Since it was first administered to a young boy with type 1 diabetes in Toronto, Canada in 1927, insulin has saved tens of thousands of lives. However, improper insulin use has cost lives too and remains one of the top three high-alert medications worldwide.
Described in the early 1920s as a “thick brown muck” (Bliss, 2007), insulin has come a long way over the past 90 years, with more purified compounds, simpler delivery devices and shorter, finer needles. Now, over 30 different insulins are available to prescribe in the UK, which offers greater choice but can create confusion, particularly for those less experienced in managing people on insulin. Traditionally, insulin was initiated and supervised by specialist teams in hospitals but over the past decade or so, many more “generalists” with an interest in diabetes are offering enhanced diabetes services including insulin initiation and ongoing management. There are benefits to offering such a service: it is usually closer to home, waiting times may be shorter and the person will often be seen by a clinician with whom they have a trusted and established relationship.
Insulin safety training
In May 2016, the PCDS invited healthcare professionals (HCPs) working in both primary and secondary care to complete a short survey on managing insulin in general practice, the results of which were published in an earlier issue of the Journal (PCDS, 2016). It was not entirely surprising that the majority of respondents, as members of the PCDS, had at least some responsibility for the ongoing management of insulin and just over half of respondents were responsible for insulin initiation. I would argue that ongoing management of insulin is the more challenging of the two, requiring careful assessment to determine reasons for suboptimal control, and to perform dose adjustment and treatment intensification. To perform this role competently, the HCP must be properly trained but they also need to be dealing with people on insulin on a regular basis and see sufficient numbers both to develop and maintain expertise and confidence. Only 60% of those completing the survey confirmed that they had undertaken training or attended an update in insulin management and, in over 20% of this group, it was more than 4 years ago.
Between 2003 and 2009, the National Patient Safety Agency (NPSA) received 16 600 medication incident reports involving insulin. The top three error types were wrong dose, strength or frequency (26%), omitted and delayed doses (20%) and wrong insulin product (14%; Cousins et al, 2011). Subsequently, in June 2010, the NPSA issued a Rapid Response Report on safer administration of insulin (NPSA, 2010), the key recommendations of which appear in Box 1 on the next page.
Insufficient training of HCPs was identified as one reason for the reported insulin errors, and the Rapid Response Report called for all organisations in the NHS and private sector to ensure that training programmes were put in place for every HCP expected to prescribe, prepare and administer insulin. The report also highlighted the responsibility of the individual HCP to recognise the limits of their personal knowledge, skills and competence in the administration of insulin therapy and stated that, where there is uncertainty, they should seek additional help and support (NPSA, 2010).
Despite some initial improvements following publication of the Rapid Response Report in 2010, errors are still occurring, as shown in the latest National Inpatient Diabetes Audit (Health and Social Care Information Centre, 2016). Over a 3-year period from January 2013 to December 2015, there were 33 605 reported errors; 22 995 of these occurred in hospitals and 8226 in the community (Health and Social Care Information Centre, 2016). These errors sometimes have tragic consequences for patients, their families and the HCP involved, and serious patient safety incidents involving insulin tend to generate considerable media attention.
“Never Events” are defined as serious incidents that are wholly preventable as national guidance or safety recommendations exist and should be implemented by all HCPs. In effect, there would be no defence if such an error occurred. It should be noted that the overdose of insulin due to abbreviations (i.e. where “u” or “iu” is used to denote units) or where an incorrect device is used (i.e. an intravenous syringe) is currently listed as a Never Event (NHS England, 2015).
In 2010, NHS Diabetes (now part of NHS Improving Quality), in partnership with the NPSA, launched a national e-learning module on insulin safety and many completed this training. However, 6 years on the module is no longer free of charge and many organisations have chosen to stop subscribing. The fact that so few HCPs responding to the PCDS survey had undertaken recent training in insulin safety or management is of concern, particularly given the pace at which things are changing in insulin management.
Developments in insulins
Recently, several higher-strength insulins have become available, such as Tresiba® (insulin degludec) 200 units/mL, Humalog® (insulin lispro) 200 units/mL and Toujeo® (insulin glargine) 300 units/mL. The first biosimilar insulin product (Abasaglar® [insulin glargine] 100 units/mL) has been launched, and there is also a fixed combination product that combines insulin with a glucagon-like peptide-1 receptor agonist (Xultophy® [100 units/mL insulin degludec and 3.6 mg/mL liraglutide]). Differences in the concentration, formulation and dosing of these new products mean there is even greater potential for medication error. Around 40% of the respondents in the survey felt “very familiar” with the full range of insulins currently available, around half were “somewhat familiar” and a small number (4%) were “not at all familiar”. The respondents represent a population of HCPs with an interest in diabetes and I would assume that, for the majority of GPs, practice nurses and district nurses who have some involvement with insulin, their familiarity with these newer agents is likely to be far less.
Drawing-up of insulin using insulin syringes
Anecdotal evidence that some HCPs were “drawing out” insulin from prefilled insulin pens and cartridges using insulin syringes prompted the PCDS to publish a statement last year to highlight the dangers of this practice (PCDS, 2015). Prefilled pens and cartridges are not designed to have the insulin extracted and the practice is not endorsed by any of the manufacturers. The practice can damage the device, lead to dosing errors and potentially result in patient harm. There is also the danger that a less experienced practitioner may mistakenly use an intravenous syringe to extract and then administer the insulin, resulting in them giving 10 times the intended dose. Worryingly, 32% of respondents in the survey said they were aware of insulin being drawn out of pens or cartridges for administration by HCPs.
The recently launched higher-strength insulin preparations are only available as prefilled pens. If higher-strength insulin is drawn from these pen devices into an insulin syringe, which measures the dose in terms of 100 units/mL, then the dose will be double that intended for 200 units/mL strength insulins and treble that for 300 units/mL strength insulins.
NHS Wales (2016) has recently issued a Patient Safety Alert (PSA004) highlighting the risks associated with extracting insulin from pen devices and state emphatically that it is not permitted. It is to be hoped that NHS England will issue a similar warning before serious harm occurs.
Correct injection technique
Correct injection technique is essential for insulin to achieve optimal effect. Poor technique, including the use of inappropriate needle length, failure to rotate injection sites correctly and the reuse of needles, can all undermine the effectiveness of insulin therapy, lead to glycaemic variation, cause hypoglycaemia and potentially adversely affect outcomes. Evidence suggests that lipohypertrophy, a common problem associated with poor injection technique, is present in over half of all people using insulin (Blanco et al, 2013; Grassi et al, 2014). Insulin users need to be taught correct injection technique at the outset, but it also needs to be discussed and re-assessed at subsequent reviews. Encouragingly, 77% of respondents in the survey said they discussed injection technique with patients routinely at every insulin review, with similar numbers inspecting injection sites at least annually. The Forum for Injection Technique is due to launch an updated 4th edition of the UK Injection Technique Best Practice Recommendations, which can be accessed in the next few months at www.fit4diabetes.com.
Insulin is a life-saving but potent drug and there is huge potential for error. Increasing numbers of people are using insulin (Holden et al, 2014), and I believe that almost every HCP will, at some point, handle, prescribe or administer insulin. We have a responsibility to ensure we understand the potential risks and avoid preventable error.
In 2015 the PCDS, in association with TREND-UK, launched a free e-learning module, “The Six Steps to Insulin Safety”. I encourage every HCP, including those with limited involvement in insulin management, to complete the training. It takes around an hour and, providing the user achieves the 75% pass mark in a short assessment, they will receive a downloadable certificate for continuing professional development. There is a facility for clinical commissioning groups and trusts to track the progress of all HCPs working in their organisation to ensure that all staff have undertaken up-to-date training in insulin safety. To access the module visit www.cpd.diabetesonthenet.com.
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3 Sep 2024