Millions of intravenous cannulas are used in the UK each year. The use of pre-filled syringes of sodium chloride 0.9% for flushing IV cannulas and vascular access devices has been prevalent for more than 10 years, but what is their legal status?
Whether organisations have reviewed the risks associated with flushing IV cannulas, and done enough to address the legal position by reviewing policies, protocols and practice and adequately addressing the steps involved in safely implementing their use in practice, is not clear.
A peripheral intravenous cannula is a CE-marked medical device (the CE mark indicates that the device conforms to European legal requirements). It is inserted into a peripheral vein (eg hands and arms) for therapeutic purposes, such as administering medications, fluids and blood products. In paediatric patients, veins of the feet are used, but these sites are usually avoided in adult patients to prevent embolism and thrombophlebitis (Dougherty and Lister, 2015). In all instances, cannulas need to be ‘flushed’ with an appropriate solution to maintain patency and ensure any residual medication is ‘flushed’ away or removed after administration.
Figures vary greatly, but some suggest that almost 60% of all patients will have an intravenous cannula in situ during their treatment or stay in a hospital or healthcare setting. (Alexandrou et al, 2018). A large NHS hospital can expect to carry out many hundreds of thousands of IV cannula flushes each year. Prescribing and documenting each occurrence will significantly impact on staff time and may be too cumbersome to manage.
An integral part of their safe use and ongoing management is that cannulas are flushed (with an appropriate solution):
- After insertion
- After each use to help avoid the risk of accidental infusion of any residual medication (Healthcare Safety Investigation Branch (HSIB), 2021)
- At regular intervals to help maintain patency and reduce the chance of cannula occlusions (Royal College of Nursing (RCN), 2016)
Regardless of the type of peripheral intravenous cannula used, four basic principles of care for the device remain the same:
- Minimise infection risk by always using the A N T T® Aseptic Non-Touch Technique (Association for Safe Aseptic Practice, 2019)
- Maintain a ‘closed’ intravenous system with minimal connections to reduce the risk of contamination
- Maintain a patent and correctly positioned cannula
- Prevent damage to the device and associated intravenous equipment.
All intravenous peripheral cannulas should be inserted, accessed, maintained and removed using ANTT and standard infection control precautions. Health professionals should also adhere to their employer's policy and current guidelines relating to the health and safety sharps regulations (Health and Safety Executive, 2013) and procedures for the Control of Substances Hazardous to Health (COSHH) regulations 2002, regulation 7 (https://tinyurl.com/3ka5m5ub).
All health professionals carrying out the procedure are fully accountable and responsible for safe practice in the insertion and removal of devices and have a professional duty to maintain their knowledge and skill. It is their responsibility to ensure that they undertake this role competently and with the required clinical skills. Cannulation should always be carried out on the request of a registered practitioner. This request could be from a medical practitioner or a registered practitioner who is acting upon specific approved protocols and guidelines. The cannula should be flushed regularly, and the insertion site checked for redness, swelling and signs of infection. A suitable Visual Infusion Phlebitis score (VIP), created by Jackson (1998), should be used to record the cannula site observation and VIP score.
Common fluids used for flushing
Traditionally a solution of ‘heparinised saline’ for the effective flushing of IV cannulas was recommended. However, apart from a few specific areas, its use has been superseded by 0.9% sodium chloride, which has been shown to be equally effective and also mitigates the risks associated with using heparin (Loveday et al, 2014; Sotnikova et al, 2020).
Today, the most common fluid administered as an IV flush is sodium chloride 0.9% due to its compatibility with many IV drugs and fluids. It is purchased and stocked as small plastic or glass ampoules, and is legally classified as a prescription-only medicine (PoM) because of the intended IV route of administration. Legislation, supported by employers' policies, stipulates that an appropriate, authorised practitioner must prescribe all PoMs for administration to patients.
Alternative arrangements include using a patient specific direction (PSD) or a patient group direction (PGD). Although commonly employed for flushing arrangements, a PGD has legal restrictions regarding which groups of staff can operate under the direction. A PGD cannot be delegated and only applies to certain groups of registered health professionals and excludes other staff groups (such as healthcare support workers, physician assistants and operating department practitioners). Documentation of administration must be made and retained using authorised records (such as a medicine prescription, in-patient administration chart, patient notes or other formal recognised recording methods), according to the Medicines Act 1968.
Several healthcare organisations in the UK have an accepted practice for administering IV flushes, using pre-filled syringes of 0.9% sodium chloride (licensed as a CE-marked medical device), without a formal prescription or administration record. They have accepted the use of such devices as part of the routine flushing of patients' IV cannulas, during insertion, for maintenance and pre- and post-IV medication, requiring a 0.9% sodium chloride flush. However, when using sodium chloride injection 0.9% ampoules as an IV flush (that is a PoM), the administration must be supported by an appropriate prescription and recorded on the appropriate documentation.
Governance in Swansea Bay University Health Board
In Swansea Bay University Health Board, more than 300 000 IV cannulas are purchased each year. Intravenous infusions account for more than 200 000 IV infusions, and this includes IV bolus, gravity and intermittent infusions, and those delivered via medical infusion pumps.
Intravenous infusions are a high-risk procedure, and patients are exposed to the risk of infection and error in each step of the process of administration. This process is safely managed, and risks mitigated, using a range of safety products, controlled processes undertaken by trained and competent staff. The products used for the safe flushing of peripheral IV cannulas and pre- and post-infusion of IV medications as used in the authors' health board are shown in Table 1.
Table 1. Components used for manually preparing an IV flush
|Item||Item description||Order via|
|1||10 ml sterile Luer slip syringe||Central stores|
|2||10 ml ampoule 0.9% sodium chloride||Pharmacy|
|3||70% alcohol wipe for cleaning ampoule before use||Pharmacy|
|4||18G blunt fill needle to withdraw from an ampoule||Central stores|
|5||Obturator (end stop) to ensure syringe sterility||Central stores|
Note: ANTT allows for sterile packaging to be used instead of an obturator to protect key-parts
When comparing the number of products and steps required to draw up an IV flush manually versus a pre-filled alternative, it is clear that a ready-made (pre-filled) device reduces the chances of wrong product selection and potential contamination.
An adequate volume—at least twice the internal volume of the extension set plus the cannula (Infusion Nurses Society, 2011; RCN, 2016)—is an important consideration in IV therapy. The administration of 5 ml for adults or 2 ml for small gauge (in paediatrics) of 0.9% sodium chloride flush (where compatible) is an integral part of peripheral IV cannulation and ongoing management for IV medications (pre- and post-administration flush). To help maintain the standard practice, the volumes shown in Table 2 are administered using a 10 ml diameter syringe to reduce pressure.
Table 2. Volumes for flushing cannula, lines and IV medications
|Cannula insertion||Volume||Flushing pre- and post-IV||Volume|
|Adult IV cannulation (flush)||5 ml||IV administration via cannula||5 ml pre- and post-|
|Paediatric small gauge or fluid restricted: IV cannulation (flush)||2 ml||Small gauge or fluid restricted IV administration||2 ml pre- and post-|
Note: the use of a 10ml diameter syringe reduces overall force and pressure when flushing cannula and IV devices
Health professional employees must check IV flushes in line with their current employer's policy. The syringe tip must be either protected from touch-contamination using a sterile single-use cap or returned to its original packaging before use. ANTT must be maintained throughout this process.
Issues of risk
For all systems of work, there are inherent risks, and IV flushing is no different. There are many steps required (Table 3) in current practice when drawing up, preparing and administering the IV flush. In some instances, this process is also a two-practitioner procedure as there is an additional risk of inadvertent drug selection and dose calculation. For example, any small ampoule used on the ward could be inadvertently picked up and used in the preparation of IV medications, such as ‘sterile water for injection’ ampoules and potassium (which could lead to fatalities) (Welsh Assembly Government, 2002)
Table 3. Steps required to draw up an IV flush
|Number of steps required to prepare, draw up and label an IV flush|
|Using separate products||Risk issues|
|1. Choose correct type of syringe and remove from packaging||Selecting the wrong type of syringe for process, ie enteral fit syringe, neuraxial fit syringe|
|2. Open separate blunt-fill* needle packaging and attach to syringe||Selecting the wrong type of needle (ie filtered, non-filtered, non-safety)|
|3. Disinfect the sodium chloride 0.9% ampoule (glass/plastic)||Forget to disinfect the ampoule-leading to contamination|
|4. Break the ampoule cover||Risk of glass injury|
|5. Remove the blunt-fill needle cover||Plastic waste|
|6. Insert blunt-fill needle into ampoule and withdraw sodium chloride 0.9%||Needlestick injury (although this is limited by use of safety needles)|
|7. Expel air from syringe||Aerosol exposure|
|8. Remove and dispose of the blunt-fill needle||Disposal via sharps box and cost|
|9. Attach a sterile cap to the syringe tip (or place back into packaging using ANTT)||No cap available, may lead to touch contamination|
|10. Write and attach a label to the syringe barrel||Legibility, and not always labelled|
As with all invasive procedures, there are inherent risks with IV cannulation and having a well-trained workforce carry out regular observations, and ensure safe use of all products, can help reduce these risks. Despite best efforts, external influences, such as pressures of work and staff shortages, may mean that staff may use ‘workarounds’ and make human errors. They may select and use an incorrect syringe-type, select the wrong product and not follow ANTT procedures. Such errors can lead to a risk of contamination, and choosing the wrong syringe type, and lead to a needlestick injury or a drug or infusion error.
All health professionals new to the role of peripheral intravenous cannulation are required to complete the Swansea Bay Health Board's approved training package and be deemed competent in using ANTT to insert a peripheral intravenous cannula. In addition, a local IV cannulation assessor will also assess practitioners who have cannulation identified in their job role, or who have previously been assessed as competent in a different organisation, for competency.
The evidence clearly shows the risk of error and contamination when using separate products and manual draw-up processes because task analysis suggests that the more steps in a procedure, the more likelihood that mistakes will occur (Embrey, 2000). Organisations can mitigate these risks with a pre-prepared (pre-filled) device. Wrong route errors are still being recorded in the NHS (HSIB, 2019). In some cases, oral medicines have been accidentally administered to patients via IV lines and cannulas by using the incorrect type of syringe (NHS England, 2021). These errors further highlight the risk of manually preparing IV flushes of 0.9% sodium chloride.
The Swansea Bay project
Until recently, the authors' health board allowed only registered staff to administer an IV flush. Registered staff were drawing up an ampoule of sodium chloride 0.9% for flushing, each requiring a prescription. This was unmanageable as every occurrence required a prescription. A PGD was then trialled in a small ward-based study, but again this proved unmanageable. Therefore another way forward was required. At the same time, the authors were leading a team looking at overall IV policy in the health board. They investigated whether using a pre-filled syringe would allow non-registered staff (such as healthcare assistants) to flush and also simplify the system for all staff.
Adoption of the medical device as an IV flush: making the case
After considering the issues, the authors made the case for changing to pre-filled syringes by presenting the evidence in the following way. To understand the rationale for adopting pre-filled flush syringes rather than using separate components and PoM medication supplied via pharmacy, the process can be broken down into separate elements:
The time taken to prepare, and draw up 0.9% sodium chloride for IV is estimated to be 48 seconds, whereas the procedure for using a pre-filled syringe takes only 15 seconds. For 200 000 infusions, this relates to a time saving of more than 1800 hours of staff time (at a band 5 mid-salary point of £23 500pa). The number of steps required (and the chance of error) is reduced, and the pre-filled device comes as a ready-to-use sterile product with a minimum shelf life of 3 years.
Manual preparation of an IV flush uses five separate products, each of which must be stocked and disposed of after use. If using a pre-filled device, only one order needs to be placed from one supplier instead of multiple orders for five separate devices; each pre-filled device is traceable for audit purposes.
The risk of accidental needlestick injury is removed when using a pre-filled syringe (albeit current practice helps reduce occurrence by using a safer sharp device, a blunt-fill needle). There is no requirement to use or dispose of a safety needle for drawing up the saline.
The risk of accidentally picking up an unlabelled IV flush syringe and mistaking this for other IV medication is removed. The pre-filled flush syringe (0.9% sodium chloride) comes ready labelled and dated with a clear indication for use, resulting in safer systems for patients and staff.
As far back as 2007, the National Patient Safety Agency (NPSA) (whose work has been taken over by NHS England/NHS Improvement) recommended a ‘purchasing for safety policy’ and a move towards ‘pre-prepared’ infusions and ‘ready-to-use’ products to help reduce risk of error and harm. The use of a pre-filled IV flushing syringe can be adopted as part of an organisation's risk reduction strategy and helps to standardise products, procedures and practice. (NPSA, 2007; NHS England/NHS Improvement, 2019).
As part of an organisation's safer sharps project, using a pre-filled syringe of 0.9% sodium chloride syringe is recommended. Despite currently using safer needles (ie blunt-fill), this will remove the need to use a needle to draw up the IV flush.
Preparation of an IV flush uses five separate products, which each need to be disposed of after use. The pre-filled flush syringe has one outer packet plus the syringe itself. An organisation's cost of waste disposal can be reduced by changing from five separate products to just one.
Whether organisations have adequately addressed the legal status of CE-marked, pre-filled syringe for flushing IV lines and cannulas, remains to be seen and legally tested. Although, on balance, they seem to offer a cost-effective alternative, for some, the costs are still prohibitive, and staff continue to draw up all IV flushes manually.
The Medicines and Healthcare products Regulatory Agency (MHRA) regulates medicines, medical devices and blood components for transfusion in the UK. As a general rule, products making medical claims will be regulated either by the medical devices regulations (MDRs) or by medicines legislation.
The current UK position on the medical devices directive describes a medical device as:
‘An instrument, apparatus, appliance, material or other article, whether used alone or in combination, together with any software necessary for its proper application, which—is intended by the manufacturer to be used for human beings.’
The medical purposes specified are as follows:
- Diagnosis, prevention, monitoring, treatment or alleviation of disease
- Diagnosis, monitoring, treatment, alleviation of or compensation for an injury or handicap
- Investigation, replacement or modification of the anatomy or of a physiological process
- Control of conception
- And does not achieve its principal intended action in or on the human body by pharmacological, immunological or metabolic means, even if it is assisted in its function by such means (Medical Devices Regulations 2002, number 618, part 1, regulation 2: https://tinyurl.com/yyc34byw).
For medicinal products, separate legislation and regulations apply. Article 1 of the EU Directive 2001/83/EC (as amended) (https://tinyurl.com/3hj6mr2a) defines a ‘medicinal product’ as:
‘Any substance or combination of substances presented as having properties for treating or preventing disease in human beings; or any substance or combination of substances which may be used in or administered to human beings either with a view to restoring, correcting or modifying physiological functions by exerting a pharmacological, immunological or metabolic action, or to making a medical diagnosis.’
A pre-filled syringe of 0.9% sodium chloride for flushing IVs carries a CE mark and is regulated as a medical device. The MHRA has issued advice around ‘borderline products’ (MHRA, 2021) and list these devices under the MDR. As a result, these products can be stocked and distributed by central stores within NHS organisations, as they do for other CE-marked products and devices. Their purchase is not limited to the traditional pharmacy model as they are not defined and subsequently classified as medicines.
When used as part of the IV process, they do not require a prescription or PGD. However, readers should note that 0.9% sodium chloride ampoules are classified as a PoM and as a result, must be prescribed and administered via a prescription, PSD or PGD.
A pre-filled syringe used to flush a cannula is not considered a medicine as the purpose is not to restore, correct or modify physiological functions. Therefore, it comes under the category of CE-marked medical device and can be purchased, stored, managed and used as such (Box 1).
Box 1.Guidance on borderlines between medical devices and medicinal products
Note: The use of a 10ml diameter syringe reduces overall force and pressure when flushing cannula and IV
|Pre-filled, single-use syringes specifically intended for mechanical flushing of ports and catheters (saline/heparin etc)||Medical Device Regulations||These are accepted as medical devices provided that they are specifically intended for the mechanical flushing of medical devices such as ports and catheters, even when the flush may result in the fluid entering the body. Such products must be clearly contraindicated for direct systemic administration. Classification will depend upon the ingredients contained in the flushing solution.Pre-filled syringes for systemic administration are always regulated as medicinal products|
Note: The use of a 10ml diameter syringe reduces overall force and pressure when flushing cannula and IV
In November 2015, an All-Wales joint working group issued guidance around using and adopting pre-filled syringes for healthcare support workers. As well as several interventions, this guidance included the use of pre-filled syringes for flushing IV devices (Box 2).
Box 2.Guidance for health boards/trusts in respect of medicines and health care support workers in Wales
Source: All Wales Medicines Strategy Group, 2015
|Intravenous saline flush: using a pre-filled syringe only||The health board/trust may decide to support this practice being undertaken|
The UK picture
As part of a scoping exercise, many healthcare organisations were asked to share their procedures and guidelines, which helped develop the bespoke cannulation guidelines at the authors' health board. Healthcare organisations across the UK showed significant variation in management of cannulation flushing. It was clear that some have adapted processes by accepting the MHRA position that they are a CE-marked medical device; some have written protocols. Some have accepted their use as an integral part of IV cannulation and IV administration process, without any further control.
The Nursing and Midwifery Council (NMC) cannot comment on the legal classification or administration of specific products, therefore employers need to seek clarification elsewhere about the exact nature and legal position of pre-filled syringes for flushing IV cannulas and lines. This classification will determine whether the device contents can be administered, with or without a prescription, PSD or PGD.
The fact it is licensed as a medical device, rather than a medical product, means that it does not meet the criteria for classification and subsequent licensing as a PoM.
The NMC reminds health professionals that section 18 of the NMC Code (NMC, 2018) states that all NMC registrants must advise on, prescribe, supply, dispense or administer medicines within the limits of their training and competence, the law, its guidance and other relevant policies, guidance and regulations.
Suppose organisations consider a pre-filled syringe for flushing to be a PoM. In that case, this will significantly impact the ongoing use, adoption, and control of pre-filled syringes for flushing IV lines and cannulas in the UK.
If these are considered PoM, this will preclude registered and non-registered staff supported by organisation policies and procedures (such as healthcare support workers trained in IV cannulation) from using them without appropriate processes. All staff using them will need to get these devices prescribed, checked and documented, and this will have an enormous impact on current workloads and practice.
The NMC and MHRA have gone some way to clarify their interpretation on pre-filled syringes for flushing IV cannulas and lines. They ask all organisations to look at how they purchase, use and prescribe these ‘borderline’ medical devices. All employees must ensure they follow policies, procedures and guidelines and that they have considered all avenues when choosing to opt for pre-filled syringes for flushing IV cannulas.
The legal status of a CE-marked, pre-filled syringe for flushing IV cannulas and lines is addressed by the MHRA and classified as a ‘borderline’ device. Although they may not require a legal prescription or PGD to use, they still need control and risk measures to mitigate risks.
When comparing the two options and assessing the cost-effectiveness of using individual components, the time taken to prepare and safety risks, using a pre-filled, ready-to-use CE-marked medical device can show benefits when all factors are taken into account.
In Swansea Bay University Health Board, the use of pre-filled CE-marked syringes (0.9% sodium chloride) for flushing IV cannulas and lines has been adopted and offers a safer, more cost-effective flushing method compared to the previous five separate product approach.
Organisations can achieve the following safety and risk-reduction strategies by using pre-filled (CE marked) syringes for IV flushes, thus:
- Reducing the number of products (and waste) required to prepare an IV flush
- Reducing the number of steps required to prepare IV flushes
- Saving time required to prepare and draw up each IV flush
- Reducing the risk of accidental wrong route errors as all pre-filled flushes come sterile, capped, labelled and ready for use
- Removing the risk of needlestick injury
- Removing the risk of possible contamination of 0.9% sodium chloride ampoules.
Identifying the legal status of CE-marked pre-filled syringes, comparing manual prescribing and PGDs and evaluating the processes involved in documenting the use of IV flushes further supported the decision to adopt these devices. Employers' policies, procedures and protocols need to reflect any move towards adopting these CE-marked devices and adequately support staff using them in practice.
This project was managed and implemented using risk assessment and quality management methodology. Keeping stakeholders informed and reporting to senior management at every level was key.
The management and adoption of CE-marked pre-filled syringes for flushing IV cannulas and lines needs to be considered using a multidisciplinary team approach to agree their legal standing and use in the clinical setting for safe IV therapy practice.
- Flushing IV cannulas and lines is an integral part of safe and effective IV therapy, but needs careful consideration and a multidisciplinary approach to ensure governance and that all risk factors are mitigated
- A pre-filled syringe of sodium chloride 0.9% for flushing can be considered a CE-marked medical device, but each employer needs to clarify this within their own policy and practice guidelines
- A patient group directive (PGD) is a legal document that must be signed by all staff working under them. This also limits PGDs to registered healthcare staff only and the PGD task cannot be delegated
- Moving to a pre-filled syringe for flushing IV lines and cannulas has helped the authors' health board reduce risk and waste and streamline the flushing process
- Accepting a pre-filled syringe as a CE-marked medical device has also allowed non-registered staff to be involved it the cannulation process and these can be used without prescription
CPD reflective questions
- Do you flush IV lines and cannulas and can you be sure that you are fully protected by your employer's guidelines and policies?
- Do you need to sign a patient group directive when you draw up IV flushes from an ampoule (which is legally a prescription only medicine)?
- Is your practice of flushing IV lines and cannulas safe and how do you demonstrate your competence under your employer's policy?
- Do you use pre-filled syringes of 0.9% sodium chloride for flushing lines, and, if so, how do you record their use?