malcolm:
Sorry, but you have absolutely no knowledge of emergency medicine. In fact, if anything, you have negative knowledge. Your ignorance actually sucks the knowledge from others. I feel less knowledgeable just consdiering the comments you've made here.
The VAST MAJORITY of IVs given outside of a hospital are gravity fed. Period. Even most of those in hospitals are gravity fed through a pump. The fact that you believe this to be false just means that you have NOT spent even the MINIMAL amount of time a simple Google search would require to show how ignorant you are.
I was a military medic for 14 years, including a recent deployment into Iraq for a year. I gave IVs there. They were gravity fed, and don't have holes in the tops of bags. That's why they use bags now, instead of bottels. You don't have to have a hole. If you wonder why this matters, look up the terms "sterile technique", "blood sepsis", and "air embolis" (no, that isn't a new shoe from Nike). I've given IVs to others under varying conditions, including combat situations, emergency situations, field situations, and in a hospital setting. My brother works as a Physician's Assistant, specializing in ortho- and neuro-surgical procedures. He also uses gravity-fed IV bags, without holes in the top. A simple look at one of the major suppliers (Baxter, for example) will show the ignorance of your claim.
Pressurization is sometimes used, but rarely. It used when, for whatever reason, you can't hang a bag. In that situation, there's devices (like BP cuffs) that wrap the bag and apply pressure, or the bag can even be placed under the patients head. Sometimes pressurization is used to increase the fluid flow...but that can be dangerous as you can blow a vein (making an ugly bruise and requiring you to find a new IV site) or induce a circulatory overload (push fluid into the system faster than the body can remove it, and you can fill up the circulatory system enough that the heart can't pump).
In short, I have the knowledge of the subject; you are an ignorant, uneducated layman without even the basic decency or drive to do minimal research before spraying bovine excrement at everyone you think you can reach. You're embarassing yourself (which is somewhat humorous).
If you'd like, I can get pictures of all the equipment (I have a fully-stocked aid bag at home), and even video of a gravity-fed IV in action. Of course, you could get a clue and just walk through a hospital...you'll see plenty of gravity-fed IVs.
), I found enough apparent visual landmarks that lead me to think that the actual impact point of the main fuselage must be farther to the "right" and beyond the camera frame.
