Use of the nine-step inflation/deflation test as a predictor of middle ear barotrauma in sports scuba divers

Results of Eustachian tube balloon dilation measured using the nine-step test

Suggested several decades ago, the nine-step test is an intuitive test of Eustachian tube function. However, studies employing the nine-step test to assess the results of Eustachian tube balloon dilation (EBD) are limited. We aimed to objectively evaluate the efficacy of EBD in opening failure patients with decreased maximal peak pressure difference (MPD) using the nine-step test. Patients who had MPD values ≤ 13 daPa in the nine-step test were enrolled. The patients were categorized into two groups according to treatment decisions after discussion with a clinician: an EBD group (N = 26) and a medication group (N = 30). One month after treatment, the seven-item Eustachian Tube Dysfunction Questionnaire (ETDQ7) and the nine-step test were administered to all participants and subgroups of symptomatic participants (ETDQ7 > 15). MPD improved (increased) in both the EBD group and the medication group. ETDQ7 values improved (decreased) in the EBD group, but not in the medication group. In subgroup analysis, MPD and ETDQ7 values improved only in the symptomatic EBD group. According to the nine-step test, EBD can normalize 53.8% of decreased MPD. Posttreatment MPD and ETDQ7 scores were significantly better in the EBD group than in the medication group. However, EBD in patients with abnormal nine-step test results seemed less efficacious when the treatment results of the medication group were considered.

Revisiting the Diagnostic Performance of the Modified Nine-Step Test for Obstructive and Patulous Eustachian Tube Dysfunction

The nine-step test is a classical method for evaluating Eustachian tube function. It directly assesses the patient’s capacity to equilibrate middle ear pressure by swallowing. However, there are insufficient studies to appraise its diagnostic performance. The purpose of this study is to evaluate the sensitivity, specificity, and cut-off value of the nine-step test in patients with obstructive Eustachian tube dysfunction (oETD) and patulous Eustachian tube (PET). Enrolled subjects were divided into three groups. Control (50 ears of healthy volunteers), oETD (19 ears with oETD), and PET (29 ears with PET). Receiver operating characteristics curve analysis was conducted to evaluate the diagnostic performance of maximal peak pressure difference (ETTmd) in the nine-step test. Both the oETD group and the PET group showed decreased ETTmd. The nine-step test showed moderate accuracy when used to diagnose oETD (area under the curve = 0.875) and PET (area under the curve = 0.769). The highest diagnostic performance was observed when the cut-off value was 13 daPa for both the oETD group (sensitivity = 73.7%, specificity = 90.0%) and the PET group (sensitivity = 58.6%, specificity = 90.0%). The nine-step test has moderate diagnostic performance for oETD and PET.

Are the hearing and eustachian tube functions of the hot air balloon pilots disturbed?

OBJECTIVE

To evaluate the hearing and Eustachian tube functions (ETF) of hot air balloon (HAB) pilots, who are exposed to high altitude occupationally.

MATERIALS AND METHODS

The study was designed as a cross-sectional controlled study. Thirty HAB pilots and 30 healthy volunteers were included. Pure tone audiometry and speech discrimination scores (SDS) were used to assess the hearing function. Pure tone average (PTA) was calculated using the hearing thresholds (HT) at the frequencies 500, 1000, 2000, and 4000 Hz. Tympanometry and automatic Williams test (ETF1) were conducted to assess the ETF of the participants. Eustachian Tube Dysfunction (ETD) was defined as the change of tympanometric peak pressure (TPP) at rest (P1) less than in 10 decapascals (daPa) with Valsalva (P2) and Toynbee (P3) maneuvers. Eustachian Tube Dysfunction Questionnaire-7 (ETDQ-7) was also administrated.

RESULTS

Mean ages of the participants were 32.03±8.12 and 32.33±9.47 years in the HAB and control groups, respectively (p = 0.865). HTs, PTAs, SDSs, P1, P2, P2-P1 and P1-P3 values were similar in the groups (p > 0.05). P3 values ​​in both ears were significantly higher in the HAB group compared to the control group (p = 0.018, p = 0.002). Positive correlations were detected between the duration of the experience of HAB pilots and their HTs at 4 kHz and 8 kHz (p < 0.05) The prevalence of ETD in at least one ear was 83.7% and in both ears was 43.3% in the HAB group, both of which were significantly higher than the control group (p = 0.001, p = 0.049). The ETDQ-7 scores were also higher in the HAB group compared to the control group (p < 0.001).

CONCLUSION

Both the subjective and objective measures of ETF indicate that ETD is common among the HAB pilots. However, the hearing functions of those seem to be unaffected.

Middle ear barotrauma in diving

INTRODUCTION

Middle ear barotrauma (MEBt) is the most common medical complication in diving, posing a serious risk to dive safety. Given this prevalence and the continuing growth of the diving industry, a comprehensive overview of the condition is warranted.

METHODS

This was a survey study. An anonymous, electronic questionnaire was distributed to 7,060 recipients: professional divers of the Finnish Border Guard, the Finnish Rescue Services, and the Finnish Heritage agency; and recreational divers registered as members of the Finnish Divers' Association reachable by e-mail (roughly two-thirds of all members and recreational divers in Finland). Primary outcomes were self-reported prevalence, clinical characteristics, and health effects of MEBt while diving. Secondary outcomes were adjusted odds ratios (OR) for frequency of MEBt with respect to possible risk factors.

RESULTS

A total of 1,881 respondents participated in the study (response rate 27%). In total, 81% of the respondents had experienced MEBt while diving. Of those affected, 38% had used medications and 1% had undergone otorhinolaryngology-related surgical procedures due to MEBt. Factors most associated with MEBt were poor subjective success in Valsalva ('occasionally' versus 'always' successful: OR 11.56; 95% CI 7.24-18.47) and Toynbee ('occasionally' versus 'always' successful: OR 3.51; 95% CI 1.95-6.30) manoeuvres.

CONCLUSIONS

MEBt is common in both recreational and professional divers, having affected 81% of the respondents. The main possible risk factors include poor success in pressure equalisation manoeuvres.

Middle Ear Barotraumas in Commercial Aircrew

BACKGROUND: Middle ear (ME) barotraumas are the most common condition in aviation medicine, sometimes seriously compromising flight safety. Considering this and the ever-increasing amount of commercial aviation, a detailed overview is warranted.METHODS: In this survey study, an anonymous, electronic questionnaire was distributed to commercial aircrew of the three major commercial airlines operating in Finland (N 3799), covering 93% of the target population (i.e., all commercial aircrew operating in Finland, N 4083). Primary outcomes were self-reported prevalence, clinical characteristics, and health and occupational effects of ME barotraumas in flight. Secondary outcomes were adjusted odds ratios (OR) for frequency of ME barotraumas with respect to possible risk factors.RESULTS: Response rate was 47% (N 1789/3799), with 85% (N 1516) having experienced ME barotraumas in flight. Of those affected, 60% had used medications, 5% had undergone surgical procedures, and 48% had been on sick leave due to ME barotraumas (40% during the last year). Factors associated with ME barotraumas included a high number of upper respiratory tract infections [3 URTIs/yr vs. 0 URTIs/yr: OR, 9.02; 95% confidence interval (CI) 3.9920.39] and poor subjective performance in Valsalva (occasionally vs. always successful: OR, 7.84; 95% CI 3.9715.51) and Toynbee (occasionally vs. always successful: OR, 9.06; 95% CI 2.6730.78) maneuvers.CONCLUSION: ME barotraumas were reported by 85% of commercial aircrew. They lead to an increased need for medications, otorhinolaryngology-related surgical procedures, and sickness absence from flight duty. Possible risk factors include a high number of URTIs and poor performance in pressure equalization maneuvers.Lindfors OH, Ketola KS, Klockars TK, Leino TK, Sinkkonen ST. Middle ear barotraumas in commercial aircrew. Aerosp Med Hum Perform. 2021; 92(3):182189.

Outcome Measures for Baro-Challenge-Induced Eustachian Tube Dysfunction: A Systematic Review

OBJECTIVES

Baro-challenge-induced Eustachian tube dysfunction (baro-induced ETD) is characterized by failure of the Eustachian tube (ET) to open adequately to permit middle-ear pressure regulation during ambient pressure changes. There are no well-characterized tests for identifying the condition, which makes both patient diagnosis and research into treatment efficacy challenging. This systematic review evaluates ET function tests as potential outcome measures for baro-induced ETD.

DATA SOURCES

MEDLINE and CENTRAL were searched (database inception to March 2017) and reference lists reviewed for all relevant English Language articles.

STUDY SELECTION

Tests in included studies were required to measure ET function in patients reporting baro-induced ear symptoms or barotrauma.

DATA EXTRACTION

Data were extracted in a standardized manner, and studies assessed according to Standards for Reporting of Diagnostic Accuracy Studies (STARD) criteria. The primary outcome of interest was the accuracy of ET function tests.

DATA SYNTHESIS

Heterogeneity of subject demographics, ET function test methodology, and reference standards only permitted narrative systematic review.

CONCLUSION

Sixteen studies involving seven different types of ET function tests were identified. The nine-step test was the most commonly used outcome measure, with overall test sensitivity and specificity ranges of 37 to 100% and 57 to 100%, respectively. Tympanometry test sensitivity was consistently poor (0-50%) while specificity was higher (52-97%). Published accuracy data for other ET function tests and test combinations were limited. Currently, no single test can be recommended for use in clinical practice. A combination of the nine-step test with other objective tests or patient-reported measures appears most promising as a core set of outcome measures for baro-induced ETD.

Eustachian tube balloon dilation in treatment of equalization problems of freediving spearfishermen

BACKGROUND

Eustachian tube balloon dilation is a minimally invasive surgical procedure used to treat Eustachian tube dysfunction which is not responsive to conventional therapies.

METHODS

In this cohort intervention series we report the results of balloon dilation in treating refractory equalization problems in 20 freediving spearfishermen; in 19 cases the problem was unilateral and in one case bilateral. All the patients had already received medical and insufflation therapy and four patients had also had nasal surgery. None of these treatments or procedures had achieved improvement. We used a 20 mm x 3 mm disposable balloon catheter inserted through a 70-degree guide catheter and inflated up to 12 ATM three times at three different depths of insertion within the Eustachian tube. Every inflation lasted 120 seconds.

RESULTS

Fifteen out of 20 patients improved. Ten patients reported a complete resolution of equalization problems, five showed improvement with persistence of a slight equalization delay on the treated side. Five patients did not report any improvement. Two complications occurred: subcutaneous emphysema of the parotid region in one case; and a mild high frequency (4-8 KHz) sensorineural hearing loss in another patient.

CONCLUSION

Balloon dilation of the Eustachian tube is an effective therapy in the treatment of equalization problems with a good success rate.

SCUBA Medicine for Otolaryngologists: Part II. Diagnostic, Treatment, and Dive Fitness Recommendations

OBJECTIVES

Challenge current practices and misconceptions in treating recreational SCUBA (Self-contained underwater breathing apparatus) divers. Differentiate patients who are fit to dive and those with relative and absolute contraindications. Redefine the standard of care for fitness to dive parameters based on the most up-to-date evidence.

METHODS

We conducted a review of the available medical and diving literature in English, German, Spanish, Italian, Turkish, and French to determine the degree of evidence or lack thereof behind recommendations for treating SCUBA divers. The databases of PubMed, Ovid Medline, and Cochrane library, as well as available textbooks, were queried for relevant data.

RESULTS

Current recommendations regarding fitness to dive are overly prohibitive given the available evidence. Insufficient evidence currently exists to justify the level of certainty with which some recommendations have been made previously. This is particularly true with regard to postsurgical patients, including those who have undergone stapedectomy or skull base repairs. Updated treatment guidelines, particularly those regarding the timely differentiation of barotrauma and decompression sickness, as well as clearance for return to diving following surgery or trauma, are presented herein.

CONCLUSION

Current guidelines for otorhinolaryngologists governing the diagnosis and treatment of SCUBA divers are lacking and in some instances founded on insufficient evidence. We present an up-to-date, comprehensive guide for otorhinolaryngologists to utilize going forward. Laryngoscope, 130:59-64, 2020.

Acoustic Transmission Characteristics of a Eustachian Tube Volitionally Opened in Two Living Subjects

OBJECTIVE

To assess the acoustic transmission characteristics of the Eustachian tube (ET) in living subjects in verified patent and closed ET states to facilitate the detection and quantification of ET function using acoustic measures such as sonotubometry.

PATIENTS

The two subjects in this study had no history of ear disease nor previous ear surgery and were capable of volitionally opening and closing their ET.

INTERVENTIONS

Tympanometry and otologic examinations were used to confirm ET patent and closed states by observing tympanic membrane movement with respiration and by acoustic immitance measurements during forced respiration. A series of 500-ms long chirps containing frequencies from 100 Hz to 10 kHz were introduced into the nasal cavity during both ET states and recorded by microphones in both the contralateral naris and external auditory canal.

MAIN OUTCOME MEASURES

Acoustic energy transmission through the ET across the 0.1 to 10 kHz frequency range in the closed state versus the patent state.

RESULTS

An increase in acoustic energy transmission occurs across the frequencies of 1 to 4 kHz between the closed and patent ET states, particularly in frequencies below 2.5 kHz.

CONCLUSIONS

Results support sonotubometry as a potential diagnostic tool for ET dysfunction. Acoustic differences between the ET states manifest as a general increase in transmitted signal amplitude. Characterizing the acoustic properties in the verified patent and closed ET states allows investigators to more reliably interpret sonotubometric tests of ET function.

Use of the nine-step inflation/deflation test and resting middle-ear pressure range as predictors of middle-ear barotrauma in aircrew members

Objective:

To explore the role of the nine-step inflation/deflation tympanometric test and resting middle-ear pressure range as predictors of barotrauma in aircrew members.

Methods:

A prospective, non-randomised study was conducted on 100 aircrew members. Resting middle-ear pressure was measured and the nine-step inflation/deflation test performed on all subjects before flights. Subjects were allocated to two groups according to resting middle-ear pressure range (group A, within the range of +26 to +100 and −26 to −100 mmH2O; group B, −25 to +25 mmH2O). All aircrew members were assessed after flights regarding the presence and the grade of barotrauma.

Results:

In both groups, the sensitivity and specificity values of the entire post-inflation/deflation test were close to those of the post-deflation part of the test. The post-deflation test had a higher negative predictive value than the post-inflation test. Ears with resting middle-ear pressure lower than −55 mmH2O experienced barotrauma, regardless of good or poor post-inflation or post-deflation test results.

Conclusion:

In an aircrew member, a resting middle-ear pressure within the range of −55 and +50 mmH2O, together with good post-deflation test results, are considered reliable predictors for fitness to fly.

Air travellers' awareness of the preventability of otic barotrauma

Objective:

Otic barotrauma is common among air travellers and can cause severe otalgia, perforation of the tympanic membrane and hearing loss. Many prevention measures exist, with varying evidence to support their use. There are no data to establish if air travellers are aware of them or indeed use them. We aimed to establish air travellers' knowledge of such prevention measures.

Methods:

We surveyed air travellers at two UK airports by means of a questionnaire. Answers to the questionnaire were collected over a two-week period.

Results:

Overall, 179 air travellers with a mean age of 28 years (range: 15–72 years) completed the questionnaire. There were 66 female and 113 male air travellers. The majority (84 per cent) complained of symptoms while flying and 30 per cent were not aware of any prevention measures. Barotrauma-related symptoms were reported in 25 per cent of air travellers who were unaware of any prevention measures. Nearly all air travellers (86 per cent) indicated that more information regarding prevention measures would be useful.

Conclusion:

Air travellers are often not aware of prevention measures to avoid otic barotrauma, and the majority suffer as a result. Increasing public awareness of simple prevention measures would have a significant impact on air travellers.

Update on middle ear barotrauma after hyperbaric oxygen therapy-insights on pathophysiology

Introduction Middle ear barotrauma is the most common side effect of hyperbaric oxygen therapy. Knowledge and understanding of its pathophysiology are crucial for an accurate diagnosis and proper decision making about treatment and prevention.

Objective Describe up-to-date information on pathophysiology of middle ear barotrauma after hyperbaric oxygen therapy considering the physiology of pressure variation of the middle ear.

Data Synthesis Middle ear barotrauma occurs especially during the compression phase of hyperbaric oxygen therapy. The hyperoxic environment in hyperbaric oxygen therapy leads to ventilatory dysfunction of the eustachian tube, especially in monoplace chambers, where the patients are pressurized with 100% O₂, favoring middle ear barotrauma.

Conclusion The eustachian tube, the tympanic cavity, and mastoid work together in a neural controlled feedback system in which various mechanisms concur for middle ear pressure regulation.

Auditory complaints in scuba divers: an overview

Pre-1970s, diving was seen as a predominantly male working occupation. Since then it has become a popular hobby, with increasing access to SCUBA diving while on holiday. For a leisure activity, diving puts the auditory system at the risk of a wide variety of complaints. However, there is still insufficient consensus on the frequency of these conditions, which ultimately would require more attention from hearing-healthcare professionals. A literature search of epidemiology studies of eight auditory complaints was conducted, using both individual and large-scale diving studies, with some reference to large-scale non-diving populations . A higher incidence was found for middle ear barotrauma, eustachian tube dysfunction, and alternobaric vertigo with a high correlation among females. Comparing these findings with a non-diving population found no statistically significant difference for hearing loss or tinnitus. Increased awareness of health professionals is required, training, and implementation of the Frenzel technique would help resolve the ambiguities of the Valsalva technique underwater.

Clinical and tympanometric findings in repeated recreational scuba diving

BACKGROUND

Due to the condition known as middle ear squeeze, scuba diving has become one of the main causes of barotrauma, and the acute form of this condition has been relatively well established. However, there are few reports available on clinical or laboratory findings in divers who practise repeated diving. The objective of the present study was to assess the otological effects of repeated dives.

METHOD

This was an observational study conducted on 19 recreational scuba divers, considered to be experienced divers according to the criteria established by the Professional Association of Dive Instructors (PADI). These divers undertook four dives per day on five consecutive days, and their tympanic membranes were assessed using tympanometry and otoscopy. Data were analysed using the chi(2)-test for trend. The level of statistical significance was set at p<0.05 in all analyses.

RESULTS

The findings suggest that multiple scuba dives over a short period of time cause damage to the structures of the ear, as evidenced by the tympanometric and otoscopic findings, which revealed cumulative effects of pressure against the tympanic membrane and within the middle ear. This condition was not observed when surface intervals exceeded 11h.

CONCLUSIONS

The results suggest that extending surface intervals may offer protection against middle ear barotrauma in recreational scuba diving.

Middle Ear Barotrauma with Hyperbaric Oxygen Therapy: Incidence and the Predictive Value of the Nine-step Inflation/Deflation Test and Otoscopy

We conducted a prospective study to determine the incidence of middle ear barotrauma in patients who were undergoing hyperbaric oxygen therapy (HBOT). We also investigated the value of the nine-step inflation/deflation test and otoscopic findings before and immediately after the initial HBOT session in predicting barotrauma in an attempt to establish some criteria for prophylaxis. The study was conducted on 36 ears of 18 adults who had no history of eustachian tube dysfunction. Patients were being treated with HBOT for sudden hearingloss, wound-healing complications, or complications of diabetes. After 7 days of HBOT, barotrauma was seen in 12 of the 18 patients (66.7%) and in 18 of the 36 ears (50.0%). The nine-step inflation/deflation tests, which were performed before and immediately after the initial HBOT session, were not predictive of barotrauma (p = 0.095 before and p = 0.099 after). However, otoscopic findings obtained immediately after the first session of HBOT were predictive of barotrauma, with a sensitivity and specificity of 83 and 100%, respectively. We conclude that patients with even minor positive pathologic findings on otoscopy immediately following HBOT are at increased risk of middle ear barotrauma if HBOT is to be continued without prophylaxis.

Evaluation of predive parameters related to eustachian tube dysfunction for symptomatic middle ear barotrauma in divers

OBJECTIVE

Eustachian tube dysfunction plays an important role in the pathogenesis of middle ear barotrauma. This investigation evaluates the predictive value of several parameters related to tubal dysfunction, in relation to symptomatic middle ear barotrauma in divers.

STUDY DESIGN

Prospective and blinded.

PATIENTS

Thirty-one sport scuba divers with normal predive audiometry, tympanometry, and general and otorhinolaryngologic examination.

METHODS

After an occurrence of middle ear barotrauma, the individual diver predive data on smoking, mild septal deviation, otitis media history, rhinosinusitis history, Valsalva, Toynbee, and nine-step inflation/deflation tympanometric test, as well as degree of mastoid pneumatization were registered for calculation of predictive value in relation to the barotrauma. All symptomatic ears were examined within 24 hours of diving by the investigator, who was blinded to the predive findings. Barotraumas that occurred during an upper respiratory tract infection were excluded.

RESULTS

Divers completed a total of 774 dives (median, 25; range, 3-100). Symptomatic middle ear barotrauma occurred in 19 ears (31%) of 14 divers (45%) at one time or another. The rate of tubal dysfunction measured by the nine-step test and a mastoid pneumatization below average were significantly higher in divers (p <0.05) as well as in ears (p <0.005) with barotrauma. Positive and negative predictive values of both parameters for subsequent barotrauma were between 69% and 76%. Combining the results into a two-test battery in a strict approach (positive on both) increased the positive predictive value to 86%.

CONCLUSION

Eustachian tube dysfunction measured by the nine-step test and a small size of the mastoid cell system seem to be risk factors for symptomatic middle ear barotrauma in otherwise healthy sport scuba divers. Evaluation of these factors in the predive examination of diving candidates may be useful in the determination of fitness to dive.

Aural barotrauma in submarine escape: is mastoid pneumatization of significance?

OBJECTIVE

Submarine escape training is carried out by preselected, healthy young men under strictly controlled conditions regarding exposure to pressure and the rate of pressure change. This provides a unique opportunity to investigate the relations between middle ear characteristics and susceptibility to barotrauma while avoiding possible confounding parameters. We examined a possible association between mastoid pneumatization and middle ear barotrauma (MEB) in submarine escape trainees.

STUDY DESIGN

Cross-sectional, parallel-group design.

METHODS

Sixty-six subjects aged 19 to 28 participated in the study. The escape simulation included pressurization to 30 or 60 feet followed by a buoyant ascent to the surface. Subjects were evaluated for MEB after each ascent. A Schuller's mastoid radiograph was taken for the evaluation of mastoid pneumatization.

RESULTS

Fifteen (23%) of the subjects suffered from MEB, and 6 (40%) of them had bilateral involvement. Repeated impedance audiometry after the completion of a successful ascent revealed a significant increase in middle ear compliance. Schuller's radiographs were obtained from 49 (74%) of the subjects. Of these radiographs, 16 (16%) were of ears that had suffered MEB. Mastoid pneumatization for all ears approached a normal Gaussian distribution, with a mean area of 9.58 cm. The mastoid areas and the proportion of ears with mastoid pneumatization at the extremes of the study population did not differ between barotrauma and no-barotrauma ears.

CONCLUSION

In a population with no history of recurrent or chronic otitis media and normal tympanic membrane morphology and compliance, the amount of mastoid pneumatization probably represents merely the normal distribution of variation in organ size and is not related to the ability to equalize pressure in the middle ear.

Eustachian tube patency and function in tympanoplasty with cartilage palisades or fascia after cholesteatoma surgery

OBJECTIVE

To compare the Eustachian tube patency and function after tympanoplasty with either cartilage palisades or fascia grafting after one-stage surgery in children with tensa cholesteatoma.

STUDY DESIGN

In children operated for tensa cholesteatoma, cartilage palisade tympanoplasty was performed in 32 ears and fascia tympanoplasty in 29 ears. The patency of the Eustachian tube was evaluated by the Valsalva maneuver before the operation, 1 to 3 months after the operation, and at a follow-up examination 46(1/2) months later (median). Eustachian tube function was evaluated by the nine-step inflation/deflation tympanometric test and the Toynbee test at the follow-up examination. Otomicroscopy and hearing evaluation were performed before and after surgery as well as at the follow-up.

MAIN OUTCOME MEASURES

Eustachian tube patency and function. Hearing, postoperative eardrum perforation/retraction, and cholesteatoma recurrence.

RESULTS

The Valsalva maneuver was positive in 30% of the ears before the operation, in 65% primarily after the operation, and in 78% at the follow-up examination. A poor tubal function was found in 57% at follow-up. Overall, the late functional hearing results were better in ears with a positive Valsalva maneuver. There were no differences in tubal patency or function in relation to graft material, cholesteatoma, and tympanoplasty type. In ears with a poor tubal function, the hearing results were significantly better in the palisade group (63% success), compared with the fascia group (17% success). All of the four perforations, most of the retractions, and a single moist eardrum were found in the fascia group at the reevaluation. We found no correlation between the condition of the eardrum and the Eustachian tube function at the last evaluation. However, in ears with a poor tubal function, a nonretracted, nonperforated drum was found with higher frequency in the palisade group. Decision matrix analysis showed that the last postoperative Valsalva maneuver was the best predictor of the drum condition at the reevaluation.

CONCLUSIONS

The Eustachian tube patency frequently improves after tympanoplasty after cholesteatoma surgery in children, regardless of graft material. The patency and function of the Eustachian tube seem to be without relation to graft material, cholesteatoma, or tympanoplasty type. Cartilage palisade tympanoplasty may be a better reconstruction technique after cholesteatoma surgery, especially in ears with a poor tubal function.

Diving emergencies

Self-Contained Underwater Breathing Apparatus (SCUBA) diving popularity is increasing tremendously, reaching a total of 9 million people in the US during 2001, and 50,000 in the UK in 1985. Over the past 10 years, new advances, equipment improvements, and improved diver education have made SCUBA diving safer and more enjoyable. Most diving injuries are related to the behaviour of the gases and pressure changes during descent and ascent. The four main pathologies in diving medicine include: barotrauma (sinus, otic, and pulmonary); decompression illness (DCI); pulmonary edema and pharmacological; and toxic effects of increased partial pressures of gases. The clinical manifestations of a diving injury may be seen during a dive or up to 24 h after it. Physicians living far away from diving places are not excluded from the possibility of encountering diver-injured patients and therefore need to be aware of these injuries. This article reviews some of the principles of diving and pathophysiology of diving injuries as well as the acute treatment, and further management of these patients.

Effects of non-invasive ventilation on middle ear function in healthy volunteers

OBJECTIVES

To evaluate the effects of non-invasive ventilation (NIV) with facial mask or helmet on middle ear (ME). DESIGN. Prospective, randomised study.

SETTING

University hospital.

PARTICIPANTS

Ten healthy subjects randomly allocated in two groups of five subjects each.

INTERVENTIONS

NIV for 1 h, with helmet (group H) or facial mask (group M). Flow-triggered pressure support was 10 cmH(2)O, PEEP 5 cmH(2)O, FiO(2) 0.21.

MEASUREMENTS AND RESULTS

Impedenzometry was performed before NIV and 5 min after NIV ended; it was repeated 60 min later. In group H the acoustic compliance increased after NIV from 2.0+/-.6 ml to 2.3+/-.6 ml ( P<.01), suggesting that the tympanic membrane became less stiff; 1 h later the compliance returned to basal values (2.0+/-.7 ml); in group M the compliance was unaffected (from 2.0+/-.5 ml to 2.0+/-.4 ml; 1.9+/-.4 ml 1 h later). The acoustic reflex, i.e., the contraction of the stapedial muscle in response to an auditory stimulus, involving the acoustic and facial nerves, was also evaluated during impedenzometry at 250 Hz, 500 Hz, 1,000 Hz, and 4,000 Hz; no significant change of the threshold was observed.

CONCLUSIONS

The tympanic membrane is tighten by the tensor tympani and a reversible loosening suggests muscle fatigue in response to the application of intermittent positive pressure applied to the external ear during NIV with helmet. The loss of tensor tympani protective action could theoretically predispose the middle and inner ear to mechanical damage during NIV with helmet, suggesting the use of protective devices (ear plugs) in selective cases requiring long-term, high-pressure treatment.

Relationship between mastoid pneumatization and middle ear barotrauma in divers

OBJECTIVES/HYPOTHESIS

Previous studies have shown a relationship between eustachian tube function and size of mastoid pneumatization, as well as eustachian tube function and middle ear (ME) barotrauma. The purpose of this study is to investigate a possible relationship between size of mastoid pneumatization and ME barotrauma in sports scuba (self-contained underwater breathing apparatus) divers.

STUDY DESIGN

Prospective, blinded.

MATERIAL AND METHODS

Twenty-four sports scuba divers (48 ears), who were fit to dive in the predive and otolaryngologic examination, were included in the study. Size of mastoid pneumatization was measured by simplified rectangular dimension method on a mastoid x-ray taken at Schüller's view. Divers were counseled to refer to the investigators if any symptoms occurred during and/or after diving. All symptomatic ears were examined within 24 hours of diving by the same investigator, who was blinded to the degree of pneumatization.

RESULTS

ME barotrauma occurred in 15 ears (31%) of 11 divers (46%) at one time or another. The median degree of pneumatization in ears with barotrauma (22.9 cm2) was significantly smaller than that in unaffected ears (34.1 cm2; (P <.001). Furthermore, findings showed that with increasing degree of pneumatization, there was a decreasing risk of symptomatic barotrauma (P <.001). No barotrauma occurred in ears with a pneumatization greater than 34.7 cm2. However, barotrauma occurred in all 3 ears with a pneumatization degree smaller than 13.6 cm2.

CONCLUSION

Our findings indicate an inverse relationship between size of pneumatization and risk of symptomatic ME barotrauma in sport scuba divers.