Factors entering into the decision:
(1) The person's body is caught under debris or in a mangled vehicle.
(2) Amputation is the only means to extricate the person in the time frame allowed.
(3) The person has to be moved immediately due to:
(3a) a critical clinical condition that is deteriorating
(3b) risk of fire, rising water, building collapse, chemical exposure, explosion, or some other environmental factor.
(4) The status of the limb (extremely mangled vs simply trapped).
Some things that might be tried to aid in the extrication:
(1) applying oil or some lubricant
(2) using a car jack or lever to lift the weight
If possible, the decision should be discussed by 2 or more physicians prior to performing the operation.
Complications:
(1) acute hemorrhage with shock
(2) infection
(3) severe pain