The use of the Hemochron in assessment of heparin reversal after cardiopulmonary bypass

Hooper, Timothy L.; Conroy, Joanne M.; McArdle, B.; Dell, A.; Watson, B. G.; Pearson, D. T.; Kesteven, P.J.L.

doi:10.1177/026765918800300407

Cited by 10 publications

(3 citation statements)

References 10 publications

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“…Despite the popularity ofthe ACT, there is still debate over its usefulness. Several studies have found that the ACT does not show a good correlation with the plasma heparin levels (13,27), and that the ACT had little value on residual heparin levels (28,29). Dietrich, on the other hand, found that the plasma heparin level itself was not a good indicator of anticoagulation (25).…”

Section: Discussionmentioning

confidence: 99%

Evaluation of the Hemochron 8000 Rx/Dx System for Heparin Management

Johnson,

Morgan,

Koenig

et al. 1997

J Extra Corpor Technol

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The Hemochron Rx/Dx uses an ACT and a heparin response tube to calculate the heparin dose to identify heparin sensitive/resistant patients. We evaluated the Rx/Dx system in 37 patients to determine if the ACT after the predicted heparin loading dose was adequate to initiate CPB. The mean heparin dose calculated by the Rx/Dx was 31,700 IU ± 8,700 IU (370 IU/kg) with a mean post ACT of 463 ± 124 sec. Our standard heparin dose (400 IU/kg) would have given an additional 2,800 IU over the Rx/Dx. Four patients (6.5%) were predicted to be heparin sensitive and all four achieved an ACT over 450 sec. Twenty-one patients (56.8%) were predicted to be resistant and yet failed to raise the ACT over 450 sec in 17 (81.0% ). Twelve patients (32.4%) were predicted to have a normal heparin response, and four (33.3%) did not achieve an ACT over 450 sec. In all, 21 patients (56.8%) did not achieve an ACT greater than 450 sec. Each institution should evaluate their heparin loading dose and the resultant ACT. In this study, we found the number of times the Rx/Dx system did not raise the ACT over 450 sec too great to justify the additional expense.

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Section: Discussionmentioning

confidence: 99%

Evaluation of the Hemochron 8000 Rx/Dx System for Heparin Management

Johnson,

Morgan,

Koenig

et al. 1997

J Extra Corpor Technol

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show abstract

“…Rather than reducing the ACT toward 123 s (poststernotomy baseline), supplemental protamine increased ACT to 161 s. This suggests that heparin was already either fully neutralized or overneutralized, because excessive protamine increases ACT (15,16). Although relative insensitivity to heparin favors the ACT for monitoring anticoagulation during CPB, it diminishes its ability to diagnose incomplete heparin neutralization after CPB adequately (6,18,19). If hemostasis had been inadequate in patient C, the comparison of sternotomy and postprotamine ACTS would have suggested the need for clotting factors, platelets, or possibly desmopressin.…”

Section: Discussionmentioning

confidence: 99%

“…If hemostasis had been inadequate in patient C, the comparison of sternotomy and postprotamine ACTS would have suggested the need for clotting factors, platelets, or possibly desmopressin. Consequently, to maximize the post-CPB diagnostic utility of a relatively imprecise test (9) that lacks sensitivity to low concentrations of heparin (6,18,19), pre-CPB baseline ACT is best obtained after surgical incision. Activated coagulation time functions well as a monitor of CPB anticoagulation because it is relatively insensitive to heparin.…”

Section: Discussionmentioning

confidence: 99%

Baseline Activated Coagulation Time Should Be Measured After Surgical Incision

Gravlee

Whitaker

Mark

et al. 1990

Anesthesia & Analgesia

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The activated coagulation time (ACT) is widely used to guide heparin and protamine dosing during cardiac surgery. A common protocol involves establishing a baseline ACT before administering heparin, then using this ACT as a target value for assessing the adequacy of heparin neutralization after cardiopulmonary bypass. Results vary in previous comparisons of baseline ACT to postprotamine ACT, with some showing postprotamine ACT significantly below baseline values. The present study examined ACTs at three possible baseline intervals in 68 patients at two institutions: (a) before anesthetic induction; (b) after anesthetic induction; and (c) after sternotomy. Baseline ACT decreased significantly with anesthesia and surgery. The poststernotomy baseline ACT best matched the postprotamine ACT. It appears likely that surgery induces a thromboplastic response that decreases ACT. Establishing baseline ACT before anesthetic induction would predispose to false diagnoses of adequate protamine neutralization after cardiopulmonary bypass, because ACT is relatively insensitive to low concentrations of unneutralized heparin. Baseline ACTs should therefore be measured after surgical incision.

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Gs²,

Gravlee³

et al. 1990

Journal of Cardiothoracic Anesthesia

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The use of the Hemochron in assessment of heparin reversal after cardiopulmonary bypass

Cited by 10 publications

References 10 publications

Evaluation of the Hemochron 8000 Rx/Dx System for Heparin Management

Evaluation of the Hemochron 8000 Rx/Dx System for Heparin Management

Baseline Activated Coagulation Time Should Be Measured After Surgical Incision

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