Ear, nose and throat

Australia does not do well in the early detection of congenital hearing impairment. Only about 25% of infants born with hearing impairment are diagnosed by the age of 12 months, and for many children deafness remains a disability leading to severe and lasting language impairment.1 The technology for newborn hearing screening has now been in regular use in many parts of the world for much of the past decade, and there is at last some persuasive evidence that very early detection helps these children achieve normal language skills.2,3 This evidence is far from perfect: 4 only one randomised controlled trial of detection rates with and without newborn screening has been reported, and no randomised controlled trial has yet examined outcomes of hearing screening. Nonetheless, universal newborn hearing screening has become not only possible but expected in the United States and Canada, the United Kingdom and many European countries. However, it has not yet been widely implemented in Australia. As a result, the excellent diagnostic and rehabilitative services available to all Australian children once the diagnosis of hearing impairment has been made contrasts strongly with our patchy and very incomplete ascertainment of hearing impairment in the first year of life. The Western Australian Newborn Hearing Screening Programme is therefore an important step, as is the recent announcement that a program will commence throughout New South Wales by the end of 2002. In a report of the WA program in this issue of the Journal, Bailey et al (page 180)5 demonstrate that a high-quality, sustainable universal newborn hearing screening program can operate in Australian birthing hospitals. It appears to be a model program, with exceptionally high coverage, high acceptability, low referral rates, and low rates of babies lost to follow-up. It exceeds most benchmarks set in 2000 by the US Joint Committee on Infant Hearing,6 and is in line with the Australian National Consensus Statement on Newborn Hearing Screening.7 Nonetheless, it raises a number of difficult issues. Bailey and colleagues report that the hearing screening program has achieved more than 96% coverage in the five participating metropolitan hospitals. However, together these screened infants represent only about half Western Australia's annual births — unfortunately, the "easy" half. The program operating throughout the US State of Colorado,8 one of the few approaching a true population coverage, has demonstrated that hospitals with fewer than 400 births annually do worse on average than large hospitals in terms of coverage (substantially lower) and referral rates (substantially higher). Australia is characterised by vast distances and a very large number of small hospitals. For instance, the State of Victoria has a similar birthrate to Colorado, but nearly twice as many birthing hospitals (about 110, compared with 60), most of which are small. Statewide or national newborn hearing screening therefore poses considerable logistic and economic obstacles in Australia, and these are not necessarily surmountable. But what are the consequences of limiting ourselves to larger hospitals? Let us assume that 50% of a State's population receives a very high quality hearing screening program which achieves 95% coverage, 90% sensitivity, 95% follow-up, and 80% compliance with early fitting of hearing aids and intervention (as some parents choose neither). This equates to less than a third of that State's hearing-impaired children benefiting from the program. If any one of these parameters is lower, then the number of children potentially benefiting falls even further. Despite individual gain, median age at diagnosis and overall outcomes for the State would improve little. If universal screening is to lead to population benefits, then universal it needs to be — despite the challenges. A poor alternative is to screen only babies with a risk factor for deafness. Asking about the presence of a risk factor becomes the universal "screen", followed by a targeted screening test of hearing itself. At face value, this may seem cheaper, but it is not easier and certainly detects fewer children. While almost all children with hearing loss detected in the Western Australian series so far have had a risk factor, in larger series this applies to only about 50% of babies.8,9 Neonatal intensive care and special care nurseries typically contain about 30%–40% of all infants found to have moderate or greater hearing loss in newborn screening programs9,10 and are relatively easily targeted, as are babies with obvious head and neck abnormalities. Other risk factors, such as family history of early hearing impairment, pose greater problems. Accurate elicitation requires skilled enquiry and mothers may not recall, or even know, that a risk factor is present until after the diagnosis is made, thus reducing sensitivity. The Victorian Infant Hearing Screening Program has recently highlighted the very low positive predictive value of family history and some other risk factors, with close to 200 babies needing to be referred to diagnose one child with hearing loss.11 Low sensitivity combined with poor positive predictive values equates to spending a lot of money to miss many children. Finally, risk-factor screening raises issues of equity, as the many children with hearing impairment, but without a discernible risk factor, would be denied access to hearing screens in such a program. A final issue is that of program sensitivity. At 0.7 per 1000, Western Australia's detection rate for children with bilateral congenital hearing impairment of more than 35 dB HL (hearing level) is lower than the usual rate of 0.9–1.0 per 1000 detected (with hearing impairment of more than 40 dB HL in the better ear).8,9 Most likely, this is a chance finding reflecting the small size of the series — it "just happened" that relatively few babies with hearing impairment were born during this time period. Alternative explanations include equipment problems or program insensitivity. The Western Australian program is unusual in that a baby is not referred until screening has shown three "fail" responses. This lowers the false positive rate and increases program specificity — both of which are desirable. But in screening programs rises in specificity are typically accompanied by falls in sensitivity. It may be that, in this case, the pendulum has swung too far towards specificity at the expense of sensitivity, and that, after years of worrying about excessive referral rates, they are — at last — too low. Currently, we are not serving well the hundreds of children born each year with moderate or greater hearing impairment in Australia. Universal newborn hearing screening seems one way of improving this situation. It is not reasonable to defer implementing a program until the evidence is stronger, since stronger evidence is unlikely to be available soon. Rather than stopping us from implementing programs, this should spur us to acquire such evidence. Because Australia has not yet widely introduced newborn hearing screening, we have an unusual capacity to study these questions prospectively. National benchmarks and a minimum dataset should be established, and we should start carefully and systematically examining outcomes for hearing-impaired babies born now against which to compare gains over the coming years. We should also keep an open mind. In 10 years' time, Australia should be able either to guarantee continuation of an effective program, or to move resources rapidly from a program that, despite best efforts, has proved ineffective.

Melissa A Wake MD, FRACP, MB ChB

Otitis media — definitions Acute otitis media without perforation: Presence of middle-ear fluid with symptoms or signs of suppurative infection. Bulging of the tympanic membrane is the most reliable sign in Aboriginal children. Acute otitis media with perforation: Acute suppurative infection with recent discharge from the middle ear (within the last 7 days). Otitis media with effusion: Presence of middle-ear fluid without symptoms or signs of suppurative infection. Chronic suppurative otitis media: Persistent discharge from the middle ear through a tympanic membrane perforation for more than 6 weeks. Chronic suppurative otitis media (CSOM) (see Box) is very uncommon in First World countries and is best regarded as a disease of poverty. The World Health Organization has indicated that a prevalence rate of CSOM greater than 4% in a defined population of children is indicative of a massive public health problem requiring urgent attention.1 That CSOM affects up to ten times this proportion of children in many Aboriginal communities is an indictment of the poor living conditions in these communities.2 The associated hearing loss has a life-long impact, as it occurs during speech and language development and the early school years. Why is chronic suppurative otitis media so recalcitrant?Many factors contribute to poor health outcomes. In biological terms, the greatest risk factor for the early onset and persistence of otitis media is nasopharyngeal colonisation by multiple bacterial species and subtypes.3 In Aboriginal communities with overcrowded households, infants are frequently exposed to siblings whose nasopharyngeal carriage rates are almost 100% for each of the major otitis media bacterial pathogens.3 In non-Aboriginal children, the host response to a low-dose infection usually eradicates pathogens, which, in turn, down-regulates inflammation and limits tissue damage. In contrast, we believe that early exposure of very young Aboriginal infants to a large bacterial inoculum (or frequent exposures to immunologically distinct pathogens)4 provides constant stimulation of the inflammatory cascade, which damages mucosal tissue yet fails to eradicate pathogens.5 This begins a vicious cycle that may persist throughout childhood: early exposure, persistent bacterial colonisation, and chronic mucosal disease. Furthermore, such infants themselves become chronic carriers and pose a risk to other, younger infants. This cycle is facilitated by overcrowded and poor living conditions, lack of appropriate washing facilities,6 and limited access to appropriate healthcare services. Bulging of the tympanic membrane is the best diagnostic predictor of perforation.7 Other signs and symptoms of acute otitis media (such as pain, fever, irritability or redness of the tympanic membrane) are frequently absent in this population. The implications of this lack of signs or symptoms are clear — parents do not see their child as unwell and thus children remain untreated. Together, this biological model and clinical pattern help us to understand the intractable nature of otitis media in Aboriginal children. Currently, failure to apply existing knowledge is a more important problem than lack of knowledge. Aboriginal children have poorer access to therapy, hearing aids, special teachers, classroom soundfield systems and other rehabilitative programs.2 Furthermore, there is inequitable distribution of funds from the Commonwealth Hearing Health Services Program, with evidence that the hearing health needs of Aboriginal children are not being met.8 What strategies have worked?A systematic review of existing evidence and primary care guidelines for the management of otitis media in Aboriginal and Torres Strait Islander people2 identified effective primary prevention strategies: improving nutrition and the home environment, increasing breastfeeding, and reducing passive smoking. A small but important role was noted for vaccines (the polysaccharide, polyvalent pneumococcal vaccine and the new pneumococcal conjugate vaccine). Controversies remain regarding the effectiveness of antibiotics in primary prevention and the impact of maternal pneumococcal vaccination on infant disease.2 High doses and prolonged courses of antibiotics are often required for the treatment of acute otitis media and CSOM,7 but the optimal use of topical ear preparations remains uncertain.2 Where appropriate primary healthcare interventions have failed, timely referral to otolaryngologists for assessment and surgical interventions can improve hearing outcomes.2 However, access to such specialist care for children in remote Aboriginal communities is suboptimal. Audiological rehabilitation is critical, requiring the provision of ongoing education about effective communication strategies and appropriate use of devices to assist hearing. These include standard hearing aids and bone conductors, as well as classroom devices such as soundfield amplification systems (which provide a uniform soundfield throughout the classroom and increase the speech-signal : noise ratio), and FM systems (a form of personal amplification whereby an FM signal from a microphone worn by the teacher is picked up by a receiver worn by a child with hearing loss).9 What needs to happen in the future?Greater community control over improvements to education, employment opportunities, housing infrastructure and primary healthcare services is long overdue. To realise these improvements requires substantially increased resources, linked to community responsibility. In the meantime, initiatives that increase access to primary healthcare for the detection and management of ear disease and facilitate access to other services should continue. An example is the Office for Aboriginal and Torres Strait Islanders Health Hearing Health Program.10 Realistic expectations about the benefits and harms of evidence-based healthcare interventions should be incorporated into updates of currently available clinical guidelines, and the information made accessible to families. The Commonwealth needs to reform the provision of rehabilitative services and coordinate approaches to soundfield amplification in schools. The research priority is to determine the best use of preventive strategies and interventions (including educational, medical, surgical and audiological initiatives). Multidisciplinary research in the areas of diagnosis, new antibiotics, the role of biofilm and vaccines is also appropriate. Bacterial biofilm is a community of interacting bacteria attached to a surface and encased in a protective matrix of exopolysaccharide. Formation of biofilm in the middle-ear mucosa of Aboriginal children with CSOM may explain the recrudescence of bacterial otorrhoea after viral upper respiratory tract infections.11 Pneumococcal conjugate and innovative protein-based vaccines are aimed at inducing a mucosal immune response. Several Australian trials are currently examining the impact of pneumococcal conjugate vaccine on nasopharyngeal carriage rates and perforation of the tympanic membrane. Only with urgent attention to improving housing and access to running water, nutrition and quality of care, and giving communities greater control over these improvements, will this massive public health problem be solved so that Aboriginal children can take their rightful place in this, the century of communication.

Harvey L Coates MS, FRACS · Peter S Morris PhD, FRACP · Amanda J Leach PhD · Sophie Couzos FRACGP, FACREM, FAFPHM

Aim: To report the preliminary findings of a pilot program to screen newborn babies for congenital bilateral permanent hearing loss.Setting: The five largest maternity hospitals in Perth, Western Australia. Screening was gradually introduced over seven months from February to August 2000.Participants: All babies born at these hospitals after the introduction of hearing screening until 30 June 2001.Methods: One or both of two automated screening devices were used: one measuring transient evoked otoacoustic emissions (TEOAE) and the other automated auditory brainstem responses (AABR). If a "pass" was not obtained in both ears, screening was repeated. All babies who did not obtain a pass in either ear at follow-up were referred for audiological assessment.Main outcome measures: Prevalence of permanent bilateral hearing loss.Results: Of 13 214 eligible babies, 12 708 (96.2%) received screening. The main reason for missing screening was early hospital discharge (309; 2.3%). Of the screened babies, 99% had a pass response in both ears at either the initial or follow-up screen. Twenty-three babies were referred for audiological assessment, and nine were diagnosed with bilateral permanent hearing loss (0.68/1000; 95% CI, 0.31–1.28).Conclusions: Despite our program meeting process quality indicators, our detection rate was low. Before extending the program to smaller hospitals, we need to validate our screening instruments and put in place a system to monitor false negative results.

Helen D Bailey BHealthSci(Nurs)Hons, MPH · Carol Bower MB BS, PhD · Jay Krishnaswamy MSc · Harvey L Coates MS, FRACS

Today, the specialty of otolaryngology/head and neck surgery encompasses a broad sweep of both medical and surgical diseases, with an emphasis on early diagnosis with the help of the telescope and the microscope. Major advances have been made in otoneurosurgery, rhinology, microlaryngeal and laser surgery, head and neck cancer surgery and paediatric otolaryngology. Figure: Digital photograph of a squamous cell carcinoma of the left vocal cord. Otology. All patients with asymmetric ear symptoms must first have audiometric assessment then a gadolinium-enhanced T1-weighted magnetic resonance imaging scan, which is sufficiently reliable to detect acoustic neuroma. The translabyrinthine (or sometimes middle cranial fossa) approach to acoustic neuromas and other tumours and cysts in the posterior cranial fossa allows preservation of facial nerve function in more than 95% of patients. Recently, skull-base surgeons have found an application for endoscopy of the cerebellopontine angle and have pioneered new approaches to the petroclival region. The investigation of dizziness, vertigo and imbalance is based on fundamental biological research and the findings from painstaking gross, microscopic and electronmicroscopic studies of the sensorineural elements of the cochlear and vestibular systems. The importance of a rehabilitation regimen and the benefit of vestibular manoeuvres for labyrinthine balance disorders have finally been recognised. Vestibular nerve section has been virtually replaced by controlled injection of gentamicin into the middle ear. With better understanding of inner-ear pathology, refined assessment of cochlear function, improved implantable devices and structured rehabilitation programs, cochlear implantation has become a routine operation. More predictable outcomes have widened the indications for younger children and for some individuals with marginal benefit from their hearing aid. Rhinology. In functional endoscopic sinus surgery (FESS) there is currently a more conservative attitude than previously, especially for paediatric patients. Because the ethmoid is such a complex structure, comprehensive computed tomography (CT) imaging is vital. In conjunction with CT scans, computer-controlled image guidance systems are now used in some centres for FESS operations and for transnasal hypophysectomy. This demanding "keyhole" surgery, performed with rigid telescopes and purpose-designed, slender instruments, requires a sound knowledge of the physiology of the mucociliary mechanism and the anatomy of the nasal cavities and paranasal sinuses. The surgeon must be familiar with the intricate anatomy and many individual variations of the ethmoid air cell system, whose delicate bony structures and lining mucosa require dexterous operative skills. The radical external operations of the past have mostly been replaced by these endoscopic techniques, which follow normal anatomical routes and aim to establish near-normal ventilation and drainage. Laryngology. Clinical interest in voice problems has been stimulated as research reveals a better understanding of laryngeal physiology in relation to the mass, elasticity, age-related contractility changes,1 viscoelastic qualities and vibration characteristics of the vocal cords. Our understanding will be enhanced by current investigations into the innervation of the larynx by central motor fibres from brainstem nuclei; cortical, subcortical and brainstem regulation; the relevance of small- and large-diameter axons; and nerve myelination. The field of neurolaryngology includes investigation of unilateral and bilateral vocal cord paralysis, paradoxical vocal cord movement and voice disorders in other neurological diseases such as multiple sclerosis and Parkinson's disease. Spasmodic dysphonia, previously untreatable, is now managed by botulinum toxin injections into the vocal folds. For diagnostic evaluation and treatment, the voice specialist and the speech pathologist use videostroboscopy, laryngeal electromyography, voice recording, objective acoustic analysis and aerodynamic assessment methods. Telescopes and special-purpose instruments (such as lasers and laryngeal microdebriders) have led to exciting advances in surgical intervention. The voice can now be restored or improved after endoscopic microsurgery or laser surgery for benign, premalignant or early malignant lesions. Head and neck surgery. Squamous cell carcinoma affects many thousands of people globally each year, yet currently available treatment with surgery, radiotherapy and chemotherapy is less than satisfactory. The five-year survival rate has shown little improvement over the past 20 years. For the future, we look forward to advances in molecular medicine and gene therapy that may improve the management of head and neck cancer, allowing preservation of function and higher cure rates. Novel molecular markers, such as the p53 gene, angiogenesis-related markers, cyclin D1 and epidermal growth factor receptor, are under intense study for their clinical implications.2 Australian otolaryngology/head and neck surgery maintains world-best standards in every respect. For young surgeons it is a popular and attractive specialty that promises an exciting and stimulating future.

Bruce NP Benjamin OBE, DLO, FRACS, FAAP