Prolonged relaxation rate of inspiratory muscles in patients with sleep apnea.

To evaluate whether inspiratory muscle function is impaired in patients with sleep apnea, we measured inspiratory muscle strength and relaxation rate before and after sleep in 13 patients. The sleep apnea group was composed of eight patients with severe obstructive sleep apnea, and the non-apnea group was composed of five patients without significant sleep apnea. We chose the time constant of relaxation (TauR) as an index of impaired inspiratory muscle contractility, and in subsets of each group, we measured the inspiratory pressure-time index as an indicator of a fatiguing breathing pattern. In patients with sleep apnea, presleep TauR was 79 +/- 22 ms (SD), longer than that of normal subjects (normal, 59 +/- 7 ms) (p less than 0.05). TauR increased by 21 +/- 16 ms during sleep (p less than 0.01). In patients without apnea, presleep TauR was 67 +/- 7 ms and it did not change after sleep. Maximal inspiratory and expiratory pressures were unchanged after sleep. We conclude that patients with sleep apnea do not develop overt inspiratory muscle failure but do have impaired contractility. We speculate that hypoxemia as well as increased work load was responsible.

Toxic effects of isoniazid in tuberculosis chemoprophylaxis. Role of biochemical monitoring in 1,000 patients.

One thousand patients receiving isoniazid chemoprophylaxis were prospectively followed up to assess the value of liver function monitoring plus monthly clinical evaluation. Two hundred twenty-two (22.2%) of the patients had at least one elevated SGOT level during the course of treatment, and 47 asymptomatic persons had isoniazid therapy discontinued because of consistent elevations greater than five times normal. Another 17 had symptoms in association with elevated SGOT levels, and therapy was stopped in these patients as well. No patient became seriously ill, and there were no deaths. Biochemical monitoring should be done routinely in patients receiving isoniazid chemoprophylaxis to avoid the development of irreversible hepatic reactions.

The diagnosis of sarcoidosis by conjunctival biopsy.

A prospective study of 21 patients with presumed sarcoidosis was performed to determine the value of conjunctival biopsy in diagnosing the disease. Conjunctival lesions were seen in 15 patients on slit-lamp examination, with eight of these showing noncaseating granulomas on biopsy. The abnormalities were seen by the unaided eye in only two cases. All eight biopsies showing noncaseating granulomas occured in the 14 black patients. No clinical, biochemical, or radiographic characteristics identified those patients who would prove to have a biopsy showing such granulomas. This simple, frequently productive procedure may be helpful in the diagnosis of sarcoidosis.

Treatment of pulmonary melioidosis with combination of trimethoprim and sulfamethoxazole.

Treatment with a combination of trimethoprim and sulfamethoxazole proved lifesaving in a patient with pulmonary melioidosis after therapeutic failure occurred with other antibiotics to which the organisms were sensitive in vitro. Antagonistic interaction of drugs occurred when the combination of trimethoprim and sulfamethoxazole was given along with other antibiotics. The combination of trimethoprim and sulfamethoxazole should be considered a major addition to the pharmacologic armamentarium for the treatment of pulmonary melioidosis.

Isoniazid chemoprophylaxis. Association with detection and incidence of liver toxicity.

The hepatotoxicity of isoniazid was studied in a double blind fashion in 120 adult patients receiving the drug for chemoprophylaxis. The incidence of abnormal SGOT values was significantly higher in those on the drug, 18.3% having elevated values as compared to 6.7% of those on placebo during the three-month study period. There was no statistical difference in the frequency of symptoms suggestive of liver diseases between the isoniazid and placebo groups. Furthermore, there was no significant relationship between symptoms and elevated SGOTs. Therefore, symptomatology would not appear to be a sensitive method for detecting early isoniazid liver toxicity. From available evidence, biochemical monitoring would appear to detect liver toxicity at an earlier and more reversible stage.

Treatment of tuberculosis by the nonpulmonary physician.

Because tuberculosis is currently being treated in many instances by the nonpulmonary physician, an evaluation of the skill with which he performs in this capacity was made. A group of 130 patients who had been treated by such physicians was analyzed, using generally accepted criteria for appropriate therapy. Seventy-three of the group were found to have been treated inappropriately. The use of isoniazid in those likely to be resistant to that drug, the use of a single drug in bacteriologically positive disease, and inadequate or excessive drug dosages were among the more common errors. Two thirds of the physicians caring for these patients were internal medicine specialists, half of them board certified. Increased education efforts in regard to this disease at all levels of training must be made.

Surgical complications of cervical and mediastinal tuberculous adenitis in an infant.

An infant whose miliary tuberculosis was resolving after five months of chemotherapy developed a tuberculous cervical lymphatic abscess followed shortly thereafter by life-threatening tracheal compression from enlarged tuberculous mediastinal nodes. Both of these complications required surgical drainage. Chemotherapy alone may be ineffective in the management of lymphadenitis caused by Mycobacterium tuberculosis.