Open wounds are treated the same in the back country as they are treated in your kitchen:
- Direct Pressure
- Pressure Point
- (now's a good time to call 911, if bleeding so far is uncontrolled)
Direct pressure - apply bandage or cloth or clothing to the wound. Never remove the cloth/bandage, as that will remove the clot and repeat the bleeding again.
Elevate the wound above the heart if possible.
Pressure Point - apply pressure to the arteries (not veins) which supply blood to the affected area, at a point between the wound and the heart, and at a place closer to the wound, which crosses a bone. This reduces pressure and supply of blood to the wound; the closer to the wound you do this, the less you affect other areas of the body which aren't injured.
Tourniquet - last resort; do this when you expect to lose a limb. Once applied, never remove - let emergency personnel handle this. If you do apply a tourniquet, mark the approximate time on the victim's head. Use a pen or blood to do this.
It is a debatable topic to remove dressings; remember that the priority is to stop blood. When you are at home recovering from surgery, your discharge instructions may call for dressing changes. But there, you are in a controlled environment with easy access to help, and, blood flow has largely been controlled already - that's why you were sent home.
But when you are in the wild, there is no guarantee of medical care coming soon. Therefore, your priority for wound care is to control and prevent further bleeding. A distant second priority is healing. Wounds should be kept relatively moist, as this promotes reepithelialization (healing). The bloody gauzes you use are moist.
Also, to prevent infection, the body itself has its own enzymes which it uses for autolytic debridement, a process the body performs to dissolve necrotic tissue.
Even if you determine that the wound has more or less healed, and the removed dressing doesn't indicate more bleeding, the wound should still be kept covered and moist; this protects it from injury, and prevents it from drying as that will slow down the healing.
One more thing: in the wild, you need to watch out for predators. Discarding bloody dressings can invite animals, you want to minimize this risk.
Keep the bandages on as long as possible.
As to giving liquids:
American Red Cross is ambiguous, Army manuals say absolutely DO NOT.
The issue is if the person goes unconscious; in this case, they could expel their stomach contents and then choke. The Army manual states you should turn the head if you must leave the victim unattended to prevent choking - and to not administer food or liquid.
Having said that, not every one goes into shock upon bleeding. In this case: yes, give fluids.
Also, don't give aspirin (that reduces blood's ability to clot), don't give acetominophen (that can upset the stomach and cause vomiting), and don't give ibuprophin or any NSAID, as that reduces swelling - the very thing the body does to reduce blood flow to an area that is injured. And it can mask other injuries that need to be looked at - like headaches and stomachaches. Basically: suffer the pain. If it's Really, Really bad, then Tylenol, Advil, or aspirin isn't going to help anyway.
Check and Treat for Shock (Army Study Guide)
First Aid/CPR/AED PARTICIPANT’S MANUAL (American Red Cross)