Otolaryngologist's role in transtracheal oxygen therapy: the minitrach procedure.

The modified Seldinger technique for transtracheal oxygen catheter insertion is relatively straightforward, but tract problems during subsequent oxygen therapy are not uncommon. With the modified Seldinger technique method, transtracheal oxygen is not initiated until 1 week after the procedure. Six to 8 weeks are required for tract epithelialization, which allows routine catheter removal and cleaning by the patient. Without removal, mucus tends to collect and form balls on the catheter tip, creating a management problem. Previous studies suggest a significant incidence of tracheal chondritis, keloid formation, and inadvertent catheter dislodgment. In 7% to 10% of patients, the epithelial tract cannot be recovered by medical personnel, and complete closure occurs. We have developed a surgical technique for the creation of a controlled tracheocutaneous tract. Highlights of the minitrach include skin flap elevation, cervical lipectomy, resection of a small window of tracheal cartilage, and approximation of the skin flaps to the window. We evaluated 33 patients who underwent the minitrach procedure as an access method for receiving transtracheal oxygen. When compared with results from 64 patients followed up for a similar period with the modified Seldinger technique, results with minitrach showed that transtracheal oxygen could be instituted sooner (<24 hours), and symptomatic mucus balls were reduced because the tract matured more quickly (approximately 14 days). With the minitrach there were no inadvertent catheter dislodgments, as compared with 41% of modified Seldinger technique patients who had one or more episodes of catheter dislodgment. Twelve percent of minitrach patients had a single episode of chondritis, as compared with 25% of the modified Seldinger technique patients, who had one or more episodes. The minitrach was well tolerated in this group of patients with severe pulmonary and/or cardiovascular disease. In 12 of these patients, a minitrach revision of their previous modified Seldinger technique tracts resolved recurrent problems with chondritis, lost tracts, and keloids. We conclude that the minitrach promotes early institution of transtracheal oxygen, simplifies an intense postprocedure educational and management process, facilitates tract maturation, and reduces the incidence of problems related to mucus balls, lost tracts, chondritis, and keloids. The minitrach can be used as a revision procedure to resolve tract problems encountered with modified Seldinger technique. We are now using the minitrach as the preferred procedure for the institution of transtracheal oxygen. The minitrach greatly improves and simplifies the transtracheal oxygen program, and the otolaryngologist becomes an important member of the transtracheal oxygen team.

Oxygen therapy using pulse and continuous flow with a transtracheal catheter and a nasal cannula.

Pulse delivery (PD) of oxygen was compared with continuous flow (CF) utilizing transtracheal oxygen catheter (TTO) and nasal cannula (NC) in 20 stable patients with chronic hypoxemia. Oxygen saturation, respiratory rate, and accuracy of pulsed oxygen delivery were measured during sleep studies and these parameters, as well as arterial blood gases, were evaluated during rest and exercise. Additionally, bulk liquid oxygen use was measured under each condition, for a period of 1 month. Pulse delivery NC was evaluated in six subjects, CF NC in 14 subjects, and PD and CF TTO in 20 subjects over the 1-month period. Results showed that, as a group, patients were adequately oxygenated when utilizing the PD with both NC and TTO as assessed by arterial blood gases, oximetry, and hematocrit. However, four subjects could not be adequately oxygenated on PD NC during exercise even at the maximum liter per minute setting and could not be studied with this mode of therapy. The PD settings in the remaining subjects were equivalent to continuous flow settings for TTO and NC as assessed by PaO2 for rest and SaO2 for exercise and sleep. Compared with standard CF NC, the daily bulk oxygen use was decreased by 29.4 percent with CF TTO, by 48.2 percent with PD NC, and by 49.9 percent with PD TTO. We conclude that, compared with CF NC, PD of oxygen via TTO or NC by this method appears to be a safe, reliable, effective, and cost-effective method of oxygen delivery in the majority of subjects when used with proper screening.

The protection of invertebrates, fish, and vascular plants against inorganic mercury poisoning by sulfur and selenium derivatives.

Protection of organisms against mercury (Hg) poisoning is most commonly associated with the antagonistic effects of selenium (Se)-compounds against mercury alkyls in higher animals. This study shows that there is no consistent difference among Periodic Group VIA derivatives including S(IV), S(II) organic, Se (IV), Se (II) organic, possibly Se VI, as well and Te (IV) in their ability to protect against mercury poisoning. The organisms used in assays were: Coleus explants (leaf abscission); turnip (germination); pea (growth inhibition and Hg uptake); a planarian (regeneration); the brineshrimp (excystment, phototaxy); the mealworm larva Tenebrio (metamorphosis) and the fish "tilapia" (survival, Hg uptake). Thiamine was the most effective of the Group VIA derivatives against the widest spectrum of organisms and test systems. In planarian regeneration, it was active where S and Se compounds failed. The most unexpected observation was the hastening of insect metamorphosis by HgCl2 and the enhancement of that effect by thiamine.

Pulmonary pathology in acute respiratory insufficiency: lung biopsy as a diagnostic tool.

Forty-two patients underwent open-lung biopsy during the early phase of acute respiratory insufficiency. Correlation between the gross appearance of the lung at operation and the microscopic findings was good. Although only fair correlation was found between lung and tracheal cultures, the findings of two positive cultures in the lung only was of utmost importance. Biopsying multiple areas from the same operation showed identical pathology in 86 per cent of cases. The mortality rate of open-lung biopsy was zero; the morbidity rate was 4 per cent. The over-all survival rate of acute respiratory insufficiency (ARI) due to trauma was 39 per cent; that of pneumonia, 11 per cent. In 17 (33 percent) patients specific diagnoses and/or specific therapies were employed as a direct result of the biopsy or the thoracotomy. The incidence and prognostic implications of fibrosis and microthromboembolism are presented and discussed. Open-lung biopsy has been extremely safe and valuable in characterizing and managing ARI.