Evaluating a Covid-19 Vaccine Centre in the UK Using a DES Model

Efficient management of a Covid-19 vaccine centre (VC) is necessary for proper-functioning of a mass vaccination programme. This study reports on an evaluation of the operational performance of a VC. There are two key considerations: the VC capacity (patients per hour) and the patient flow-time (total time patients spent in the centre). In this paper, Witness Horizon a simulation model tool that can be used to enhance the effectiveness of vaccination facilities is introduced. The model is developed using discrete event simulation. The model utilises animation whilst dynamically displaying key performance indicators. The uniqueness of this approach is the ability to simulate and analyse VC scenarios stochastically by varying hourly arrivals, walk-ins to drive-in ratios, staffing levels, registration, immunization, and observation capacities. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

Improving health outcomes in COVID19: Use of flash glucose monitoring in diabetic ketoacidosis

Introduction: COVID-19 has been linked to an increased risk of new-onset diabetes mellitus and increased incidence of diabetic ketoacidosis (DKA) either as a new presentation or with pre-existing diabetes. Various mechanisms such as impaired insulin secretion, impaired glucose disposal or increased counter regulatory responses are proposed.2 Case report: A 57-year-old man diagnosed with COVID-19 one month prior presented with epigastric pain, shortness of breath and weight loss. Investigations confirmed DKA (pH 7.22, bicarbonate 2.6 mmol/L, blood glucose 11.6 mmol/L, blood ketones 5.8 mmol/L) with HbA1c of 95 mmol/mol. Initial treatment was started as per national DKA guidelines. Upon discharge, the patient was prescribed a basal-bolus regime (total 30 units of insulin) and a FreeStyle Libre flash glucose monitoring (FGM) device. Rapid improvement in blood glucose levels was observed, with regular down titration of insulin and complete discontinuation after 24 days. HbA1c was 37 mmol/mol 96 days later. C-peptide normalised at 3 months for paired glucose at 837 pmol/L. Discussion: The use of diabetes technology (FGM device) with remote monitoring of blood glucose was instrumental in the safe and effective management of this patient. Given that the available literature suggests transient beta-cell dysfunction in the majority of COVID-19 patients resulting in DKA,3 we propose that patients who have been diagnosed with COVID-19 presenting with DKA should be discharged with insulin and FGM from secondary care. This enables remote insulin titration with ease, de-escalation of treatment with confidence and avoiding hypoglycaemia in the recovery phase of the illness in those with transient beta-cell dysfunction due to COVID-19.