Continuous Bloodsugar Monitoring System With a Sensor Compared to Fingerstick Bloodsugar Monitoring

Glucose control in surgical patients at risk of hyperglycemia and hypoglycemia is essential, as these conditions can lead to infections, poor surgical outcomes, prolonged hospital stays, and death. In 2022, the prevalence of diagnosed diabetes in Denmark was 6.2%. With the global incidence of diabetes on the rise, the number of patients requiring glucose control during surgical admissions is increasing.

Point-of-care (POC) fingerstick capillary glucose monitoring (FSGM) is standard in many hospitals; however, FSGM can be painful, disrupt sleep, and increase postoperative stress for patients. Additionally, it can be time-consuming, requiring up to two hours of nursing work per patient daily. This makes timely and prescribed glucose monitoring challenging in busy surgical wards, potentially leading to untreated hyperglycemia and hypoglycemia. Moreover, FSGM provides only a snapshot of glucose levels, without indicating whether glucose is stable, rising, or falling.

An alternative to FSGM is continuous glucose monitoring systems (CGMS), which measure glucose levels via a subcutaneous sensor every few minutes. CGMS is predominantly used in ambulatory settings and has been shown to improve glucose regulation. Several studies have confirmed the accuracy of CGMS compared to FSGM in surgical and medical wards, reporting an overall mean absolute relative difference ranging from 9.4 to 12.9, making it acceptable for use in surgical wards. Other studies have reported that CGMS in surgical and medical wards results in superior glycemic control, reduced hypoglycemia, insulin usage, and in-hospital complications, and detected significant duration of both hypo- and hyperglycemia despite protocolized perioperative diabetes management compared to FSGM.

Studies on patients' perspectives of CGMS have been limited to everyday life and outpatient settings. One review on patients with type 1 and 2 diabetes experienced improved convenience, control, and freedom by the use of CGMS but were also overwhelmed by data and frustrated by inaccuracy, and technical issues, which is consistent with findings from another review of patients with diabetes type 2. Another study reported that patients with type 2 diabetes found the technology helpful for disease management, although it could also serve as an unpleasant reminder of disease progression and cause discomfort.

One case report has described nurses' experiences with CGMS in hospital wards for patients with type 1 diabetes. The nurses experienced an increased workload due to difficulties hearing the device receiver, leading to more frequent patient observations.

In summary, CGMS has been reported to be safe and beneficial in ambulatory settings, while challenges and knowledge gaps remain in hospital wards. To date, no studies have compared glucose levels from CGMS with those from a laboratory plasma glucose analyzer as the reference. This study aims to investigate the effect of CGMS compared to FSGM in patients with hyperglycemia in general surgical wards on glucose levels, complications, length of hospital stay, and patient satisfaction and experience with glucose management during hospitalization and up to three months after discharge. Additionally, the study will investigate the nursing staff's workload and experience in the surgical ward, and the accuracy of CGMS throughout hospitalization, including during surgical procedures and medical imaging.

Seven substudies will be conducted:

Substudy 1 - Glucose levels and management for surgical patients in relation to hospitalization: Compares point-of-care glucose levels and management using point-of-care FSGM and point-of-care CGMS during hospitalization and FSGM and continuous glucose monitoring (CGM) up to three months after discharge.

Substudy 2 - Patient satisfaction with glucose monitoring and management in surgical wards: Compares patient satisfaction with glucose monitoring and management for surgical patients using point-of-care FSGM and point-of-care CGMS during hospitalization.

Substudy 3 - Nursing staff's glucose monitoring and management workload in the surgical ward: Compares the nursing staff's workload with point-of-care FSGM to point-of-care CGMS for surgical patients.

Substudy 4 (qualitative study) - Patient experience of glucose monitoring and management in relation to hospitalization in surgical wards: Compares the patient experience with point-of-care FSGM to point-of-care CGMS and glucose management during hospitalization in the surgical ward and one compares the patient experience of FSGM with CGM one month after discharge.

Substudy 5 - Continuous glucose level for surgical patients in relation to hospitalization in the surgical ward: Compares the continuous glucose levels when glucose monitoring and management are performed by point-of-care FSGM and point-of-care CGMS in the surgical ward. Further, it compares continuous glucose levels using point-of-care FSGM and CGM after discharge.

Substudy 6 - Accuracy of CGMS for surgical patients during hospitalization: Investigates the accuracy of CGMS by comparing CGMS data with FSGM and plasma glucose data.

Substudy 7 (qualitative study) - Nursing staff's experience with fingerstick monitoring and CGSM for surgical patients: Compares the nursing staff's experience with point-of-care FSGM to point-of-care CGMS and glucose management for surgical patients.

Inclusion criteria

• Hospitalized patients (≥ 18 years old) in surgical wards
• Glucose measurements at least 4 times (OUH) and 3 times (SUH) daily for at least three days, prescribed by surgeon
• Expected hospitalization for at least three days
• Communicates in Danish
• Signed a declaration of consent to study participation
• At risk of hypo- and hyperglycemia (with or without a diabetes diagnosis)
• Specific for substudy 4 inclusion criteria as above with the following add on: Patients being treated with insulin at discharge and patients residing within the OUH admission area.

Exclusion criteria

• Cognitively impaired patients
• Indication for glucose monitoring solely because of parenteral nutrition treatment
• Patients admitted with a CGMS
• Patients from the point-of-care fingerstick capillary glucose monitoring group cannot be included in the continuous glucose monitoring system group

Eligibility criteria solely for substudy 7

Inclusion criteria

• Nursing staff with at least one month of experience with both point-of-care fingerstick capillary glucose monitoring and continuous glucose monitoring system and are registered nurses or certified nursing assistants