A single-blinded case controlled study on effects of cardiopulmonary circulation on hearing during coronary artery bypass grafting

Sensorineural hearing loss in patients with coronary artery bypass surgery

BACKGROUND

This study is planned to obtain a better understanding of the correlation between sudden sensorineural hearing loss and cardiopulmonary bypass. There are many causes for sudden hearing loss which include infectious, circulatory, inner ear problems like meniere's disease, neoplastic, traumatic, metabolic, neurologic, immunologic, toxic, cochlear, idiopathic (unknown cause) and other causes. One of the less common cause is surgery include cardiopulmonary bypass procedures.

MATERIALS AND METHODS

This study is a self controlled clinical trial on 105 patients that was carried out in chamran Hospital, Esfahan, Iran. Participants were including all those patients undergoing coronary artery bypass surgery in the hospital who fell under the criteria for inclusion. Patients underwent audiometric testing at our hospital on three or two different occasions during the course of this study, Initially before the procedure to test the baseline hearing capacity; then two week after the procedure to assess any changes in hearing ability following the surgery. Data analysis performed by co-variance analysis.

RESULTS

In our study the changes in the threshold of hearing in frequency of 1000 in right ear and in frequencies of 2000 and 4000 in left ear were significant, but this changes were about 2-3 db and were not noticeable. The difference in degree of SNHL, before and after surgery in different frequencies were been shown.

CONCLUSION

As loss of the patients with symptomatic sensory neural hearing loss in this study, It isn't commanded the routin auditory assessment pre and post surgery was been done.