIC score and platelet count. ADAMTS13 (OR=5.3), APACHE II (OR=4.13) and DIC scores (OR=7.32) were significant risk factors for mortality.Conclusions: Low ADAMTS13 was associated with increased mortality in patients with severe sepsis and septic shock and was comparable to APACHE II scores for predicting mortality.

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