title: Sensitivity and specificity of the Hemochron, Hemotec and APTT for the detection of low concentrations of heparin.
abstract: This study compared two bedside methods recommended for the detection of low concentrations of heparin and the activated partial thromboplastin time (APTT), with reference to a laboratory measure of heparin concentration. Patients undergoing cardiopulmonary bypass had blood drawn at four stages when low levels of heparin could be expected. At each stage four tests were performed: whole blood clotting time using a Hemochron analyser with a Saline-Rinsed test cartridge, whole blood clotting time using a Hemotec analyser with a High Range Heparinase test cartridge, APTT, and heparin concentration by polybrene neutralization. Thirty patients were studied. The sensitivity of the Saline-Rinsed Hemochron, Hemotec High Range Heparinase, and APTT in detecting concentrations of heparin less than 1 U/ml was 38%, 40% and 97%, respectively, while specificities were 87%, 90%, and 30%, respectively. Neither the Saline Rinsed Hemochron, nor the Hemotec Heparinase cartridge reliably detected concentrations of heparin less than 1 U/ml.
authors.affiliation: Department of Anaesthesia, Sir Charles Gairdner Hospital, Perth, W.A.
authors.forename: W M
authors.initials: WM
authors.lastname: Weightman
authors.forename: A O
authors.initials: AO
authors.lastname: Clapin
authors.forename: N
authors.initials: N
authors.lastname: Michalopoulis
authors.forename: N M
authors.initials: NM
authors.lastname: Gibbs
mesh_terms: D000925:Anticoagulants / Q000008:administration & dosage / Q000097:blood*; D002315:Cardiopulmonary Bypass; D004864:Equipment and Supplies; D005069:Evaluation Studies as Topic; D006493:Heparin / Q000008:administration & dosage / Q000097:blood* / Q000172:deficiency; D006801:Humans; D007262:Infusions, Intravenous; D008875:Middle Aged; D010314:Partial Thromboplastin Time; D011300:Preoperative Care; D012680:Sensitivity and Specificity
chemical_list: D000925:Anticoagulants; D006493:Heparin