Which of the following steps is essential when administering an epinephrine auto-injector?

Pressing the device firmly in place and holding it for 3 to 5 seconds is essential when administering an epinephrine auto-injector because this ensures that the medication is adequately delivered into the muscle. Epinephrine needs to penetrate the muscle tissue effectively for optimal absorption and to achieve the desired rapid response in an acute allergic reaction or anaphylaxis. The recommended duration of 3 to 5 seconds allows the medication to be properly injected and absorbed.

Holding the device in place during this time also prevents the injector from being accidentally dislodged and ensures that the entire dose is delivered as intended. Proper technique is crucial in emergency situations where the timely administration of epinephrine can be life-saving.