The use of heparinase to neutralize residual heparin in blood samples drawn through pediatric indwelling central venous catheters

doi:10.1016/S0022-3476(98)70506-2

The Journal of Pediatrics

Volume 132, Issue 1, January 1998, Pages 165-167

https://doi.org/10.1016/S0022-3476(98)70506-2 Get rights and content

Abstract

Routine coagulation screening is unreliable if obtained through a previously heparinized central venous catheter. Screening tests were performed on 14 paired peripheral and central venous catheter samples without and with heparinase. The heparinase treated central venous catheter samples correlated well with the peripheral samples and can be used to atraumatically screen for hemostatic abnormalities. (J Pediatr 1998;132:165-7)

Section snippets

Patients

Children and adolescents with a permanent, indwelling CVC (five with acute lymphoblastic leukemia, two with non-Hodgkins lymphoma, one with aplastic anemia, one with Wilms' tumor, and one with histiocytosis) were eligible for the study. All catheters were routinely flushed with a saline solution containing 100 units of heparin per milliliter. Six patients had external catheters and four had subcutaneous port catheters. Informed consent was obtained from all participants and their legal

Results

Fourteen paired blood samples were obtained from 10 patients. Multiple samples were obtained from three patients.

Results of the correlation analysis are presented in graphic form in the Figure.

Figure. Correlation analysis of peripheral and CVC samples for the aPTT and PT in seconds. The peripheral sample not treated with heparinase (P-H) is the standard and is plotted on the x-axis on each plot. Other aliquots are represented on the y-axis. A, CVC sample not treated with heparinase (CVC -H). B,

Discussion

The use of permanent indwelling CVCs has become common practice for children undergoing therapy for malignant and chronic diseases. Many institutions routinely flush CVCs with a heparin-containing solution when not in use to minimize the potential for catheter occlusion by thrombus formation. Our results confirm the unreliability of using the aPTT and PT for coagulation screening when drawn through a previously heparinized CVC, despite a standardized protocol for withdrawing a set volume before

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The presence of HLS in the liver failure patient’s blood was suspected based on laboratory data (Table 1). The aPTT coagulation assays of patient plasma showed a 2.5- to 3-times higher value for untreated plasma compared to heparinase-treated plasma (Hepzymed process (Keller et al., 1998)) despite the absence of exogenously administered HP, suggesting the presence of endogenous plasma HP or HS. The patient repeatedly had measurable anti-Xa activity and a thrombin time (TT) of >120 s with a reference range of 15−18 s. Another recently reported case described an infant with HLS induced bleeding that developed after 2 weeks post liver transplantation (Nacoti et al., 2018).
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^☆: From the Departments of Pediatrics and Medicine, West Virginia University School of Medicine, Morgantown, West Virginia.

^☆☆: Reprint requests: Frank G. Keller, MD, Assistant Professor, Pediatrics, PO Box 9214, Robert C. Byrd Health Sciences Center, West Virginia University School of Medicine, Morgantown, WV 26506-9214.

^★: 9/22/82367

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The use of heparinase to neutralize residual heparin in blood samples drawn through pediatric indwelling central venous catheters☆,☆☆,★

Abstract

Section snippets

Patients

Results

Discussion

J Pediatr

J Biol Chem

Thromb Res

Coagulation nondisease

N Engl J Med

Discard volumes necessary for clinically useful coagulation studies from heparinized Hickman catheters

Oncol Nurs Forum

latrogenic prolonged aPTT: a nondisease state

JAMA