Why use dextrose instead of glucagon for lows? B/C patient liver function may be compromised more often in the in patient setting?
Additionally, dextrose is inexpensive, more available (rural county hospitals don't stock glucagon), easier to mix and store, has a longer shelf life, and most importantly, has a far quicker response time.
Glucagon has promise for outpatient work, where the volume of fluid is much more of a factor, though the stability and cost are still unsolved problems. The patients we treat are in a bed, monitored periodically by trained healthcare providers, with routine access to a pharmacy.
TL:DR Hospital control is just a different beast!