For this review, the MEDLINE, EMBASE andCochrane databases were investigated for relevant studies. These searches wereconducted in order to identify clinical trials on the treatment of suddensensorineural hearing loss. The PICOS structure was utilised in order to definethe research strategy. It was mandatory for the published studies to be writtenin the English, Dutch or German language.
Also, the date of issue had to be between2002 and 2017 (timespan of 15 years). The following search terms wereemphasized while conducting the research: suddensensorineural hearing loss, suddendeafness and idiopathic suddenhearing loss. Restrictive search terms were hyperbaric therapy, oxygen therapy, corticosteroids and dexamethasone. In order to specify onsubject matters, a differentiation was established based upon oral, intratympanic and intravenoustreatments. Supplemental information was gathered by utilising the snowball method, a technique which exploitsreferences within articles. Criteriafor inclusionAllarticles were identified by conducting a comprehensive search through variousdatabases. In order to be integrated in the review, the articles had to meetcertain criteria. Each study had to be a clinical trial that compared thetreatment of sudden sensorineural hearing loss with a control group.
Intravenous,oral and intratympanic corticosteroid treatment combinations with/withouthyperbaric oxygen therapy were included. Patients with a hearing lossequivalent to at least 30 dB fit inclusion. Criteriafor exclusionSeveral criteria for exclusion had to becontained in order to keep unwanted data out of prospect.
Several criteria forexclusion were applied: 1) Patients who had an etiological cause for theirsudden sensorineural hearing loss such as noise, infections or medicines. 2)conductive forms of hearing impairment. 3) case reports, comments on articlesand reviews were excluded 4) Only the English, Dutch or German language wereassessed as viable. Reports were not excluded on behalf of the qualitative orquantitative definitions of idiopathic sudden sensorineural hearing loss.
Patientswho received therapy after 30 days of the onset of symptoms were excluded fromthe study DataextractionAfterscreening on title, abstract and full text, the remaining articles werecritically appraised for risk of bias. The primary outcome measure was thepure-tone average (PTA) score. Pure-tone average (PTA) is an average hearingsensitivity test on frequencies as 500, 1000 and 2000. Additional outcomemeasures of interest included objective measures, such as speech receptionthresholds and speech discrimination scores, and subjective measures, such asperceived hearing improvement. Outcome data of the included studies wereextracted and analyzed by two independent authors Quality assessmentThe resultsof all studies were reviewed systematically. The following data were collectedfor all patients: age, sex, maximum diving depth, diving time, diving gas, extentof hearing loss, presence of vestibular symptoms, time between dive and symptomonset, time between symptom onset and hyperbaric oxygen therapy, hyperbaricoxygen treatment table, number of hyperbaric oxygen therapy sessions,additional corticosteroid treatment, follow up, diagnosis, and outcome. 1) evaluation of the studypopulation, (2) the intervention, (3) the control treatment, and (4) thereported out- comes.
Assessment of the validity included (1) baseline criteria,(2) standardization of intervention and control groups, (3) standardiza- tionof the outcome, (4) randomization, (5) blinding for intervention, (6) intentionto treat analysis, (7) missing data, (8) handling of missing data, (9) loss tofollow-up, and (10) cross-over. Aftercritical appraisal, we extracted study characteristics and descriptive data onhearing loss and otologic manifestations from the included studies. If theprevalence was not given in the article, it was calculated by dividing thenumber of affected patients by the total number of assessed patients. The initialsearch resulted in 18 articles of which 5 didn’t meet the inclusion criteria.The remaining 13 articles are represented in this review. With the use ofreference searching I was able to find a few extra articles which gave somemore insight in the illness itself.
The total numbers that met the inclusioncriteria was brought to 17.