record

but: not sure at all at all

I've made this point before, but it's worth restating that it's far too dangerous to guess on abbreviations in medical reports. I translate a lot of hospital discharge notes for patients taking part in clinical trials, and unless it's something obvious like BD for blood pressure followed by a logical set of figures I always ask the client to tell me what it stands for. My dictionary of Abkürzung und Begriffe in der Medizin contains 9 terms that could match DS. If the client can't provide any further information, I would suggest highlighting the term and providing suggestions as translator's notes, but certainly not simply putting in your best guess.