1208 NITROGEN WASHOUT (NW) TECHNIQUE FOR THE TREATMENT OF PULMONARY INTERSTITIAL EMPHYSEMA (PIE) IN NEWBORN INFANTS

Abstract

We describe a nonsurgical treatment for severe hyperinflation of the lung due to PIE. PIE occurs frequently in mechanically ventilated newborn infants (NBI) with respiratory distress syndrome (RDS). There is a significant increase in morbidity and mortality associated with PIE. We have adapted a modification of the method of NW proposed by Chernick and by Rhodes to the treatment of PIE. The rationale is replacement (“washout”) of trapped nitrogen by oxygen, which is then absorbed by blood. Inspired fraction of oxygen (P1O2) was raised .2-.5 while PEEP and peak inspiration pressure (PIP) were decreased. After a 2-6 hour treatment, the F1O2 was weaned to previous settings, 4 NBI were treated with this regimen. PaO2 improved in all patients, allowing a decreased FIO2 at both 4-6 hrs and 24 hrs post NW. A progressive improvement was seen in ventilation as estimated by PaCO2 and ventilator settings so that by 24 hrs post NW all patients had lower arterial PCO2, with unchanged or decreased ventilator support. Chest x-rays at 4-6 hrs and at 24 hrs improved over pre NW films in all cases. Three of the infants survived. We have found NW to be a useful and, thus far, a safe method of treating PIE in NBI with RDS and PIE.