Oxigenoterapia hiperbárica en el tratamiento de la hipoacusia súbita neurosensorial

Abstract

Sudden sensorineural hearing loss (SSHL) is a frustrating and frightening experience for a patient. It occurs within 72 h and is defined as hearing loss of at least 30 dB at three or more consecutive frequencies. Several therapeutic methods have been applied so far for the treatment of SSHL. Steroids are the primary method, but vasodilators, anticoagulants, antioxidants, antivirals, vitamins, and plasma expanders are also used [1].

The cochlea is an organ with a high oxygen demand. However, due to its location in the temporal bone, the blood supply is limited to a single terminal artery (labyrinthine). Therefore, the cochlear hair cells are vulnerable to a decrease in tissue oxygen supply [2]. According to the vascular etiologic theory of SSHL, the reduction in blood flow to the inner ear may result in local ischemia, and there is an absolute need to increase the oxygen level in the perilymph. Studies have supported that the partial pressure of oxygen in the blood and via the capillaries of the cochlea increased significantly under hyperbaric conditions [3]. This process can minimize ischemic damage following SSHL and predispose a patient to vascular recovery [4]. Hyperbaric oxygen (HBO) was first used in the treatment of SSHL in the late 1970s [5]. HBO can increase perilymph oxygenation when administered once daily in a multiplace hyperbaric chamber at a constant pressure of 2.2 atmospheres [6, 7]; each HBOT session consists of two 40 min periods under 100% oxygen conditions, with an intervening 5 min air break to prevent oxygen toxicity [6].

According to the 2019 American Academy of Otolaryngology–Head and Neck Surgery guidelines (updated) for the treatment of SSHL, HBO therapy remains an option but only when combined with steroid therapy for either initial or salvage therapy [8]. It was suggested that initial therapy should begin within 2 weeks of SSHL onset and that salvage therapy should start within 1 month of SSHL onset [8]. However, in the Consensus Conference on Hyperbaric Medicine in 2016, HBO combined with medical therapy was strongly recommended for use in patients with SSHL who presented within 2 weeks from disease onset [9].