Heparin solution in the prevention of occlusions in Hickman® catheters a randomized clinical trial

Central venous access device terminologies, complications, and reason for removal in oncology: a scoping review

BACKGROUND

Lack of agreed terminology and definitions in healthcare compromises communication, patient safety, optimal management of adverse events, and research progress. The purpose of this scoping review was to understand the terminologies used to describe central venous access devices (CVADs), associated complications and reasons for premature removal in people undergoing cancer treatment. It also sought to identify the definitional sources for complications and premature removal reasons. The objective was to map language and descriptions used and to explore opportunities for standardisation.

METHODS

A systematic search of MedLine, PubMed, Cochrane, CINAHL Complete and Embase databases was performed. Eligibility criteria included, but were not limited to, adult patients with cancer, and studies published between 2017 and 2022. Articles were screened and data extracted in Covidence. Data charting included study characteristics and detailed information on CVADs including terminologies and definitional sources for complications and premature removal reasons. Descriptive statistics, tables and bar graphs were used to summarise charted data.

RESULTS

From a total of 2363 potentially eligible studies, 292 were included in the review. Most were observational studies (n = 174/60%). A total of 213 unique descriptors were used to refer to CVADs, with all reasons for premature CVAD removal defined in 84 (44%) of the 193 studies only, and complications defined in 56 (57%) of the 292 studies. Where available, definitions were author-derived and/or from national resources and/or other published studies.

CONCLUSION

Substantial variation in CVAD terminology and a lack of standard definitions for associated complications and premature removal reasons was identified. This scoping review demonstrates the need to standardise CVAD nomenclature to enhance communication between healthcare professionals as patients undergoing cancer treatment transition between acute and long-term care, to enhance patient safety and rigor of research protocols, and improve the capacity for data sharing.

Mediport use as an acceptable standard for CAR T cell infusion

Introduction

Mediport use as a clinical option for the administration of chimeric antigen receptor T cell (CAR T cell) therapy in patients with B-cell malignancies has yet to be standardized. Concern for mediport dislodgement, cell infiltration, and ineffective therapy delivery to systemic circulation has resulted in variable practice with intravenous administration of CAR T cell therapy. With CAR T cell commercialization, it is important to establish practice standards for CAR T cell delivery. We conducted a study to establish usage patterns of mediports in the clinical setting and provide a standard of care recommendation for mediport use as an acceptable form of access for CAR T cell infusions.

Methods

In this retrospective cohort study, data on mediport use and infiltration rate was collected from a survey across 34 medical centers in the Pediatric Real-World CAR Consortium, capturing 504 CAR T cell infusion routes across 489 patients. Data represents the largest, and to our knowledge sole, report on clinical CAR T cell infusion practice patterns since FDA approval and CAR T cell commercialization in 2017.

Results

Across 34 sites, all reported tunneled central venous catheters, including Broviac® and Hickman® catheters, as accepted standard venous options for CAR T cell infusion. Use of mediports as a standard clinical practice was reported in 29 of 34 sites (85%). Of 489 evaluable patients with reported route of CAR T cell infusion, 184 patients were infused using mediports, with no reported incidences of CAR T cell infiltration.

Discussion/Conclusion

Based on current clinical practice, mediports are a commonly utilized form of access for CAR T cell therapy administration. These findings support the safe practice of mediport usage as an accepted standard line option for CAR T cell infusion.

Comparison of Heparin and Saline for Prevention of Central Venous Catheter Occlusion in Pediatric Oncology: A Systematic Review and Meta-Analysis

OBJECTIVE

The management of central venous catheter (CVC) occlusion remains an area without clear evidence-based guidelines. Studies have been conducted that compare the use of heparin and normal saline for reducing thrombosis, but the evidence is not strong enough to suggest a significant advantage of one over the other. Therefore, the study aimed to assess the effectiveness of heparin and normal saline flushing in preventing CVC occlusion in pediatric patients with cancer.

DATA SOURCES

A comprehensive search was conducted in PubMed, Web of Science, Cochrane, MEDLINE, CINAHL, Embase, World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.gov platform using specific keywords. The search was conducted until March 2022. Five randomized controlled trials are included in this study.

CONCLUSION

Five studies with a total of 316 pediatric cancer patients met the inclusion criteria. The studies were found to be heterogeneous due to variations in the types of cancer, heparin concentration, flushing frequency of CVCs, and methods used to measure occlusion. Despite these differences, there was no significant difference in the effect of flushing with heparin and normal saline in preventing CVC occlusion. The analysis revealed that normal saline is as effective as heparin in preventing CVC occlusion among pediatric cancer patients.

IMPLICATIONS FOR NURSING PRACTICE

This systematic review and meta-analysis demonstrated that there is no significant difference between the use of heparin and normal saline flushing in preventing CVC occlusion among pediatric cancer patients. Considering the potential risks of heparin, the use of normal saline flushing may be recommended to prevent CVC obstruction.

The methods for removal of direct oral anticoagulants and heparins to improve the monitoring of hemostasis: a narrative literature review

The assessment of hemostasis is necessary to make suitable decisions on the management of patients with thrombotic disorders. In some clinical situations, for example, during thrombophilia screening, the presence of anticoagulants in sample makes diagnosis impossible. Various elimination methods may overcome anticoagulant interference. DOAC-Stop, DOAC-Remove and DOAC Filter are available methods to remove direct oral anticoagulants in diagnostic tests, although there are still reports on their incomplete efficacy in several assays. The new antidotes for direct oral anticoagulants - idarucizumab and andexanet alfa - could be potentially useful, but have their drawbacks. The necessity to remove heparins is also arising as heparin contamination from central venous catheter or therapy with heparin disturbs the appropriate hemostasis assessment. Heparinase and polybrene are already present in commercial reagents but a fully-effective neutralizer is still a challenge for researchers, thus promising candidates remain in the research phase.

Heparin versus 0.9% sodium chloride locking for prevention of occlusion in central venous catheters in adults

BACKGROUND

Intermittent locking of central venous catheters (CVCs) is undertaken to help maintain their patency and performance. There are systematic variations in care: some practitioners use heparin (at different concentrations), whilst others use 0.9% sodium chloride (normal saline). This review looks at the effectiveness and safety of intermittent locking with heparin compared to normal saline, to see if the evidence establishes whether one is better than the other. This is an update of an earlier Cochrane Review.

OBJECTIVES

To evaluate the benefits and harms of intermittent locking of CVCs with heparin versus normal saline in adults to prevent occlusion.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 20 October 2021.

SELECTION CRITERIA

We included randomised controlled trials in adults ≥ 18 years of age with a CVC that compared intermittent locking with heparin at any concentration versus normal saline. We excluded studies on infants and children from this review.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were occlusion of CVCs and duration of catheter patency. Our secondary outcomes were CVC-related bloodstream infections and CVC-related colonisation, mortality, haemorrhage, heparin-induced thrombocytopaenia, CVC-related thrombosis, number of additional CVC insertions, abnormality of coagulation profile and allergic reactions to heparin. We used GRADE to assess the certainty of evidence for each outcome.

MAIN RESULTS

We identified one new RCT with 30 participants for this update. We included a total of 12 RCTs with 2422 participants. Data for meta-analysis were available from all RCTs. We noted differences in methods used by the included studies and variation in heparin concentrations (10 to 5000 IU/mL), time to follow-up (1 to 251.8 days), and the unit of analysis used (participant, catheter, line access). Five studies included ICU (intensive care unit) patients, two studies included oncology patients, and the remaining studies included miscellaneous patients (chronic kidney disease, haemodialysis, home care patients, etc.). Primary outcomes Overall, combined results may show fewer occlusions with heparin compared to normal saline but this is uncertain (risk ratio (RR) 0.70, 95% confidence interval (CI) 0.51 to 0.95; 10 studies; 1672 participants; low-certainty evidence). We pooled studies that used participant or catheter as the unit of analysis. We carried out subgroup analysis by unit of analysis. No clear differences were detected after testing for subgroup differences (P = 0.23). We found no clear evidence of a difference in the duration of catheter patency with heparin compared to normal saline (mean difference (MD) 0.44 days, 95% CI -0.10 to 0.99; 6 studies; 1788 participants; low-certainty evidence). Secondary outcomes We found no clear evidence of a difference in the following outcomes: CVC-related bloodstream infections (RR 0.66, 95% CI 0.08 to 5.80; 3 studies; 1127 participants; very low-certainty evidence); mortality (RR 0.76, 95% CI 0.44 to 1.31; 3 studies; 1100 participants; very low-certainty evidence); haemorrhage (RR 1.54, 95% CI 0.41 to 5.74; 3 studies; 1197 participants; very low-certainty evidence); or heparin-induced thrombocytopaenia (RR 0.21, 95% CI 0.01 to 4.27; 3 studies; 443 participants; very low-certainty evidence). The main reasons for downgrading the certainty of evidence for the primary and secondary outcomes were unclear allocation concealment, suspicion of publication bias, imprecision and inconsistency.

AUTHORS' CONCLUSIONS

Given the low-certainty evidence, we are uncertain whether intermittent locking with heparin results in fewer central venous catheter occlusions than intermittent locking with normal saline in adults. Low-certainty evidence suggests that heparin may have little or no effect on catheter patency duration. Although we found no evidence of differences in safety (CVC-related bloodstream infections, mortality, or haemorrhage), the combined studies were not powered to detect rare adverse events such as heparin-induced thrombocytopaenia. Further research conducted over longer periods would reduce the current uncertainties.

Monitoring of Anticoagulant Activity of Dabigatran and Rivaroxaban in the Presence of Heparins

The routine monitoring of direct oral anticoagulants (DOACs) may be considered in patients with renal impairment, patients who are heavily obese, or patients requiring elective surgery. Using the heparin-binding copolymer (HBC) and polybrene, we aimed to develop a solution for monitoring the anticoagulant activity of DOACs in human plasma in the interfering presence of unfractionated heparin (UFH) and enoxaparin. The thrombin time (TT) and anti-factor Xa activity were monitored in pooled plasma from healthy volunteers. In these tests, plasma with dabigatran or rivaroxaban was mixed with UFH or enoxaparin and then incubated with HBC or polybrene, respectively. HBC and polybrene neutralized heparins and enabled monitoring of anticoagulant activity of dabigatran in the TT test. Both agents allowed for accurate measurement of anti-factor Xa activity in the plasma containing rivaroxaban and heparins in the concentration range reached in patients’ blood. Here, we present diagnostic tools that may improve the control of anticoagulation by eliminating the contamination of blood samples with heparins and enabling the monitoring of DOACs’ activity.