“…12,13 We chose to administer fentanyl intranasally due to its ease of use in multiple settings, onset within minutes, [14][15][16][17] duration of action of around 60 minutes at maximal effect, 15,16 70% to 89% bioavailability, 18,19 and acceptability by patients. 20,21 We hoped the onset within minutes [14][15][16][17] might offer an advantage over other opioids when used in anticipation of movement, especially for activities where patients may not be able to anticipate the need for ambulation very far in advance. We also hoped the short duration of action 15,16 might avoid prolonged or excessive sedation after the stimulation of exertion was over, for this vulnerable population.…”