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Biomedical subjects

K T Kavanagh

Publications and source records attributed to K T Kavanagh.

At least 37 records · Page 2Linked to original sources
PubMed1989

Promotion of patient appointment compliance in indigent pediatric medical care by use of a microcomputer.

A computerized system for appointment scheduling, medical record keeping, medical billing, patient tracking, and epidemiologic data generation was developed and applied in an indigent pediatric otologic clinic. Functions used to augment appointment compliance are 1) notifying the referring physicians, agencies, and health department coordinators of failed appointments and sending medical information on the attended appointments, 2) listing patients who failed appointments, 3) production of mailings for failed appointments, 4) automatic rescheduling of failed appointments, and 5) automatic calculation of patient attendance ratios. The attendance ratio can be used to help identify patients for referral to social service workers and to implement rewards designed to promote medical compliance. The automatic rescheduling of failed appointments resulted in 21% of new patients and 30% of return patients above controls returning for a medical visit. The recalled had much lower economic status than our average clinic patient, ie, the system was effective in reaching the target population.

Ambulatory Care Information Systems↗
PubMed1988

Digital filtering and spectral analysis of the low intensity ABR.

Spectral analysis along with zero and standard-phase shift digital filtering were performed on evoked potentials recorded from 12 normal hearing subjects. The results indicated a progressive shifting of the mean spectral content of the ABR toward the low frequencies as the stimulus intensity was lowered. Despite this, the effects of zero-phase shift high-pass digital filtering at 100 Hz (36 dB/oct) did not significantly differ between waveforms elicited by a 75 dB nHL, 55 dB nHL, and 35 dB nHL stimulus. The major response frequency of the ABR is related to the distance between the peak (IV/V) and the following major trough (approximates one-half the response period). In waveforms where the major trough occurred before 10 msec, the use of 100 Hz, 36 dB/oct, zero-phase shift high-pass filters produced only a small reduction in response amplitude, even at low stimulus intensity levels. Waveforms which had a major trough (Na1) between 10 to 15 msec were reduced in amplitude by 100 Hz, 36 dB/oct, zero-phase shift high-pass filters (the longer period of the response energy in these waveforms corresponds to a lower energy frequency). However, this trough has a latency that prevents it from being recorded on a 10 msec time base or defined as an ABR. Based on these results, the use of zero-phase shift high-pass filters with a high-pass cutoff frequency that is equal to or less than the resolution of the time base (1/time base) appears to be a desirable method of reducing muscle artifact and other electrical contamination of the ABR.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Adenotonsillectomy in children: indications and contraindications.

Adenoidectomy and tonsillectomy are the most common major operations done on children. The indications for tonsillectomy in certain clinical situations are constantly being debated in the literature and among professionals. We studied the efficacy (or lack of it) of adenotonsillectomy for chronic tonsillitis (recurrent throat infections), oral nasal obstruction, peritonsillar abscess, elimination of a bacterial carrier state, biopsy, and prevention of tongue thrusting with resultant anterior open bite. Adenoidectomy has been advocated in the literature for the treatment of nasal obstruction, sinusitis, and chronic serous otitis media. Complications of tonsillectomy and adenoidectomy include hemorrhage, anesthetic death, infection, nasopharyngeal stenosis, patulous eustachian tube, and hypernasality. Children at risk for hypernasality are those with mental retardation, cerebral palsy, neuromuscular disorders, and submucous cleft of the soft palate. Because of the severity of the complications that can be encountered in any child, medical and conservative therapy should be attempted before operation is done. Proper antibiotic therapy will often control chronic serous otitis, sinusitis, and chronic, recurrent tonsillitis. Bacterial synergy is important to consider when selecting antibiotic therapy, since beta-lactamase production may protect pathogens commonly considered susceptible to standard antibiotic therapy.

Adenoidectomy↗
PubMed1987

High pass digital and analog filtering of the middle latency response.

Digital filtration with zero and standard-phase shift characteristics was performed on unfiltered auditory evoked potentials recorded from 10 adult subjects. Standard-phase shift filters were seen to distort the response. Mild phase shift distortion often augmented the IV/V-Na1 amplitude (auditory brain stem response). When recording the IV/V-Na1 amplitude on a narrow timebase (20 msec), we recommend using a phase shift filter that has a high-pass cutoff frequency approximating 15 Hz and a slope of 12 to 24 dB/octave, in order to take advantage of the observed phase shift augmentation. The augmentation of the IV/V-Na1 amplitude is at the expense of the IV/V-Na2 amplitude. Thus, this phase shift distortion is not desirable if a long timebase (50 msec) is used. If a high-pass standard-phase shift filter of 100 Hz is used to eliminate muscle artifact, a reduction in the IV/V-Na1 amplitude from phase shift distortion is seen compared to the zero-phase shift control. In site-of-lesion testing, a nondistorted waveform produced by digital zero-phase shift filtration is also desirable over a distorted analog response. It is recommended that the slow wave activity of the response be recorded with a timebase of at least 40 to 50 msec and with a filter that produces minimal or no phase shifting. The major recorded response will be the Na trough and Pa peak. Evoked response units with steep filters will phase shift the response and produce a reduction in the IV/V-Na amplitude and a concomitant augmentation of the latter middle latency response waveforms.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Miniature battery foreign bodies in auditory and nasal cavities.

A series of cases involving button batteries lodged in the ear or nasal cavity is presented. All produced tissue destruction. Injuries were generally severe, and included tympanic membrane perforation (three patients) or total destruction (three), marked necrosis of dermis of the external ear canal with exposed bone (seven), documented further impairment of hearing (three), destruction of ossicles (two), facial nerve paralysis and chondritis (one), nasal septal perforation (one), and superficial burns of nasal mucosa (one). Otic and nasal drops must be withheld as they provide an external electrolyte bath for the battery, enhancing leakage and generation of an external current, with subsequent tissue electrolysis and hydroxide formation. Instead, batteries lodged in the ear or nose must be removed promptly.

Aged↗
PubMed1986

Shave excision and dermabrasion of midline angiofibroma in tuberous sclerosis.

We encountered a rare case of massive angiofibroma involving the midface. Treatment consisted of shave excision of long slightly vascular "shag-rug" papules, followed by repeated deep dermabrasion. The methods of treatment will vary, depending on size and vascularity of the lesions. Indications for treatment include facial hygiene, cosmetic reasons, and the cessation of chronic bleeding. Prognosis is that the angiofibroma may be expected to slowly recur and thus require further treatment.

Adult↗
PubMed1986

High-pass digital filtration of the 40 Hz response and its relationship to the spectral content of the middle latency and 40 Hz responses.

This study analyzed the effects of high-pass filtration on the 40 Hz response using zero and standard phase shift digital filtration. Filtration effects were compared to the spectral content of the middle latency response (MLR) and 40 Hz response. The spectral composition of the MLR was found to contain major response energy at 10 and 40 Hz. The major energy of the 40 Hz response was at 40 Hz with minor peaks every 40 Hz above the fundamental frequency. The elimination of the 10 Hz response energy in the 40 Hz response was due to cancellation caused by phase differences which occurred in the production of a steady state potential. The reduction was confirmed by the minor amplitude effects created by zero-phase-shift high-phase filtration (cutoff frequency 30 Hz with 36 dB/oct slopes) on the 40 Hz response as compared to the MLR. The only beneficial effect of high-pass filtration was the elimination of the mild undulation of the unfiltered waveform. The major effect of phase-shift high-pass filtration on the 40 Hz response was the displacement of the high frequency ABR from the peak to the descending slope and finally to the trough of the MLR. Shifting of the ABR from the peak of the MLR resulted in amplitude loss which may affect response identification at threshold. The authors recommend minimal high-pass filtration (i.e., less than 12 dB/oct slope and a cutoff frequency less than or equal to 15 Hz) when recording the 40 Hz response. The spectral analysis of the evoked response may be able to predict the optimal rate for eliciting a steady state response in divergent subject populations.

Adult↗
PubMed1986

Analog and zero phase-shift digital filtering of the auditory brain stem response waveform.

Auditory brain stem response waveforms, derived from normal ears, were analyzed with a computer-based digital filtering program as a means of systematically evaluating the effects of phase-shift distortion. Off-line analysis involved the stimulated responses of a Butterworth-type filter at five high-pass and four low-pass frequencies, three filter slopes, and standard versus zero phase-shifting. Phase-shift, as seen with analog filters, proved to be a major cause of waveform distortion including significant latency and amplitude changes. A discussion on the need and use of digital filtering as well as suggested analog filter parameter settings is included.

Adult↗
PubMed1986

Risks and benefits of adenotonsillectomy for children with Down syndrome.

A questionnaire survey of 74 parents of children with Down syndrome was conducted. Results indicated that adenotonsillectomy benefited their children by eliminating or reducing the symptoms of snoring, sleep apnea, nasal drainage, and mouth breathing. On the basis of parental responses, it appears that in the absence of nasal obstruction, adenotonsillectomy fails to improve drooling or tongue protrusion. Adenoid tissue is physiologically important to the child with Down syndrome and its removal can result in hypernasality. Two children in the survey sample who underwent adenoidectomy and/or tonsillectomy developed this complication. They were given complete speech and language testing and evaluated with cinefluoroscopy. Both structural and functional causes of hypernasality were identified. Structural abnormalities included a high-arched short hard palate and a short soft palate. Hypotonia, slowed motor learning, and oral motor developmental delay were confounding functional factors in these patients. The incidence of postoperative hypernasality found in these patients is higher than in the general population and should be an important consideration before performing an adenoidectomy.

Adenoidectomy↗
PubMed1986

Extramedullary hematopoiesis within the hypotympanicum presenting as a glomus tympanicum.

We discuss the case of a 22-year-old black woman who presented with a mass in the left hypotympanicum. Both the pre- and postoperative diagnosis of the lesion was a glomus tympanicum. Histopathologic examination revealed the "tumor" to be a nodule of extramedullary hematopoiesis. Many sickled erythrocytes were also noted within the lesion. A multilingual literature search (English, French, German, Spanish, Portuguese, Italian, and Russian) failed to reveal a documented case of extramedullary hematopoiesis in the hypotympanicum. We assume that the patient's hemoglobinopathy was the cause of her unusual focus of extramedullary hematopoiesis.

Adult↗
PubMed1985

Familial nasal acilia syndrome.

We have described a family in which the father and three children appear to have an absence of nasal cilia, resulting in inadequate nasociliary clearance, stasis of nasal secretions, and secondary bacterial contamination. This condition should be considered in chronic rhinitis of obscure etiology.

Adult↗
PubMed1983

Ototoxicity of oral neomycin and vancomycin.

In contrast to parenteral neomycin, which may result in severe and progressive ototoxicity, oral neomycin has been widely used for 25 years, and its index of safety has been regarded as high. Ototoxicity is viewed as an uncommon complication of oral neomycin most likely to occur in patients with renal failure or gastrointestinal inflammation. Two cases of ototoxicity resulting from oral neomycin are presented. Serial audiometric and neomycin blood level testing are suggested as a means of auditory monitoring in patients receiving the drug. A review of experience with oral vancomycin indicates that this drug has not been shown to cause ototoxicity.

Administration, Oral↗