The study actually shows ketamine works as well with anesthetia (45%) as without (40%), if you read the non-anesthetia study linked in https://news.ycombinator.com/item?id=36030251.
(Of course you can argue they are not using enough K at the 0.5 mg/kg mark, because disccociation starts at 1 to 3 mg/kg per StatPearls.)