Several studies have documented the
effectiveness of hyperbaric oxygen in models of acute and delayed
crush injury. Intermittent exposure to hyperbaric hyperoxia serves
to interrupt the injury cycle of edema, ischemia and tissue
necrosis(1), as well as hemorrhagic hypotension(2), which in turn
leads to former edema and ischemia. Tissue ischemia is countered by
the ability of hyperbaric doses of oxygen to elevate tissue oxygen
Furthermore, edema is reduced, secondary to
hyperoxia-induced arteriolar vasoconstriction(4), leading to
improved tissue viability, thereby reducing necrosis(1). Hyperbaric
oxygen has also been studied in models of peripheral nerve
Researchers from the US Air Force School
Aerospace Medicine and Louisiana State University recently sought to
determine what, if any, morphologic changes are associated with
hyperbaric oxygen treated peripheral nerve injury(6). Their model
involved a crushed sciatic nerve in the rabbit. Exposure to
hyperbaric oxygen across the range of current clinical dose
schedules was compared to untreated, and pressure (hyperbaric air)
controls. The extent of nerve regeneration was documented via
morphologic analysis of electron micrographs, by a pathologist
blinded as to group.
All of the animals exposed to hyperbaric doses
of oxygen were reported to demonstrate advanced stages of a healed
nerve, in contrast to both control groups.
As this research was limited to a determination
of regeneration of morphology, the exact effects of hyperbaric
oxygen were not known. The authors speculate, however, that there
may be several suggesting increased myelination, decreased edema,
reduced internal collagen and improvements in neurofilamentous
material density. They conclude that this study provides additional
evidence of a link between tissue oxygen levels and the health of
... all animals exposed to hyperbaric oxygen
"demonstrated characteristics expected of in the advanced stages of
a healed nerve"
- Strauss MB et al.: Delayed use of hyperbaric oxygen for
treatment of a model anterior compartment syndrome. Journal of
Orthopedic Research 1986;
- Skyhar MJ et al.: Hyperbaric oxygen reduces edema and
necrosis of skeletal muscle in compartment syndromes associated
with hemorrhagic hypotension. Journal of Bone and Joint Surgery
- Nylander G: Tissue ischemia and hyperbaric oxygen
treatment. Scand 1986; suppl. 533.
- Nylander G et al.: Reduction of postischemic edema with
hyperbaric oxygen. Plastic and Reconstructive Surgery
- Zamboni WA et al.: Functional evaluation of
peripheral-nerve repair and the effect of hyperbaric oxygen.
Journal of Reconstructive Microsurgery 1995; 11:27-29.
- Bradshaw PO, et al.: Effect of hyperbaric oxygenation on
peripheral nerve regeneration in adult male rabbits. Undersea and
Hyperbaric Medicine 1996; 23(2): 107-113.