Animal trials usually involve a ethics committee. The big problem is that outside of mathematical/computer experiments, it is almost impossible to do medical testing in an ethical way. With exception to experiments done on brain dead (which still involve some measure of uncertainty), on who or what should test be conducted on. In the past we used war criminals or criminals sentenced to death, but that has an obviously ethically problem. We could use military recruits that volunteers, or poor people who would volunteer in exchange for monetary compensation, but how well understand is the consent and how ethical is it use people like that? We could use patients who are out of options, but how ethical is it to exploit people who has no realistic choices?

It is hard to view animal testing as anything else than cruelty to animals. I can only hope that it was there was no other options, and that they indeed got anaesthetised.

(Someone here mentioned experiments in breathing in oxygen-rich perfluorocarbons that used navy recruits. I have seen discussions about how much those consent should actually count considering the power balance and hierarchical culture that exist in the military).