A Los Angeles jury Tuesday found in favor of Childrens Hospital of Los Angeles and two doctors in a $19-million civil lawsuit filed by a Tujunga man who said they had operated on his infant son without his consent. Eduardo Rivas sued in Los Angeles County Superior Court in June, alleging that doctors had operated on his 6-month-old son, Nathan, to repair a double hernia in 2007 after he had refused permission. After the surgery, Nathan, who was born four months premature and arrived at the hospital with a nasal breathing tube, became dependent on a ventilator and feeding tube.