Hearing Outcomes of Treatment for Acute Noise-induced Hearing Loss: A Systematic Review and Meta-analysis.

Abstract

To determine the efficacy of various treatment modalities used for acute noise-induced hearing loss (aNIHL) from acute acoustic trauma (AAT) via a systematic review and meta-analysis. PubMed, Cochrane, and Scopus databases. The scientific literature was searched up to October 2018 for articles evaluating hearing outcomes after treatment of aNIHL. The following were extracted: Oxford level of evidence, number of patients, mean age, time to presentation, source of noise exposure, method of treatment/intervention, baseline hearing threshold, posttreatment hearing threshold, hearing gain, proportion of patients with no recovery, partial recovery, or complete recovery, and treatment complications. Sixteen studies with 932 patients met inclusion criteria for systematic review and four studies with 187 patients were included in the meta-analysis. Treatment modalities identified were steroids, vascular agents, nootropics, antioxidants, vitamins, cell apoptosis inhibitors, and hyperbaric oxygen therapy. Meta-analysis demonstrated significant improvement in mean hearing threshold for patients with high-frequency hearing loss, those treated within 48 hours, and those receiving treatment with a nootropic agent. Significant heterogeneity was present in experimental design among included studies and many were of lower levels of evidence. More prospective, large scale, randomized, double-blinded, placebo-controlled clinical trials are required to determine optimal treatment regimens for patients suffering from aNIHL caused by AAT.