Subcutaneous Glucagon May Be Better Than Oral Glucose for Prehospital Treatment of Symptomatic Hypoglycemia

The optimal management of symptomatic hypoglycemia in the prehospital setting remains uncertain, particularly in the absence of intravenous access (1,2). We performed an audit in Toronto, ON, Canada, and compared prehospital patient care outcomes following administration of oral glucose gel versus subcutaneous glucagon. For the city’s population of >2.5 million people, there is a single Emergency Medical Service system made up of both ambulance and fire services, which are directed by one base hospital.

Our study included all consecutive patients attended by primary care paramedics for symptomatic hypoglycemia, defined as a capillary glucose concentration <4.0 mmol/l (72 mg/dl). Initially, the primary care paramedics followed a standard protocol, using up to 20 g of 100% d-glucose gel, given orally in 50-ml doses. After a period of certified training, the primary care paramedics began to administer 1 mg subcutaneous glucagon, stored in lyophilized form and reconstituted in 1 ml sterile water before administration. All other aspects of primary care paramedic training and patient care between periods remained otherwise unchanged. A repeat dose of either agent could be administered if the first dose was not effective after 10 min. Primary care paramedics were required to record each patient’s initial capillary glucose concentration and 15-point Glasgow Coma Scale (GCS), and to reassess these parameters every 10 mins until arriving at the hospital. The Research Ethics Board of Sunnybrook and Women’s College Health Sciences Center approved this study.

During the study period, primary care paramedics encountered 601 patients with confirmed hypoglycemia, of whom 86 were excluded, mostly because they did not receive any treatment or a posttreatment capillary blood glucose concentration was not recorded.

The baseline characteristics and outcomes of the remaining glucagon (n = 235) and glucose gel (n = 282) recipients are presented in Table 1. Those treated with subcutaneous glucagon had a significant 0.9 mmol/l (16 mg/dl) greater net increase in mean capillary glucose concentration than those who received oral glucose. Glucagon recipients displayed greater improvement in their GCS, required fewer repeat drug doses, and had fewer related safety or logistical problems than glucose gel recipients, such as patient treatment refusal or inability to swallow the gel (Table 1).

Incomplete or imprecise data recording or GCS assessment, as well as lack of masking between treatments and outcomes, likely biased this retrospective study. The novelty of subcutaneous glucagon might have carried with it a greater expectation about its potential efficacy in the eyes of the primary care paramedic, and may have enabled them to be more familiar with, and capable of, administering subcutaneous glucagon than oral glucose gel.

Our study and those of others (3,4) suggest that subcutaneous glucagon may be easier to administer than oral or intravenous glucose. While a randomized clinical trial may be more informative about the optimal method to treat serious hypoglycemia in a community setting, subcutaneous glucagon will likely remain a sensible and safe treatment option in the hands of a trained user.