> I'm curious... why is it that so much antivenin was required? If that much is needed, why do hospitals only stock six vials apiece?
Because odds are they won't need it. They stock to buy time until they can get enough for a single patient.
To put it another way, if there's an average of one patient/year in an area with 10 hospitals, what's the right amount for each hospital to stock? Remember - they have lots of other things that they could stock with comparable odds.
The dose is based on the extent of envenomation, weight of the person, and ongoing symptoms.
Horse serum is actually a giant pain in the ass to deal with. It's a crystalline structure that is really hard to dissolve. And, when it gets dissolved, it tends to foam terribly. It generally takes at least 1/2 an hour of slow mixing to dissolve the crystals and get them to stop foaming.
So, to compensate for the difficulty in mixing the horse serum, they don't put as crystallized serum into a vial, and the dose requires multiple vials. The standard adult dose is 4-6 vials depending on the size of the person.
Hospitals don't stock too much of the stuff (unless you're in an area where rattlesnake bites are endemic) because of cost and infrequency of use.
