Blood glucose (BG) level homeostasis is necessary for normal physiological function and both hyperglycaemia and hypoglycaemia have notable adverse effects. Hyperglycaemia is defined by the American Diabetes Association (ADA) and American Association of Clinical Endocrinologists as a BG > 7.8 mmol/L [1]. Persistent hyperglycaemia can have many adverse effects, including micro and macrovascular complications [2]. Microvascular complications include the ‘microvascular triad’ of retinopathy, nephropathy, and neuropathy. Macrovascular complications include stroke, coronary artery disease and peripheral arterial disease [2]. These vascular complications of hyperglycaemia are a major source of morbidity and mortality in Type I Diabetes Mellitus (T1DM) and Type II Diabetes Mellitus (T2DM) [3]. Hyperglycaemia can also result in hyperglycaemic emergencies such as Diabetic Ketoacidosis (DKA) and Hyperosmolar Hyperglycaemic Syndrome (HHS), with DKA occurring mainly in T1DM and HHS in T2DM [4]. In addition to DKA and HHS, inpatient hyperglycaemia is also associated with poor clinical outcomes in general [5]. Hypoglycaemia is defined by the ADA as a BG level lower than 3.9 mmol/L [6]. It is further classified into Level 1 (hypoglycaemia alert), Level 2 (clinically significant hypoglycaemia), and Level 3. Level 1 hypoglycaemia is a BG level between 3.0–3.9 mmol/L. Level 2 is a BG level below 3.0 mmol/L. Level 3 does not have a specific glucose level but is measured clinically; it is characterised by cognitive or physical impairment requiring external assistance for recovery. Both Level 2 and Level 3 require prompt medical attention [7]. Hypoglycaemia can lead to serious sequelae, including seizure, loss of consciousness, and coma [8]. Causes of hypoglycaemia include excessive insulin dosing or inappropriate timing of insulin administration with food intake; errors in medication orders or administration [9]; administration of systemic steroids [10]; polypharmacy; and delayed or missed meals [11]; and organ failure, such as liver or kidney failure [12].

Treating both hyperglycaemic and hypoglycaemic patients is vital for improving outcomes in hospitalised patient populations. A retrospective study of over 250,000 ICU-admitted veterans in the US found that hyperglycaemia with or without a diagnosis of diabetes was “independently associated with increased mortality after adjustment for severity of illness” [13]. The same study also noted an increased risk of death proportional to increasing BG levels [13]. The same is also seen in non-ICU hospital settings [5]. Hypoglycaemia is associated with both increased length of stay in hospital and higher mortality during hospitalisation [14]. In fact, hypoglycaemia in the ICU population was found to be an independent risk factor for mortality [12]. Hypoglycaemia is a risk factor for cardiovascular events [15], including cardiac ischemia [16]. It is also a risk factor for falls during hospitalisation [17], particularly in older populations [18].

In order to prevent dysglycaemic events and treat them appropriately when they do occur, it is necessary to identify at-risk patients promptly. This can be difficult because both hyperglycaemia and hypoglycaemia are often asymptomatic [11, 19]. Therefore, it is imperative that BG levels of hospitalised patients are frequently monitored. This is especially critical in diabetic patient populations, as they are most at risk of hyperglycaemia and iatrogenic hypoglycaemia. Point-of-care (POC) BG testing is an effective way to monitor patient BG levels [20], and allows healthcare providers to identify cases of dysglycaemia, thus enabling timely intervention and prevention of the adverse outcomes associated with both dysglycaemic states. However, it must be noted that these POC devices can only be used for monitoring of blood sugar and not to diagnose diabetes, as per their licence. There are various protocols established at international, national, and local levels to ensure monitoring is done with appropriate timing and frequency. Although hyperglycaemia is defined as BG > 7.8 mmol/L [1], the consensus statement by the ADA and Clinical Practical Guidelines of the Endocrine Society recommend BG targets between 7.8 mmol/L and 10 mmol/L for diabetic patients [21, 22]. Although strict control of BG to < 7.8 mmol/L may be at times beneficial [23, 24], various other trials [25,26,27] have found no benefit in patient outcomes and have actually found increased risks associated with intensive glycaemic control such as the increased incidence of hypoglycaemic events. As such, targets for diabetic patients are set to 7.8—10 mmol/L [21].

In addition to identifying dysglycaemic patients quickly, having specialised care teams consult them while in hospital can improve patient care, through improving glycaemic control [28], and reducing length of stay [29,30,31]. TUH has an inpatient diabetes team for adult patients, which aims to provide consults to both known diabetic patients and newly diagnosed patients. It is not known, however, what percentage of patients this team consults while they are in hospital or how quickly after at-risk patients are identified this team visits them.

As outlined above, dysglycaemia can result in poor patient outcomes. As such, it is important that BG levels are regularly monitored. In this audit, data were analysed from POC BG measurements in TUH over an 8-day period (12/03/2023 – 19/03/2023) to assess overall glucometer usage in TUH. As explained above, the ADA recommends BG targets between 7.8 mmol/L to 10 mmol/L for diabetic patients. Tallaght University Hospital (TUH) has slightly different protocols, with glycaemic targets for diabetic patients of 6—10 mmol/L, per the ‘Adult Medicine Guide.’ The ADA recommends a HbA1C test for diabetic and hyperglycaemic patients who have not had a HbA1C test done within three months [21]. Common practice at TUH is to perform a HbA1C on patients with persistent hyperglycaemia, defined as a BG of ≥ 10.0 mmol/L on two separate occasions if they have not had a HbA1C recorded in the last three months. Adherence to these glucose monitoring protocols in TUH, including monitoring for persistent hyperglycaemia and checking for HbA1C in persistently hyperglycaemic patients, were investigated. Inpatient consults of persistently hyperglycaemic adult patients by the TUH inpatient diabetes consult team were also assessed.