Heparin therapy during extracorporeal circulation (original) (raw)
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PubMed, 1975
Five heparin protocols, representative of about 30 presently used throughout the country, were analyzed. The adequacy of anticoagulation during and the precision of protamine neutralization at the conclusion of extracorporeal circulation were studied. In each of 50 patient's age, height, weight, or surface area was of no help in predicting heparin kinetics. The study group consisted of the 2 patients with the longest and the 2 patients with the shortest heparin half lives, as well as the 2 patients who showed the greatest sensitivity to heparin and the 2 who showed the least. By computer simulation, each was managed according to the five protocols and by a monitoring procedure. The protocols failed to provide safe anticoagulation or precise protamine neutralization, whereas the simplified monitoring approach was uniformly successful.
International Journal of Clinical Monitoring and Computing, 1989
Two methods of heparin monitoring, semi-automated in-vivo heparin protamine titration (ttPT) and activated clotting time (ACT), were compared in each of sixteen adult patients undergoing extracorporea! circulation (ECC) for coronary artery bypass surgery. The HPT method determined the initial and maintenance level of heparin for ECC, as welt as, the amount of protamine needed for neutralization of heparin. ACT determinations were made in parallel to calculate heparin levels, heparin sensitivity, and protamine requirements. ACT determinations increased from 502 + 31 seconds after heparinization to 739 +_ 49 seconds (p < 0.05) five minutes after the start of ECC. The HPT method determined heparin sensitivy to be 153 _+ 17 secs/mg/kg and this did not change after the institution of ECC. The increase in ACT observed after the start of ECC resulted in an increase in heparin sensitivity from 151 _+ 13 secs/mg/kg initially, to 247 +_ 17 secs/mg/kg after the institution of ECC (p < 0.01). During ECC, the HPT method reported heparin levels which remained near the initial value of 2.40 _+ 0.12 mg/kg. The ACT method's initial heparin level of 2.66 ± 0.12mg/kg rose after the start of ECC to 4.39_+ 0.55mg/kg (p < 0.05). The HPT method adequately predicted protamine requirements, 2.66 ± 0.15 mg/kg protamine vs. 3.47 _+ 0.14 mg/kg actual dose while the ACT method predicted excess: 5.02 +_ 0.34 mg/kg (p < 0.01). In-vivo heparin-protamine titration method provided more consistent information during ECC and directed a significantly smaller dose of protamine for heparin neutralization.
Long-term extracorporeal circulation management: the role of low- and high-range heparin ACT tests
The Journal of extra-corporeal technology, 2008
Modern management of extracorporeal circulation, especially during long-term support of post-cardiac surgical patients, remains challenging and requires optimal care of the patient's fluid balance and coagulation hemostasis for its successful outcome. The activated clotting time assay is one of the tests used to manage extracorporeal circulation and is available in a low- and high-range level. The question of which assay is more appropriate for procedures that require low to moderate heparin dosing is still unclear. We report our experience with a neonate diagnosed with hypoplastic left heart syndrome who needed emergent extracorporeal membrane oxygenation support for 13 days after Norwood stage I palliation using a Sano shunt. Although successful, bleeding complications prompted us to review our strategy for management of coagulation hemostasis.
The journal of extra-corporeal technology, 2013
In 1966, Hattersley (2) described the activated clotting time (ACT). This test is the most economic and common method for coagulation and anticoagulation control of patients during cardiac surgery (3–6). Later, in 1975, Bull et al. established that each patient responded differently to the anticoagulation level reached with a dose of heparin (1,7). Using a coordinate chart, we observe this response (Figure 1). Bull et al. also proposed the individualization of the doses of heparin and protamine in accordance with the dose–response curve (1,7,8). Since then, several publications have coincided with the desirability of adjusting the dose of these drugs (5,9–17). However, the most widespread practice consists of administering a standard dose of 3 mg heparin per kilogram of patient weight without establishing the dose–response curve (5) but rather by confirming anticoagulation with the ACT greater than 400 seconds (5,8,9,15). With respect to protamine administration, there have been var...
Anticoagulation monitoring during extracorporeal circulation with the Hepcon/HMS device
Perfusion, 2012
The objective of our study was to compare the standard protocol of anticoagulation to the Hepcon/HMS. This study included forty-four patients who underwent coronary bypass grafting surgery (CABG), or biological aortic valve replacement (AVR). Unfractionated heparin (UH) was used for patients who underwent operations in the control group (n = 22) (300U/Kg of UH with a goal of an ACT of 400s). The heparin was antagonized dose/dose by protamine. For the patients who underwent operations in the HMS group (n = 22), the heparin and protamine doses were assessed by the Hepcon/HMS device. The sex ratio amounted to 1.93 (29 men and 15 women) and the mean age was 70 ± 11 years. The patients in the HMS group had a chest closure time that was significantly shorter than patients in the control group. The times were, respectively, 42 ± 15 minutes and 68 ± 27 minutes (p = 0.001). The protamine/heparin ratio was significantly lower in the HMS group (0.62 ± 0.13 vs. 1 ± 0.11) (p = 0.0001). The postoperative bleeding amounted to 804 ± 729 ml in the HMS group versus 1416 ± 1103 in the control group (p = 0.016). In multivariate linear regression analysis, only two independent factors were significantly associated with bleeding: the Hepcon/HMS (OR = 0.1-p = 0.03) and the preoperative hemoglobin rate (OR = 1.4 - p = 0.05). Postoperatively, within 72 hours, the red blood cell transfusion was 1.04 ± 1.5 units for the HMS group and 2.1 ± 1.87 units for the control group (p = 0.05). During cardiac surgery under CPB, heparin and protamine titration with the Hepcon/HMS device could predict a lower protamine dose and lower postoperative bleeding without higher thromboembolic events, and lower perioperative red blood cell transfusion with a shorter chest closure time.
Assessment of Heparin Anticoagulation: Comparison of Two Commercially Available Methods
2010
Background. The activated clotting time is a bedside method routinely used to monitor heparin anticoagulation during operations requiring cardiopulmonary bypass. The thrombolytic assessment system heparin management test is a new bedside method for monitoring heparin effect. We compared these methods with respect to their ability to reflect the actual heparin concentration in plasma determined by an anti-FXa method.
Perfusion, 2002
The correct monitoring of heparin therapy and its reversal determines the successful conduct of cardiovascular surgery with extracorporeal circulation (ECC). The activated coagulation time (ACT) and the heparin management test (HMT) are the most frequently used tests in the operating room. Three compact monitors for ACT or HMT are here evaluated. Forty samples were obtained, at 10-min intervals, from eight patients during ECC. The ACT or HMT was immediately performed using: Hemochron Junior 2 2 2 2 2 2 2 2 2 ACT, CoaguCeck 2 2 2 2 2 2 2 2 2 Pro (ACT) and Rapid Point Coag (HMT). Data were compared between them and with the heparin levels, measured as anti-Xa. The simple least squares linear regression among, respectively, Hemochron Junior ACT, CoaguCeck Pro ACT, Rapid Point Coag HMT and anti-Xa activity were i= 452.3, s= 15.2, Sy/x= 37.5, r= 0.18; i= 411.9, s= 22.1, Sy/x= 48.7, r= 0.21 and i= 479.4, s= 9.0, Sy/x= 9.3; r= 0.41. CoaguCeck Pro ACT results were above the upper detection limit (500 s) in 37 of 40 determinations. The comparison between ACT Hemocron and HMT Rapid Point Coag shows i= 35.7, s= 0.9, Sy/ x= 35.4, r= 0.68, with a bias of 29.0 s (CI: 17.9 -40.1), 95% of agreement between ¡41.5 s (CI: ¡60.7 to ¡22.3) and 99.5 s (CI: 80 . Taking a concentration of 2.0 U/ ml of heparin to discriminate between high-and low-risk conditions, receiver-operator characteristic (ROC) curve was used to rank the performance of the methods. Areas under the ROC curve± SE for Hemochron Junior ACT and Rapid Point Coag HMT were 0.629± 0.097 and 0.543± 0.096. The results obtained by HMT appear similar to those obtained by the ACT for monitoring high-dose heparin therapy in patients undergoing ECC. HMT appeared to perform better than ACT in measuring the heparin effect, while the ROC analysis gives a little more accuracy for ACT. Neither of the two methods is able to achieve enough evidence of diagnostic accuracy. Since these tests are widely used, and there are no laboratory alternatives, a real comparison with the outcome of the patients should be helpful for an evidence-based evaluation of these point-of-care tests.