RESUMO
PURPOSE: This study was performed to observe the relationship of plasma L-arginine level and the severity of disease and pulmonary artery pressure in respiratory distress syndrome of premature infants. METHODS: Peripheral blood samples were obtained at 1st, 3rd and 7th day from 21 premature in fants with respiratory distress syndrome to analyze the L-arginine concentration. Oxygenation index (OI), an indicator of the severity of the disease, was calculated at the same time of the blood sampling. And pulmonary artery pressure was measured by Doppler echocardiography at each period. Plasma L-arginine level, OI and right ventricular systolic time interval(RVSTI) were analyzed. RESULTS: Plasma L-arginine concentration of the 1st day was lower than 3rd and 7th day. OI and RVSTI were significantly correlated with each other(r=0.772, P<0.01). Plasma L- arginine level was correlated with oxygenation index(r=-0.346, P<0.01) and RVSTI(r=-0.416, P<0.01). CONCLUSIONS: Plasma L-arginine level was lowest in the 1st day during the study period. Plasma L- arginine concentration correlated significantly with the severity of respiratory distress syndrome and pulmonary artery pressure in premature infants.