Air splints need to be used carefully for sure, but they also have the benefit of being able to stabilize low blood pressure due to shock in emergencies. They can save a life and have literally done that when used carefully for set periods of time. Naturally for too long or too much pressure can cause compartment syndrome and careful attention to pressure due to altitude and atmospheric pressure changes are needed. Training is the most important thing.

Training and practice are also very important when it comes to suturing in the field, proper practice and wound care are essential. Naturally the larger the wound and the deeper the wound the more skill and knowledge is required.

As far as the V-Zap and such devices, I have used this method to treat snake bite, many spider bites and numerous other venomous stings over the years all with great success. This was after there was significant swelling and pain.

I know of several doctors who have used this method many times with great success and I know personally the doctor who cured river blindness and supervised a 30 year long program using this method in Ecuador. I know several missionaries who use this method all the time to treat snake bite and regularly save lives even when limbs would normally require fasciotomy. The swelling immediately starts to go down, the skin wrinkles up again and the pain goes away very quickly.

All that to say that it does work, and it works well if you do it properly. The V-zap is a lower voltage higher frequency unit and is my preferred device for a first aid kit as it works best for kids and those who are sensitive to electricity. Anyone who can use a TENS unit can use the V-zap, which is not the same for improvised treatment using small petrol engine spark systems which however require fewer treatment cycles.