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Biomedical subjects

C D Bluestone

Publications and source records attributed to C D Bluestone.

At least 37 records · Page 2Linked to original sources
PubMed1998

Role of surgery for otitis media in the era of resistant bacteria.

Otitis media is currently the most common diagnosis made by clinicians, and its prevalence has an impact on managed health care. With the emergence of bacterial pathogens resistant to many antimicrobial agents, an urgent need exists to reassess the indications for surgical management of this more prevalent disease. In an effort to determine the causative bacterial etiology of acute otitis media, which may be resistant to commonly prescribed antimicrobial agents, tympanocentesis is indicated today more than ever, especially when patients fail to improve or worsen while receiving antibiotics (i.e. treatment failures). In an effort to reduce the use of antimicrobial agents, prophylactic administration of these drugs for prevention of recurrent otitis media should only be prescribed on an individualized basis, with myringotomy and tympanostomy tube insertion being a more reasonable alternative. Adenoidectomy should be also considered when moderate to severe nasal obstruction is present or when repeat tympanostomy tube placement is needed. Likewise when chronic otitis media with effusion is unresponsive to a trial of antimicrobial therapy, tympanostomy tube insertion, adenoidectomy or both procedures should be considered, as opposed to re-treating with a variety of antibiotics. The role of these surgical procedures has become more important today in this era of antibiotic-resistant bacteria. Also in our cost-conscious environment, it is uncertain which method of management is more expensive, surgery or prolonged medical management.

Acute Disease↗
PubMed1998

Treatment of chronic suppurative otitis media with topical ciprofloxacin.

To date, only ofloxacin has been approved by the US Food and Drug Administration for treatment of ears with a nonintact tympanic membrane. The purpose of this study was to determine the safety and efficacy of topical ciprofloxacin hydrochloride in the treatment of experimental chronic suppurative otitis media caused by Pseudomonas aeruginosa infection in cynomolgus monkeys. Forty adult cynomolgus monkeys were divided into 4 equal groups, and their ears were challenged with P aeruginosa, drained for 3 weeks, then treated twice daily for 4 weeks with 1 of 4 randomly assigned agents: 1) ciprofloxacin, 2) saline, 3) Cortisporin, or 4) vehicle. The animals were followed up with auditory brain stem response testing, culture, otoscopy, and histopathology. Both ciprofloxacin and Cortisporin treatment resulted in a significantly more rapid rate of clearance of P aeruginosa as compared to treatment with saline (100% versus 20%). Eradication was not associated with resolution of otorrhea after a 4-week period of treatment. There were no significant changes in auditory brain stem response wave latencies for any of the treatment groups. Histopathologic data revealed that there was no statistically significant difference in the amount of outer hair cell loss for the ciprofloxacin group as compared to the control ear and other treatment groups. We conclude, therefore, that topical ciprofloxacin is not ototoxic and is effective in sterilizing the otorrhea, but does not promote resolution of the drainage, in this animal model.

Administration, Topical↗
PubMed1997

Effects of systemic hyperoxia on eustachian tube ventilatory function.

Middle ear negative pressure and effusions, decreased middle ear compliance, and abnormal tympanometry results have been described after diving on oxygen. Middle ear gas hyperoxia has been shown to down-regulate the eustachian tube ventilatory function (ETVF). The purpose of the present study was to investigate to what extent systemic hyperoxia in the face of air-equivalent middle ear gas composition might interfere with the ETVF. ETVF was investigated in four young adult female cynomolgus monkeys by the forced-response and inflation-deflation tests using air while the animals breathed either room air or 100% normobaric oxygen. Higher opening, closing, and steady-state pressures were observed under systemic hyperoxia. The percentage of the applied pressure equalized, and the maximal pressure change on a single swallow in the deflation test were both lower under hyperoxic conditions. The results show that systemic hyperoxia might impair ETVF. This observation adds to our understanding of the pathophysiology of middle ear dysfunction observed after diving on oxygen.

Animals↗
PubMed1996

Universal newborn screening for hearing loss: ideal vs. reality and the role of otolaryngologists.

In 1993 the National Institutes of Health Consensus Statement, Early Identification of Hearing Impairment in Infants and Young Children, recommended "universal screening for hearing impairment prior to three months of age." However, the decision to invoke screening programs that include all newborns remains highly controversial, even though such programs now exist in at least 60 hospitals in 18 states. Unfortunately, otolaryngologists in the United States have not been actively involved in this ongoing debate, despite the role of those in our specialty as "gatekeepers" of hearing loss in patients of all ages. In relation to identification of hearing loss in the neonatal period, we have abrogated our responsibility to other health care professionals. Otolaryngologists, this is your "wake up call."

Attitude of Health Personnel↗
PubMed1996

Effects of middle ear oxygen and carbon dioxide tensions on eustachian tube ventilatory function.

The objective of this study was to determine the effect of middle ear (ME) gas composition on eustachian tube ventilatory function (ETVF). ETVF was evaluated by using forced-response and inflation-de-flation tests in four alert cynomolgus monkeys during test sessions with different gas compositions. The ME was flushed with one of the four gas mixtures: 1. air; 2. 12% oxygen, 88% nitrogen; 3. 100% oxygen; and 4. 5% carbon dioxide, 21% oxygen, and 74% nitrogen before and during testing. The results documented lower opening, steady-state, and closing pressures, lower passive and active resistance, and greater dilatory efficiency following ME flushes with the hypercarbic and hypoxic gas mixtures when compared to the others. Also, for applied ME overpressure, the maximum pressure change during a swallow, the average pressure drop for all swallows, and the percentage of the applied pressure equalized were greater under hypoxic and hypercarbic conditions. These results show that ME gas composition affects ETVF and support feedback modulation of ME pressure regulation.

Animals↗
PubMed1996

Efficacy of ceftibuten compared with amoxicillin for otitis media with effusion in infants and children.

OBJECTIVES: This trial compared the efficacy of ceftibuten with that of amoxicillin in resolving otitis media with effusion. METHODS: Two hundred ten children with otitis media with effusion were randomly assigned to receive either ceftibuten (9 mg/kg/day in one daily dose) or amoxicillin (40 mg/kg/day divided into 3 daily doses) for 14 days. Outcome was assessed at 2 and 4 weeks in all subjects; those without middle ear effusion at the 4-week visit were examined at 8, 12 and 16 weeks. Middle ear status was determined by pneumatic otoscopy and by an algorithm combining pneumatic otoscopy with tympanometry. RESULTS: The percentages of subjects who were effusion-free in the ceftibuten and amoxicillin groups at 2 weeks by otoscopy were 29.8 and 27.2%, respectively (P = 0.59), and by the algorithm, 23.4 and 20.4%, respectively (P = 0.47). In children who were effusion-free at 2 weeks, recurrence of effusion by 16 weeks was noted in approximately 60% of the ceftibuten group and 67% of the amoxicillin group. No medication side effects were reported by 88% of subjects in the ceftibuten group and by 93% of subjects in the amoxicillin group. We found no significant differences between the ceftibuten and amoxicillin groups with respect to resolution of middle ear effusion, rate of recurrence or side effects. CONCLUSIONS: Amoxicillin remains the drug of first choice for treatment of otitis media with effusion when treatment is deemed advisable, but ceftibuten may be an alternative drug in selected situations.

Amoxicillin↗
PubMed1996

Efficacy of antimicrobial prophylaxis for recurrent middle ear effusion.

OBJECTIVES: This trial compared the efficacy of amoxicillin prophylaxis with that of placebo for the management of recurrent middle ear effusion (MEE) in children. METHODS: Children between 7 months and 12 years of age who were effusion-free at entry but had histories of chronic or recurrent MEE were randomly assigned to receive either amoxicillin (20 mg/kg once daily) or placebo for 1 year. They were examined monthly and when there were symptoms of ear, nose or throat disease. Acute otitis media (AOM) and new episodes of otitis media with effusion (OME) were treated with amoxicillin-clavulanate; tympanocentesis was performed when possible for episodes of AOM. Throat cultures were obtained at entry; 4, 8 and 12 months after entry; and with new episodes of AOM and OME. Tympanometry was performed at each visit and audiometry was performed at entry and 4, 8 and 12 months after entry. RESULTS: One hundred eleven children were entered in this study. The rates per person year of new episodes of disease in the amoxicillin and placebo groups, respectively, were: MEE, 1.81 vs. 3.18 (P < 0.001); AOM, 0.28 vs. 1.04 (P < 0.001); and OME, 1.53 vs. 2.15 (P = 0.016). Subjects in the amoxicillin group had less time with MEE than the placebo group (19.7 and 33.2%, respectively; P = 0.002). Middle ear and throat cultures did not reveal any increase in beta-lactamase-producing organisms or in Streptococcus pneumoniae attributable to daily use of amoxicillin. CONCLUSIONS: Amoxicillin prophylaxis lowered the rates of occurrence of MEE, AOM and OME and decreased the percentage of time with MEE. However, because of present day concerns regarding antibiotic resistance, management should be individualized.

Acoustic Impedance Tests↗
PubMed1996

Efficacy of clarithromycin treatment of acute otitis media caused by infection with penicillin-susceptible, -intermediate, and -resistant Streptococcus pneumoniae in the chinchilla.

Because of the increasing frequencies of recovery of penicillin-resistant Streptococcus pneumoniae from the middle ears of children with acute otitis media, non-beta-lactam antibiotics are being explored as treatment alternatives to amoxicillin. In this study, the efficacy of a 10-day course of clarithromycin was evaluated with chinchillas. After the pharmacokinetic profiles for clarithromycin were established, 180 animals were assigned to one of three susceptibility groups (n = 60/group; penicillin-susceptible, -intermediate, and -resistant S. pneumoniae), and the right middle ear was infected with the appropriate strain of S. pneumoniae. Equal numbers of animals in each group were treated orally beginning on day 2 with a 10-day course of clarithromycin (15 mg/kg of body weight; given twice a day) or amoxicillin as a control (20 mg/kg twice a day). On days 4, 9, and 13, otomicroscopy and tympanometry were performed, and on day 13, the middle ears were cultured for bacteria. The results showed 100% eradication of the challenge organism in both treatment groups for the susceptible strains of S. pneumoniae. Cultures were negative in 87 and 74% (P > 0.05) of the animals challenged with the intermediate resistant strains and in 100 and 56% (P < 0.05) of the animals challenged with the resistant strains and treated with clarithromycin and amoxicillin, respectively. There were no differences between treatments in the diagnosis of effusion for any group. These results support the use of the chinchilla to evaluate drug efficacy in the treatment of acute otitis media and show clarithromycin to be effective in sterilizing the middle ears of animals challenged with penicillin-susceptible, -intermediate, and -resistant strains of S. pneumoniae.

Amoxicillin↗
PubMed1995

Otitis media in a population of black American and white American infants, 0-2 years of age.

To determine the incidence of otitis media (OM) and the bacteriology of acute otitis media (AOM) in a clinic population of young children in Pittsburgh, 138 black infants and 60 white infants were followed from birth to 2 years of age, examined at monthly intervals and whenever an upper respiratory tract infection (URI) or OM intervened. By 24 months of age the cumulative incidence of episodes of AOM was 43% and 42%, and of episodes of middle-ear effusion (MEE) was 86% and 85% in black and white infants, respectively. The average rate of episodes of AOM was 0.41 and 0.39 and of episodes of MEE was 1.68 and 1.70 in black and white infants, respectively. Tympanocentesis was performed for episodes of AOM and the following organisms were isolated from black and white infants, respectively: Streptococcus pneumoniae 43% and 43% of episodes; Moraxella catarrhalis 24% and 24%; non-typable Haemophilus influenzae 18% and 24%; and Haemophilus influenzae type b 5% and 0%. In both black and white infants first born children had less ear disease. We found no difference in the incidence of otitis media during the first 2 years of life between black and white infants.

Acute Disease↗
PubMed1995

Head and neck space infections in infants and children.

A retrospective study was performed in 117 children with head and neck space infections treated at the Children's Hospital of Pittsburgh from January 1986 through June 1992. Peritonsillar space infections were the most common (49%), followed by retropharyngeal (22%), submandibular (14%), buccal (11%), parapharyngeal (2%), and canine (2%) space infections. The most common pathogens isolated (N = 78) were the aerobes beta-hemolytic streptococcus (18%) and Staphylococcus aureus (18%), the anaerobes Bacteroides melaninogenicus (17%) and Veillonella (14%), and the gram-negative organism Haemophilus parainfluenzae (14%). beta-Lactamase production by aerobic pathogens was detected in 22% of cultures. Computed tomography scans (N = 16) were reviewed in blinded fashion and compared with operative findings. The sensitivity of computed tomography scan in detecting the presence of an abscess vs. cellulitis was high (91%), whereas the specificity was rather low (60%). Treatment of head and neck space infections in children should consist of accurate physical diagnosis aided by imaging studies, empiric antibiotic therapy that covers gram-negative and beta-lactamase--producing organisms as well as gram-positive organisms and anaerobes, and timely surgical intervention, when indicated.

Abscess↗
PubMed1995

Efficacy of 20- versus 10-day antimicrobial treatment for acute otitis media.

OBJECTIVE: The purpose of this trial was to determine whether 20 days of antimicrobial treatment is more efficacious than 10 days of treatment for acute otitis media (AOM) in clearing middle ear effusion and preventing recurrences of AOM, and whether changing to a beta-lactamase-stable antimicrobial agent after the initial 10-day treatment with amoxicillin for AOM is advantageous. METHODS: Children between 7 months and 12 years of age with AOM were randomly assigned to three treatment groups: (1) amoxicillin for days 1 through 10, then amoxicillin for days 11 through 20; (2) amoxicillin for days 1 through 10, then amoxicillin-clavulanate for days 11 through 20; and (3) amoxicillin for days 1 through 10, then a placebo for either amoxicillin or amoxicillin-clavulanate for days 11 through 20. Medication was dispensed in a double-blind manner. Children underwent tympanocentesis at entry and were re-examined on days 10, 20, 30, 60, and 90 after entry. RESULTS: Two hundred sixty-seven children entered the trial. At the 20-day visit, the percentages of children who were effusion free in the amoxicillin, amoxicillin-clavulanate, and placebo groups were 72.4%, 80.8%, and 52.5%, respectively. There was no statistically significant difference in the percentage of children who were effusion free between the amoxicillin and amoxicillin-clavulanate groups (95% confidence interval, -21.7, 4.9). Subsequent to the day 10 visit, the average proportions of time with middle ear effusion were not significantly different in the amoxicillin, amoxicillin-clavulanate, and placebo groups (0.29, 0.27, and 0.34, respectively), nor were there significant differences in the rates of recurrent episodes of AOM (0.56, 0.59, and 0.68, respectively). Regardless of treatment group, approximately 75% of children were effusion free at the time of their last visit. CONCLUSIONS: More children were effusion free by the day 20 visit if given antimicrobial treatment for 20 days rather than for 10 days, but this advantage was present for only a short time; by the end of the 90-day study period, the treatment groups were comparable with regard to effusion status. Recurrence of AOM during the study period was not prevented by the additional 10 days of treatment. Routine use of an additional 10-day course of antimicrobial treatment is therefore not recommended if a child is symptom free after the initial 10 days of treatment for AOM.

Acute Disease↗