A study on hearing evaluation in patients of chronic renal failure

Aims and Objective: The aim of the study was to evaluate hearing threshold and the severity of hearing loss at different frequencies (250Hz, 500Hz, 1000Hz, 2000Hz, 3000Hz, 4000Hz, 6000Hz, and 8000Hz) in patients of chronic renal failure (CRF), and to analyze the role of duration of disease on hearing threshold in patients of CRF. Materials and Methods: Fifty two patients of CRF were evaluated in Nephrology unit and ENT OPD. Cases with middle ear involvement were not included in the study. Pure tone audiometry was done in all cases to establish hearing threshold at different frequencies. Cases with hearing loss were classified according to the severity of hearing loss. In patients with sensorineural hearing loss, mean hearing threshold was calculated. Cases were classified in two groups on the basis of duration of disease (less than two years and more than two years) and the mean hearing thresholds were calculated. The significant differences between the mean hearing thresholds of these two groups were assessed using students t test for unequal samples. Results : A total of 52 patients (28 males and 24 females) were included in the study. Majority of the patients were in 21 to 40 year age group (mean age 36.84 years). Of the 104 ears, 76 ears (73.07%) had sensorineural hearing loss and 28 ears (26.93%) had normal hearing. Majority of the ears with hearing loss had mild (44.73%) or moderate (42.11%) sensorineural hearing loss. Mean hearing threshold was higher at low frequencies and high frequencies with a relative sparing of mid frequencies. Comparison of the mean hearing threshold in patients of Group I (duration of disease less than two years - 42 ears) and Group II (duration of disease more than two years - 34 ears) showed a statistically significant difference (P < 0.05) in mean hearing threshold at 250 Hz. Conclusion: Hearing loss is present in majority of the patients of CRF. Most of the cases have mild to moderate sensorineural hearing loss. Hearing threshold worsens at low frequency (250 Hz) as the duration of disease increases.