Q) A 60 year old male is contemplating hyperbaric oxygen therapy for radiation proctitis. Which of the following is not true regarding this?
A. Indicated in acute radiation proctitis but not in subacute or chronic radiation proctitis B. Oxygen increases the growth of residual tumor and hence tumor should be completely resected C. Complications include Parkinsonism, barotrauma D. Usually 30-40 sessions are required for treatment
Ans a
Hyperbaric oxygen overcomes chronic tissue hypoxia in radiation damaged tissues and with repeated sessions induces growth of regenerative tissue, capillaries, and epithelium. Successful therapy may take multiple sessions. 18 to 60 treatments
Ref Shackelford page 2211
HBO treatments for hypoxic wounds are usually delivered at 1.9 to 2.5 atm for sessions of 90 to 120 minutes each. Treatments are given once daily, five to six times per week and should be given as an adjunct to surgical or medical therapies. Clinical evidence of wound improvement should be noted after 15 to 20 treatments.
Complications of HBO therapy are caused by changes in atmospheric pressure and elevated PO2. Middle ear barotrauma, ranging from tympanic membrane hyperemia to eardrum perforation, is the most common complication.
Pneumothorax brain oxygen toxicity, manifested by convulsions resembling grand mal seizures; oxygen lung toxicity, resulting from damage from oxygen free radicals to lung parenchyma and airways and ranging from tracheobronchitis to full-blown respiratory distress syndrome; and transient myopia.
Absolute contraindications to HBO therapy are
(1) uncontrolled pneumothorax
(2) current or recent treatment with bleomycin or doxorubicin (potential aggravation of cardiac and pulmonary toxicity), and
(3) treatment with disulfiram (increases risk of developing oxygen toxicity).
