You are administering oxygen at 2 lpm through a nasal cannula to a confused patient. During transport, you note the SpO2 to be 91%, up from 90% on scene. The patient remains confused. What would your next action be?

A) Keep the oxygen flow at 2 lpm and continue to monitor
B) Administer oxygen at 15 lpm through a nonrebreather mask
C) Start positive pressure ventilation with supplemental oxygen
D) Increase the oxygen flow to 4 lpm

D) Increase the oxygen flow to 4 lpm