Carboxyhemoglobin elevation in trauma victims

Background: Products of the hemeoxygenase enzyme include carboxyhemoglobin (COH) and bilirubin, which have protective effects in stressed states, Heme oxygenase-1 enzyme up-regulates in states of oxidative stress. We hypothesi zed that COB is elevated in septic trauma patients compared with nonseptic patients, Methods: A prospective study was carried out at a Level I trauma center inv olving all patients admitted to the trauma intensive care unit. During a 3. 5-month period, 45 patients were enrolled, with 76 samples being drawn on a dmission and at later time points. The samples were classified as septic (B one's criteria), stressed (based on expired gas analysis), or nonstressed n onseptic, Correlations with Acute Physiology and Chronic Health Evaluation III score, white blood cell count, temperature, partial pressure of oxygen, and percentage of inspired oxygen were evaluated. Results: COR levels in samples drawn from patients presenting in shock (sys tolic blood pressure less than or equal to 90 mm Hg) were significantly hig her than levels in samples from patients not in shock (systolic blood press ure > 90 mm Hg) (3.27 +/- 1.09 vs. 2.75 +/- 0.64; p = 0,013), Samples from septic patients with infection were associated with significantly higher In jury Severity Scares (34.1 +/- 11.2 vs. 21.8 +/- 18.3; p less than or equal to 0.05) and a lower percentage of inspired oxygen (41.6 +/- 10.3 vs. 61.0 +/- 26.3; p less than or equal to 0,05), Conclusion: COH was significantly elevated in samples drawn during stress, sepsis, and shock states. There was overlap between sepsis and stress COH s ample values, limiting the clinical usefulness of the assays in predicting sepsis, Further studies focusing on hemeoxygenase-1 expression and the role of its by-products in the outcomes of trauma patients are-warranted.