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procedural process of how aPTT samples are obtained from patients with central
lines while Heparin is concurrently infusing.
A nursing team was formed to complete this EBP project to address the practice
of drawing aPTT samples from central lines. The team included adult medicine
nurses working on the progressive care unit, the unit educator, and the director
of professional practice. The EBP question was this: In an adult hospitalized pa-
tient, what are the best-known practices for drawing blood from a central line to
obtain an aPTT sample while Heparin is concurrently being infused?
Evidence
A literature search was conducted using PubMed, CINAHL, Cochrane, and JBI
with the assistance of the medical librarian. Twenty-one articles were identified
from the search, and 12 articles were appraised using the tools from the JHNEBP
Model. There were 10 Level II articles and 2 Level IV articles. Overall, the find-
ings showed that blood sample contamination influences aPPT results. Examples
of techniques to prevent blood sample contamination may be flushing the line,
providing a sufficient waiting period, and discarding enough blood before a sam-
ple is obtained. It was recommended to obtain aPTT samples from the peripheral
venipuncture, if possible, and to use central lines with Heparin infusing as a last
resort. Additionally, a step-by-step process based on evidence must be followed.
Findings showed that the median aPTT difference when a specimen was obtained
from a central line with a Heparin infusion port was –20.5 seconds (p=.008).
Translation
Based on the evidence, peripheral venipuncture is recommended as the first op-
tion, and CVAD with Heparin infusing should be used as the last resort. Because
of the infrequent use of CVAD lines in obtaining specimens, practice needed to
be changed by following the step-by-step process based on evidence to prevent
blood contamination. A guideline was adopted to obtain aPTT samples from
patients with central lines with a Heparin infusion. The new guideline was pre-
sented and approved by the practice and leadership councils.
