Immune status and eustachian tube function in recurrence of otitis media with effusion

OBJECTIVE: To study the combined role of immune status and eustachian tube function in the development of recurrent bilateral otitis media with effusion (OME). DESIGN: Prospective cohort study. SETTING: Three academic and general hospitals. PATIENTS: Children aged 2 to 7 years with a first clinical episode of bilateral OME that persisted for at least 3 months; 136 (81%) of 168 eligible children participated. All children received bilateral tympanostomy tubes at study entry. MAIN OUTCOME MEASURE: Recurrence of bilateral OME within 6 months after tube extrusion. RESULTS: Univariate analyses of various immunologic factors (IgA, IgG1, IgG2, IgG3, IgG4, mannose-binding lectin, and the FcgammaRIIa-H/R131 genotype) and eustachian tube function (forced response test) did not show any significant associations with bilateral OME recurrence. Multivariate analyses showed that children with closing pressures higher than the 75th percentile and IgA or IgG2 levels below the 50th percentile of the cohort were more likely to develop recurrent OME than children with closing pressures higher than the 75th percentile and IgA or IgG2 levels above the 50th percentile. The corresponding risk ratios were 6.3 (95% confidence interval [CI], 1.0-40.1) for IgA level and 3.0 (95% CI, 1.1-8.2) for IgG2 level. The multivariate analyses also revealed that increasing serum levels of functional mannose-binding lectin were associated with decreasing probabilities of developing recurrent OME (odds ratio, 0.7; 95% CI, 0.6-1.0). CONCLUSION: Recurrence of bilateral OME after tympanostomy tube placement is more likely in children with a combination of low IgA or low IgG2 levels with poor eustachian tube function and decreased levels of mannose-binding lectin.     

Compliance of the eustachian tube in patients with otitis media with effusion

To analyze the compliance of the eustachian tube, we measured the decrease in tubal resistance (pressure/air flow) with increasing air flow rate through the eustachian tubal lumen. When the eustachian tube is compliant, the tubal resistance decreases greatly because of the high distensibility of the tube. The tubal compliance index (TCI), which is the ratio of the tubal resistance between two different air flow rates, was compared among three groups: 36 ears of children with otitis media with effusion (OME), 26 ears of adult OME patients, and 10 otherwise normal ears with traumatic perforations of the eardrum. Compared with normal subjects, OME children had a significantly higher TCI (P less than .005), whereas OME adults had a significantly lower TCI (P less than .05). From these results, we concluded that eustachian tubes are compliant in children with OME but rigid in adults with OME.     

Otitis media with effusion: Recurrence after tympanostomy tube extrusion

Objective

The incidence rate of recurrence of otitis media with effusion (OME) in children after tympanostomy tube extrusion and the relationship between recurrence and tube retention time was investigated. Also relationship between recurrence rate and initial age of tube insertion was analysed.

Study Design

A retrospective case series of patients who had tympanostomy tube insertion.

Methods

A total of 91 children (169 ears) were reviewed. Ears of children divided into three groups according to retention time of tympanostomy tubes. Group I: tympanostomy tube retention time less than 6 months. Group II: tympanostomy tube retention time 6 months to 12 months. Group III: tympanostomy tube retention time 12 months or more.

Results

OME recurrence rate after tube extrusion was 20.7% in the study. The longer the tympanostomy tube retention time was the lower was the recurrence rate of OME. The comparison of the three groups indicated that recurrence rates were higher in group I (36.54%), than in group II (17.74%) and in group III (9.1%). There were statistically significant differences in recurrence rates between group I and group III, and between group I and II (p < 0.05, p < 0.05). However, the difference in recurrence rates between group II and group III was statistically not significant (p > 0.05). In the preschool age group and school age group, the recurrence rates were 5.5% and 15.4%, respectively. There was no significant difference between these two groups (p > 0.05). OME recurrence was observed in 9.9% of males and in 11% of females. There was no significant difference in recurrence rates between males and females (p > 0.05).

Conclusion

After extrusion of tympanostomy tube, children should be followed-up regularly for recurrence of OME. The shorter the retention time of tympanostomy tubes was the higher was the recurrence rate. For the treatment of OME the ideal type of tubes should have the lowest complication and recurrence rates. Further studies are needed to ascertain the relationship between the incidence of OME and optimal tympanostomy tubes duration of tube stay in tympanic membrane. Therefore, new studies with larger series are necessary to investigate the correlation between the recurrence rates and different tympanostomy tubes after extrusion of tubes.     

Negative middle ear pressure and otitis media with effusion after surgery under general anesthesia

Abstract Conclusion: Negative middle ear pressure was observed in many patients and otitis media with effusion (OME) developed in 3.3% of ears after surgery under general anesthesia. Gas dynamics in the middle ear cavity induced by nitrous oxide inhalation anesthesia and transient blockage of the eustachian tube induced by surgery are considered to be involved in development of OME after surgery under general anesthesia. Objectives: The goal of this prospective study was to investigate middle ear pressure and the prevalence of middle ear effusion in patients after surgery under general anesthesia, to ascertain whether surgery under general anesthesia induces OME. Methods: Otoscopic inspection and tympanometry were performed before surgery (Pre), 1-2 days after surgery (Post-1), and 5-9 days after surgery (Post-2) under general anesthesia in 180 ears of 97 adult patients. Results: Effusion accumulated in the tympanum in six ears (3.3%) of five patients at Post-1. All patients were anesthetized with nitrous oxide. At Post-2, effusion disappeared in all cases. The mean middle ear pressure in all ears was -17.8 daPa at Pre and -60.6 daPa at Post-1, showing a significant reduction from Pre to Post-1 (p < 0.001). At Post-2, the pressure was -18.4 daPa, with no significant difference from that at Pre (p = 0.74).     

Eustachian tube function varies over time in children with secretory otitis media

Impaired opening and closing functions of the Eustachian tube are considered to be pathogenic factors in secretory otitis media (SOM). As the clinical course of SOM is variable, the variability of tubal function is of interest. We aimed to explore the short- and long-term variability of tubal opening and closing functions in SOM. The study comprised 42 ears in 21 children (13 males and 8 females) with tympanostomy tubes due to SOM. The middle ear pressure was recorded during repeated passive forced openings, equalization of + 100 daPa and - 100 daPa by swallowing, Valsalva inflation and forceful sniffing. Test sessions were performed twice (separated by 30 min) on each of 2 days, with a mean interval of 3.7 months in between. In the forced opening test there was a considerable intra-individual variability over time. Expressed as SD of the mean, the variability of the forced opening and closing pressures in individual ears was on average 15% and 23%, respectively, between sessions and 20% and 30% respectively, between test days. In the equalization, Valsalva and sniff tests the rates of responses that changed from positive to negative between sessions and test days ranged from 12% to 33%. Female gender and retraction pockets were related to poorer opening function in the forced opening test. Ears with serous effusion (in contrast to mucoid) showed a similar trend and also a lower occurrence of positive equalization, Valsalva and sniff tests. It was concluded that Eustachian tube opening and closing functions are highly variable in ears with SOM. Consequently, single tubal function tests have low value when used as a prognostic tool in individual ears.     

Longitudinal assessment of eustachian tube function in children

Eustachian tube function was evaluated in 27 children (32 ears) with tympanostomy tubes at 6-week intervals for 12 to 30 months. Using a modified inflation-deflation test of passive and active ventilatory function, it was found that the ears had persistent functional obstruction. Most ears exhibited no significant change in tubal function throughout the observation period. There was no difference in the ventilatory function when the nasal airway was congested (other than due to purulent upper respiratory tract infection) and not congested. However, significant seasonal effects on Eustachian tube ventilatory function were recorded: function was poorer in the winter than in the summer. No relationship was found between Eustachian tube ventilatory function and the age of the child.     

Nebulized surfactant as a treatment choice for otitis media with effusion: an experimental study in the rabbit.

Exogenous surfactant can improve eustachian tube function in experimentally induced otitis media with effusion (OME). Performing tympanometric recordings, the efficacy of inhaled nebulized surfactant, as compared with inhaled nebulized physiological saline was investigated, for the treatment of OME experimentally induced in the rabbit by intrabullar inoculation of heat-killed Streptococcus pneumoniae. In addition, the histological changes in middle ears after the treatment were investigated in order to establish whether the pathological findings correlated with the results. Middle-ear pressure values before, and after, treatment were analyzed by the Wilcoxon statistical method, and the Mann-Whitney U test was used to compare the post-treatment values between groups. In all ears with OME in the affected animals, which were treated with nebulized surfactant inhalation, a positively significant (p<0.05) increase of pressure more than 20 daPa was recorded. In the control group, after inhalation of nebulized physiological saline, there was no positive increase in the affected middle-ear pressures; on the contrary, more negative pressure changes were recorded. In the histological evaluation, middle-ear epithelia and sub-epithelial space were normal in surfactant-treated ears with OME, whereas mucosal thickening with an oedematous sub-epithelial space containing occasional inflammatory cells and increases in connective tissue and vascularity, and effusions on the epithelial surface were present in the ears with OME in the control group. The significant improvement in the negative middle-ear pressure after nebulized surfactant treatment and the histological findings shown in our study can support the theory that surface-active agents are of importance in eustachian tube function even under pathologic conditions, such as OME.     

Evaluation of the Polytetrafluoroethylene-Membrane Ventilation Tube

In an effort to evaluate the safety and efficacy of the currently available polytetrafluoroethylene (PTFE)-membrane ventilation tube, in a group of 41 children, the experimental tube was inserted into one ear and a conventional tympanostomy tube was placed in the other ear. The membrane tubes, except in a few instances, were inserted into ears without effusion. After the procedure the children were forbidden to swim and their ears were protected during bathing. In addition to pneumatic otoscopy, a specially designed tympanometric test—which determined if the membrane tube was functioning—was used to assess the operation of the new device postoperatively. In many of the children, Eustachian tube function studies were also performed on the ears with the conventional tympanostomy tubes. The study was aborted early in the clinical trial period due to the early findings: only 10 of 41 (24%) of the membrane tubes continued to function, the remainder having become occluded; whereas 35 of 41 (85%) of the conventional tympanostomy tubes were found to be still functioning during the same period of observation. Twelve of the 41 membrane tubes had to be removed prematurely and replaced with conventional tympanostomy tubes due to recurrence of middle ear effusion. Scanning electron microscopic studies of the removed tubes revealed blockage of the membrane pores. From the extraordinarily high failure rate of the PTFE-membrane ventilation tube in this study, it is evident that the experimental tube should not replace the conventional tympanostomy tube at this time. The selection of the PTFE covering-membrane on this tube was ill advised, but the rationale of a semipermeable-membrane ventilation tube has merit. However, should another membrane ventilation tube be designed, its routine use must await controlled clinical trials to determine safety and efficacy in humans.     

Evaluation of factors affecting outcome of surgery for otitis media with effusion in clinical practice

In discussing surgery for otitis media with effusion (OME), tympanostomy tubes and adenoidectomy are important. Sinus surgery is less important and cleft palate surgery needs to be mentioned for completeness sake. There is no evidence supporting the value of tonsillectomy in the treatment of OME. Tympanostomy tubes are possibly best regarded as artificial eustachian tubes, which remain in position for a variable amount of time. It is therefore apparent that resolution of OME from tympanostomy tube placement largely depends on whether underlying aetiological factors have either resolved or been corrected when the tympanostomy tube was in position.     

Birth characteristics and recurrent otitis media with effusion in young children

OBJECTIVE: To study the association between birth characteristics and the recurrence of otitis media with effusion (OME). METHODS: Prospective cohort study on 136 children aged 2-7 years, who received tympanostomy tubes for bilateral otitis media with effusion. Checkups were planned 1 week after tube insertion and once every 3 months thereafter. An otologist examined the ear status to assess tube extrusion and otitis media with effusion recurrence. Outcome measure was the recurrence of otitis media with effusion within 6 months after documentation of spontaneous tube extrusion. Birth characteristics were investigated in relation with the recurrence of otitis media with effusion in 90 children with known clinical outcome. RESULTS: No statistically significant associations were found between various birth characteristics and the recurrence of otitis media with effusion. Multivariate analyses showed positive but fairly weak associations between recurrence of otitis media with effusion and low birth weight (<2500 g) and/or low gestational age (<37 weeks) and/or a history of incubator care (odds ratio (OR) 1.95, 95% confidence interval (CI): 0.21-18.2), male sex (OR 1.85, 95% CI: 0.56-6.13) and maternal medication use during pregnancy (OR 4.80, 95% CI: 0.57-40.72). A remarkable finding was the asymmetrical distribution of certain birth characteristics within the group of children with recurrence of otitis media with effusion: children with unilateral recurrence had a relatively lower gestational age, lower birth weight, lower 'birth length to birth weight' ratio than the children with bilateral recurrence. CONCLUSION: These findings suggest that determination of birth characteristics cannot help us in the treatment strategy for recurrent otitis media with effusion in childhood.     

Predictors of chronic suppurative otitis media in children

OBJECTIVE: To determine which factors predict development of chronic suppurative otitis media (CSOM) in children. DESIGN: Case-control study, with univariate and multivariate logistic regression analysis applied to determine which factors independently predict CSOM. SUBJECTS: Prognostic factors for CSOM were identified in (1) 100 children with CSOM and 161 controls aged 1 to 12 years and (2) 83 children who developed CSOM in the presence of a tympanostomy tube and 136 children with tympanostomy tubes who did not develop CSOM. RESULTS: Independent predictors for CSOM were previous tympanostomy tube insertion (odds ratio [OR], 121.4 [95% confidence interval {CI}, 38.9-379.3]); having had more than 3 upper respiratory tract infections in the past 6 months (OR, 12.2 [95% CI, 3.5-42.3]); having parents with a low education level (OR, 14.1 [95% CI, 2.9-68.6]); and having older siblings (OR, 4.4 [95% CI, 1.6-12.6]). Independent predictors for CSOM after tympanostomy tube insertion were having experienced more than 3 episodes of otitis media in the past year (OR, 4.9 [95% CI, 2.2-11.0]; attending day care (OR, 3.6 [95% CI, 1.7-7.8]); and having older siblings (OR, 2.6 [95% CI, 1.2-5.5]). CONCLUSIONS: Treatment with tympanostomy tubes is the most important prognostic factor for CSOM in children. In children who are being treated with tympanostomy tubes for persistent middle ear effusion, the most important prognostic factor for CSOM is a history of recurrent episodes of acute otitis media. This information should be taken into consideration and discussed with parents when considering insertion of tympanostomy tubes in children.     

Hyperbaric oxygen therapy: effect on middle ear and eustachian tube function.

Hyperbaric oxygen therapy (HBO) involves intermittent inhalation of 100% oxygen under a pressure greater than 1 atm. It is an important mode of adjuvant therapy for disease processes such as decompression sickness, osteomyelitis, carbon monoxide poisoning, and poorly healing wounds. Patients undergoing this therapy often complain of ear pain and/or fullness which can be transient or long standing. This prospective study objectively measured the changes in eustachian tube function before and after HBO treatment in 33 adult patients by the 9-step inflation-deflation test described by Bluestone. The results show 15 of the 33 patients (45%) had evidence of eustachian tube dysfunction after treatment was initiated. Of these, 15 (100%) developed the sensation of fullness, 13 (87%) developed serous otitis media, and 7 (47%) required tympanostomy tubes. The overall incidence of middle ear problems was 27 patients (82%) experiencing a sensation of fullness, 17 (52%) developing serous otitis media, and 8 (24%) requiring tympanostomy tubes. The middle ear complications reported in this study are much higher than those in previous reports in the literature. Twelve of 33 patients presented with a subjective history of eustachian tube dysfunction, and all 12 (100%) developed fullness in their ears and serous otitis media during the course of the treatment. The findings reveal that patients manifesting eustachian tube dysfunction after their first HBO treatment were at significantly greater risk toward developing symptoms of fullness and serous otitis media, often requiring tympanostomy tube placement. In addition, a history of eustachian tube dysfunction accurately predicted the development of fullness and serous otitis media.     

A 14-year prospective follow-up study of children treated early in life with tympanostomy tubes: Part 1: Clinical outcomes

OBJECTIVE: To determine 14-year otological outcomes in young children treated with early insertion of ventilation tubes (VTs) for recurrent acute otitis media or otitis media with effusion (OME). DESIGN: Prospective 14-year follow-up. SETTING: Central Hospital of Central Finland, a tertiary care hospital.Patients Three hundred five consecutive infants and young children aged 5 to 16 months with otitis media were enrolled for early initial tympanostomy tube insertion. The final study group comprised 237 patients (77.7%) attending the 14-year checkup. MAIN OUTCOME MEASURES: At the 14-year checkups, abnormal otological findings were recorded and results compared with those of the 5-year checkups. RESULTS: From 5 to 14 years' follow-up, the number of healed ears increased from 156 (65.8%) to 177 (74.7%), while the number healed of ears with abnormal outcomes decreased from 81 (34.2%) to 60 (25.3%). Of 156 healed ears, 142 (91.0%) remained healed, and 35 (43.2%) of 81 ears with abnormal outcomes healed. The proportion of abnormal outcomes was higher among ears with OME (P = .02) and with 3 or more VT insertions (P<.001). Repeated tympanostomy tube insertion was performed in 141 ears (59.5%), more often in those with OME (P = .003), and ear surgery was performed in 9 ears (3.8%), 8 with OME. CONCLUSIONS: Early VT treatment is recommended for young children with recurrent acute otitis media or persistent OME. Parents should be informed of the long follow-up, of the possible need for repeated VT insertion, and of potential sequelae that sometimes necessitate surgical intervention. Patients healed after 5 years do not need further follow-up.     

A meta-analysis of swimming and water precautions

OBJECTIVE: To reconcile conflicting reports concerning the incidence of otorrhea in children with tympanostomy tubes who swim without ear protection. STUDY SELECTION: Articles were identified by MEDLINE search, Current Contents, and references from review articles, textbook chapters, and retrieved reports. Controlled trials of water precautions following tympanostomy tube placement were selected by independent observers and scored on 10 measures of study validity. Five English-language articles met all inclusion criteria. DATA EXTRACTION: Data were abstracted for an endpoint of otorrhea following swimming without ear protection with a minimum follow-up of 6 weeks. DATA SYNTHESIS: Pooled analysis of 619 children revealed a rate difference of -5.04 (95% confidence interval [CI], -11.62 to 1.54). No significant difference in the incidence of otorrhea was noted between patients who swam without ear protection and nonswimmers. CONCLUSION: There is no increase in incidence of otorrhea in children who swim without ear protection compared with children who do not swim following tympanostomy tube placement.     

Transtympanic endoscopic findings in patients with otitis media with effusion

Using a fine, rigid endoscope (Olympus, SES-1711K), we examined the middle ear, including the tympanic orifice of the eustachian tube, of children with otitis media with effusion (OME) in its active stage (26 ears), in the convalescent stage (13 ears), and during treatment with ventilation tubes for 10 days to 6 months (five ears) through myringotomy with the patients under general anesthesia. Several color photographs of representative ears are shown. In the active stage of OME, edema (73.1%) and hyperemia (23.1%) were characteristic features of the middle ear mucosa, and normal mucosa was seen in only one ear (3.1%). The tympanic orifice of the eustachian tube, which could be examined in 12 ears, were stenosed with edema in four ears (33.3%) or plugged with effusion in three ears (25.0%) in this group. In the convalescent stage of OME, dilated vessels were most often seen (69.2%), but the rest of the patients had normal mucosa (30.8%) in the middle ear, and none of them had edema nor hyperemia. The tympanic orifice of the eustachian tube, which could be examined in five ears, was clearly patent in all the patients in this group. One ear that was treated with a ventilation tube for 1 month showed dilated vessels and less severe inflammation than did ears that were in the active stage of OME, and three ears that were treated for more than 3 months showed almost normal middle ear mucosa.     

Implications of laser assisted tympanostomy in adults.

OBJECTIVES: To assess outcome in adult individuals undergoing laser-assisted tympanostomy without ventilation tube placement. STUDY DESIGN: Case series with 2-month follow-up. SETTING: Faculty practice, research protocol, tertiary care academic medical center. PATIENTS AND METHOD: Laser-assisted tympanostomy was performed on a total of 142 ears (108 individuals). Indications included serous otitis media with effusion (66 ears/47 patients), functional eustachian tube dysfunction (48 ears/36 patients), acute otitis media (19 ears/16 patients), and endoscopic visualization of the middle ear (9 ears/9 patients). INTERVENTION: The laser-assisted tympanostomy procedure is performed with a CO2 laser under local anesthesia on an outpatient basis. MAIN OUTCOME MEASURES: Patency time of the tympanostomy, presence of fluid after the closure of the tympanostomy, tympanometry and tone audiometry findings, relief of symptoms. RESULTS: Middle ear disease was resolved after the closure of tympanostomy in 47.9% of patients with serous otitis media with effusion. In 79.1% of patients with functional eustachian tube dysfunction, symptoms were diminished. All patients with acute otitis media had a satisfactory outcome. Laser-assisted tympanostomy was found to be quite helpful in patients undergoing middle ear endoscopy. CONCLUSIONS: Laser-assisted tympanostomy without ventilation tubes provides a safe alternative surgical option in adult patients in certain cases. The selection criteria for this procedure are addressed in detail.     

The role of allergic rhinitis in the development of otitis media with effusion: effect on eustachian tube function

PURPOSE: The pathogenesis of otitis media with effusion (OME) is considered multifactorial, with viral upper respiratory tract infection and eustachian tube dysfunction. Allergy may be related to the pathogenesis of OME or to another etiological factor. We investigated the role of allergic rhinitis (AR) in children with OME and evaluated eustachian tube function in patients with AR. MATERIALS AND METHODS: We prospectively analyzed the prevalence of AR, serum eosinophil count, and serum total IgE concentrations in 123 children with OME and in 141 controls. IgE concentration in middle ear effusion was compared in children with OME with and without AR, and eustachian tube function after a nasal provocation test was compared between patients with AR and controls. RESULTS: The prevalence of AR in children with OME (28.4%) and control subjects (24.1%) did not differ significantly. These 2 groups also showed no differences in total eosinophil count and serum and middle ear effusion IgE concentration. Abnormalities in eustachian tube function were the same in patients with AR and controls. CONCLUSIONS: Allergic rhinitis may not be related to the development of OME in children.     

When should retained Paparella type I tympanostomy tubes be removed in asymptomatic children?

Objectives

Tympanostomy tubes are routinely used for the treatment of otitis media with effusion (OME). There is no definite consensus on the optimal length of the intubation period and the timing of tube removal. This study was designed to determine the appropriate time for tympanostomy tube removal in asymptomatic patients of preschool age.

Methods

A retrospective study was conducted in 336 patients (478 ears) under the age of 7 years old who underwent tympanostomy tube insertion or removal from January 2006 to September 2010 at our institution. The information gathered from chart review included patients’ age at the time of tube insertion, duration of intubation, and the presence of complications, such as tube site infection and persistent tympanic membrane perforation. Logistic regression, chi-square test and Fisher's exact test were used to determine the statistical significance of observations.

Results

The spontaneous extrusion rate of tympanostomy tubes was about 90% at 18 months and showed a plateau after 18 months. The OME recurrence rate decreased after 12 months of intubation, and complications such as tube site infection and persistent tympanic membrane perforation increased after 15 months of intubation.

Conclusion

Tympanostomy tubes removed before 12 months showed a high possibility of recurrence. Removal after 15 months showed an increased possibility of complications. Spontaneous extrusion seldom occurred after 18 months. From these findings, we concluded that asymptomatically retained tympanostomy tubes are recommended to remove when a tube is retained for more than 18 months.     

Experimental conditions for the development of persistent otitis media with effusion

Summary The purpose of this study was to investigate sufficient conditions for the development of long-lasting otitis media with effusion (OME) without any organic obstruction of the eustachian tube. Three experimental conditions were employed using 20 adult cats (27 ears). Only tubal ventilatory dysfunction with transection of the tensor veli palatini muscle and excision of the pterygoid hamulus resulted in a small incidence of OME (7.1%), which lasted for 5 weeks. Instillation of Escherichia coli endotoxin into the middle ears formed only a transient OME in 50% of the animals. Combination of these two procedures brought a high incidence of OME (85.7%), most of which lasted for more than 8 weeks. These studies showed that tubal ventilatory dysfunction alone was not a sufficient condition for the development of OME but was important for prolongation of the pathological state of OME. The production of inflammatory exudate was considered to be a trigger for the formation of OME.Offprint requests to: H. Takahashi     

Variability of Eustachian tube function in children with secretory otitis media. Evaluations at tube insertion and at follow-up

OBJECTIVE: Despite the variable clinical course of diseases related to Eustachian tube function, the variability of tubal function has been less focused than outcomes of single tests. This study aimed to compare the passive and active tubal function and its variability in children with secretory otitis media (SOM) at tube insertion and at follow-up. METHOD: Thirty-eight ears in 19 children aged 4-10 years (mean 7.0 years) with long-standing SOM were examined 4-6 h after tube insertion, at 4 months and at 9 months. The pressure in the middle ear and the nasopharynx were recorded while performing (1) forced opening test, (2) equalization of +100 and -100 daPa, (3) Valsalva test, and (4) sniff test. The procedure was repeated after 30 min. Relationships were analyzed by uni- and multi-variate analysis of variance. RESULTS: From tube insertion to 4 months, the mean forced opening pressure increased from 282+/-128 to 355+/-153 daPa (P<0.01), and the mean closing pressure from 91+/-51 to 126+/-82 daPa (P<0.01). There was no further change at 9 months. Female gender, serous effusion (in contrast to mucoid), and more than three previous episodes of acute otitis media were related to higher opening and closing pressures. At tube insertion, 60% and 16% equalized +100 and -100 daPa, respectively, and 28% succeeded in performing Valsalva inflation. The sniff test was positive in 32%, indicating a closing failure. These rates did not change significantly over time. For individual ears, outcomes of all tests varied considerably when retested after 30 min; P(o) changed by +/-12% and P(c) by +/-26%, and 9-29% of the ears changed from a positive to negative response, or vice versa, in the equalization, Valsalva, and sniff tests. CONCLUSIONS: The unexpected finding of weaker closing forces at the day of tube insertion and increased tubal resistance at follow-up might be ascribed to changes in the muco-adhesive forces related to the disease and tube treatment. The pronounced intra-individual variability of test outcomes indicates that tubal function is dynamic and variable in ears prone to SOM, which emphasizes that results of single tubal function tests have very low prognostic value.