the use of suction has all ways been in debate, put it to you how I was taught.
If you are more then 2hrs from hospital care, and only pre hospital care is availible, using MECHANICAL (never your mouth) within five minutes of the bite, after the five minutes, the venom is diluted in the blood and suction will do nothing.
That said, many EMS agencies have eliminated suction for venomous bites, and only some will still use a constricting band.
my SOP's state that I am NOT to use constricting bands, nor suction, after initial assessment (LOC and ABC's) administer o2, elevate patient above the bite site, clean and dress the wound and cover with cold packs. patching through to patient drop off is a wise Idea so they can procure the needed anti-venom before you arrive.
This is all text book, from my 5 years of pre-hospital medical care experience, If I have a BLS unit or an ALS unit and can transport, I will. If im miles in the back country and the only thing to help a buddy is me and I have a snake kit ( not generally carried this far north) I will use suction and do WHATEVER I can to aid him/her.
theres a time and a place, situation dictates action. plain and simple