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The function of a grommet is to ventilate the middle ear, rather than drain it. Grommets thus replace the function of the blocked eustachian tube in glue ear and improve hearing.

Post-operatively the ear should be kept dry and any further discharge mopped up and treated with antibiotic/steroid drops. If discharge continues another referral may be required.

There is controversy about swimming and other activities in the period before the grommet falls out - research seems to suggest that bathwater is the worst culprit.

The grommet will extrude after a variable period - 6 to 18 months. Repeated insertion may be necessary as 1 in 5 children requiring surgical treatment.

A horse shoe shaped thickening and calcification of the drum may follow grommet insertion, though this rarely causes hearing loss.

NICE suggest that the persistence of bilateral otitis media with effusion (OME) and hearing loss should be confirmed over a period of 3 months before intervention is considered. The child's hearing should be re-tested at the end of this time:

  • during the active observation period, advice on educational and behavioural strategies to minimise the effects of the hearing loss should be offered
  • children who will benefit from surgical intervention
    • children with persistent bilateral OME documented over a period of 3 months with a hearing level in the better ear of 25-30 dBHL or worse averaged at 0.5, 1, 2 and 4 kHz (or equivalent dBA where dBHL not available) should be considered for surgical intervention
    • exceptionally, healthcare professionals should consider surgical intervention in children with persistent bilateral OME with a hearing loss less than 25-30 dBHL where the impact of the hearing loss on a child's developmental, social or educational status is judged to be significant
    • once a decision has been taken to offer surgical intervention for OME in children, the insertion of ventilation tubes is recommended. Adjuvant adenoidectomy is not recommended in the absence of persistent and/or frequent upper respiratory tract symptoms
    • children who have undergone insertion of ventilation tubes for OME should be followed up and their hearing should be re-assessed.


  • study evidence however suggests that the role of grommets in the management of glue ear is unclear.
    • a systematic review concerning the use of grommets in glue ear (otitis media with effusion) concluded that the benefits of grommets in children appear small (2)
      • the effect of grommets on hearing diminished during the first year
      • potentially adverse effects on the tympanic membrane are common after grommet insertion
        • ears treated with grommets had an additional risk for tympanosclerosis of 0.33 (95% CI 0.21 to 0.45) one to five years later
      • the authors recommended that an initial period of watchful waiting seems to be an appropriate management strategy for most children with otitis media with effusion
    • a study showed that, in infants and toddlers with persistent middle ear infusion, prompt insertion of tympanostomy tubes was not more effective than delayed insertion for developmental outcomes at 9-11 years (3)
        • this study provides further evidence to show that a conservative wait-and-see approach will give the best outcome in children <= 3 years of age, avoiding unnecessary operations

  • use of tympanostomy tubes in children with recurrent otitis media
    • randomly assigned children 6 to 35 months of age who had had at least three episodes of acute otitis media within 6 months, or at least four episodes within 12 months with at least one episode within the preceding 6 months, to either undergo tympanostomy-tube placement or receive medical management involving episodic antimicrobial treatment
    • in intention-to-treat analysis (n=250; age 6-35 months), the rate of episodes of acute otitis media during a 2-year period was not significantly lower with tympanostomy-tube placement than with medical management (involving episodic antimicrobial treatment) (mean 1.48 vs 1.56 episodes per child/year, respectively; p=0.66) (4)
      • editorial (5) notes that although frequency of episodes of acute otitis media was similar in the two groups, a significant difference was observed in a per-protocol analysis (1.47 vs. 1.72, respectively), and it might be expected that qualitatively the episodes of acute otitis media were substantially different between the two groups. It adds that despite this, the results of this trial are very useful for shared decision making with caregivers; they can be informed that:
        • the present course of medical management may be continued with no greater likelihood of antimicrobial resistance than if a surgical option is selected.
        • in a child older than 2 years of age, it is predicted that infections will be fewer in the coming year and that medical treatment should be continued.
        • in the younger child, there is a nearly 50% likelihood that the frequency of infections will continue; the child is likely to have fewer and less severe episodes of acute otitis media with less exposure to antibiotics if tympanostomy-tube placement is undertaken, with only occasional development of persistent otorrhoea.


  1. NICE (February 2008). Surgical management of otitis media with effusion in children
  2. Lous J et al. Grommets (ventilation tubes) for hearing loss associated with otitis media with effusion in children. Cochrane Database Syst Rev 2005; (1): CD001801
  3. Paradise JL et al.Tympanostomy tubes and developmental outcomes at 9 to 11 years of age. N Engl J Med. 2007 Jan 18;356(3):248-61.
  4. Hoberman A et al. Tympanostomy Tubes or Medical Management for Recurrent Acute Otitis Media.N Engl J Med 2021; 384:1789-1799
  5. Wald ER. Management of Recurrent Acute Otitis Media. N Engl J Med 2021; 384:1859-1860

Last edited 05/2021 and last reviewed 06/2021