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Decision-Making Algorithm in Otorhinolaryngology & Head and Neck Surgery

Conductive Hearing Loss

Localising the air–bone gap — urgency triage, the audiologic work-up, and a site-of-lesion phenotype that routes the canal, tympanic-membrane, middle-ear, stapes-fixation and third-window pathologies to their repair or rehabilitation

Step 1

Step 1 of 8

Presentation & Urgency Triage

Hearing loss/fullness/otorrhoea/autophony — sort emergent (fracture, facial palsy, mastoiditis, CSF) vs urgent vs routine

Conductive hearing loss presents as hearing loss, a failed hearing screen, aural fullness, otorrhoea, tinnitus, autophony, or — in a child — speech and language delay, and the first task is to triage for urgency before settling into the orderly work-up. The emergent group needs urgent imaging and specialist management: temporal-bone fracture, facial paralysis, acute mastoiditis, a suspected intracranial complication, CSF otorrhoea, and acutely complicated cholesteatoma. The urgent group needs an expedited workup: pulsatile tinnitus, a retrotympanic pulsatile mass, progressive unilateral conductive loss, a persistent unilateral effusion in an adult, and any suspected neoplasm.

The routine group — chronic stable conductive loss, otosclerosis, congenital conductive loss, and a dry tympanic-membrane perforation — proceeds through history, examination, and audiology at standard pace. This triage is not a formality: it separates the patient who needs a CT scan and an operating theatre this week from the one who can be fully characterised in clinic, and it front-loads the two errors most worth avoiding — touching a vascular retrotympanic mass, and dismissing a unilateral adult effusion that is masking a nasopharyngeal carcinoma. Everything that follows assumes the emergent and urgent flags have already been actively sought and excluded.

  • Presentation — hearing loss, failed screen, fullness, otorrhoea, tinnitus, autophony, paediatric speech delay
  • Emergent — temporal-bone fracture, facial palsy, mastoiditis, intracranial complication, CSF otorrhoea, complicated cholesteatoma → urgent imaging + specialist
  • Urgent — pulsatile tinnitus, retrotympanic pulsatile mass, progressive unilateral CHL, adult unilateral effusion, suspected neoplasm → expedite
  • Routine — chronic stable CHL, otosclerosis, congenital CHL, dry perforation

★ High-yield pearls (chapter-wide)

  • A negative Rinne and a Weber that lateralises to the worse-hearing ear confirm conduction at the bedside — but the air–bone gap on the audiogram, not the tuning forks, quantifies it and drives the decision.
  • Conductive hearing loss behind a normal-looking tympanic membrane is the high-yield problem — think otosclerosis, congenital ossicular fixation, ossicular discontinuity, congenital cholesteatoma, and superior semicircular canal dehiscence, and let the acoustic reflexes and HRCT separate them.
  • Preserved acoustic reflexes in an ear with a conductive loss are the tell of a third-window disorder — most often superior semicircular canal dehiscence — because a true ossicular conductive loss abolishes the reflex.
  • Autophony, the Tullio phenomenon, and pressure-induced vertigo with a low-frequency air–bone gap are superior canal dehiscence until VEMP and high-resolution CT say otherwise — and stapes surgery on a misdiagnosed dehiscence makes the patient worse.
  • A retrotympanic mass — pulsatile, blue, or vascular — must be imaged before it is biopsied or a myringotomy is performed, because an aberrant carotid, a dehiscent jugular bulb, or a glomus tumour bleeds catastrophically.
  • A unilateral middle-ear effusion in an adult is nasopharyngeal carcinoma until a nasopharyngoscopy proves otherwise — never simply ventilate it and move on.
  • Persistent conductive loss despite a patent ventilation tube means the problem is not the effusion — look for ossicular pathology, cholesteatoma, or adhesive middle-ear disease.
  • In congenital aural atresia the Jahrsdoerfer score grades surgical candidacy — a score of 7 or more supports atresiaplasty, while a lower score favours a bone-conduction device, and early bone-conduction amplification protects speech and language regardless.
  • Otosclerosis is the progressive conductive loss behind an intact drum in an adult — Carhart's notch on the audiogram is the clue, and stapedotomy reliably closes the gap while a hearing aid is an equally valid, lower-risk choice.
  • The air–bone gap is closed by repairing the conductive lesion (tympanoplasty, ossiculoplasty, stapedotomy, atresiaplasty) or bypassed by amplification — and bone-conduction devices rescue the draining, atretic, or reconstruction-failed ear that a conventional aid cannot.

Evidence base

3 sources
  1. HIGH

    Wuthukananchai N, Hunsaker DH, Vance D · Ear Nose Throat J · 2024Systematic reviewPMID 38895947

    Systematic review of conductive hearing loss behind an intact tympanic membrane — the differential of otosclerosis, ossicular fixation and discontinuity, congenital cholesteatoma and third-window lesions, and the role of acoustic reflexes and high-resolution CT in separating them.

  2. HIGH

    Rosenfeld RM, Shin JJ, Schwartz SR · Otolaryngol Head Neck Surg · 2016Practice guidelinePMID 26832942

    The AAO-HNS clinical practice guideline for otitis media with effusion — watchful waiting, the hearing and developmental assessment, and the tympanostomy-tube (with adenoidectomy) decision in children.

  3. HIGH

    Ho ML · Neuroimaging Clin N Am · 2019Imaging reviewPMID 30466645

    Imaging review of third-window lesions of the inner ear, detailing the CT appearances of superior and posterior canal dehiscence and related defects that cause a conductive hearing loss with intact ossicles.

Decision tree

The triage screen is the first gate. Classification routes the stable patient to one of the aetiology-keyed pathways below. Cross-cut cards capture the chapter's must-not-miss rules.

Conductive hearing lossUrgency triage?Emergent / massEmergent / retrotympanic massFracture, facial palsy, CSF, vascular mass — image before touchingRoutineAudiogram + reflexes → classify site of lesionCanal & atresiaCerumen/exostosis/atresia — clear, observe, or Jahrsdoerfer-graded repairTM perforationDry the ear, exclude cholesteatoma, then tympanoplastyRetraction / ETDET dysfunction — medical → tube → ossiculoplasty if gap persistsCholesteatomaRetraction/keratin/otorrhoea — CT, tympanomastoidectomy, DWI surveillanceOtosclerosis / ossicularNormal drum — otosclerosis / ossicular fixation or discontinuity; CT + reflexesThird window / SSCDAutophony + preserved reflexes → SSCD; VEMP + CT, never drill the stapesRetrotympanic massBlue/pulsatile mass — image before any myringotomy or biopsyMiddle-ear effusionChild: observe → tube; adult unilateral: nasopharynx until excludedEustachian-tube dysfunctionETDQ-7 + Type C — treat the nose; balloon dilation if persistentUrgency triage is the priority gate; the audiogram and acoustic reflexes then classify the loss by site of lesion into one pathway.
Step 1

Disclaimer

For educational purposes only. Not for clinical use. This platform is an instructional resource intended to support learning about clinical decision-making and the interpretation of investigations. Clinicians remain completely responsible for the interpretation of findings, the formulation of a differential diagnosis, and any clinical decision. Nothing in this application replaces individualized assessment, hands-on training, expert consultation, or established practice guidelines.

Not for profit effort by

Dr. Prahlada N.B

  • MBBS (JJMMC), MS (PGIMER, Chandigarh)
  • MBA in Hospital & Healthcare Management (BITS, Pilani)
  • Postgraduate Certificate in Technology Leadership and Innovation (MIT, USA)
  • Executive Programme in Strategic Management (IIM, Lucknow)
  • Senior Management Programme in Healthcare Management (IIM, Kozhikode)
  • Advanced Certificate in AI for Digital Health and Imaging Program (IISc, Bengaluru)

Supporting organisations

  • Karnataka ENT Hospital and Research Centre (R)
  • Champions Educational and Medical Society (R)
  • Amogh Foundation