Appraising the Evidence on Saline Versus Heparin Locks for Implanted Ports: A Four-Source Appraisal Matrix With Quality Ratings
[Student Name]
University of Phoenix
NSG/455: Evidence-Based Practice and Statistics
Week 4 Assignment
[Instructor Name]
[Date]
The infusion center is a composite written for a model paper; the four appraised sources are real publications, described at the level of design and main findings.
The question under appraisal is whether, for adult oncology outpatients with implanted ports, saline locks result in no higher rate of occlusion or catheter-related bloodstream infection than heparin 100 units/mL over the life of the port. The Week 2 search retained nine sources, four of them central. This paper appraises those four using a consistent matrix and rates their quality using the Johns Hopkins evidence-based practice model, in which every source receives a level reflecting its design and a letter grade, A, B or C, reflecting consistency, sample size, control of bias, soundness of conclusions and scope (Dang et al., 2021). The goal is not to decide which article is best; it is to decide how much the four together can be trusted to change practice.
Source 1: Cochrane Systematic Review
Citation and purpose. This Cochrane review assessed the effectiveness and safety of heparin compared with 0.9% sodium chloride for locking central venous catheters in adults (López-Briz et al., 2018).
Design and sample. Pooled analysis of randomized trials enrolling adults with central venous catheters, including implanted ports and other device types, across hospital and outpatient settings.
Measures and findings. The primary outcome was catheter occlusion; secondary outcomes included catheter-related bloodstream infection, duration of catheter patency, mortality and adverse events. The authors found low-certainty evidence and could not conclude that heparin was clearly superior to saline for preventing occlusion, with no clear differences in bloodstream infection or other outcomes.
Strengths. Rigorous Cochrane methods, comprehensive search, formal rating of the certainty of evidence.
Limitations. Heterogeneous devices, heparin concentrations and definitions of occlusion; several included trials were small or carried a risk of bias; results apply to central catheters broadly, not ports alone.
Level and quality. Level I, grade B (good) quality, limited by the certainty of the underlying trials.
Source 2: Randomized Non-Inferiority Trial in Cancer Patients
Citation and purpose. Goossens et al. (2013) compared normal saline with diluted heparin as lock solutions for adult cancer patients' non-valved ports, testing whether saline was non-inferior.
Design and sample. Randomized, open-label, non-inferiority trial at a single university hospital, enrolling several hundred adults with newly implanted ports and following them over the life of the device.
Measures and findings. The primary outcome concerned functional problems, particularly difficulty withdrawing blood; secondary outcomes included bloodstream infection. The authors reported that saline was non-inferior to heparin for the primary outcome, with no difference in catheter-related bloodstream infection.
Strengths. Directly matches the PICOT population and question; prespecified non-inferiority design; large sample for this field; long follow-up.
Limitations. Open label, so nurses knew the assigned solution, which could influence judgments of withdrawal problems; single center; non-valved ports only.
Level and quality. Level II, grade A (high) quality for the question, with the blinding limitation noted.
Source 3: Multicenter Randomized Trial
Citation and purpose. Dal Molin et al. (2015) compared normal saline with heparin solution for locking implanted ports.
Design and sample. Multicenter randomized trial in several Italian oncology centers, enrolling adults with implanted ports.
Measures and findings. The main outcome was port occlusion. The authors reported no significant difference in occlusion between saline and heparin locks, supporting saline as an alternative.
Strengths. Multicenter design increases generalizability; population matches the PICOT question.
Limitations. Designed and reported as a comparison rather than a formal non-inferiority test with a prespecified margin, so a nonsignificant difference cannot be read as proof of equivalence; blinding not possible for staff; event numbers modest.
Level and quality. Level II, grade B (good) quality.
Source 4: National Infusion Standards
Citation and purpose. Gorski et al. (2021), writing for the Infusion Nurses Society, published standards of practice for infusion therapy, including flushing and locking of vascular access devices.
Design. Expert-developed clinical practice standards, with each recommendation graded by the strength of its supporting evidence.
Findings. The standards address locking solutions for central devices, recognizing that both heparin and preservative-free saline are used, directing clinicians to follow manufacturers' directions for use and organizational policy and noting the limited evidence that heparin is superior for all devices.
Strengths. Authoritative, widely adopted in U.S. practice, recent, evidence-graded.
Limitations. Not original research; recommendations are broad across device types.
Level and quality. Level VII in the research hierarchy as expert guidance, rated high quality as a clinical practice guideline.
Sources Considered and Set Aside
Five other retained sources were reviewed but given less weight. Two small single-center trials compared heparin and saline in mixed central line populations, with too few events to inform the question. Two observational before-and-after reports described centers that switched to saline and saw no rise in occlusions, but without control groups they cannot separate the effect of the switch from other changes over time. One pediatric trial was excluded from the synthesis because children's ports and heparin dosing differ. Documenting why these sources carry less weight prevents the synthesis from quietly counting weak studies as if they were strong, and it shows that the conclusion does not depend on them.
Summary Across Sources
The four sources are consistent in direction. The Cochrane review found no clear advantage of heparin for central catheters generally, with low-certainty evidence. Two randomized trials in patients with implanted ports found saline non-inferior or not significantly different for occlusion, with no difference in infection. The national standards allow either solution and emphasize following device instructions. Using the Johns Hopkins criteria, the body of evidence is consistent, includes adequately sized trials in the target population and supports a conclusion of good overall strength that saline locking of implanted ports is a reasonable alternative to heparin (Dang et al., 2021).
The evidence has gaps. No trial was blinded, occlusion definitions varied and valved and non-valved ports may behave differently. The center should check the manufacturer's instructions for the specific ports it uses before changing practice.
Conclusion
Appraising four key sources with a consistent matrix and a named quality model showed a coherent body of evidence: a systematic review with no clear advantage for heparin, two randomized trials supporting saline for implanted ports and national standards that accept either solution. The evidence is strong enough to consider a practice change, with attention to device instructions and to measuring outcomes after the change, which the Week 5 synthesis will propose.
References
Dal Molin, A., Clerico, M., Baccini, M., Guerretta, L., Sartorello, B., & Rasero, L. (2015). Normal saline versus heparin solution to lock totally implanted venous access devices: Results from a multicenter randomized trial. European Journal of Oncology Nursing, 19(6), 638-643. https://doi.org/10.1016/j.ejon.2015.04.001
Dang, D., Dearholt, S. L., Bissett, K., Ascenzi, J., & Whalen, M. (2021). Johns Hopkins evidence-based practice for nurses and healthcare professionals: Model and guidelines (4th ed.). Sigma Theta Tau International.
Goossens, G. A., Jerome, M., Janssens, C., Peetermans, W. E., Fieuws, S., Moons, P., Verschakelen, J., Peerlinck, K., Jacquemin, M., & Stas, M. (2013). Comparing normal saline versus diluted heparin to lock non-valved totally implantable venous access devices in cancer patients: A randomised, non-inferiority, open trial. Annals of Oncology, 24(7), 1892-1899. https://doi.org/10.1093/annonc/mdt114
Gorski, L. A., Hadaway, L., Hagle, M. E., Broadhurst, D., Clare, S., Kleidon, T., Meyer, B. M., Nickel, B., Rowley, S., Sharpe, E., & Alexander, M. (2021). Infusion therapy standards of practice, 8th edition. Journal of Infusion Nursing, 44(1S), S1-S224. https://doi.org/10.1097/NAN.0000000000000396
López-Briz, E., Ruiz Garcia, V., Cabello, J. B., Bort-Martí, S., Carbonell Sanchis, R., & Burls, A. (2018). Heparin versus 0.9% sodium chloride locking for prevention of occlusion in central venous catheters in adults. Cochrane Database of Systematic Reviews, 2018(7), Article CD008462. https://doi.org/10.1002/14651858.CD008462.pub3
How this NSG 455 Week 4 example is structured
The NSG/455 shelf page describes Week 4 as article appraisal, sometimes split across a learning team matrix. The paper presents each source under the same headings so the sources can be compared, rates quality with a named appraisal model and ends with a cross-source summary, because appraisal is only useful when it tells the reader how much confidence the whole body of evidence deserves. Findings are described at the level each source reports them, without adding precision the sources do not provide. Students search this week as NSG 455 Week 4, NSG455 Wk 4 or NSG/455 Wk 4; all three are the same assignment.
NSG/455 Week 4 questions, answered
What does NSG/455 Week 4 usually ask for?
The course shelf describes Week 4 as article appraisal, sometimes in a learning team matrix. Many sections ask you to appraise the research articles found for your PICOT question using a structured tool, rating their level and quality and summarizing their findings.
What goes in an appraisal matrix?
Typically the citation, purpose, design, sample and setting, intervention and comparison, outcome measures, main findings, strengths, limitations, level of evidence and quality rating. Using the same columns for every source makes comparison possible.
What is the difference between level and quality of evidence?
Level refers to the design, such as a randomized trial or a systematic review. Quality refers to how well that particular study was conducted and reported. A randomized trial is high level but can be low quality if it has serious flaws.
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