Hyperbaric Oxygen Treatments Attenuate the Neutrophil-to-Lymphocyte Ratio in Patients with Idiopathic Sudden Sensorineural Hearing Loss

Objective Hyperbaric oxygen therapy (HBOT) is a promising treatment in the management of idiopathic sudden sensorineural hearing loss (ISSNHL), but the specific mechanisms of HBOT in ISSNHL are still unclear. The curative effects of HBOT in many diseases are related to the attenuation of inflammatory response. The neutrophil-to-lymphocyte ratio (NLR) is a new inflammatory marker that can be assessed quickly. We investigated the relationship between HBOT and the inflammatory response in ISSNHL using the NLR. Study Design Case series with chart review Setting Tertiary teaching and research hospital Subjects and Methods Between December 2007 and December 2013, 41 ISSNHL patients who underwent HBOT, 45 ISSNHL patients who did not undergo HBOT, and 14 healthy control subjects who underwent HBOT were included in the study. NLRs were assessed at 2 time points: at baseline (pretreatment) and on day 1 after 10 sessions of HBOT (posttreatment). Audiometric testing was performed at the above 2 time points. Results The mean post-HBOT NLRs, neutrophil, and white blood cell count values of the ISSNHL patients were significantly lower than their pretreatment values (P < .001). Compared with the ISSNHL patients who did not undergo HBOT, the posttreatment NLR levels of the ISSNHL patients who underwent HBOT were much lower (P = .036). Higher relative hearing gains were significantly associated with a greater reduction in the NLR after HBOT (r = -0.885, P = .001). Conclusions The beneficial effect of HBOT on ISSNHL may be mediated at least in part by a decrease of inflammation.