We reviewed reactions previously reported in patients treated with isoniazid, who ate certain fish and cheeses. We observed similar reactions in two patients after they ingested cheese and wine. Isoniazid is an inhibitor of both monoamine and diamine oxidases, which contribute to the metabolism of histamine that may be present in some fish and cheeses. Monoamine oxidase also acts in the metabolism of tyramine, present in some cheeses and wines. Reactions reported after eating fish or cheese, in patients treated with isoniazid, are similar in that both are characterized by headache, palpitations, skin flushing, nausea, vomiting, and pruritus. Reactions after fish have not been associated with increased blood pressure, whereas those following cheese ingestion frequently result in modest increases in blood pressure. Patients treated with isoniazid should be alerted to the possibility of reactions after eating certain foods.

Adult↗

PubMedDate not supplied

Effect of airway diameter, suction catheters, and the bronchofiberscope on airflow in endotracheal and tracheostomy tubes.

Pressure-flow relationships of an artificial airway-mechanical ventilator system were investigated. Endotracheal tubes varying from 7 to 9.5 mm. internal diameter and tracheostomy tubes from 7 to 10 mm. internal diameter were tested over flow-rates from 0.3 to 1.4 L. per second using a tidal volume of 500 ml. The effect of partial obstruction within these airways by suction catheters and the bronchofiberscope was examined. Depending on the internal diameter and the flow-rate, the driving pressure necessary to overcome the resistance of the tubes ranged from 5 to 20 cm. H2O. Partial obstruction of the artificial airways by suction catheters further increased this pressure. The introduction of the bronchofiberscope through an endotracheal tube of 7.5 mm. internal diameter, leaving an effective diameter of 4.9 mm., produced a driving pressure as high as 70 cm. H2O and reduced the flow rate to 50 per cent and the tidal volume to 80 per cent of its set value. Attention should be paid to duration of tracheobronchial suction while the patient is removed from the respirator since a high-grade resistance is created by passage of a suction catheter through an endotracheal tube. Bronchofiberscopy should be cautiously performed through cuffed artificial airways with at least 8 mm. internal diameter because the airway may be too comprised even if mechanical ventilatory assistance is employed.

Bronchoscopes↗