By Steve Gorman LOS ANGELES (Reuters) -“Friends” star Matthew Perry died from the “acute effects” of the powerful sedative ketamine that, combined with other factors, caused the actor to lose consciousness and drown in his hot tub, according to an autopsy released on Friday. The report from the Los Angeles County Medical Examiner came nearly seven weeks after Perry, 54, who publicly acknowledged decades of drug and alcohol abuse, was found by his live-in assistant floating face down and lifeless in the jacuzzi of his Los Angeles home. Toxicology tests found ketamine, a short-acting anesthetic …