From what I know you`re supposed to follow the first part of the SID.In case that the aircraft capabilities cannot meet the requirements(gradients),than the airport,togheter with the publisher of the charts develop an escape route named the Engine Out procedure.In Jeppesen Manuals,it`s the chart nr 10-7 for every airport.At least this is the SOP in our Company.If you don`t have a 10_7 you`ll just follow the first part of the SID until clear of obstacles then decide the course of action.