Simultaneous administration of inhaled nitric oxide in two children with pulmonary hypertension.

We administered inhaled nitric oxide (NO) in two children with postoperative pulmonary hypertension after surgical repair of congenital heart diseases. Different concentrations of NO, varying from 0.1 to 10.0 ppm, were administered simultaneously to these patients using the same chemiluminescence analyzer (CLD 700 AL, Eco Physic; Diirnten, Switzerland) for the measurement of NO and nitrous oxide (N02). Each patient received NO through an H-type cylinder and a flowmeter (316 ST; Matheson Gas Products; Montgomeryville, Pa), which were connected to the inspiratory limb of continuous flow, timecycled, pressure limited ventilators (Sechrist IV-100B [Sechrist Industries GMBH; Steinen, Switzerland], Babylog 8000 [Drager; Lubeck, Germany]). As shown in Figure 1, analyses of NO and N02 in the first child were done through usual connections. Those in the second patient wrere made by connecting the tube of teflon to the valve at the side port, which usually serves for calibration of the analyzer. NO and N02 concentrations were checked every hour by respiratoiy therapists in the alternate patient by switching the valve toward the second mechanical ventilator. Although the need to simultaneously administer NO in more than one patient actually may be uncommon, it may become