Ambulance clinician use of capillary blood ketone meters to improve emergency hyperglycaemia care: A stepped-wedged controlled, mixed-methods feasibility study

Aim

To determine whether it was feasible, safe and acceptable for ambulance clinicians to use capillary blood ketone meters for ‘high-risk’ diabetic ketoacidosis (DKA) recognition and fluid initiation, to inform the need for a full-powered, multi-centre trial.

Methods

Adopting a stepped-wedge controlled design, participants with hyperglycaemia (capillary blood glucose >11.0 mmol/L) or diabetes and unwell were recruited. ‘High-risk’ DKA intervention participants (capillary blood ketones ≥3.0 mmol/L) received paramedic-led fluid therapy. Participant demographic and clinical data were collated from ambulance and hospital care records. Twenty ambulance and Emergency Department clinicians were interviewed to understand their hyperglycaemia and DKA care experiences.

Results

In this study, 388 participants were recruited (Control: n = 203; Intervention: n = 185). Most presented with hyperglycaemia, and incidence of type 1 and type 2 diabetes was 18.5% and 74.3%, respectively. Ketone meter use facilitated ‘high-risk’ DKA identification (control: 2.5%, n = 5; intervention: 6.5%, n = 12) and was associated with improved hospital pre-alerting. Ambulance clinicians appeared to have a high index of suspicion for hospital-diagnosed DKA participants. One third (33.3%; n = 3) of Control and almost half (45.5%; n = 5) of Intervention DKA participants received pre-hospital fluid therapy.

Key interview themes included clinical assessment, ambulance DKA fluid therapy, clinical handovers; decision support tool; hospital DKA management; barriers to hospital DKA care.

Conclusions

Ambulance capillary blood ketone meter use was deemed feasible, safe and acceptable. Opportunities for improved clinical decision making, support and safety-netting, as well as in-hospital DKA care, were recognised. As participant recruitment was below progression threshold, it is recommended that future-related research considers alternative trial designs. Clinicaltrials.gov: NCT04940897.