Doctor: Charlie Sounded Like He Was in Severe Pain

2/1/2011 6:00 PM PST

Charlie Sheen's Doctor Video : He Sounded Like He Was in Severe Pain

Dr. Paul Nassif -- the guy who called 911 the night Charlie Sheen was rushed to the hospital -- described Charlie as sounding like he was in "severe pain" when he spoke to him on the phone that night ... but couldn't tell if Sheen was inebriated.

Dr. Nassif also described the drive home from the hospital with Charlie -- during which, as we first reported, Charlie was acting like nothing ever happened.

The interview airs tonight on HLN's "Showbiz Tonight."