Home ventilator care.

The need for continuous home ventilatory care can arise when patients who are otherwise stable cannot be weaned from mechanical ventilatory support. Two cases are presented that show these patients can be cared for at home at a cost less than their care in the hospital. Before deciding on home ventilatory care for a patient, one should carefully consider all supportive measures, including drug therapy and psychosocial factors. The choice of home care equipment depends on many individualized considerations. The successful management of a patient on a home ventilator requires careful preparation, extensive home instruction, and continued follow-up by a home health care team.

Occupational asthma due to tetrachlorophthalic anhydride.

The plastics industry utilizes a number of organic chemicals which have the potential of producing pulmonary reactions, particularly in susceptible individuals. Five workers are reported who were involved in the production of epoxy resins and developed recurrent respiratory symptoms and physiologic abnormalities following exposure to tetrachlorophthalic anhydride (TCPA). Inhalation challenge with TCPA reproduced their symptoms and demonstrated both an immediate and late (4-6 hours) physiologic response. Although the clinical picture strongly suggested a hypersensitivity reaction, immunologic studies failed to demonstrate precipitating or specific IgE antibody. Avoidance of exposure resulted in resolution of symptoms; however, three of the five individuals had residual functional impairment.

Interstital lung disease due to contamination of forced air systems.

Eight patients had hypersensitivity pneumonitis due to contaminated home or office forced-air heating or air-conditioning systems. We studied their clinical and laboratory features, and the results indicated that this disease may occur as an acute or insidious form differing in type and intensity of respiratory and systemic symptoms. Thermophilic actinomycetes contaminatinf the forced air systems were identified as the sensitizing agents in most cases. Precipitating antibodies to the organisms could be shown in the serums of the patients and the antigen identified by immunofluorescent studies in the three lung biopsies examined by this method. Inhalation challenge studies with the cultured organism or other materials obtained from the forced air systems reproduced the clinical syndrome in the four patients tested. Avoidance of the contaminated system, and the use of corticosteroids in more severe cases,seems to be appropriate therapy for patients with this disease.

Hypersensitivity studies in popple (Aspen tree) peelers.

In the course of investigation of the relationship between hypersensitivity pneumonitis and the wood industry 45 popple peelers were studied. Four roentgenograms consistent with diffuse lung disease were found. All cases were in examinees who were also dairy farmers. Questionnaires revealed no instance of clinical symptoms of hypersensitivity pneumonitis. Gel immunodiffusion studies were positive to various antigens in eight cases, but no correlation could be made with pulmonary function or chest roentgenogram abnormalities in relation to occupation. Cultures of the wood and the surrounding environment yielded thermophilic fungi as well as other known antigenic material. It is concluded that the occupation of popple peeling does not represent an increased risk of development of hypersensitivity pneumonitis.