URINARY NITRITE EXCRETION IN LOW-BIRTH-WEIGHT NEONATES WITH SYSTEMIC INFLAMMATORY RESPONSE SYNDROME

Increased nitric oxide (NO) levels are thought to play an important ro le in the pathophysiology of the systemic inflammatory response syndro me (SIRS) which is caused by disseminated vascular endothelial damage. Clinical studies have shown that urinary nitrite (NO2-) and nitrate ( NO3-) excretions can be utilized as indexes of NO formation. The SIRS and NO relationship was investigated in 15 neonates with SIRS, gestati onal age 32.5 +/- 4.4 weeks and weight 1,737 +/- 753 g. The control gr oup comprised 18 neonates with a gestational age of 32.8 +/- 3.5 weeks and a weight of 1,778 +/- 538 g. There was no significant difference in birth weights and gestational ages between the two groups (p > 0.05 and p > 0.05). The urinary nitrite levels obtained in the subjects we re normalized for urinary creatinine concentrations. The mean urinary nitrite levels in the control group neonates were found to be 4.22 +/- 1.8 mu mol/mmol creatinine on the Ist day, 4.09 +/- 2.28 on the 2nd, 3.62 +/- 1.6 on the 3rd, and 4.01 +/- 1.12 mu mol/mmol creatinine on t he 7th day. There were no statistically significant differences betwee n these levels (p > 0.05). We determined urinary levels of nitrite in neonates in the study group within the first 24 h of SIRS symptoms and found these levels (18.35 +/- 11.16 mu mol nitrite/mmol creatinine) t o be elevated as compared with those of the control subjects on the 7t h day of life (p < 0.0005). In conclusion, urinary nitrite excretion i s significantly elevated in neonates with SIRS due to septic events, a nd these results suggest that NO might play a part in SIRS.