Changes of serum nitric oxide concentration in different stages of traumatic brain edema

Nitric Oxide (NO) is one of the most important neurotransmitters in the brain which has a key role in brain edema and ischemia pathophysiology. The aim of this study was to determine the serum NO concentration in traumatic brain injury and its relation with Glascow Coma Scale (GCS) and consciousness level. In this analytic-descriptive study, patients with traumatic brain injury who had a mass volume in CT scan less than 25mm were assessed. GCS was measured during the study (14 days) and serum NO level was measured on days 0, 7 and 14 using Griess reagent method. Data were analyzed by one-way variance analysis and Pearson correlation coefficient (P < 0.05). Results showed that there was no significant difference in serum NO concentration in different GCS scores (GCS ≤ 7:7.61 ± 0.51, GCS ═ 8: 9.65 ± 1.52, GCS ≥ 9:8.5 ± 0.95 μ mol/lit). Also, serum NO level had no significant correlation with GCS score. It seems that serum NO concentration has no correlation with GCS score in traumatic brain injury. More studies on local brain NO changes in brain and CSF are needed.