Pharyngeal swallowing and swallow apnea in spontaneous swallows of saliva and swallowing maneuvers of contrast medium, with the respiratory-phase pattern E-E, at baseline recordings, indicated “baseline” and after infusion of either morphine (0.1 mg/kg) (A) or midazolam (0.05 mg/kg) (B). After infusion was stopped, recordings were repeated at two occasions, after 10 and 30 min, respectively. The start of pharyngeal swallowing was defined as the onset of pressure rise at the tongue base (TB), and all pharyngeal manometry events as well as start and end of swallow apnea were referenced in time (ms) to this event. Start of swallow apnea is indicated “Apnea-start” and end of swallow apnea as “Apnea-end.” Apnea before swallowing was prolonged after morphine (A). Mean (ms) ± 95% CI. *P < 0.05 versus baseline. C = swallowing maneuvers of contrast medium; E-E = the respiratory-phase pattern with inspiration-expiration-swallow apnea-expiration; Mi = midazolam; Mo = morphine; Mo_10min/Mi_10min, Mo_30min/Mi_30min = recordings 10 and 30 min after infusion of morphine/midazolam was stopped; Ph Up-start and Ph Low-start = onset of pressure rise at the upper and lower pharyngeal transducer level; S = spontaneous swallows of saliva; TB-start = onset of pressure rise at the tongue base, that is, onset of pharyngeal swallowing (= time 0); UES = the upper esophageal sphincter; UES-start = onset of pressure rise at the UES; UES relaxation-start = onset of relaxation of the UES.