Interventions for ear discharge associated with grommets (ventilation tubes)

The insertion of grommets (also known as ventilation or tympanostomy tubes) is one of the most common surgical procedures performed on children. Postoperative otorrhoea (discharge) is the most common complication with a reported incidence ranging from 10% to 50%. In the UK, many ENT surgeons treat with topical antibiotics/steroid combinations, but general practitioners, mainly through fears of ototoxicity, are unlikely to prescribe these and choose systemic broad-spectrum antibiotics.

1. To identify the most effective non-surgical management of discharge from ears with grommets in place.2. To identify the risks of non-surgical management for this condition (e.g. ototoxicity), and to set benefits of treatment against these risks.

We searched the Cochrane Ear, Nose and Throat Disorders Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 1, 2005), MEDLINE (1966 to 2005) and EMBASE (1974 to 2005). We also searched the CINAHL, AMED, LILACS, ISI WEB OF KNOWLEDGE, ISI PROCEEDINGS, mRCT, NNR, ZETOC, KOREAMED, CSA, MEDCARIB, INDMED and SAMED databases. The date of the last search was February 2005.

Randomised controlled trials of adults or children, with any type of grommet and an ear with discharge were included. The trials compared treatment with placebo or one treatment with another. The primary outcome measure was the duration of the discharge.

The trials were selected independently according to the above criteria by the four reviewers. Differences in opinion over the inclusion of studies were resolved by discussion. The studies were graded using the CASP critical appraisal tool. Analyses were based on the presence of discharge seven days from the onset of treatment.

There was very little good quality evidence. Four studies were included, all of them investigating different interventions and therefore a meta-analysis was not possible. Only one study demonstrated a significant difference. Oral amoxicillin clavulanate was compared to placebo in 79 patients. The odds of having a discharge persisting eight days after starting treatment was 0.19 (95% CI 0.07 to 0.49) . The number needed to treat to achieve that benefit is 2.5. Participants in both arms of this study also received daily aural toilet. The results will therefore not be applicable to most settings including primary care. No significant benefit was shown in the two studies investigating steroids (oral prednisolone with oral amoxicillin clavulanate and topical dexamethasone with topical ciprofloxacin ear drops), or the one study comparing an antibiotic-steroid combination (Otosporin(R)) drops versus spray (Otomize(R)) (although more patients preferred the spray form).

The authors of this review have been unable to identify the most effective intervention or to assess the associated risks. Research is urgently needed into the effectiveness of oral versus topical antibiotics in this group of patients. Clinicians considering antibiotic treatment need to balance any potential benefit against the risks of side effects and antibiotic resistance.