Are nitrite/nitrate (NOx) levels elevated by inhalation injury?

The relationship between airway burn and nitric oxide (NO) levels in the early burn stage was investigated by quantifying nitrite/nitrate (NOx), which are the final metabolites of NO, in 22 burn patients. Although total body surface area (TBSA) and burn index (BI) were significantly higher in patients with airway-burn than in patients without airway burn (P=0.0347 and 0.0422, respectively), no significant difference in NOx levels was observed between the two groups (P=0.6196). The NOx levels were found to correlate significantly with TBSA (r=0.4775, P=0.0246). A significant correlation was also noted between the NOx levels and BI (r=0.4391, P=0.0409). These results suggest that NO reflects the intensity of inflammation in the early burn stage, but that excessive NO formation is unlikely to be induced by stress, such as that caused by airway burn.