Early detection of noise induced hearing loss by extended high frequency audiometery

Surrounding noise, especially in industrial environments, is one of the most common etiologic factors of sensory-neural hearing loss [SNHL], which is not curable, but preventable. By industrialization of communities, the prevalence of the disease and its unfavorable socioeconomic outcome is growing up. Since the preventable defect, early diagnosis has the utmost importance. In recent years, the role of extended high frequency audiometry [EHFA] as a sensitive diagnostic tool for noise induced hearing loss has received much attention. This study deals with the role of EHFA in early diagnosis of this disorder. This was a retrospective cohort study during 2003-4 in Isfahan, Iran. A total number of 30 male labors, aged 20-50 years working in a noisy industrial environment, were compared with an equal number of controls with normal conventional audiometry, and no risk factor for other causes of SNHL according to their history and otoscopic examination. All 60 individuals underwent both types of conventional and extended high-frequency audiometry. Data were analyzed with SPSS software using t-test, paired t-test and correlation tests of Pearson and Spearman. There was no difference between the right and left ears. The exposed subjects had significantly worse hearing than the non exposed group, at all tested frequencies [especially at 16 KHz]. The age effect was notable in both groups. The correlation between high frequency threshold and duration of noise-exposure was significant only at 16, 18 and 20 KHz. The higher mean frequency threshold of the cases was predictable; the normal findings of conventional audiometry, reveal that EHFA can be useful in early diagnosis of acoustic injuries

survey of the different concentrations of epinephrine on the volume of blood loss in septorhinoplasty under halothane anesthesia

Epinephrine usages in septoplasty and Septorhinoplasty have less hemorrhage during operation and blood loss field rule. But under general anesthesia with halothane usage of solutions, epinephrine will be with some risk. The question is which concentrations of epinephrine will be more efficacious and have less complication. This study was arranged as a clinical trial on 80 patients equally divided in four groups. In group 1 we used solution of epinephrine 1/100000 in group 2, solution of epinephrine 1/100000 with normal saline was used. In group 3 we used solution of epinephrine 1/200000 with Lidocaine 1% at last, solution of epinephrine 1/200000 with normal saline was used in the 4th group. Each of the groups included 20 patients who underwent septoplasty or Septorhinoplasty under general anesthesia with halothane. We monitored changes of systolic and diastolic blood pressures, pulse rates, volume of blood loss and any finding about dangerous dysrrhythmias such as ventricular arrhythmia. The mean percent of changes for systolic blood pressure was measured 8.46 +/- 4.59, this percent for diastolic blood pressure was measured as 10.55 +/- 5.89, and for pulse rates the mean percent of changes evaluated 7.85 +/- 4.61. In all of the groups, the percents were evaluated as less than 15% that were clinically acceptable. The mean volume of blood loss was evaluated as 73.13 +/- 30.02 milliliters. The differences were not statistically significant among the four groups. In the group 1, one case experienced an episode of ventricular tachycardia and in the second group one patient had ventricular tachycardia. Another patient showed an episode of ventricular fibrillation. Despite no statistically significant difference between group using solutions of epinephrine 1/100000 and solutions of epinephrine 1/200000 about mean percents of changes in systolic blood pressures, pulse rates and volume of blood losing, the higher concentrations of epinephrine 1/100000 raised the risk of dangerous ventricular arrhythmias, so this concentration is not recommended