If you had a Mount Rushmore of Emergency Department drugs fentanyl would make a pretty solid case for its inclusion. This synthetic opioid is roughly 100x more potent than morphine. The onset is rapid – two to three minutes. This is in contrast to morphine, which can take up to 20 minutes. The duration of action is relatively short – 30 to 60 minutes. Again, for purpose of comparison, the duration of action of morphine is up to 4 hours. As opposed to other opioids (namely morphine) there is no histamine release.

The risk of hypoxemia and respiratory muscle depression is there of course, but more pronounced when used with other sedative agents (like midazolam). Chest wall rigidity is a rare idiosyncratic reaction that you hope you won’t see, and only responds to paralysis and endotracheal intubation. These patients cannot be bagged! The risk may be increased with large doses (>4 mcg/kg), but it reported to have been seen in doses as low as 1 mcg/kg.

There are two main routes of administration for fentanyl for use in most Pediatric Emergency Department settings. Nebulized, transdermal and oral versions are also available but will not be discussed here.