I cannot imageine mil hospital ships without doors that lock from the outside, but I have zero personal knowlege. If the rooms have toilets and sinks and can lock from the outside, definitely could be dual purpose.
As a general rule, naval ships have very few spaces which are locked from the outside and even fewer that cannot be opened from the inside. It is a basic safety/ damage control precaution.
That doesn't mean that internal door latches can't be changed relatively fast.
WWG1WGA
Garde la Foi, mes amis! Nous nous sommes les sauveurs de la République! Maintenant et Toujours!
(Keep the Faith, my friends! We are the saviors of the Republic! Now and Forever!)
LonePalm, le Républicain du verre cassé (The Broken Glass Republican)