Unilateral Positive Pressure Breathing as a Means of Partial Shift of the Pulmonary Blood Flow

¹ The Servicio de Asistencia y Preservación Antituberculosa del Ministerio de Salud Pública; and the Instituto de Tisiología de la Facultad de Medicina de Montevideo.

A description is given of a method of blood shunt from a particular lung area towards the remaining pulmonary parenchyma, through local hypertension obtained by connecting the bronchus of the area under study with an atmosphere of positive pressure of 25 cm. of water or less.

The blood flow reduction, in the areas which undergo positive pressure, was demonstrated by means of angiopneumography on 10 patients: four normal, and six with unilateral pulmonary tuberculosis. Therefore, this technique permits estimate of the potential functional value of the remaining parenchyma.

As a complementary work, on a total of 40 subjects (6 normal and 34 patients with unilateral pulmonary tuberculosis), we have studied the alterations in the spirometric tracing of an oxygen breathing lung at atmospheric pressure, when the other lung was ventilated in open circuit with nitrogen at atmospheric or positive pressure or with oxygen at positive pressure.