Erdem I. Cantekin

Effect of a Topical Nasal Decongestant on Eustachian Tube Function in Children with Tympanostomy Tubes

The effect of a topical nasal decongestant spray on Eustachian tube function was evaluated in 40 children with tympanostomy tubes. Five parameters of tubal function were assessed employing a modified inflation-deflation test and forced response test before and after spraying the nose with either oxymetazoline hydrochloride or a placebo according to a randomized double-blind study design. The results showed no significant differences between the two treatment groups. However, all the children in the study group had severe functional tubal dysfunction, as documented by the increased resistance of the Eustachian tube during swallowing. It is possible that efficacy may be shown in subjects with less severe dysfunction of the Eustachian tube than these involved in this study. It was concluded that further studies of the efficacy of topical decongestants for secretory otitis media and related conditions of Eustachian tube dysfunction are warranted to justify the widespread use of these medications.

An Animal Model of Acute Otitis Media Consequent to β-Lactamase-Producing Nontypable Haemophilus Influenzae

A chinchilla model of acute otitis media with effusion consequent to β-lactamase-producing nontypable Haemophilus influenzae was developed using the method of direct inoculation of 145 colony-forming units (CFU) or 252 CFU of β-lactamase—producing nontypable H influenzae into the right superior bullae of 40 chinchillas. The course of the disease was documented longitudinally by otomicroscopy, tympanometry, and periodic culturing of the middle ears. Onset of the disease occurred in 100% of the animals between two and six days postinoculation and resolution was complete in all ears by day 36. Results of rechallenge with the same organism support the combined effect of a local and weaker systemic middle ear protective mechanism rendering resistance to reinfection with a homologous organism in the chinchilla.

Middle ear pressure after changes in steady state

The combined effect of changes in middle ear (ME) gas composition and changes in systemic arterial blood oxygenation on total ME pressure was studied in three anesthetized juvenile Rhesus monkeys (Macaca mulatta). The gas composition of the ME was altered by ME inflation (politzerization) using either pure nitrogen, oxygen, or carbon dioxide while the animal was ventilated with either room air or 100% oxygen at constant carbon dioxide blood gas tension. Total ME pressure was measured indirectly by tympanometry (acoustic impedance) for a 5-hour duration. The changes in ME pressure were consistent and reproducible, exhibiting different pressure-time patterns unique for each gas. Carbon dioxide resulted in the most rapid decrease in ME pressure, followed by oxygen. The slowest decrease was observed in experiments with nitrogen. The systemic hyperoxygenation had little or no effect on the results. The findings were explained by the differences in relative permeabilities of these gases influencing ME gas diffusion, but the lack of systemic hyperoxygenation effect remained unexplained.

Auditory brain stem responses in rhesus monkey with otitis media with effusion.

Auditory brain stem response (ABR) tests were conducted on 17 anesthetized juvenile rhesus monkeys. Recordings were obtained for 13 control ears without otitis media with effusion (OME) and seven experimental ears with OME. The results demonstrated an increase in response latencies for the experimental ears with OME at each of four stimulus presentation levels (80, 60, 40, and 20 dB hearing level). Interwave latencies were the same for both groups of ears. The results suggest an average 25-dB peripheral loss of predominantly middle ear origin associated with OME. The ABR appeared to be a viable technique for documenting auditory impairment associated with OME in this nonhuman primate model.

Antibiotics Are Not Effective for Otitis media with Effusion: Reanalysis of Meta-Analyses

Objective: To determine the effectiveness of antibiotic therapy for otitis media with effusion (OME) and to examine the validity of meta-analysis for combining the results of published randomized controlled trials (RCTs) to reach generalized efficacy conclusions. Data Sources: English-language publications in refereed journals and proceedings published between 1980 and 1997, inclusive, producing 16 usable RCTs involving 2,067 children. Study Selection: RCTs evaluating the efficacy of antimicrobials for the treatment of OME with or without placebo controls. Data Synthesis: We used the technique of Der Simonian and Laird to determine heterogeneity and estimated the mean rate difference (RD). We also used weighted regression analysis to evaluate efficacy trends in light of changing quality of the included randomized trials, and sensitivity analysis to investigate the effects of quality differences among the clinical trials on estimated RDs. Results: The placebo-controlled trials had RDs significantly lower than non-placebo-controlled trials (RD of 0.04 vs. RD of 0.32; p < 0.001). When conventional techniques of meta-analysis were used for data synthesis, the presence of significant heterogeneity (p < 0.0001) precludes reaching any efficacy conclusions. Using weighted regression analysis to account for the effects of study quality on efficacy, we found that antimicrobial efficacy for OME is insignificant, less than 2% for an ideal clinical trial (p = 0.660). Conclusions: We conclude that meta-analysis as applied conventionally is inadequate to detect selection bias and is not useful for estimating true RDs when the results of the RCTs vary systematically with study quality. Our meta-analysis fails to support the continued use of antibiotics in the treatment of OME.

Eustachian Tube Function in Children with Tympanostomy Tubes

Eustachian tube (ET) function was evaluated in a group of 47 children with tympanostomy tubes who had previously documented persistent otitis media with effusion (OME). Tubal function was assessed using the inflation-deflation and forced-response tests. The study children were between the ages of 2 and 11 years. The passive ET function parameters of these children were within the limits of normal children with negative otologic histories. However, their active tubal function was radically different than normal children; none of them could equilibrate negative pressure, and only four could equilibrate positive pressure. During the forced-response test, further dilation of the ET lumen by swallowing was observed in only five of these 47 children. The findings of the present study suggest that this observed tubal dysfunction is secondary to a defect in the active function.

Aggressive and Ineffective Therapy for Otitis media

Objective: The standard American clinical practice for the management of acute otitis media (AOM), otitis media with effusion (OME), and recurrent otitis media (ROM) calls for repeated courses of wide-spectrum antibiotic therapy including extended duration antibiotic prophylaxis, followed by surgical insertion of typanostomy tubes with or without adenoidectomy. This is an attempt to assemble the scientific evidence to justify this practice. Methods: A systematic review of the literature involving clinical studies, randomized clinical trials (RCTs), and meta-analyses to summarize the existing database. Results: For the efficacy of antibiotics for AOM, only 3 of the 13 clinical studies and RCTs had positive results with marginal benefits. Among the 16 RCTs on the effectiveness of antibiotics for OME involving 2,067 children, 8 RCTs with placebo controls had pooled average antibiotic efficacy of 4% or less. Pooled data from 13 RCTs on antibiotic prophylaxis, ranging in duration 1 week to 2 years, for ROM provided no significant clinical prevention (less than 0.4 episodes per year). The surgery, based on the outcome of 22 RCTs, is not shown to be effective with the exception of extreme disease cases. In fact, it is estimated that over 90% of surgical cases for otitis media in the US are unnecessary. Conclusions: A scientific database is lacking to support the present American clinical practice of aggressive interventions. It is not an evidence-based medical practice that yields patient benefits. Rather, it is an unnecessary intervention with compelling adverse effects to the patient and the community.

Classification of Spectral Patterns Obtained from Eustachian Tube Sonometry

Spectral patterns of sound transmission through the Eustachian tube (ET) have been obtained in a series of experiments designed to identify ET dysfunction. Previous studies of ET function using sonometry have relied on heuristic and somewhat arbitrary methods in interpreting the data. In this study, an automated classification algorithm was developed to separate these sonograms into three distinct groups. From a total of 150 sample spectra, 75 were used in the formation of learning sets. The remaining spectra were classified into these three groups using standard Bayesian techniques. Both parametric and nonparametric methods were applied in estimating conditional probability density functions. Results of classification are compared with an independent test of ET function. Agreement between our classifier and the results of the independent test was as good as 97.3 percent. The results of this study indicate that an automated classification procedure can effectively distinguish among the three major types of sonograms obtained from ET sonometry.

Slow negative evoked potentials in the rhesus monkey (Macaca mulatta): myogenic versus neurogenic influences

The influence of myogenic activity on the generation of slow negative evoked potentials (SN10) to octave, toneburst stimuli (0.5-2 Hz) was investigated in 5 rhesus monkeys (M. mulatta) by comparing responses obtained prior to and during total paralysis induced with curare. The SN10 could be easily elicited during paralysis, regardless of stimulus intensity, rate, or frequency. During paralysis, there were no systematic changes in either response latency or amplitude; variability in latency was less than 10% and changes in response amplitude were within 30%. These findings suggest that the myogenic contribution to the SN10 response is negligible and that this response is of neurogenic origin in the rhesus monkey.