A 10-month-old with Tetralogy of Fallot becomes suddenly irr…

A 10-month-old with Tetralogy of Fallot becomes suddenly irritable, cyanotic, and has rapid breathing during crying. The nurse recognizes this as a hypercyanotic spell (or “tet spell”). To improve systemic vascular resistance and reduce right-to-left shunting, the nurse should do what to help circulation?