There is no NEC code, or IEEE code regarding the orientation of the receptacle. But... the question has been raised to NEC many times and if you look at any GFCI receptacle you will notice the orientation of the writing is with the ground up. Which brings up a concern that 90 percent of all plugs that are made for devices are designed to have the ground down.
For safety sake in a hospital where an oxygen rich atmosphere exist you will want to go with the standard practice of most electricians and engineers of having the ground up. Reason being: should the center screw of the receptacle cover come off and the plate fall off it will land on the ground terminal if the plug is not seated all the way in. Or, should any metal material, scalpel, wire, picture frame, necklace fall on a partially seated plug you will not get a flash arc event causing a possible oxygen explosion. Hopefully some day the manufaturers of plugs will design them with the ground up.
But in all cases it is a far better liability concern to always mount your ground up. If your plug is to be sideways, mount it with the large blade, Neutral in the up position also.