How long should patients remain in the supine treatment position after intratympanic dexamethasone injection (ITDI)?
Background: ITDI provides the potential for direct delivery of high concentration steroid to the inner ear while avoiding systemic effects. Many studies have shown that ITDI is an effective treatment in patients with sudden hearing loss, especially in those with refractory hearing loss. Although many clinicians use ITDI for sudden hearing loss, the detailed injection protocol varies according to the provider, with treatment times ranging from 15 to 40 minutes.
Explore this issue:December 2014
Study design: Prospective study.
Setting: Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, Republic of Korea
Synopsis: Through an in vivo animal study, the researchers used 24 six-week-old male mice randomized into six groups of four mice each, according to treatment wait time after intratympanic injection: 5, 10, 15, 20, 25, and 30 minutes post injection. The dexamethasone solution was created with dexamethasone 21-phosphate disocium salt and 0.9% NaCl. All mice received 10 µL of solution. The perilymph was sampled through the round window. The concetration of dexamethasone in the samples was analyzed immediately, along with the concentration of verapamil.
In a separate prospective clinical study, 79 patients with refractory sudden hearing loss underwent intratympanic injection, and remained in the supine position with their heads rotated 45 degrees to the unaffected side. Patients were divided into two groups based on wait time postinjection: 30 minutes and 10 minutes.
In the in vivo study, the concentration of dexamethasone showed no significant increase after 10 minutes, and in the clinical study, hearing improvement was similar for both the 30-minute and the 10-minute groups.
Bottom line: Ten minutes is a sufficient time to remain in the supine treatment position after ITDI in patients with sudden hearing loss.