What is the primary use of glucagon in a medical emergency?

Glucagon is primarily used in medical emergencies to treat severe hypoglycemia, which occurs when blood sugar levels drop dangerously low. In such situations, the body’s ability to produce glucose from glycogen stores is impaired, and glucagon acts as a critical treatment by stimulating the liver to convert glycogen back into glucose and release it into the bloodstream. This rapid increase in blood glucose levels can quickly reverse the effects of hypoglycemia, helping to prevent serious complications such as seizures or unconsciousness.

Other options, although relevant in different medical contexts, do not align with glucagon's primary use in emergencies. Elevating blood pressure is generally managed with fluid resuscitation or vasopressors, asthma attacks typically require bronchodilators, and acute pain management usually involves analgesics. Thus, glucagon's specific role in addressing severe hypoglycemia distinguishes it as the correct answer in this scenario.