Functional examination of each lung before and after the paralysis of the phrenic nerve.

In a previous work we started the study of the influences of different methods of collapse-therapy-and particularly pneumothorax-on the respiratory function of each lung. We are presenting here the results of the air content analysis of each lung before and after the surgical paralysis of the phrenic nerve. Oianotti and Ceruti2 have seen in tracheotomized dogs that the ventilation of the lungs and the oxygen consumption diminishes after the excision of the phrenic nerve and that these effects persist after several weeks. The reduction in the respiratory values is somewhat higher in the bilateral than in the unilateral paralysis. Brea and Ferrari3 made a functional study of seven cases of pulmonary tuberculosis before the paralysis of the phrenic nerve and also a few days and again one month after the surgical paralysis (by excision, alcoholization or crushing). After a few days they found a diminution of the voluntary apnea, the vital capacity, the respiratory volume per minute, the oxygen consumption, CO., elimination, and in the O., content of the alveolar air. Due to the development of compensatory mechanisms all these changes return to normal values one month after the intervention. Cournand and Richards: in eight cases of therapeutic phrenic paralysis found striking impairment of the pulmonary function, as evidenced by decreased breathing reserve, unsaturation of arterial blood and a distinct tendency to pulmonary congestion after intravenous infusion. According to Rossier, Petzold, Decker and Michaud, cited by Steh~l in ,~ the paralysis of phrenic nerve results in an unsaturation of arterial blood during moderate work and sometimes even during rest. To explain this finding it is suggested that although there is a reduced ventilation, the amount of blood circulating through the lower part of the homolateral lung remains constant. A pendular phenomenon in the air of lungs due to the paradoxical movement of the diaphragm has also been described.