The role of hyperbaric oxygen therapy (HOT) as an otoprotection agent against cisplatin ototoxicity

Abstract

PURPOSE: Hyperbaric oxygen therapy (HOT) consists of intermittent inhalations of 100% oxygen at a pressure higher than 1 atm. It is an important adjuvant therapy in pathological processes like soft tissue infections, radiation injury, gas gangrene, osteomyelitis and decompressive diseases. Cisplatin, a potent antineoplastic drug, widely used in cancer therapy is highly ototoxic causing bilateral, irreversible damage to the hearing of high frequency sounds (4-8 KHz). OBJECTIVE:This experimental study conducted at the Faculty of Medicine of Ribeirao Preto, University of Sao Paulo aims to evaluate Hyperbaric Oxygen Therapy as an otoprotection agent against drug toxicity. METHODS: Albino guinea pigs were divided into two groups: in Group A, 5 animals (10 cochlea) received cisplatin, i. p., 8.0 mg/kg/day during three days and afterwards were submitted to HOT; in Group B, 3 animals (6cochlea) received cisplatin, i. p. 8.0mg/kg/day during three days. Guinea pigs were evaluated by acoustic otoemissions (AOE) and scanning electron microscopy (SEM). RESULTS: Group B animals showed loss of auditory functions as measured by AOE and distorted outer hair cells by SEM. In Group A, outer hair cells shown by SEM images were mostly preserved. CONCLUSION: It is presumed that Hyperbaric Oxygen Therapy has a protector effect against cisplatin ototoxicity.