Sarah, I am so very sorry to hear of the death of your husband! Please accept my condolences for your loss.
If you are not a member of the Home Dialyzors United group, you might briefly join--or at least call them--and see if they have members who might want some of these supplies or know of someone on dialysis who could use them. http://homedialyzorsunited.org
Otherwise, for unused NxStage fluid, we have a tip that veterinarians use PD fluid to dialyze cats and dogs, and are happy for the donation (possibly because they still charge for the service, but at least it still gets used!). It can also be used to water plants--lots of good minerals in it. So, that's not a total waste if you can find a nearby vet who would take it.
The rest of the equipment--BP cuff, stethoscope, etc., would likely be welcomed by an overseas relief agency (Philippines?) or even one more local to you. I did a quick Google search for "where to donate used medical equipment," and lots of options showed up. Goodwill, St. Vincent De Paul, etc. would take these as well.
Needles and syringes may be usable overseas, or perhaps by crafters or mechanics (it can sometimes be handy to have a syringe for epoxy, etc.). I'm not sure, personally, that I'd want to take the risk of donating those anywhere, though. in case someone hurts themselves and comes back to you with a lawsuit. You could load those into a sharps box and just throw them away.