Airway resistance and work of breathing in tracheostomy tubes.

Recommendations for sizing of tracheostomy tubes are generally based on anatomic considerations with the largest fitting tube most commonly placed. Once in the tracheostomy site, the tube assumes the new role of the upper airway. Consideration of the airway resistance of each tracheostomy tube and change in work of breathing are important in maintaining the respiratory system homeostasis. The airflow dynamics of neonatal, pediatric, and adult tracheostomy tubes were studied. Flow rates were plotted against change in pressure for inspiratory and expiratory flows and resistances for each tube were calculated. The expiratory resistances were larger for the neonatal tubes and pediatric tubes 0 and 00, while inspiratory resistances were the limiting factor in the adult tubes and the larger pediatric tubes. Comparison of calculated resistances of the tracheostomy tubes was made with known physiologic airway resistances. Adult tubes 8 and 10 most closely simulated the upper airway resistance of adults and neonatal tube 0 appeared most appropriate for the newborn. Work of breathing was determined for each tracheostomy tube. Increasing tube diameter as well as decreasing tidal volume and respiratory rate decreased the amount of work required to maintain a given flow.

Partial endoscopic middle turbinectomy augmenting functional endoscopic sinus surgery.

Endoscopic sinus surgery has gained acceptance in the otolaryngologic community as an effective and safe method of treating inflammatory disease of the paranasal sinuses. At our institution, partial endoscopic middle turbinectomy has become a standard component of the procedure and our experience is reported. Middle turbinectomy enhances surgical exposure, specific anatomic anomalies are more completely corrected, and subpopulations of patients at risk for failure because of their underlying disease enjoy decreased rates of synechiae formation and closure of the middle meatus antrostomy when followed over time. Photodocumentation of the surgical technique and a discussion regarding the impact of middle turbinectomy on normal nasal physiology are presented. It is reported that the procedure is safe, and no complications directly attributable to middle turbinectomy (including atrophic rhinitis) are reported in a series of 298 patients.

Anaphylaxis in immunotherapy.

Although anaphylactic reactions resulting from immunotherapy rarely occur, when they do occur they can be life-threatening. The literature reveals more than 30 deaths attributed to immunotherapy but numerous reports of anaphylaxis. We reviewed a 5-year experience of immunotherapy in a University practice and their experience with systemic reactions is presented. More than 125,000 injections were given in this time period. Of the 550 patients receiving immunotherapy, 14% experienced anaphylactic reactions, the majority of which were mild.

Audiology in medicine.

Among the most common complaints a physician confronts are those concerned with hearing loss and dizziness. It is essential that all practitioners acquaint themselves with the diagnostic information provided by an audiological evaluation. The authors describe the frequently used tests and present case studies to illustrate the value and scope of diagnostic audiology.

Laryngeal airway resistance. The relationships of airflow, pressure, and aperture.

In the surgical treatment of the paralyzed larynx, a compromise often needs to be made between an orifice size needed to preserve voice and that needed for adequate inspiratory airflow rates. To assess the negative pressures needed to generate normal airflows across a narrowed vocal cord aperture, we measured pressure and flow changes across cadaveric larynges while altering aperture size. Best-fit quadratic equations for each aperture area selected were derived and showed that if the aperture were 0.5 cm2 or less, the resistance to normal breathing would be significantly increased. Aperture sizes of 0.67 cm2 or greater are not associated with such an increase in resistance.

Patency rate of endoscopic middle meatus antrostomy.

A series of 145 patients with chronic sinusitis were treated with functional endoscopic sinus surgery. Patency of the middle meatus was evaluated by actuarial life-table methods. After 24 months' follow-up, the overall patency rate of endoscopic middle meatotomy was 94.08%. Questionnaire data indicated that 91.8% of these patients were improved or asymptomatic. This preliminary study indicates that the patency rate of middle meatal antrostomy appears to be greater than that of inferior meatal antrostomy when compared to literature controls, and that a high percentage of these patients are improved by this surgery.

Middle meatus anstrostomy: patency rates and risk factors.

Two hundred patients with chronic sinusitis were operated on using functional endoscopic sinus surgery (FESS) techniques. These patients were followed closely over 3 years. Patency of the endoscopic middle meatotomy was recorded using actuarial life-table methods. The overall patency rate of the endoscopic middle meatotomy was 93.55%, and the actuarial patency rate at 36 months was 87.47%. The presence of seasonal allergy with nasal polyps was the most important variable in predicting closure. Middle turbinectomy was the most important variable in predicting patency. Symptoms were evaluated by questionnaire at 1 year. Questionnaire data indicate that 96% of these patients are improved or asymptomatic.

Secondary and metastatic tumors of the orbit.

We have presented three cases of metastatic tumor to the orbit. The first case illustrated metastatic tumor that originated from a cutaneous basosquamous cell carcinoma. This lesion, first reported by MacCormac as being morphologically intermediate between basal and squamous cell carcinoma, has become a topic of some controversy. Conley reported these tumors to represent 1% of basal cell carcinomas. Several authors have reported a higher incidence of recurrence with these lesions, as compared with the ordinary basal cell tumors. Recurrence of basal cell carcinomas are reported as approximately 10%, but are four times greater in the basosquamous cell tumors. The incidence of metastasis with the basosquamous cell tumors has been reported in between 37% and 51% of cases. The second case represented involvement of the orbit by direct extension of a facial squamous cell carcinoma. As illustrated by this case, these tumors can be very aggressive and should be treated with respect. The third case showed the metastatic potential of the nephroblastoma with metastatic tumor that involved the eye, orbit, and maxilla. Diagnostic techniques available in evaluation of these tumors include CT scan, magnetic resonance (MR) imaging, ultrasound, open biopsy, and fine-needle aspiration. Li et al., in an article that compared MR imaging, CT scan, and ultrasound concluded that MR imaging, with the use of the 0.15 T resistive magnet, offered no distinct advantage over the combination of CT and ultrasound in evaluation of patients with orbital tumors.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of sterile inflammation on skin flap survival.

Several investigations have suggested that a sterile inflammatory reaction in a skin flap enhances flap survival. A chemical peel produces a mild chemical burn, which is one form of nonbacterial inflammatory response. Some authors advocate the concomitant use of face lift and chemical peel, while others caution that the peel might jeopardize the facial flaps. To determine whether the reaction caused by a chemical peel enhances or impairs skin flap survival, a study using miniature pigs was undertaken. Survival length of flaps treated with a chemical peel was compared to that of untreated flaps. A total of 36 dorsally based random flaps were used on three miniature pigs. Six identical 14 X 4 cm flaps were designed on each side of the pigs. A chemical peel was applied to the area of 18 of the proposed flaps 2 days prior to elevation. Alternate flaps on each side of the pigs were treated. As the flaps were elevated, the tips were examined to document the inflammatory response histologically. After 14 days, the surviving length of the flaps was measured. As determined by the Wilcoxon matched-pairs signed-ranks test, there was no significant difference between the treated and untreated groups. Our study shows that a nonbacterial inflammatory response produced by a chemical peel does not improve skin flap survival, at least not in pigs.

Postauricular epidermoid cysts: treatment with electric current.

We believe the use of electric current to treat epidermoid inclusion cysts in the postauricular area is a simple, effective method that results generally in prolonged decompression of the cyst. The length of time that the fistula remains patent is unknown at present. Local control is, however, prolonged and may be permanent. Over time the induration subsides and the sac atrophies.

Hemifacial spasm caused by cholesteatoma.

Hemifacial spasm is a rare disease. Usually a specific etiologic factor is not found and nonspecific treatments are used. A case of hemifacial spasm secondary to a middle ear cholesteatoma is presented. This origin should be considered in any patient who has hemifacial spasm.

Oropharyngeal tularemia.

A case of oropharyngeal tularemia mimicking a peritonsillar abscess is presented. This diagnosis should be entertained in patients who are seen initially with ulcerative-exudative pharyngitis with or without tonsillitis and whose routine cultures are negative and/or are unresponsive to penicillin. Institution of appropriate therapy depends largely on the clinical diagnosis because cultures on ordinary media are routinely negative, and it takes several days for antibody titers to reach diagnostic significance.

Parotid fistula: current management.

The most common cause of parotid fistula is trauma. Other causes include operative complications, infection, and malignancy. In the acute phase of ductal injury, primary reconstruction, if possible, is the treatment of choice. Acute parenchymal injury is treated by tight closure and expectancy. When diverting or flow-blocking measures fail to correct chronic ductal fistula, the treatment of choice for this situation as well as for chronic parenchymal fistula may be tympanic neurectomy, which can be done under local anesthesia, is associated with low morbidity, is relatively uncomplicated and has given excellent results to date in our hands.

Recurrent nerve locating system.

One recurring problem for otolaryngologists is the patient with vocal cord paralysis after thyroid surgery. We review the literature to assess the magnitude of this problem and to assess presently available techniques for sparing the recurrent laryngeal nerve. We present a new system for intraoperative recurrent laryngeal nerve location during thyroid surgery.

Design and testing of a transistorized nerve stimulator.

Presently available equipment for nerve stimulation includes the relatively expensive multifunction pulse generators and the disposable dc stimulators. We have designed a semidisposable, two-transistor pulse generator that is portable, inexpensive, and capable of dynamic nerve stimulation.