Technical and logistical details of ITS service
As detailed in figure 1, our department reviews patients within 72 hours
of onset for an audiogram and assessment. If deemed to have SSNHL, they
are given oral prednisolone. Two weeks later, audiometry is repeated
within an emergency clinic. If hearing thresholds have not improved by
an average of 30dB relative to the unaffected ear, patients are offered
ITS therapy. This constitutes three ITS injections, of between
0.4-0.8mls of 40mg/ml Methylprednisolone, injected into the middle ear
through a phenol anaesthetised tympanic membrane segment, with patients
placed in a recumbent position facing away from the affected side, and
asked to not swallow for 30 minutes. Injections are undertaken in a
specialty doctor run minor ops clinic, which runs half-daily each week,
allowing up to 4 injections per session. Each injection is given a week
apart. After six weeks, a final PTA is performed to qualitatively assess
changes in hearing. An MRI is performed to exclude retrocochlear
pathology.5