Fig. 2. (A ) Mean pulmonary arterial pressure and (B ) pulmonary vascular resistance index measured during and after transfusion of fresh and stored packed erythrocytes (PRBC) in awake lambs. Some lambs received inhaled nitric oxide during and after transfusion of stored PRBC. *P < 0.05, stored PRBC value differs from both fresh PRBC and stored PRBC + iNO, ANOVA. All data mean ± SD. iNO = inhaled nitric oxide; PAP = mean pulmonary arterial pressure; PRBC = packed erythrocytes; PVRI = pulmonary vascular resistance index.