If the severed limb has been stored at room temperature, then surgery performed after 12 hours has a higher failure rate. If the limb has been stored properly at a reduced temperature (without freezing), then surgery can be done later but outcomes worsen as the interval before reattachment increases.
Indications for hyperbaric oxygen therapy in these patients:
(1) prolonged interval between the accident and the reattachment procedure
(2) suboptimal preservation of amputated structure (kept at room temperature, etc)
(3) disturbed microcirculation in the reimplanted limb
(4) disorder of the arterial anastomosis (thrombosis, vasospasm, etc) pending definitive therapy
(5) reattachment of an ear or other structure for which conventional surgery is often unsuccessful
Outcomes associated with hyperbaric oxygen therapy:
(1) reduced infection rate
(2) improved healing
(3) greater overall success rates