A prospective study evaluated potential risk factors associated with laryngeal injury after prolonged endotracheal tube intubation for longer than 3 days. Ninety-seven patients were evaluated after oral endotracheal tube intubation (mean, 9 days). This study updates a previously reported evaluation of 44 patients. The additional sample size has provided findings of unreported patient risk factors of laryngeal injury and confirmation of previous associations. The majority of the 97 patients had some type of laryngeal injury, ranging from mild mucosal erythema to ulceration, granuloma formation, or true vocal cord immobility. Patient examinations were continued until the larynx returned to normal or stabilized or the patient was lost to follow-up. Postextubation examinations in the survival group revealed the following. (1) Laryngeal erythema occurred in 94%, and ulceration occurred in 76% of the patients with resolution within 6 weeks. (2) Laryngeal granulomas occurred in 44% of the patients; the majority of the granulomas (57%) developed an average of 4 weeks after extubation. Associated risk factors included duration of endotracheal tube intubation (p < 0.05) and presence of nasogastric tube (p < 0.05). (3) Vocal cord immobility was observed in 16 patients (20%). Eight patients had true vocal cord immobility noted initially after extubation, and the remaining eight had true vocal cord immobility an average of 4 weeks after extubation. Initial and delayed true vocal cord immobility were associated with duration of intubation and size of endotracheal tube (p < 0.01). Delayed true vocal cord immobility developed only in patients with a size 8 endotracheal tube.(ABSTRACT TRUNCATED AT 250 WORDS)

Fifty-four patients, diagnosed with Menière's disease and treated with diuretics and a low-salt diet, were evaluated retrospectively with the 1985 AAO/HNS Committee on Hearing and Equilibrium (CHE) guidelines for vertigo and hearing changes. The patient data base was also evaluated with other methods that helped determine the effectiveness of the 1985 AAO/HNS CHE guidelines. After 24 months of therapy, vertigo control was complete or substantial in 79% of the patients, limited or insignificant in 19%, and worse in 2% as evaluated by the CHE 1985 guidelines. Hearing improved in 35% of the patients, was unchanged in 29%, was worse in 22%, and could not be classified by CHE guidelines in 14%. Hearing was also evaluated by comparison of individual thresholds before medical therapy, and at 22 and 74 months after the start of medical therapy. We found a stabilization of low- and mid-threshold frequencies, with an average rate of hearing loss approximating 0 dB/yr with 74 months of followup. The results of this preliminary study suggest that diuretics and a low-salt diet may decrease the natural progression of sensorineural hearing loss in patients with Menière's disease. Compared with other methods of data analysis, the 1985 CHE guidelines lacked sensitivity to evaluate the hearing changes observed.

Nerve growth factor (NGF) and laminin are important factors for neural development and regeneration. We examined the effects of increasing the local concentration and duration of action of NGF and laminin on peripheral nerve regeneration in the adult mouse sciatic nerve. A Silastic (silicone rubber) channel with intraluminal NGF solution was secured between transected nerve ends. The second channel tested, formed from a polysaccharide called chitosan, was prepared with NGF and laminin in the channel walls and provided a sustained release of NGF. At six weeks post-implantation, no improvement in nerve regeneration was identified in those channels prepared with NGF when comparing electromyographic thresholds (microA), maximum potentials (mV), nerve diameter, myelin sheath thickness, myelinated axon counts, or diameter. However, increased angiogenesis was demonstrated within the chitosan and Silastic channels prepared with NGF compared to those channels without NGF. Silastic exhibited minimal inflammation. Chitosan was associated with inflammation in many nerve channels.

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The potential therapeutic effect of hyperbaric oxygen (HBO) after rat peroneal nerve crush was evaluated. Animals were given 100% oxygen at 2.5 atmosphere absolute for 90 minutes twice daily for 1 week and then once daily for 1 week. Edema increased in crushed nerves compared with control nerves, but no effect was associated with the administration of HBO. Gait analysis demonstrated injury at 1, 7, and 14 days after nerve crush, but no difference was found at 22 and 28 days after injury (analysis of variance: P < .001, 10 animals per group). Eight weeks after injury, nerve stimulation and muscle force measurements were 114 g for the injured group and 146 g for the control group (P < .001). There were no HBO-associated changes in gait parameter or nerve/muscle force measurements. This study demonstrated that rat peroneal nerve crush injury causes acute intraneural edema and temporary decrement of gait parameters. Elicited nerve stimulation demonstrated persistent loss of force 4 weeks after normalization of gait, but no HBO effect.