I have come to find that the Med Kits are completely useless for me because though you do get a blood bag and a syringe the is no way to check the blood and blood test kits seem very hard to find. It was easier to find a saline bag and i just think it would be nice to put a blood testing kit inside the Med Kit so you can effectively heal another player.
Blood Bags aren't nearly as good as the Saline Bag so just make blood bags a little more safe and practical inside the med kit.