ORIGINAL ARTICLESPoint-of-care platelet function tests: detection of platelet inhibition induced by nonopioid analgesic drugsScharbert, Gisela; Gebhardt, Kristina; Sow, Zacharia; Duris, Monika; Deusch, Engelbert; Kozek-Langenecker, SibylleAuthor Information Department of Anaesthesiology, General Intensive Care, and Pain Control, Vienna Medical University, Vienna, Austria Received 18 December, 2006 Revised 16 July, 2007 Accepted 8 August, 2007 Correspondence to Sibylle Kozek-Langenecker, MD, Department of Anaesthesiology, General Intensive Care, and Pain Control, Vienna Medical University, Währinger Gürtel 18–20, 1090 Vienna, Austria Tel: +43 1 40400 4144; fax: +43 1 40400 6422; e-mail: email@example.com Blood Coagulation & Fibrinolysis: December 2007 - Volume 18 - Issue 8 - p 775-780 doi: 10.1097/MBC.0b013e3282f10289 Buy Metrics Abstract Detection of platelet inhibition is of clinical relevance in the preinterventional risk–benefit assessment in chronic low-back-pain patients scheduled for invasive pain therapy. We evaluated the sensitivity of various point-of-care platelet function tests for the detection of platelet inhibition induced by nonopioid analgesic drugs. After Institutional Review Board approval and informed consent, citrated whole blood from 40 patients with chronic unspecific low back pain was investigated before and 30 min after intravenous infusion of the study medication consisting of diclofenac 75 mg (plus orphenadrin 30 mg; Neodolpasse; Fresenius Kabi Austria GmbH, Austria), parecoxib 40 mg (Dynastat; Pharmacia Europe EEIG, UK), paracetamol 1 g (Perfalgan; Bieffe Medital S.P.A., Italy), or normal saline in a randomized, cross-over, double-blinded, placebo-controlled study. Platelet function was assessed using the PFA-100 platelet function analyzer and thromboelastometry, as well as impedance aggregometry (in the last 17 patients recruited after it became commercially available). Sensitivity for detecting diclofenac-induced platelet inhibition was 85% for the PFA-100 using epinephrine as agonist and 94% for arachidonic acid-induced impedance aggregometry. ADP-induced platelet function tests, as well as cytochalasin D-modified thromboelastometry were unreliable. All tests had a low incidence of false-positive test results after normal saline. Paracetamol and parecoxib had no significant platelet inhibiting effect. The PFA-100 using epinephrine as agonist and arachidonic acid-induced impedance aggregometry are recommended for the detection of cyclooxygenase-I-inhibiting effects of nonsteroidal anti-inflammatory drugs such as diclofenac. Our findings confirm that a single rescue dose of paracetamol and parecoxib has no antiplatelet effect. © 2007 Lippincott Williams & Wilkins, Inc.