Most of the props in the sanatorium were left over from when the building was abandoned. Apparently the building owners could not get a cleaning crew to stay to properly remove the materials longer than a week. They would all leave after experiencing supernatural occurrences.
Most of the special effects for the film were shot in one day after principle photography was wrapped. The special effects were first constructed with silicone heads life cast from the actors. They were then enhanced with digital effects afterwards. The actors were shot in the same positions and then their faces were composed on top of the dummies.