National survey of central venous catheter flushing in the intensive care unit

Flushing in Intravenous Catheters: Observational Study of Nursing Practice in Intensive Care in Brazil

An observational study was developed with 108 nursing professionals who managed vascular access devices in 4 intensive care units of a university hospital in Rio de Janeiro, Brazil. The objective was to analyze the practice of the nursing staff in performing flushing for the maintenance of vascular access devices in critically ill patients. Data were collected by observing the flushing procedure using a structured checklist and analyzed using descriptive and inferential statistics. In 23% of the 404 observations, there was no flushing. When performed at some point during catheter management (77%), flushing was predominant after drug administration with 1 or 2 drugs administered. There were flaws in the flushing technique applied in terms of volume and method of preparation. Time of professional experience >5 years, knowledge about recommendations, and training on flushing were variables associated with technique performance. It was concluded that the flushing procedure did not meet the recommendations of good practices, with failures that constituted medication errors.

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.

“Evidence On Port-locking With Heparin versus Saline in Cancer Patients Not Receiving Chemotherapy. Randomized Clinical Trial”

Objective

To assess the safety and efficacy of port-locking with heparin every 2 months vs. every 4 months and vs. saline solution every 2 months in patients with cancer not receiving active chemotherapy. The hypothesis stated that locking with heparin at four-month intervals and saline at two-month intervals would not increment > 10% of port obstructions.

Methods

Multicentre, phase IV parallel, post-test control group study took place at the two chemotherapy units of oncology hospitals. Included patients with cancer with ports that completed the chemotherapy treatment but still having port maintenance care or blood samples taken up to four months. A sample of 126 patients with cancer in three arms was needed to detect a maximum difference of 10% for bioequivalence on the locking methods. Consecutive cases non-probabilistic sampling and randomized to one of the three groups; group A: received heparin 60 IU/mL every two months (control) vs. group B heparin every four months and vs. saline every two months in group C. Primary variables were the type of locking regimen, port obstruction, and absence of blood return, port-related infection, or venous thrombosis during the study period. Clinical and sociodemographic variables were also collected.

Results

A total of 143 patients were randomly assigned; group A, 47 patients with heparin every 2 months, group B, 51 patients with heparin 4 months, and group C, 45 patients with saline every 2 months. All participants presented an adequate blood return and no obstructions, until the month of the 10th, when one participant in the group A receiving was withdrawn due to an absence of blood flow (P ​= ​0.587).

Conclusions

Port locks with heparin every 4 months or saline every 2 months did not show differences in safety maintenance, infection, or thrombosis compared to heparin every 2 months.

What do we know about flushing for intravenous catheter maintenance in hospitalized adults?

ABSTRACT Objective: to evidence the use of flushing to prevent complications from intravenous therapy. Methods: an integrative review in databases, using descriptors and selection criteria. Data were collected in 12 articles using an instrument and later classified, summarized and aggregated for knowledge synthesis. Results: it was evident that: the pre-filled syringe resulted in a lower occurrence of catheter obstruction; irregular flushing frequency caused advanced phlebitis; the use of Venous Arterial Blood Management Protection (VAMP) generated a lower incidence of blood infection; heparinized solution did not result in a lower central catheter failure rate; flushing volume and frequency were not predictors of catheter failure; flushing practice was not shown to be incorporated among professionals. Conclusion: there are disagreements about the volume, frequency, solution and devices used in flushing. New technologies can reduce complications such as obstruction and infection.

Chinese expert consensus and practice guideline of totally implantable access port for digestive tract carcinomas

Totally implantable access port is a fully implantable drug delivery system that is implanted subcutaneously and can be retained for a long time. Advantages of ports include a simple nursing process, low risk of infection and embolism, and high patient comfort. In order to promote the standardized application of ports in the treatment of digestive tract tumors and reduce port-related complications, the Chinese Research Hospital Association Digestive Tumor Committee, the Chinese Association of Upper Gastrointestinal Surgeons, the Chinese Gastric Cancer Association, and the Gastrointestinal Surgical Group of Chinese Surgical Society Affiliated to Chinese Medical Association have organized multidisciplinary expert discussions at the General Hospital of the People's Liberation Army and nation-wide expert letter reviews and on-site seminars, and formulated an expert consensus of the operation guidelines.

Examination of nursing drug administration practices via central venous catheter: An observational study

AIM

To determine the compliance with nursing drug administration procedure steps associated with access to the central venous catheter for bolus infusion in intensive care units.

METHODS

This observational study was conducted with 30 nurses working in an intensive care unit of a university hospital. The drug administrations practiced by nurses via central venous catheter were monitored simultaneously at 12:00 a.m., 02:00 p.m., and 06:00 p.m. by two observers. The data were collected using a data collection form and central venous catheter drug administration procedure steps.

RESULTS

A total of 90 different drug administrations were observed in three different treatment hours from 30 nurses. The interobserver conformity was found to be moderate in two steps (kappa = 0.520-0.627, P = 0.01) and perfect in all other steps (kappa = 0.821-1.000, P = 0.000). According to the drug administration procedure steps via a central venous catheter, all nurses applied the following steps correctly during all treatment hours: drug card control, preparation of treatment materials, checking the patient's identity, and steps of drug treatment administration. The following tasks were frequently performed incorrectly or not at all: hand hygiene (before treatment 87.8%; after treatment 82.2%), scrubbing the three-way stopcock entrance with an alcohol swab (55.6%), waiting for the alcohol to dry (81.1%), and flushing the lumen with a compatible fluid (before treatment 84.4%: after treatment 75.6%).

CONCLUSION

Observation of drug administration procedure steps via central venous catheter according to the treatment hours showed that the nurses performed many incomplete or inaccurate drug administration procedure steps and the mistakes increased toward the evening hours.

Heparin flush vs. normal saline flush to maintain the patency of central venous catheter among adult patients: A systematic review and meta-analysis

BACKGROUND

Around the globe, protocols for flushing the catheter to maintain the patency of central venous catheter (CVC) vary by institution to institution or by practitioner to practitioner. Therefore, this review was carried out with the aim of evaluating the efficacy of heparin flush vs. normal saline flush to maintain the patency of CVC among adult patients.

METHODS

We followed the guidelines of Cochrane handbook for interventions and searched in MEDLINE, Embase, Cochrane library, Clinical trials database, and reference list of related articles, which were published from Jan. 2012 to 31 Dec. 2018 in English language. We included only randomized controlled trials, and nine studies were included in this review. The pooled standard mean difference and relative risk were calculated by using Rev Man Review Manager 5.

RESULTS

We identified nine eligible studies with a total number of 3,113 participants. Consolidated results from eight studies conveyed little favorable effect to maintain patency of CVC with heparin when compared with normal saline as evident by risk ratio 0.83, 95% CI 0.50 - 1.40; P = 0.13. We also carried out analysis for secondary outcomes, and there was no evidence that heparin was better than normal saline in terms of safety except heparin-induced thrombocytopenia.

CONCLUSIONS

Heparin has little favorable effects to maintain patency of catheter than normal saline but not in secondary outcomes. As the quality of evidence was very low, therefore, results should be comprehend with care.

Implanted vascular access device options: a focused review on safety and outcomes

Implantable vascular access devices are frequently used in patients who have poor peripheral venous access. These devices can be partially implanted as tunneled and nontunneled central catheters, or they can be fully implanted as ports. Compared with long-term catheters, implanted ports have lower infection rates and improved perceptions of quality of life, but complications still occur in 2% to 18% of patients, frequently requiring removal of the device. Since the conception of implantable vascular access device ports, numerous advances in port design, materials, and techniques for implantation and care have been developed with the goal of overcoming frequent complications. We review the evidence related to these advances and their effect on the safety profile and complications of implantable vascular access device ports.

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. There are systematic variations in care: some practitioners use heparin (at different concentrations), whilst others use 0.9% NaCl (normal saline). This review looks at the effectiveness and safety of intermittent locking with heparin compared to 0.9% NaCl to see if the evidence establishes whether one is better than the other. This work is an update of a review first published in 2014.

OBJECTIVES

To assess the effectiveness and safety of intermittent locking of CVCs with heparin versus normal saline (NS) in adults to prevent occlusion.

SEARCH METHODS

The Cochrane Vascular Information Specialist (CIS) searched the Specialised Register (last searched 11 June 2018) and the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 5). Searches were also carried out in MEDLINE, Embase, CINAHL, and clinical trials databases (11 June 2018).

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 NS. We applied no restriction on language.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, assessed quality, and extracted data. We contacted trial authors to retrieve additional information, when necessary. We carried out statistical analysis using Review Manager 5 and assessed the overall quality of the evidence supporting assessed outcomes using GRADE. We carried out prespecified subgroup analysis.

MAIN RESULTS

We identified five new studies for this update (six prior studies were included in the original review), bringing the number of eligible studies to 11, with a total of 2392 participants. 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).Combined results from these studies showed fewer occlusions with heparin than with NS (risk ratio (RR) 0.70, 95% confidence interval (CI) 0.51 to 0.95; P = 0.02; 1672 participants; 1025 catheters from 10 studies; I² = 14%) and provided very low-quality evidence.We carried out subgroup analysis by unit of analysis (testing for subgroup differences (P = 0.23; I² = 30.3%). When the unit of analysis was the participant, results show no clear differences in all occlusions between heparin and NS (RR 0.79, 95% CI 0.58 to 1.08; P = 0.15; 1672 participants; seven studies). Subgroup analysis using the catheter as the unit of analysis shows fewer occlusions with heparin use (RR 0.53, 95% CI 0.29 to 0.95; P = 0.03; 1025 catheters; three studies). When the unit of analysis was line access, results show no clear differences in occlusions between heparin and NS (RR 1.08, 95% CI 0.84 to 1.40; 770 line accesses; one study).We found no clear differences in the duration of catheter patency (mean difference (MD) 0.44 days, 95% CI -0.10 to 0.99; P = 0.11; 1036 participants; 752 catheters; six studies; low-quality evidence).We found no clear evidence of a difference in the following: CVC-related sepsis (RR 0.74, 95% CI 0.03 to 19.54; P = 0.86; 1097 participants; two studies; low-quality evidence); mortality (RR 0.76, 95% CI 0.44 to 1.31; P = 0.33; 1100 participants; three studies; low-quality evidence); haemorrhage at any site (RR 1.32, 95% CI 0.57 to 3.07; P = 0.52; 1245 participants; four studies; moderate-quality evidence); or heparin-induced thrombocytopaenia (RR 0.21, 95% CI 0.01 to 4.27; P = 0.31; 443 participants; three studies; low-quality evidence).The main reasons for downgrading the quality of evidence were unclear allocation concealment, imprecision, and suspicion of publication bias.

AUTHORS' CONCLUSIONS

Given the very low quality of the evidence, we are uncertain whether intermittent locking with heparin results in fewer occlusions than intermittent locking with NS. Low-quality evidence suggests that heparin may have little or no effect on catheter patency. Although we found no evidence of differences in safety (sepsis, mortality, or haemorrhage), the combined trials are not powered to detect rare adverse events such as heparin-induced thrombocytopaenia.

Normal saline versus heparin for patency of central venous catheters in adult patients - a systematic review and meta-analysis

BACKGROUND

Heparin saline (HS) is theoretically superior to normal saline (NS) for maintaining the patency of central venous catheters (CVCs), but the comparative efficacy of them remains controversial. The aim of this systematic review and meta-analysis was to assess the efficacy of NS versus HS in the maintenance of the patency of CVCs in adult patients.

METHODS

We searched PubMed, Embase and the Cochrane library databases. Randomized controlled trials (RCTs) evaluating the use of NS vs. HS to maintain the permeability of CVCs among adult patients were included in our meta-analysis. References of relevant papers were reviewed manually. No language restriction was applied. Non-human studies were excluded. Pooled relative risk (RR) was calculated using a Mantel-Haenszel random-effects model. We also performed subgroup analysis examining the effect of the duration of catheter placement on the outcome. All statistical tests were two-sided using a significance level of 0.05.

RESULTS

Ten RCTs involving 7875 subjects (with analysis at patient, catheter, lumen and line access level) were included in this meta-analysis. Whether in terms of pooled or local analysis (RR with 95% confidence interval spans 1), NS can be equally, if not more effective, in keeping the CVCs open. Of studies reporting secondary outcomes (maneuver needed, heparin-induced thrombocytopenia, haemorrhage, central venous thrombosis and catheter-related bloodstream infection), heparinised saline was shown not to be superior to non-heparinised solution. Subgroup analysis in patients with short vs long term CVC placement was consistent with the main outcome partly and in particular for maintenance of catheter patency in patients with a long-term placement i.e. >30 days, the RR was 0.97 (n = 6589; 95% CI = 0.76 to 1.23; P = 0.796). However, for patients in whom the catheter was in place for <30 days, the RR was 1.52 (n = 1286; 95% CI = 1.02 to 2.27; P = 0.041).

CONCLUSIONS

Based on the results of this meta-analysis, HS is not superior to NS in reducing CVCs occlusion. But in the short term, the use of HS is slightly superior to NS for flushing catheters from a statistical point of view.

[Effectiveness of heparin versus 0.9% saline solution in maintaining the permeability of central venous catheters: a systematic review]

OBJECTIVE

Determining which is the most effective solution (heparin flush compared to 0.9% saline flush) for reducing the risk of occlusions in central venous catheters (CVC) in adults.

METHOD

The systematic review followed the principles proposed by the Cochrane Handbook; critical analysis, extraction and synthesis of data were performed by two independent researchers; statistical analysis was performed using the RevMan program 5.2.8.

RESULTS

Eight randomized controlled trials and one cohort study were included and the results of the meta-analysis showed no difference (RR=0.68, 95% CI=0.41-1.10; p=0.12). Analysis by subgroups showed that there was no difference in fully deployed CVC (RR=1.09, CI 95%=0.53-2.22; p=0.82); Multi-Lumen CVC showed beneficial effects in the heparin group (RR=0.53, CI 95%=0.29-0.95; p=0.03); in Double-Lumen CVC for hemodialysis (RR=1.18, CI 95%=0.08-17.82; p=0.90) and Peripherally inserted CVC (RR=0.14, CI 95%=0.01-2.60; p=0.19) also showed no difference.

CONCLUSION

Saline solution is sufficient for maintaining patency of the central venous catheter, preventing the risks associated with heparin administration.

Flushing and Locking of Venous Catheters: Available Evidence and Evidence Deficit

Flushing and locking of intravenous catheters are thought to be essential in the prevention of occlusion. The clinical sign of an occlusion is catheter malfunction and flushing is strongly recommended to ensure a well-functioning catheter. Therefore fluid dynamics, flushing techniques, and sufficient flushing volumes are important matters in adequate flushing in all catheter types. If a catheter is not in use, it is locked. For years, it has been thought that the catheter has to be filled with an anticoagulant to prevent catheter occlusion. Heparin has played a key role in locking venous catheters. However, the high number of risks associated with heparin forces us to look for alternatives. A long time ago, 0.9% sodium chloride was already introduced as locking solution in peripheral cannulas. More recently, a 0.9% sodium chloride lock has also been investigated in other types of catheters. Thrombolytic agents have also been studied as a locking solution because their antithrombotic effect was suggested as superior to heparin. Other catheter lock solutions focus on the anti-infective properties of the locks such as antibiotics and chelating agents. Still, the most effective locking solution will depend on the catheter type and the patient's condition.

Normal saline versus heparin solution to lock totally implanted venous access devices: Results from a multicenter randomized trial

PURPOSE

Our aim was to determine the non-inferiority of normal saline flushing compared to heparin flushing in maintaining the patency of totally implanted venous access devices (TIVADs).

METHOD

Four hundred and thirty patients were recruited from 14 Italian centres. Patients were randomized to heparin group or to normal saline group. The primary outcome of the study was TIVAD occlusion.

RESULTS

After randomisation, 203 patients were assigned to normal saline group and 212 to heparin group. Median follow up time was 204 days in normal saline group and 294 in the heparin group. We observed 24 withdrawal occlusions (5.78%): 10 in the heparin group and 14 in the normal saline group. One total occlusion was observed in the normal saline group. Taking as reference the arm treated with heparin, the absolute risk difference was 2.67 with the 90% CI including the non - inferiority margin of 4%. No significant difference between hazards of occlusion was found.

CONCLUSIONS

This study failed to demonstrate that normal saline flushing is not inferior to heparin flushing, even if a significant difference between the two treatments was not found. The use of heparin is controversial and other prospective trials are necessary in this field.

TRIAL REGISTRATION

EudraCT number: 2009-013620-22.

The establishment and evaluation of rabbit model for peripherally inserted central catheter

PURPOSE

To establish a model to simulate the clinical specific process of peripherally inserted central catheter (PICC) on rabbits, and detect how long the catheter can be indwelled.

METHODS

Seventeen healthy New Zealand white rabbits were inserted the PICC according to the clinical specific procedure. With the principle of random, the rabbits were divided into four groups (14d, 21d, 28d, 35d). Each group contains four rabbits, and Group 1 was served as blank control group. When finishing the experiment, we took the blood vessels which was inserted the catheter and observed the changes of vascular endothelium using the Hematoxylin-Eosin (HE) staining.

RESULTS

90% animals were succeeded in inserting PICC. Early signs of endovascular inflammation were predominantly neutrophils, then mainly monocytes, visible fibrous tissue hyperplasia of the vessel wall, vascular endothelial proliferation and granuloma formation. And after that the irreversible changes in the blood vessels could be observed, especially five weeks after catheterization.

CONCLUSIONS

We have succeeded in establishing the rabbit model for peripherally inserted central catheter, and provided a new way for nursing teaching and training. Since the irreversible changes of the vascular endothelium, it is recommended that the time of indwelling is not more than five weeks on animal.

Comparison of the effects of heparin and 0.9% sodium chloride solutions in maintenance of patency of central venous catheters

BACKGROUND

Occlusion of central venous catheters is one of the limiting factors in using them. Heparinized saline solution is the standard solution used for keeping the catheters open.

OBJECTIVES

This study aimed to determine the effect of heparin saline solution and normal saline in maintenance of patency of central venous catheters.

PATIENTS AND METHODS

This double-blind study was performed on 84 patients of intensive care unit who had central venous catheters. The patients were randomly divided into two groups of heparin saline receivers and normal saline receivers. In the heparin group after each drug injection into the lumen, 3 mL of heparin saline solution was injected in the catheter as well. The other group only received 10 mL of normal saline instead. The catheters were examined for blood return and flushing every eight hours for 21 days. Data was analyzed using SPSS software version 20 and descriptive and analytic statistics were studied.

RESULTS

There was no significant difference in the rate of flushing (P = 0.872) and possibility of taking blood samples from catheters (P = 0.745) in the two groups of heparin and normal saline receivers. Furthermore, using heparin had no effect on prolonging the survival of catheters.

CONCLUSIONS

Considering possible side effects of heparin and the increase in treatment charges and the fact that using heparin did not have a significant effect on patency and survival of catheters in the studied patients, it is recommended to use normal saline solution to maintain the patency of central venous catheters.

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

BACKGROUND

Heparin intermittent flushing is a standard practice in the maintenance of patency in central venous catheters. However, we could find no systematic review examining its effectiveness and safety.

OBJECTIVES

To assess the effectiveness of intermittent flushing with heparin versus 0.9% sodium chloride (normal saline) solution in adults with central venous catheters in terms of prevention of occlusion and overall benefits versus harms.

SEARCH METHODS

The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched December 2013) and the Cochrane Central Register of Controlled Trials (CENTRAL) (2013, Issue 11). Searches were also carried out in MEDLINE, EMBASE, CINAHL and clinical trials databases (December 2013).

SELECTION CRITERIA

Randomised controlled trials (RCTs) in adults 18 years of age and older with a central venous catheter (CVC) in which intermittent flushing with heparin (any dose with or without other drugs) was compared with 0.9% normal saline were included. No restriction on language was applied.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, assessed trial quality and extracted data. Trial authors were contacted to retrieve additional information, when necessary.

MAIN RESULTS

Six eligible studies with a total of 1433 participants were included. The heparin concentrations used in these studies were very different (10-5000 IU/mL), and follow-up varied from 20 days to 180 days. The overall risk of bias in the studies was low. The quality of the evidence ranged from very low to moderate for the main outcomes (occlusion of CVC, duration of catheter patency, CVC-related sepsis, mortality and haemorrhage at any site).Combined findings from three trials in which the unit of analysis was the catheter suggest that heparin was associated with reduced CVC occlusion rates (risk ratio (RR) 0.53, 95% confidence interval (CI) 0.29 to 0.94). However, no clear evidence of a similar effect was found when the results of two studies in which the unit of analysis was the participant were combined (RR 0.21, 95% CI 0.03 to 1.70), nor when findings were derived from one study, which considered total line accesses (RR 1.08, 95% CI 0.84 to 1.40). Furthermore, results for other estimated effects were found to be imprecise and compatible with benefit and harm: catheter duration in days (mean difference (MD) 0.41, 95% CI -1.29 to 2.12), CVC-related thrombosis (RR 1.22, 95% CI 0.74 to 1.99), CVC-related sepsis (RR 1.02, 95% CI 0.34 to 3.03), mortality (RR 0.77, 95% CI 0.45 to 1.32) and haemorrhage at any site (RR 1.37, 95% CI 0.49 to 3.85).

AUTHORS' CONCLUSIONS

We found no conclusive evidence of important differences when heparin intermittent flushing was compared with 0.9% normal saline flushing for central venous catheter maintenance in terms of efficacy or safety. As heparin is more expensive than normal saline, our findings challenge its continued use in CVC flushing outside the context of clinical trials.

Flushing the central venous catheter: is heparin necessary?

PURPOSE

The aim of this systematic review was to assess the efficacy of heparin flushing in the lock of central venous catheters.

METHODS

We searched MEDLINE and CINAHL databases. Eligible studies were randomized controlled trials evaluating the use of heparin versus normal saline or other solution in the flushing of central catheter among adult patients. No language restrictions were applied. Two reviewers independently screened titles and abstracts in order to identify relevant publications. The same two reviewers retrieved and evaluated full texts. Parameter estimates regarding catheter occlusion were pooled using network meta-analysis with Bayesian hierarchical modeling.

RESULTS

We identified 462 references. Eight studies were included. There was no evidence that heparin was more effective than normal saline in reducing occlusions. It was unclear whether urokinase and lepirudin were more effective than heparin in reducing occlusions. Vitamin C solution does not appear to prolong catheter patency.

CONCLUSIONS

There is no evidence of a different effectiveness between heparin flushing and normal saline or other solutions in reducing catheter occlusions. Due to the little and inconclusive evidence available in this field, further studies might be necessary.