Legal framework
Before an individual may receive a medical exposure of ionising radiation, there are specific clinical circumstances that must be considered at each stage of the care pathway.
There are separate legal frameworks to consider – the justification and authorisation of the medical exposure to ionising radiation, and the authorisation of the supply and administration of medicines. One does not confer legal authority for the other. The advice in this article is relevant to all imaging examinations where justification and authorisation are undertaken.
Legal classifications
All injected contrast agents, such as intravenous (IV) contrast, and some other medicines used, are prescription only medicines (POMs), therefore the restrictions that govern the use of POMs apply. Some contrast agents and other medicines used to assist the radiology process (sometimes called adjunct medicines) are Pharmacy (P) or General Sales List (GSL) medicines.
For advice on P or GSL medicines see:
Regulation
The Ionising Radiation (Medical Exposure) Regulations 2017 (IR(ME)R) is the legislation which provides a framework intended to protect individuals from the hazards associated with ionising radiation.
Compliance
Responsibility for compliance with IR(ME)R firmly rests with the employer and all the “entitled” duty holders as defined in the Regulations. Specific individuals will be trained and entitled to undertake these roles within each radiology department.
Clinical assessment and justification
Before a request for clinical imaging is accepted, the IR(ME)R practitioner, who must be a registered healthcare professional, makes a judgement to justify and authorise the exposure of an individual to ionising radiation. To perform this action, the request for the exposure is assessed against the clinical data supplied by the referrer. The practitioner must have had adequate training and be competent and entitled to consider the potential detriment of the exposure, or not performing the exposure, against the potential benefits for that individual. In doing so they will consider alternative techniques that do not involve ionising radiation.
Further detail is available here.
The practitioner may allocate the task of authorisation of a medical exposure to an entitled IR(ME)R operator (regulation 11[5]) but the practitioner retains responsibility for its justification. This requires the operator to precisely follow the authorisation guidelines provided by the practitioner.
After reviewing the referral information and if the referral is appropriate, the IR(ME)R practitioner justifies and authorises the medical radiation exposure as required.
Legal mechanisms for the administration and supply of parenteral contrast
A locally agreed clinical imaging protocol does not in itself confer any legal authority to the radiographer or any other healthcare professional (i.e. the operator) to administer or supply any medicines/contrast specified within that protocol.
Where the examination requires the use of contrast media or other adjunct medicines, the operator must also have a legal authority to be able to administer or supply that medicine. This requires careful consideration.
Non-parenteral contrast
The advice in this section applies to POM contrast agents, which are being injected.
If the contrast agent is a POM but is being administered by any other route (e.g. oral, rectal or vaginal) it must be prescribed or supplied and/or administered under a patient group direction (PGD).
If the contrast agent is a P or GSL medicine, follow the advice in P and GSL medicines with PGDs.
Prescribing
The preferred way for individuals to receive medicines is for a prescriber to provide care for an individual on a one-to-one basis.
Contrast may be prescribed by the radiologist, or IR(ME)R practitioner with a legal entitlement to prescribe, when justifying an imaging procedure. This is not commonly undertaken as further assessment is required at the time an individual presents to the imaging service. The patient assessment includes, but is not limited to, confirmation of current renal status, allergies and pregnancy status, which may affect the decision to proceed and the contrast type/dose etc required. These assessments are in addition to the IR(ME)R checks required in the employer’s written procedures.
In practice, it is often the radiographer who is responsible for determining the suitability for contrast prior to administration.
Patient group directions
A patient group direction (PGD) must be a standalone written instruction for the registered healthcare professional to follow. A PGD should contain all the information necessary for the safe administration of the medicine.
PGDs are commonly used to support administration – where a PGD is used the radiographer undertakes a full clinical assessment (commonly supported by a locally developed clinical checklist) before determining if contrast is suitable for administration to an individual.
If practice requires clinical judgement beyond the written instruction within the PGD, then a PGD is not appropriate.
PGDs in imaging services
In the case of imaging, the decision to undertake an imaging procedure requiring contrast is not made by the radiographer administering or supplying the contrast but by the healthcare professional justifying the imaging procedure. Therefore, the radiographer working under the PGD is unable to do so completely autonomously, as the decision that contrast is required is made by the IR(ME)R practitioner justifying and authorising the imaging.
The use of PGDs has been considered by representatives from NHS England (NHSE), the Royal College of Radiologists (RCR), the Society of Radiographers (SoR) and SPS. It has been acknowledged that whilst PGDs are not the most appropriate legal mechanism for the administration of contrast in imaging services, there are currently no alternative legal mechanisms that would enable the same high level of service provision.
Future changes
The RCR and the SoR, working with the Medicines and Healthcare Products Regulatory Agency (MHRA), NHSE and the Department of Health and Social Care (DHSC), are exploring the use of exemptions under the Human Medicines Regulations 2012 and the extension of non-medical prescribing to diagnostic radiographers, but these mechanisms will take time to realise.
Whilst these legislation changes are realised, PGDs may continue to be used to support services and ensure that individuals have safe and timely access to care.
National PGD templates for injectable contrast media
SPS has worked with the RCR, SoR and specialist radiographers and pharmacists to produce exemplar PGD templates for commonly used injectable contrast media. These should be adopted by NHS organisations and independent providers of NHS commissioned imaging services.
The aim of the templates is to produce a consistent presentation, which has been reviewed by specialists within the field, who will ensure that the legislative and clinical parameters have been fully considered and met as far as is possible.
These PGDs will remain available, and updated as required, until other legal mechanisms for the administration of contrast agents are achieved.
The published contrast template PGDs are available here.