S Svenmarker1, M Appelblad, E Jansson, S Häggmark. 1. Department of Surgical and Perioperative Science, University Hospital of Umeå, Umeå, Sweden. staffan.svenmarker.us@vll.se
Abstract
BACKGROUND: Measurement of the activated clotting time (ACT) represents a standard method for coagulatory assessments. The test employs specific agents to trigger the coagulation process. The present study aimed to compare kaolin (Hemotec) versus a combination of silica, kaolin and phospholipid (Hemochron Jr) ACTs. METHODS: Hemotec and Hemochron Jr ACT monitors were compared by simultaneous measurement of paired arterial blood samples (n = 114) with respect to precision and bias during clinical conditions of cardiopulmonary bypass (CPB). The influence of haemodilution on the ACT was tested in an ex-vivo model. RESULTS: The precision of Hemotec and Hemochron Jr ACT measurements attained 21 +/- 2.6 s versus 27.0 +/- 2.6 s (p = 0.126) during CPB and 2.5 +/- 2.2 s versus 9.4 +/- 6.9 s (p = 0.000) after protamine administration, respectively. The Hemochron Jr monitor was associated with a bias of -102 +/- 13.7 s compared to the Hemotec ACT monitor (p = 0.000) during CPB and -6.9 +/- 2.9 s after protamine (p = 0.025). Linear regression analysis of ACT readings between monitors reached r = 0.526 (p = 0.000). Hemochron Jr ACT values correlated with the erythrocyte volume fraction r = 0.379 (p = 0.000). Ex-vivo data indicated that the Hemotec ACT monitor was associated with relatively higher ACT readings after haemodilution. CONCLUSION: The ACT is not a standardized measure. Test results are strongly associated with the specific compounds used to initiate the coagulation process.
BACKGROUND: Measurement of the activated clotting time (ACT) represents a standard method for coagulatory assessments. The test employs specific agents to trigger the coagulation process. The present study aimed to compare kaolin (Hemotec) versus a combination of silica, kaolin and phospholipid (Hemochron Jr) ACTs. METHODS: Hemotec and Hemochron Jr ACT monitors were compared by simultaneous measurement of paired arterial blood samples (n = 114) with respect to precision and bias during clinical conditions of cardiopulmonary bypass (CPB). The influence of haemodilution on the ACT was tested in an ex-vivo model. RESULTS: The precision of Hemotec and Hemochron Jr ACT measurements attained 21 +/- 2.6 s versus 27.0 +/- 2.6 s (p = 0.126) during CPB and 2.5 +/- 2.2 s versus 9.4 +/- 6.9 s (p = 0.000) after protamine administration, respectively. The Hemochron Jr monitor was associated with a bias of -102 +/- 13.7 s compared to the Hemotec ACT monitor (p = 0.000) during CPB and -6.9 +/- 2.9 s after protamine (p = 0.025). Linear regression analysis of ACT readings between monitors reached r = 0.526 (p = 0.000). Hemochron Jr ACT values correlated with the erythrocyte volume fraction r = 0.379 (p = 0.000). Ex-vivo data indicated that the Hemotec ACT monitor was associated with relatively higher ACT readings after haemodilution. CONCLUSION: The ACT is not a standardized measure. Test results are strongly associated with the specific compounds used to initiate the coagulation process.
Authors: Donald S Likosky; Robert A Baker; Timothy A Dickinson; Daniel J FitzGerald; M Filip De Somer; Robert C Groom; David FitzGerald; Kenneth G Shann; Michael Poullis; Bruce D Spiess; Karim Jabr; Mark T Lucas; James D Ferguson; Shahna L Bronson Journal: J Extra Corpor Technol Date: 2015-06
Authors: Colleen E Gruenwald; Cedric Manlhiot; Lynn Crawford-Lean; Celeste Foreman; Leonardo R Brandão; Brian W McCrindle; Helen Holtby; Ross Richards; Helen Moriarty; Glen Van Arsdell; Anthony K Chan Journal: J Extra Corpor Technol Date: 2010-03
Authors: Jung Min Lee; Eun Young Park; Kyung Mi Kim; Jong Chan Won; Tack Koon Jung; Soo Kyung Lee Journal: J Int Med Res Date: 2017-10-04 Impact factor: 1.671