Dosage regimens of intranasal aerosolized surfactant on otitis media with effusion in an animal model.

OBJECTIVE: To determine optimal dosage regimens of intranasal metered dose aerosolized surfactant with and without other medications in the treatment of otitis media with effusion (OME). STUDY DESIGN: Resolution of experimental OME in gerbils was determined based on otomicroscopy and tympanometry. Experimental intranasal drugs were: surfactant, surfactant with betamethasone, surfactant with phenylephrine, and a normal saline solution placebo. Medications were administered once or twice daily via a metered dose inhaler. RESULTS: For twice-daily dosing, mean days to OME resolution were 8.5 for the aerosolized surfactant, 6.3 for the surfactant with betamethasone, 18.7 for the surfactant with phenylephrine, and 16 each for control and placebo. Resolution with the once-daily dosage was longer for all conditions. Results were comparable using tympanometry. CONCLUSION: OME resolved faster than the natural course when treated with intranasal surfactant with and without steroids. Twice-daily dosing was statistically superior. SIGNIFICANCE: This study reiterates the effectiveness of OME treatment with an aerosolized synthetic surfactant with and without steroids and establishes a superior twice-daily dosage schedule.

A national survey of air medical infectious disease control practices.

INTRODUCTION: Caring for an infectious patient in the air medical environment presents a special challenge to all air crew members (ACMs) involved. The purpose of this study was to survey the infectious disease control practices of air medical programs (AMPs) that are members of the Association of Air Medical Services. METHODS: A structured telephone survey was designed to gather data. Using one interviewer (an undergraduate student) with no knowledge of the study's goal minimized experimental bias. AMPs from 151 geographically selected areas were called between June and August 1996. Only the programs' chief flight nurses (CFNs) were targeted as respondents. RESULTS: The response rate was 91% (138 of 151). Although no program refused to participate, 13 CFNs were unavailable to be interviewed. Mission profile was 32% scene and 68% interhospital with an annual average of 950 patient transports per program. Transport type was 61% rotor-wing aircraft, 17% fixed-wing, and 22% both. Flight physicals for ACMs were required by 57% of the AMPs. Pre-employment screenings for rubella, tuberculosis (TB), and varicella were noted. Interestingly, 17% of the AMPs reported pre-employment HIV testing. Immunization was mandated by 57% of AMPs, including hepatitis B virus, measles, rubella, and tetanus. Nine percent of the respondents refused to accept a transport with specific contagious conditions, primarily TB. A formal decontamination policy was in effect at 88% of the AMPs, and OSHA-approved filter masks were available at 70%. Pathogen exposure reporting was required by 97%. CONCLUSION: A current, comprehensive infection control program, continuing education, and 100% compliance with standard precautions will help reduce the possibility of accidental exposures. These strategies to reduce transmission also can be extended during training sessions to the prehospital and hospital personnel with whom the air medical program serves.

Intranasal surfactant aerosol therapy for otitis media with effusion.

OBJECTIVE: To determine the effect of surfactant alone and with other medications delivered intranasally as a metered dose inhaler (MDI) aerosol on the resolution of experimentally induced otitis media with effusion (OME). BACKGROUND: Eustachian tube dysfunction is a primary factor in the pathogenesis of OME. Intranasal surfactant via MDI has been shown in this laboratory to reduce passive opening pressure of the eustachian tube in normal gerbils and mice. STUDY DESIGN: OME was developed in 35 gerbils by transtympanic injection of 10 microg lipopolysaccharide from Klebsiella pneumoniae. Pretreatment otomicroscopy and tympanometry were performed to exclude pre-existing middle ear disease, and postinfection evaluations were performed on alternate days for a period of 30 days. Five animals received no treatment (control group); four were treated with propellant only (placebo); seven received surfactant alone; eight received surfactant and betamethasone; and six received surfactant with phenylephrine. All medications were sprayed intranasally as an aerosolized MDI and administered daily from postinfection day 2 onward. RESULTS: OME resolved after 16.0 +/- 0.44 days (mean + SD) in controls. There was no difference seen in the placebo or the surfactant with phenylephrine groups. Treatment with surfactant yielded resolution in 10.57 +/- 0.37 days; this was reduced to 8.57 +/- 0.37 days with surfactant plus betamethasone. These differences are statistically significant. There was no recurrence of OME in any group. CONCLUSION: This study demonstrates that using an aerosolized MDI surfactant with and without betamethasone decreases the duration of OME in this in vivo gerbil model.

Dexamethasone pharmacokinetics in the inner ear: comparison of route of administration and use of facilitating agents.

There is growing otologic interest in treating inner ear disorders, such as sudden sensorineural hearing loss and acute or unremitting Meniere's disease, with intratympanic dexamethasone (IT-DEX). Although anecdotally reported, there are no scientific clinical papers and few prior laboratory research publications on the subject. This study compares perilymph dexamethasone concentrations after systemic and intratympanic administration and assesses the role of 3 potential transport facilitators of IT-DEX into perilymph. Forty guinea pigs (79 ears) were randomly separated into 5 groups. Dexamethasone levels were measured by radioimmunoassay. IT-DEX resulted in higher perilymph steroid levels than intravenous dexamethasone (P < 0.05). Histamine facilitator resulted in significantly higher perilymph steroid levels than IT-DEX alone (P < 0.05). Neither hyaluronic acid nor dimethylsulfoxide was a potent facilitator. This study demonstrates that IT-DEX administration results in superior perilymph levels within 1 hour of administration and does not result in systemic absorption. Histamine is a potent facilitating agent. The clinical implications are considerable.

Otologic and audiologic evaluation of human immunodeficiency virus-infected patients.

PURPOSE: To quantify the incidence of ear disease in patients infected with human immunodeficiency virus (HIV). MATERIALS AND METHODS: This is a descriptive case series of HIV-positive patients, with data collected using an otologic questionnaire. otologic examination, audiologic evaluation, and chart review. The study was performed at an urban University Hospital's outpatient Infectious Disease and Otolaryngology clinics. A consecutive sample of 50 HIV-infected patients volunteered for this study. Ten subjects refused. Almost all patients received public assistance for medical care. Descriptive results were tabulated. Audiometric data were analyzed for ear, Centers for Disease Control (CDC) group, otologic complaint, and age effects. Data were compared with established norms. RESULTS: Twenty-three men and 27 women with a mean age of 40 years and mean duration of HIV disease of 3.5 years were studied. Eighteen percent of patients were in category CDC-A, 38% in CDC-B, and 44% in CDC-C. Otologic complaints were more prevalent than expected: 34% of patients reported aural fullness, 32% dizziness, 29% hearing loss, 26% tinnitus, 23% otalgia, and 5% otorrhea. Results of the neuro-otologic examination were abnormal in 33%. Tympanometric examination was abnormal in 21%. A significant degree of high-frequency sensorineural hearing loss was observed. CDC-B and CDC-C patients had worse hearing than CDC-A patients at 3 frequencies. Patients who complained of hearing loss had significantly worse otoacoustic emission results and hearing results than patients who did not, at all frequencies except 1,000 Hz. Patients in their 30s had better hearing in the speech frequencies than did all other patients. CONCLUSIONS: Ear disease affects up to 33% of HIV-infected patients. Otitis media is a frequent finding. Sensorineural hearing loss is more severe in patients with more severe HIV infection. Patients with ear complaints have demonstrable otopathology. Continuation of this preliminary descriptive work is necessary.