Abstract: A novel hyperbaric oxygenation apparatus, and related methods, the apparatus comprising a chamber in the form of a disposable inflatable bag of impervious inexpensive synthetic resinous material which can be used at any desired location, such as a hospital, a home or other site where oxygen can be appropriately made available. The pressure of the oxygen in the collapsible bag is pulsated between maximum and minimum positive values. The patient cyclically experiences first a medicinal increase in the blood gas levels in the limb under treatment with a corresponding restricted bloow flow and, thereafter, a progressive return to normal blood flow rates in the limb of the patient as the pressure in the chamber changes from maximum to minimum positive pressure. A respirator, normally used for intubated respiratory patients, in conjunction with a single oxygen influent/effluent port in hyperbaric oxygenation apparatus is efficacious to provide the oxygen and generate the desired pressure variations.