Blast injury of the ears: The experience from Yala Hospital, Southern Thailand

Abstract

Objective: To report acute and subacute consequences of blast injury to the ear from terrorists' bombings experienced from Yala Provincial Hospital, Southern Thailand. Study design: Retrospective chart review was done on 54 patients who suffered otologic injuries from bombing attacks in Yala Province from January to May 2005. Only 33 patients who had complete otologic and audiologic examination with a 3-month follow-up were studied. Material and Method: The ear symptoms, the size of tympanic membrane perforation, degree of hearing loss at first examination within 30 days after injuries were recorded. After a 3-month follow-up, the rate of spontaneous healing, rate of operation needed and long-term complications including hearing loss were analyzed. Results: The two most common initial symptoms were hearing loss (72.73%) and tinnitus (66.67%). Tympanic membrane perforations were encountered in 31 ears of 22 out of 33 patients. Spontaneous healing occurred in 23 ears (74.19%) with the highest incidence in small perforations (size < 50%). All healings occurred within 8 weeks. Tympanoplasty was done on the rest, except one patient. Eight patients (24.24%) had sensorineural hearing loss without tympanic membrane perforation. They still have sensorineural hearing loss, which is rather mild and typically affects in high tone with five of this group having normal hearing in speech range. Eleven patients from the tympanic membrane perforation group still have mixed hearing loss, which were also mostly mild. Conclusion: Patients with aural symptoms after a blast injury need thorough otologic and audiological examination. The spontaneous healing of tympanic membrane perforation from explosive injury was relatively high (74.19%) after an 8-week follow-up, only 8/31 ears required surgical repair. At 3-months follow-up, more than two-thirds of the patients still had residual hearing loss, which was rather mild and affected mainly in high tone.