Diabetes is a long-term condition that affects the production of insulin and, therefore, the blood glucose levels in the body. There are several types of diabetes, for example T1 and T2, although the focus here will be on insulin-dependent diabetes. High glucose levels (hyperglycaemia) can affect multiple body systems over time, including eyesight, the nerves and the renal system. Low glucose levels (hypoglycaemia) are a medical emergency that can cause seizures, coma and death. It is reasonable to state that diabetes is an incurable condition; although diabetes can be controlled with diet, exercise, and medications, it is not cured.
It is the role of the district nurse (DN) to manage the care of insulin-dependent diabetic patients who are unable to manage themselves. Although diabetes specialist nurses and general practitioners (GPs) contribute their knowledge for prescribing and titrating doses, it is the district nursing team that visits patients, monitors their blood sugar levels, and administers the insulin.
Blood glucose monitoring
The testing of glucose levels is an important intervention. The test results help to determine the best type and dose to be titrated (Gordon, 2019), giving the best results for glycaemic control and better patient outcomes. In current practice, the nurse will check a patient's glucose levels by using a lancet to prick a finger to obtain a blood sample. The nurse will place the sample of blood onto a testing strip and then insert the strip into a calibrated glucometer. This gives a reading after a few seconds.
This method has advanced significantly since the beginning of glucose testing in 1925, when glucose levels were measured by mixing drops of urine with Benedict's solution, then boiled in a test tube to obtain a result (Benjamin, 2002). From then on, further advancements lead to the urine dip test (Defeat Diabetes Foundation, 2014). As science and technology advanced, it became apparent that testing urine was not the most accurate method. This is because the glucose levels were indicative from when the kidneys produced the urine, which was hours behind by the time of urine excretion. It was also dependent on a stable renal function (Gordon, 2019). The current method of capillary finger prick with a glucometer is now almost 60 years old (Olczuk and Priefer, 2018). Although this achieves almost instant results (Gordon, 2019), there is certainly room for improvement.
Problems with current blood glucose monitoring
The most common complaint from the patient's point of view is the pain and discomfort associated with the finger prick (Olczuk and Priefer, 2018; Bruttomesso et al, 2019; Hayek et al, 2019). However, it is likely that the pain could be minimised if the correct procedure was applied. Thomas and Prassana (2022) highlighted the need to warm up the fingertips beforehand and to use the side of the fingers, where there are fewer pain receptors. Using the correct lancet size for the patient's build is also important. Following best practices like this would be especially beneficial for patients who also have other painful conditions, such as rheumatoid arthritis or fibromyalgia. Many authors have claimed that patients can find the finger-prick method burdensome and inconvenient (Bruttomesso et al, 2019; Kashimada, 2021). Therefore, it is not surprising that patients do not test themselves as often as they should (Hayek et al, 2019). Gordon (2019) contended that insulin-dependent patients should check their blood sugar levels four times a day. However, evidence from the work of Gomez-Peralta (2020) highlighted that more frequent testing (eight or more times a day) could lead to better glycaemic control. Therefore, this may contribute to better health outcomes.
It is questionable whether district nurses are getting the full picture of the patients' glycaemic readings. The district nurse team visits these patients in the morning and at evening, with some warranting visits at lunch and in the evening. Kashimada (2021) argued that a few daily finger prick results are insufficient data to make clinical decisions. In effect, the nurses are only gaining a snapshot (Babaya et al, 2020), especially given that we do not visit to check readings overnight. The issue with this is paramount; hypoglycaemic events can go undetected. This has been proven in the work of Rowney and Lipscomb (2019), who monitored patients overnight within their district nurse teams and found frequent hypoglycaemic events that would otherwise not have been picked up by the district nurse due to the time of the visits. These hypoglycaemic events are at the detriment of the patient's health.
As it stands, the district nurse teams visit patients during the day for blood glucose monitoring. It is not always possible to visit before meals, which would give a more consistent and accurate blood glucose reading. This is because of the high demand for visits during these peak times. District nurse teams typically have large caseloads of patients, with increasing numbers of people treated with insulin (Gregory, 2020) as reflected by Public Health England's (2016) estimation that almost one in ten people will be diabetic by 2035. Therefore, it is not surprising that blood glucose monitoring and insulin administration have become ‘task-orientated’ (Gregory, 2020), with nurses solely going for that task purpose and not having the time to look holistically at the patient and personalise care towards the patient's needs.
An innovative painless approach with continuous glucose monitoring: a painless approach
Over the years, technology has advanced to offer the first painless approach to glucose monitoring: continuous glucose monitoring (CGM). Continuous glucose monitors are small devices inserted under the skin, measuring the glucose levels that are in the interstitial fluid; this is a continuous process where results are obtained at any time of the day. Some continuous glucose monitors can titrate insulin doses according to results. However, these devices are not without problems; for example, they still need to be calibrated before use.
Flash glucose sensing
The most common variation of CGM used in the community setting is flash glucose sensing (FGS), which can be understood as a cross between CGM and glucometry. However, unlike continuous glucose monitors, these devices must first be scanned with a sensor to obtain a result. The advantage is that they do not require calibration.
District nurses are seeing more frequent usage of FGS with their service users. Díez-Fernández et al (2021) highlighted that FGS has improved patients' quality of life and patient satisfaction. However, given that this is a new intervention, the long-term implications or benefits are not yet fully understood. As it stands, the main benefit for the patient is that FGS is painless and convenient; therefore, research has found a higher incidence of testing amongst users (Kashimada, 2021). This leads to better glycaemic control and better Hba1c blood sample results (Hayek et al, 2019). More recently, there is evidence that, after 12 months of use, FGS can reduce hospital admissions because of fewer hypoglycaemic events and reduced incidence of ketoacidosis. Overall, this can lead to a reduction in falls, comas and acute illness (Wysham and Kruger, 2021), which could equate to reduced costs for the NHS because of fewer hospital admissions. Additionally, Bruttomesso et al (2019) highlighted that, with FGS, patients can feel more in control, and it reduces the fear of hypoglycaemia because they can monitor any downward trends and react appropriately (eat). This could also impact patients' lifestyle choices and diet as they become more knowledgeable about their body and their glucose levels, which leads to better adherence to treatment that could have long-term benefits (Wysham and Kruger, 2021).
Promoting independence and self-care is paramount, as highlighted in the NHS Long-Term Plan (NHS, 2019). Given the rising caseloads for district nurses, it is even more desirable. Some patients who do not have the dexterity to check their blood glucose with a glucometer may be able to scan the simple device; if not, their carers could do this for them, reducing demands on the district nurse service. Overall, it is evident that FGS may allow for safe and more personalised care and control for the patient. However, from the district nurse's perspective, it is not without issues.
Disadvantages of flash glucose sensing
FGS is not suitable for every patient. Wysham and Kruger (2021) argued that patients with impaired glycaemic awareness and serious episodes of hypoglycaemia will not be suited to FGS, and a finger prick test would still be required. There have also been reports of skin irritations for some patients (Medicines and Healthcare products Regulatory Agency (MHRA), 2019). Interestingly, small-scale studies in those over 65 years old have shown that FGS does not interfere with day-to-day activities such as sleeping, emphasising its adaptability and ease of use (Mattishent et al, 2019). However, a larger-scale study would be beneficial, specifically in older patient groups with decreasing dexterity.
Functionally, FGS may not be appropriate for all patients; considering that this is a technological device, some older patients may not feel comfortable using it. Newer models have added settings and alarm functions that may deter some patients from using the device. This emphasises the need for personalised and holistic care to assess FGS suitability for the patient.
One of the main concerns about this device is the difference between blood glucose readings and interstitial fluid readings of FGS. Evidence suggests there is a lag in this time. From research, this lag in time is never over 15 minutes (Cowart and Zgibor, 2022; Freckmann et al, 2021) and can be as little as 2.4 minutes (Abbott Laboratories, 2022). Therefore, blood glucose does correlate to glucose in the interstitial fluid. However, time lags may be more prominent during physical activity and hypoglycaemia due to rapidly changing levels (Cowart and Zgibor, 2022). Adding to this, evidence suggests that FGS is accurate and dependable. In a study by Alva et al (2022), the latest version of Flash expressed its accuracy with a mean absolute relative difference (MARD) of 9.2% in adults over 18 years, in comparison to the self-monitoring of blood glucose, which was 10.7% in the same age group. The reliability of this extended over the 2-week proposed usage of the device.
Olczuk and Priefer (2018) stressed that many still require a capillary finger prick before intervention. This is the case for some district nurse teams because they must ensure the safety of the patient by using the most up-to-date readings before administering insulin. However, it is worth considering if district nurses could work around this barrier, in the hope of offering more individualised care. If a patient did not want a capillary finger prick, the FGS device could be scanned before and after insulin administration. This way, the district nurse could react to any steep falls in glucose levels, for example, following trust guidelines in hypoglycaemia, such as glucose tablets or sugary drinks to increase glucose levels. This would ensure that the district nursing team is moving away from task-orientated care and towards holistic care.
Policy and guidance
Standard glucometers are calibrated by trust laboratory departments (points of contact). This will be in line with local policy, which is based on the best available evidence to ensure the equipment has been tested and is working correctly and is reliable (Gordon, 2019). Therefore, there will be policies and procedures for the district nurse to follow and these may stipulate that blood glucose readings must be taken with a calibrated glucometer. However, unlike CGM, FGS devices are factory calibrated (Kashimada, 2021). Therefore, this disputes the argument over calibration.
It is time to rethink current policies to reflect the advances in technology. The standard finger pricking and blood glucose readings have never been perfect: for example, the testing strips can show disputed results when people are on dialysis or if people have a peripheral circulatory failure, or even during severe hydration (Gordon, 2019). Despite this, they are still used in everyday practice. District nurses come across many complex patients with comorbidities, with some being acutely unwell. Yet, this is still the standard procedure for blood glucose monitoring for those patients.
One could argue it would be unsafe not to consider FGS. In the work of Rowney and Lipscomb (2019), when trialling FGS with type 2 diabetic insulin-dependent patients, it became apparent that the district nurse was only seeing a snapshot of the patient's blood glucose measurements when using a glucometer, when, in fact, some of these patients were having hypoglycaemic events during the night, which the flash device showed. This led to insulin regimes being altered to suit the patients' needs and, for some, the discontinuation of insulin altogether because it was no longer required. This implies that FGS could lead to a major change in the monitoring, management and treatment of diabetes.
On the 31 March 2022, the National Institute of Health and Care Excellence (NICE) created new guidance and recommendations (NG17) on blood glucose monitoring, specifically recommending a wider use of CGM and FGS for those with type 1 diabetes or type 2 insulin-dependent diabetes (NICE, 2022). This is welcome news, especially given that previous guidance from NICE (2015) gave no reference to FGS and appeared subjective and open for interpretation. Therefore, it was not surprising that local trust policies could vary, depending on their interpretation of the guidance. Having the new guidance specifically for CGM and FGS will hopefully now recognise these devices as a positive way to improve the management and care of diabetes.
An influencing factor encouraging the use of FGS is the potential cost savings for the NHS. As per the British National Formulary (BNF) (2022), the standard cost of a flash glucose monitor is £35.00, with 14 days of usage. In comparison, test strips alone can cost £6.00-£16.00 for 50 strips, depending on the glucometer device. Adding to this, a glucometer and lancets would be required at additional costs. Simply put, FGS is more cost-effective for patients who are more frequent in their blood glucose testing; so, predominantly, this will be those with unmanaged diabetes with a higher risk of hypoglycaemia. Within this patient group, those with FGS may require fewer appointments with healthcare professionalsand fewer hospital admissions, making it a safer and cost-effective method.
Going forward
In line with the new NICE guidance, the district nurse is in the prime position to identify patients who would benefit from FGS, because the district nurse visits patients in their home environment and is, therefore, able to holistically assess the individual needs of the patient.
There have been anecdotal instances where FGS has been prescribed for the patient, despite the device not being suitable for their needs. Gordon (2019) argued that one must check the equipment needs of the patient. It is essential to check the equipment needs while the patient is in their home environment; therefore, the district nurse should complete a full nursing assessment considering the service users' main priorities of care. This collaboration with the patient is paramount, leading to patient satisfaction and improved clinical outcomes (Wysham and Kruger, 2021). Additionally, this will minimise inadequate prescribing, at cost to the NHS.
Some professionals who prescribe FGS are not aware of the governance issues with which district nurses must work. The fact is that patients have been prescribed FGS and are then disappointed that (depending on trust policy) the district nurse must also take a capillary blood sample with a trust-calibrated glucometer. Thus, this further amplifies the reality that their holistic needs are not being considered during prescribing. For best practice, there should be a multidisciplinary team approach by involving the patient, the district nurseand the diabetes specialist, with the patient at the forefront. Additionally, Cowart and Zgibor (2022) suggested that pharmacists can offer advice and suitability for prescribing FGS because of their knowledge and position within the community.
If local trust policy stipulates that a blood glucose reading is still necessary, then the district nurse must continue to encourage the patient to use the FGS because of the benefits of increasing independence by becoming more involved in their own care and having a better understanding of their diabetes management. This also applies to carers (both family and paid carers), as they may not be bound by the same policy and procedures and may be able to scan the FGS device without the requirement of taking a capillary finger prick. However, if a district nurse must take a capillary reading, they must ensure best practice to minimise pain and discomfort. If FGS empowered more patients to be able to self-care, this could allow the district nurse to minimise their diabetic patient caseload, allowing for more timely visits (before meals) to improve the accuracy of blood sugar readings. However, it is not fully understood how a wider rollout of FGS in the community would affect patients in their day-to-day living and how this would affect the district nurse service.
In line with changes and updates to NICE guidance, trusts must ensure that their policy on blood glucose monitoring is up to date and reflects current evidence. The policy must be clear for nurses to follow. Any changes must be circulated to all nursing teams with relevant training provided: for example, e-learning that will then allow the nurses to support patients in the community. The district nurse could identify suitable patients for FGS and monitor the impact it has on the district nurse service and the patient in the short, medium and long term. This would be the safest way to implement changes, and any changes to the service can be adapted as more is learnt about the impact of FGS.
Conclusion
The intervention of monitoring glucose has changed dramatically over the years. The main drawbacks of standard glucose monitoring with a glucometer are pain and inconvenience. As technology has advanced, district nurse have found them selves with innovative tools that can change the way their service manages the caseload of insulin-dependent diabetic patients. The most appropriate innovation is FGM. Recent studies show the additional benefits of this device, such as the reduction in hypoglycaemic events. Thus, this warrants further exploration. However, FGS may not be suitable for all patients. Therefore, the district nurse must complete a holistic nursing assessment and personalise care towards the patients' needs.
In line with the new guidance from NICE, it may now be the time to rethink practice.
Key points
- Pain and inconvenience are associated with capillary blood glucose testing
- Innovations such as continuous glucose monitoring and flash glucose sensing are revolutionising diabetes care
- Current local policy may restrict the use of FGS, although this is set to change following national guidance changes
- The district nurse is in the prime position to identify patients who may benefit from FGS