Eustachian Tube Opening Pressure Research Articles

Concordance Analysis of the Pressure Chamber and Tubomanometer According to Estève for the Determination of Eustachian Tube Opening Pressure.

For the diagnosis of Eustachian tube dysfunction (ETD), clinical procedures such as tympanometry, micro-otoscopy, and maneuvers according to Toynbee and Valsalva only allow an indirect assessment for the moment. With a prevalence of up to 5%, the selection of patients with ETD and its subtypes is clinically relevant. Dynamic methods of Eustachian tube function assessment include a hypo/hyperbaric pressure chamber and Estève's tubomanometer (TMM). One method of assessing ETD is the evaluation of Eustachian tube opening pressure (ETOP). We performed a concordance analysis between pressure chamber and TMM to determine ETOP. For this purpose, we analyzed the measurements of both methods from 28 healthy subjects using Bland-Altman plots, regression according to Passing-Bablok and Lin's concordance correlations coefficient. The maximum tolerated clinical deviation of measured values was set at 10%. A maximum of 53 measurements of ETOP between pressure chamber and TMM were compared. Mean ETOP for TMM was 28.7 hPa, passive opening was 32 hPa, Toynbee maneuver was 28.4 hPa, and Valsalva maneuver was 54.6 hPa. Concordance analysis revealed following results: passive opening versus TMM: Bland-Altman mean difference 3.3 hPa, limits of agreement ±31.8 hPa; Passing-Bablok regression y = 0.67 x + 9.36; Lin's rccc = 0.18. Toynbee versus TMM: Bland-Altman mean difference 0.7 hPa, limits of agreement ±35.8 hPa; Passing-Bablok regression y = 0.47x + 14.03; Lin's rccc = 0.14. Valsalva versus TMM: Bland-Altman mean difference 24.2 hPa, limits of agreement ±117.5 hPa; Passing-Bablok regression y = 0.17x + 25.12; Lin's rccc = 0.18. Estève's tubomanometer and pressure chamber measurements of ETOP are not concordant. The two methods cannot be interchanged without reservation.

Intraindividual variability of the Eustachian tube function: a longitudinal study in a pressure chamber.

The Eustachian tube (ET) is essential for fast and direct pressure equalisation between middle ear and ambient pressure. It is not yet known to what extent Eustachian tube function in healthy adults changes in a weekly periodicity due to internal and external factors. This question is particularly interesting with regard to scuba divers among whom there is a need to evaluate intraindividual ET function variability. Continuous impedance measurement in a pressure chamber was performed three times at one-week intervals between measurements. Twenty healthy participants (40 ears) were enrolled. Using a monoplace hyperbaric chamber, individual subjects were exposed to a standardised pressure profile consisting of a 20 kPa decompression over 1 min, a 40 kPa compression over 2 min, and a 20 kPa decompression over 1 min. Measurements of Eustachian tube opening pressure (ETOP), opening duration (ETOD), and opening frequency (ETOF) were made. Intraindividual variability was assessed. Mean ETOD during compression (actively induced pressure equalisation) on the right side was 273.8 (SD 158.8) ms, 259.4 (157.7) ms, and 249.2 (154.1) ms (Chi-square 7.30, P = 0.026) across weeks 1-3. Mean ETOD for both sides was 265.6 (153.3) ms, 256.1 (154.6) ms, and 245.7 (147.8) ms (Chi-square 10.00, P = 0.007) across weeks 1-3. There were no other significant differences in ETOD, ETOP and ETOF across the three weekly measurements. This longitudinal study suggests low week-to-week intraindividual variability of Eustachian tube function.

Correlation between acoustic immittance and ETS in eustachian tube function test

Objective:To investigate the correlation between acoustic immittance and eustachian tube score（ETS） in eustachian tube function test. Methods:124 ears eustachian tube function with tympanic tension perforation of 107 patients with chronic suppurative otitis media were measured by acoustic immittance positive pressure balance method and ETS. According to the positive pressure balance test results of acoustic immittance, the ear eustachian tube open pressure between 100 and 200 daPa is assigned 2, the ear with open pressure between 200 and 300 daPa is assigned 3, the ear with open pressure betwween 300 and 400 daPa is assigned 4, the ear open pressure is greater than 400 daPa but eustachian tube open after swallowing is assigned 5, and the ear which eustachian tube open pressure is greater than 400 daPa and cannot open after swallowing is assigned 6. Then compare the results. Results:In the acoustic immittance test, there was no ears whose eustachian tube opening pressure less than 100 daPa, 10 ears（8.1%） open pressure between 100 and 200 daPa, 16 ears（12.9%） open pressure between 200 and 300 daPa, 46 ears（37.1%） open pressure between 300 and 400 daPa, 19 ears（15.3%） whose eustachian tube don't open pressure at 400 daPa but open after swallowing, and the cumulative percentage of the above was 73.4%. There were 33 ears（26.6%） whose eustachian tubes not opening after receiving maximum pressure（400 daPa） and repeated swallowing. The score of acoustic immittance eustachian tube function test was significantly correlated with the scores of ETS, eustachian tube manometry（TMM） and subjective part of ETS（P<0.05）. The result of acoustic immittance was moderately negatively correlated with ETS（r=-0.439） and TMM（r=-0.425）, and weakly negatively correlated with subjective part of ETS（r=-0.249）. The scores of 2-5 points （the affected ears with open eustachian tube in all acoustic impedance test methods） were defined as the normal group, and the scores of 6 point were defined as the abnormal group. The results of acoustic immittance between the normal group and the abnormal group showed that there were significant differences with the subjective scores of ETS, TMM and ETS. The consistency compared the results of acoustic immittance eustachian tube test with the results of ETS was poor（kappa value was negative）, and the difference was statistically significant. Conclusion:The open pressure of acoustic immittance positive pressure balance method is a good predictor of the subjective scores of ETS, TMM and ETS. The smaller the open pressure is, the better the subjective scores of ETS, TMM and ETS may be. This two methods results are inconsistent and cannot be replaced. More consideration should be given to the middle ear. The open pressure, equilibrium pressure and the difference between them need to be paid attention to at the same time.

Prospective study on the Eustachian tube function during Frenzel maneuver in a hypobaric/hyperbaric pressure chamber

IntroductionThe Frenzel maneuver describes a technique for middle ear equalizing which is frequently used by apnea divers. It offers advantages compared to the most commonly used techniques such as the Valsalva or Toynbee maneuver. Until now, there is insufficient literature about the pressure dynamics and Eustachian tube (ET) function during the Frenzel maneuver. The aim of the present study was to characterize the ET function during the Frenzel maneuver.Materials and methodsBy means of an established standardized profile of compression and decompression in a hypo/hyperbaric pressure chamber, we examined different parameters such as the ET opening pressure (ETOP), ET opening duration (ETOD), and ET opening frequency (ETOF) in 11 experienced apnea divers and compared them to the parameters during the Valsalva and Toynbee maneuver.ResultsStandard values for ETOP, ETOD, and ETOF could be established for the Frenzel maneuver under standardized conditions in a hypo/hyperbaric pressure chamber. Compared to the Frenzel maneuver, ETOP was higher and ETOD longer (both p < 0.001) during the Valsalva maneuver whereas ETOP was lower and ETOD shorter (both p < 0.001) during the Toynbee maneuver. No difference regarding ETOF was observed between the Frenzel, Valsalva, and Toynbee maneuver.DiscussionThe Frenzel maneuver was shown to be at least as effective as the Valsalva maneuver concerning ET opening. We believe that knowledge of the Frenzel technique might facilitate the pressure equalization during diving and recommend implementation of an appropriate equalization training in apnea and scuba diving education.

Subjective and Objective Effectiveness of Eustachian Tube Balloon Dilatation for Patients With Eustachian Tube Dysfunction-Evaluation in a Pressure Chamber.

The Eustachian tube plays a crucial role in pressure equalization between the middle ear and ambient pressure for fast and large pressure differences. In patients with chronic Eustachian tube dysfunction, Eustachian tube balloon dilatation is increasingly used as surgical therapy. Subjectively, many patients report an improvement of the symptoms postoperatively. Hence, there is a need to objectively measure this effect. The objectivity of Eustachian tube balloon dilatation was evaluated using a precise method of measuring Eustachian tube function. In a hypo/hyperbaric pressure chamber, 23 ears in 13 patients were exposed to a standardized profile of compression and decompression before Eustachian tube balloon dilatation and 4 weeks afterwards. Standardized parameters of Eustachian tube function were determined and statistically compared before and 4 weeks after intervention. In addition, an Eustachian Tube Dysfunction Questionnaire-7 (ETDQ7) questionnaire was completed beforehand and 4 weeks postoperatively to determine subjective surgical success. The results from the ETDQ7 questionnaire showed a significant improvement in symptoms after Eustachian tube balloon dilatation (p = 0.0002). Objective measurements results showed a significant reduction of the Eustachian tube opening pressure during pressure decrease 4 weeks after intervention (p = 0.0012). Eustachian tube balloon dilatation significantly reduced Eustachian tube opening pressure, in addition to subjective improvement of symptoms determined by ETDQ7.

Feasibility and Safety of Transtympanic Balloon Dilatation of Eustachian Tube.

Assess safety and feasibility of transtympanic dilatation of proximal (tympanic-end) of the cartilaginous segment of the Eustachian tube in patients undergoing surgery for chronic ear disease. Case series. Tertiary care hospital. We reviewed the charts of 40 consecutive patients undergoing chronic ear surgery in our practice with manometric evidence of obstruction who underwent attempted transtympanic dilatation of proximal (tympanic-end) segment of the Eustachian tube. A range of outcome measures were reported that included pre and postdilatation opening pressure measurement of the Eustachian tube, closure of perforation, audiometric data, and complications. Dilatation of proximal (tympanic-end) of the cartilaginous segment of the Eustachian tube was technically feasible in 37 of 40 patients (93%). Postdilatation inspection of protympanum showed increased aperture in all dilated tubes. Opening pressure of Eustachian tube declined in 36 of 37 patients (97%). Residual perforation was evident in 5 of 40 patients (12%). No facial nerve or carotid complications were observed. Two patients had severe dizziness (5%) with one patient sustaining severe cochlear loss. Transtympanic dilatation increases the patency of the Eustachian tube immediately after instrumentation. No carotid complications were observed. Continuous endoscopic control is essential to avoid subluxation of stapes. Further study of this technique is warranted to identify its role, if any, in chronic ear surgery.

Impact of xylomethazoline on eustachian tube function in healthy participants.

The use of decongestants is common in otitis media eustachian tube (ET) dysfunction. However, the underlying mechanism and the type of action on the complex middle ear pressure equalization system are poorly understood. Here, by use of the pressure chamber, we investigated the impact of intranasal decongestive therapy (xylomethazoline) on ET function. Thirty healthy participants (60 ears) were exposed to a predetermined profile of phases of compression and decompression in a hypobaric and hyperbaric pressure chamber. ET opening pressure, ET opening duration, ET opening frequency, and ET closing pressure were determined before and after intranasal application of xylomethazoline. A significantly higher number of ET openings (ET opening frequency) in passive equalization condition could be measured after application of decongestants than before. No significant difference could be found in the values of ET opening pressure, ET opening duration, and ET closing pressure parameters before in comparison with the values after application of xylomethazoline. We conclude that xylomethazoline might only have a minor effect during active and passive middle ear pressure equalization. Larger cohorts and targeted application of decongestants should be tested to confirm these preliminary data and to find new evidence on the effects of decongestants.

Charakterisierung der passiven Tubenöffnung in einer hypo-/hyperbaren Druckkammer

Beside arbitrary and not arbitrary active pressure equalization systems there is a passive equalization system via the Eustachian tube (ET) at pressure difference between the epipharyngeal space and the middle ear. Aim of this study was to characterize this passive equalization system in a hypobaric/hyperbaric pressure chamber by continuously measuring the tympanic impedance. In contrast to other studies, which are measured only in a hypobaric pressure chamber it is possible to include participants with Eustachian tube dysfunction (ETD). Following a fixed pressure profile 39 participants were exposed to phases of pressure rising and decompression. By continuously measuring the tympanic impedance in the pressure chamber it was possible to measure data of the Eustachian Tube opening Pressure (ETOP), Eustachian Tube closing pressure (ETCP) and Eustachian Tube opening duration (ETOD). In addition it was possible to characterize the gradient of pressure during decompression, while the ET was open. Beside the measurement of the arithmetic average of the ETOP (30.2 ± 15.1 mbar), ETCP (9.1 ± 7.7 mbar) and ETOD (0.65 ± 0.38 s) it was obvious that there are recurrent samples of pressure progression during the phase of tube opening. Generally it is possible to differentiate between the type of complete opening and partial opening. The fundamental characterization of the action of the passive tube opening, including the measurement of the ETOP, ETCP and ETOD, is a first step in understanding the physiological and pathophysiological function of the ET.

Sensitivity and Specificity of Eustachian Tube Function Tests in Adults

The study demonstrates the utility of eustachian tube (ET) function (ETF) test results for accurately assigning ears to disease state. To determine if ETF tests can identify ears with physician-diagnosed ET dysfunction (ETD) in a mixed population at high sensitivity and specificity and to define the interrelatedness of ETF test parameters. Through use of the forced-response, inflation-deflation, Valsalva, and sniffing tests, ETF was evaluated in 15 control ears of adult subjects after unilateral myringotomy (group 1) and in 23 ears of 19 adult subjects with ventilation tubes inserted for ETD (group 2). Data were analyzed using logistic regression including each parameter independently and then a step-down discriminant analysis including all ETF test parameters to predict group assignment. Factor analysis operating over all parameters was used to explore relatedness. ETF testing. ETF parameters for the forced response, inflation-deflation, Valsalva, and sniffing tests measured in 15 control ears of adult subjects after unilateral myringotomy (group 1) and in 23 ears of 19 adult subjects with ventilation tubes inserted for ETD (group 2). The discriminant analysis identified 4 ETF test parameters (Valsalva, ET opening pressure, dilatory efficiency, and percentage of positive pressure equilibrated) that together correctly assigned ears to group 2 at a sensitivity of 95% and a specificity of 83%. Individual parameters representing the efficiency of ET opening during swallowing showed moderately accurate assignments of ears to their respective groups. Three factors captured approximately 98% of the variance among parameters: the first had negative loadings of the ETF structural parameters; the second had positive loadings of the muscle-assisted ET opening parameters; and the third had negative loadings of the muscle-assisted ET opening parameters and positive loadings of the structural parameters. These results show that ETF tests can correctly assign individual ears to physician-diagnosed ETD with high sensitivity and specificity and that ETF test parameters can be grouped into structural-functional categories.

Eustachian tube function as a predictor of the recurrence of middle ear effusion in children

In children with ventilation tubes (VTs) inserted for chronic otitis media with effusion (COME), the authors sought to determine whether any parameter of Eustachian tube (ET) function measured by the forced response test (FRT) predicts disease recurrence after the VT becomes nonfunctional. Prospective study of those factors that predict disease recurrence in children with VTs inserted for COME. Forty-nine subjects (73 ears; 28 male, 34 white, aged 5.3 ± 1.2 years) with COME had VTs inserted and were evaluable for disease status after the VT(s) became nonfunctional. The FRT was done when the VTs were patent, and results for the last test before the VT became nonfunctional were used in the analysis. After each VT became nonfunctional, the children were followed for disease recurrence over a 12-month period. Logistic regression was used to determine whether the ET opening pressure, closing pressure, and/or dilatory efficiency predicted disease recurrence. That model was expanded to include age, sex, race, history of adenoidectomy, previous VTs, and duration of VT patency as potential predictive factors. Twenty-nine (40%) ears had recurrence of significant disease within 12 months after the VT became nonfunctional. For the complete logistic regression model, male gender (P = .03), nonwhite race (P = .02), shorter period of VT patency (P = .01), and low dilatory efficiency (P = .01) were significant predictors of disease recurrence. A measure of active ET function, dilatory efficiency, but not measures of passive function predicted disease recurrence within the 12 months after the VT became nonfunctional in children with COME.

Reproducibility of the Forced Response Test in Children With Chronic Otitis Media With Effusion

Eustachian tube function is stable over time in children with ventilation tubes for chronic otitis media with effusion. Clinical studies report that Eustachian tube function tests in patients with a persistent tympanic membrane perforation predict the success of myringoplasty, and those in patients with ventilation tubes for chronic otitis media predict disease recurrence after the tubes become nonfunctional. In those studies, Eustachian tube function was usually tested only once, which presumes a semi-stable basal level of function for greatest diagnostic and prognostic usefulness. We investigated the stability of repeated measurements of Eustachian tube function using the forced response test. Thirty-nine children aged 36 to 83 months with bilateral ventilation tubes for chronic otitis media with effusion were evaluated using the forced response test 3 times at 3- to 4-month intervals. The variability across test sessions in the Eustachian tube opening pressure, closing pressure, and dilatory efficiency was estimated using regression/correlation analyses. For all test parameters, the between-session and between-ear correlation coefficients were significant, but the shared variance in the parameters among test sessions and between ears at the same test session was relatively low. The average slope for each parameter as a function of the time with a ventilation tube was zero. The low between-test shared variance for the test parameters raises questions as to whether a single forced response test captures sufficient information to accurately diagnose the cause of any dysfunction or to predict with high specificity and sensitivity future disease experience or surgical results.

A Pilot Study Evaluating Surfactant on Eustachian Tube Function in Divers

Middle ear barotrauma (MEBT) is the most common medical complication in diving, aviation, and hyperbaric medicine. Eustachian tube dysfunction (ETD) quantifies the inability to open the eustachian tube (ET), risking MEBT. Surfactant administration improved ET function and efficaciously treated otitis media in a host of animal models. We performed a pilot study evaluating the efficacy of intranasal surfactant administration in reducing MEBT in repetitive diving. Eight divers participated in a subject-blinded, placebo-controlled, random order, multiarm (air and O2)-repeated measures trial investigating the relative efficacy of intranasally administered surfactant, acetylcysteine and oxymetazoline, and orally administered pseudoephedrine versus saline-placebo in middle ear equilibration during repetitive, multiday diving. Subjects were tested with the Nine-Step Inflation/Deflation Tympanometry Test (NSI/DT) and sonotubometry (testing eustachian tube opening pressure [ETOP]) before and immediately after each dive. Significant interaction effects were found for drug-by-test (F8,668 = 4.05; p < 0.001) and the three-way interaction of drug-by-dive-by-test (F16,668 = 2.47; p = 0.001) in sonotubometry testing. The ETOP revealed trends toward lowered (improved) values post-versus predive in all treatment arms, which was significant for oxymetazoline (p = 0.04). Only four of the eight subjects experienced any holds during diving. Statistical analysis of the NSI/DT data showed that none of the drug interventions resulted in improvements in ET function over that expected by chance. There is large intra- and intersubject variability in daily functioning of the ET as measured using the NSI/DT and sonotubomtery (ETOP). Sonotubometry engendered trends toward lowered (improved) values post-versus predive in all treatment arms. The repetitive dives did not result in a significant decrease in ET function as evidenced in the saline-placebo trials, circumventing an ability to detect superiority among the various treatment arms in our subject population. Additionally, since our study was underpowered to detect significant effects, we can only assert that various inhalational agents may improve middle ear ventilation in repetitive diving warranting further study. A larger subject population including subjects diagnosed with ET dysfunction may provide more statistical power to discern the benefit of inhaled agents as a useful prophylactic for preventing or reducing ET dysfunction during diving and/or hyperbaric/hypobaric pressure changes.

Intranasal phenylephrine-surfactant treatment is not beneficial in otitis media with effusion

Otitis media is the most common reason for non-well-child visits to the primary care physician. Various treatments are in use to try to ameliorate the pain arising from Eustachian tube (ET) dysfunction. One such treatment is topical phenylephrine spray, despite clinical evidence disputing its use. Previous research by this laboratory has demonstrated the beneficial effect of topical surfactant treatment in reducing ET opening pressure, allowing the tube to open. This study is designed to test the effectiveness of topical phenylephrine, delivered with surfactant, in reducing days of effusion in OME, in an animal model. OME was generated by injecting Klebsiella pneumoniae lipopolysaccharide into the right bullae of 28 gerbils. After frank OME resulted, the animals were divided into four groups. Group 1 received no treatment or propellant spray alone (placebo). Group 2 received intranasal surfactant spray once daily. Group 3 received intranasal surfactant-phenylephrine spray once daily. Group 4 received intranasal surfactant-phenylephrine spray twice daily. All animals were evaluated on a daily basis by both otomicroscopy and tympanometry, and treatment was ceased when the ear returned to normal appearance. Evaluations were continued for a total of 30 days. Chi-squared analysis with significance set at .05 was performed. In the untreated and placebo groups, middle ear effusion resolved at 16.25 days by otomicroscopy and 28.26 days by tympanometry. In Group 2 (surfactant alone), effusion resolved at 10.57 days and 15.71 days, respectively. In Group 3 (surfactant-phenylephrine once daily), effusion resolved at 15.67 days and 28.33 days. In Group 4 (surfactant-phenylephrine twice daily), effusion resolved at 18.67 days and 28.33 days. These results were statistically significant. Intranasal phenylephrine-surfactant treatment is shown to be at least ineffective, and possibly detrimental, in the resolution of OME, in this animal model. The hypothesis is that surfactant potentiates the drying effect of phenylephrine at the ET by allowing it to get to the ET more easily; in addition, the drying effect of phenylephrine prevents full surfactant action. We believe that these results can be extrapolated to humans and that phenylephrine should be avoided in these cases.

Effect of surface tension and surfactant administration on Eustachian tube mechanics.

Development of otitis media has been related to abnormal Eustachian tube (ET) mechanics. ET is a collapsible tube that is periodically opened to regulate middle ear pressure and to clear middle ear fluid into the nasopharynx. The ability to perform these physiological functions depends on several mechanical properties, including the ET's opening pressure (P(open)), compliance (ETC), and hysteresis (eta). In this study, a previously developed modified force-response protocol was used to determine ET mechanical properties after experimental manipulation of the mucosal surface condition. Specifically, these properties were measured in the right ear of six cynomologous monkeys under baseline conditions after "washing out" the normal ET mucous layer and after instillation of a pulmonary surfactant, Infasurf. Removal of the normal mucosa did not significantly alter P(open) but did result in a decrease in ETC and eta (P < 0.05). Treatment of the mucosa with Infasurf was effective in reducing P(open) and increasing both ETC and eta to baseline values (P < 0.05). These results indicate that the mucosa-air surface tension can affect the overall ETC and eta properties of the ET. In addition, this study indicates that surfactant therapy may only be beneficial in patients with rigid or inelastic ETs (large P(open) and low ETC and eta).

Nebulized surfactant for experimentally induced otitis media with effusion.

Eustachian tube dysfunction frequently results in clinical evidence of otitis media with effusion (OME). Surface active substances, surfactants, are hypothesized to play a role in normal eustachian tube function. Recent work in a rodent model has demonstrated improved eustachian tube function with topical application of surfactants to the middle ear. A novel, noninvasive, and clinically practical method of delivering surfactant to the eustachian tube was studied in a gerbil model of OME. Otitis media with effusion was experimentally induced in 20 gerbils by transtympanic inoculation of heat-killed Streptococcus pneumoniae. This represents a well established model for creating a serous effusion in the gerbil that significantly increases eustachian tube opening pressure. Effusion developed in 27 of 40 ears (67.5%) after inoculation. An inhaled nebulized surfactant was used to treat the animals with microscopically confirmed OME in one or both ears. The treatment period was 5 days. Eustachian tube opening studies were performed on both affected and nonaffected animals. Successful eustachian tube opening pressures were obtained in 30 of 36 ears (83.3%). The mean opening pressure for ears without effusion (healthy ears) was 42.8 mmHg. The mean opening pressure for ears with effusion in animals treated with nebulized surfactant was 41.4 mmHg. The difference between these mean values was not statistically significant (t = 0.32; p > 0.50). This pilot study suggests that inhaled nebulized surfactant may be efficacious in treating eustachian tube dysfunction when manifested in disorders such as OME.

Nebulized surfactant for experimentally induced otitis media with effusion

Eustachian tube dysfunction frequently results in clinical evidence of otitis media with effusion (OME). Surface active substances, surfactants, are hypothesized to play a role in normal eustachian tube function. Recent work in a rodent model has demonstrated improved eustachian tube function with topical application of surfactants to the middle ear. A novel, noninvasive, and clinically practical method of delivering surfactant to the eustachian tube was studied in a gerbil model of OME. Otitis media with effusion was experimentally induced in 20 gerbils by transtympanic inoculation of heat-killed Streptococcus pneumoniae. This represents a well established model for creating a serous effusion in the gerbil that significantly increases eustachian tube opening pressure. Effusion developed in 27 of 40 ears (67.5%) after inoculation. An inhaled nebulized surfactant was used to treat the animals with microscopically confirmed OME in one or both ears. The treatment period was 5 days. Eustachian tube opening studies were performed on both affected and nonaffected animals. Successful eustachian tube opening pressures were obtained in 30 of 36 ears (83.3%). The mean opening pressure for ears without effusion (healthy ears) was 42.8 mmHg. The mean opening pressure for ears with effusion in animals treated with nebulized surfactant was 41.4 mmHg. The difference between these mean values was not statistically significant ( t = 0.32; p > 0.50). This pilot study suggests that inhaled nebulized surfactant may be efficacious in treating eustachian tube dysfunction when manifested in disorders such as OME. (Otolaryngol Head Neck Surg 1997;117:475-9.)

Role of allergy in eustachian tube blockage and otitis media with effusion: A review

Recent studies continue to support a role for allergy in the pathogenesis of otitis media with effusion. Although a variety of mechanisms have been proposed to relate these two disease conditions causally, none has been completely validated by experimental or clinical studies. This review suggests that the observed relationship between allergy and otitis media with effusion is caused by mediators of inflammation and cytokines and colony-stimulating factors released by mucosal mast cells and other inflammatory and epithelial cells in the nose and nasopharynx. These mediators produce blockage of the eustachian tube through a number of mechanisms, which may include local injury or vascular- or neural-mediated changes in the eustachian tube opening pressure and in middle ear perfusion. It is likely that the nasal allergic response in patients predisposes to eustachian tube blockage and, if prolonged, causes changes in gas absorption in the middle ear space. This gas exchange primarily involves nitrogen absorption, which may take several days to develop. This persistent underpressure will then lead to middle ear effusion. Irrespective of the theoretical mechanism, the relationship between allergy and otitis media with effusion will remain controversial until well-controlled clinical studies are conducted documenting that in select populations antiallergy therapy is efficacious in preventing or limiting the duration of otitis media with effusion. (Otolaryngol Head Neck Surg 1996;114:562-8.)

Role of Allergy in Eustachian Tube Blockage and Otitis Media with Effusion: A Review

Recent studies continue to support a role for allergy in the pathogenesis of otitis media with effusion. Although a variety of mechanisms have been proposed to relate these two disease conditions causally, none has been completely validated by experimental or clinical studies. This review suggests that the observed relationship between allergy and otitis media with effusion is caused by mediators of inflammation and cytokines and colony-stimulating factors released by mucosal mast cells and other inflammatory and epithelial cells in the nose and nasopharynx. These mediators produce blockage of the eustachian tube through a number of mechanisms, which may include local injury or vascular- or neural-mediated changes in the eustachian tube opening pressure and in middle ear perfusion. It is likely that the nasal allergic response in patients predisposes to eustachian tube blockage and, if prolonged, causes changes in gas absorption in the middle ear space. This gas exchange primarily involves nitrogen absorption, which may take several days to develop. This persistent underpressure will then lead to middle ear effusion. Irrespective of the theoretical mechanism, the relationship between allergy and otitis media with effusion will remain controversial until well-controlled clinical studies are conducted documenting that in select populations antiallergy therapy is efficacious in preventing or limiting the duration of otitis media with effusion.

The effect of surfactant on eustachian tube function in a gerbil model of otitis media with effusion

The relationship of eustachian tube surfactant and otitis media with effusion on eustachian tube opening pressure was studied in a gerbil model. Injection of killed Streptococcus pneumoniae bacteria created a serous effusion that increased eustachian tube opening pressure. The introduction of exogenous surfactant to this system resulted in a dramatic decrease in eustachian tube opening pressure in both normal ears and those with effusion. Identifying means to increase surfactant in the eustachian tube could be beneficial in reducing persistent otitis media with effusion.

The effects of grommet insertion on Eustachian tube function.

A prospective study on the effect of grommet insertion on the passive Eustachian tube opening pressure was undertaken in children's ears with otitis media with effusion. After an initial immediate improvement following aspiration of the middle ear no further change in Eustachian tube function occurred over 4 subsequent weeks. Grommet insertion probably has no effect on Eustachian tube function.