Biomedical subjects

C A Buchman

Publications and source records attributed to C A Buchman.

23 records · Page 2Linked to original sources

PubMed1994

Nasal and otologic effects of experimental influenza A virus infection.

Past studies showed that experimental rhinovirus colds in adults resulted in eustachian tube dysfunction and abnormal middle ear pressures. In the present study, the symptoms and pathophysiologic findings accompanying experimental influenza viral infection were documented. A total of 33 healthy adult volunteers were intranasally challenged with an influenza A/Kawasaki/86 (H1N1) virus and cloistered over a 9-day postchallenge period to monitor for evidence of infection, signs and symptoms of illness, and the extent and frequency of pathophysiologic responses of the nose, eustachian tube, and middle ear. Results showed a protective effect of high (> or = 16) prechallenge specific hemagglutination-inhibition antibody titer on the rate of infection and the magnitude and extent of provoked symptoms and pathophysiologic findings. Infected subjects with low (< 16) prechallenge serum antibody titers (n = 21) developed significant respiratory illness. These subjects also had objectively measurable increases in nasal secretion production, and decreased nasal patency and mucociliary clearance rates. More than 80% of the infected subjects developed eustachian tube dysfunction, and approximately 80% had middle ear underpressures of less than -100 mm H2O on study days 4 and 5. Five of 21 infected subjects with low prechallenge antibody titers had otoscopic evidence of otitis media with effusion. These results support a causal role for viral upper respiratory tract infection in the pathogenesis of otitis media, possibly mediated by the early development of eustachian tube dysfunction and abnormal middle ear pressure.

Adult↗

PubMed1994

Otologic manifestations of experimental rhinovirus infection.

Episodes of acute otitis media are commonly associated with viral upper respiratory tract infections. Rhinoviruses account for approximately 40% of these infections, and were previously shown to alter eustachian tube function and middle ear pressures. However, progression to otitis media has not been prospectively documented. In the present study, changes in tympanometric pressures and otoscopic findings resulting from experimental intranasal rhinovirus type-39 inoculation were documented in 60 adult volunteers. Fifty-seven (95%) subjects became infected and 34 (60%) of these had a clinical cold. Prior to viral inoculation, 3 (5%) subjects had middle ear pressures of less than -100 mm H2O and two of these subjects developed middle ear effusions following infection. In all, 22 (39%) subjects developed middle ear pressures of less than -100 mm H2O. No subject with normal middle ear pressures prior to infection developed evidence of effusion. This study extends the otologic manifestations of rhinovirus infection to include otitis media. Furthermore, these results support the hypothesized relationship between upper respiratory tract infections, eustachian tube dysfunction, and otitis media.

Acoustic Impedance Tests↗

PubMed1994

Functional-anatomic correlation of eustachian tube obstruction related to the adenoid in a patient with otitis media with effusion: a case report.

Prospective randomized clinical trials have shown modest but significant reductions in morbidity from otitis media with effusion following adenoidectomy. However, the precise role of the adenoid in the pathogenesis of otitis media with effusion remains unknown. Some authors have hypothesized that the adenoid may compress or obstruct the Eustachian tube lumen, thereby causing middle ear underpressures and subsequent effusion formation. Functional-anatomic correlation for this theory is lacking. Herein, we present a single case of a pediatric patient with otitis media with effusion and manometrically proven active and passive Eustachian tube obstruction which was relieved by adenoidectomy. Photographic anatomic correlation is presented.

Adenoidectomy↗

PubMed1993

Eustachian tube function in the ferret.

The role of viral upper respiratory tract infections (URI) in the pathogenesis of otitis media (OM) may be related to Eustachian tube (ET) dysfunction. Preliminary experimental evidence suggests that the ferret may be an appropriate animal for modeling of pathophysiologic process related to URI's and ET dysfunction. In an effort to determine the applicability of this animal model, normal ET function was evaluated in 10 ferrets using the inflation-deflation and forced-response testing protocols. The results indicate that the ET of the ferret functions as a small-scale version of its rhesus monkey and human counterparts. The ET-middle ear (ME) system could maintain applied positive and negative ME pressures in all instances. Nearly complete swallow-induced pressure equilibrations were demonstrated in all ears tested. Elevated passive function parameters suggested a small tubal lumen. The efficiency of the tubal dilatory mechanism as expressed by the normalizing calculation (R0/RA) was shown to be quite similar to that in primates and man. These findings suggest that the ferret's ET functions in a manner similar to humans and is, therefore, an appropriate animal to study the pathogenesis of otitis media in the context of ET dysfunction.

Acoustic Impedance Tests↗

PubMedDate not supplied

Comparison of argon and CO2 laser stapedotomy in primary otosclerosis surgery.

PURPOSE: The primary use for the laser in otosclerosis surgery is to create a stapes footplate fenestration that obviates the need for mechanical footplate removal. Experimental studies that evaluate the potential safety of visible (argon and potassium-titanyl-phosphate [KTP]) and invisible (CO2) light laser systems in stapes surgery report conflicting results. The purpose of this study is to compare the clinical safety and efficacy of the CO2 and argon laser systems when used for primary laser stapedotomy. MATERIALS AND METHODS: A retrospective case review of 124 primary laser stapedotomies using either the argon (n = 59) or CO2 (n = 65) laser was performed. Data consisted of pre- and postoperative air and bone conduction audiometry, speech discrimination scores (SDS), intraoperative findings, and postoperative complications. Between group differences (argon v CO2) were sought using standard statistical methodology. RESULTS: The argon and CO2 laser groups were comparable with regards to age, sex, preoperative air-bone gap, and laterality. Mean preoperative air and bone conduction pure-tone average (PTA) and SDS were somewhat higher in the CO2 laser group (P < .05). Postoperatively, both groups showed similar results in mean change in air conduction PTA, air-bone gap, and SDS, as well as in the frequency of complications. There were no anacoustic ears in either group. CONCLUSIONS: The results suggest that the argon and CO2 laser systems are comparable with regards to safety and efficacy when used by experienced surgeons for stapedotomy.

Adult↗