Importance of oxidative stress in the evaluation of acute pulmonary embolism severity.

Background: Pulmonary embolism (PE) is a common and potentially life-threatening disorder. Our study was aimed to investigate whether oxidative stress markers can be used as clinical markers in the evaluation of acute PE (APE) severity.

Methods: 47 patients with objectively documented diagnosis of APE were recorded. Of these patients, 14 had low-risk PE, 16 had moderate-risk PE, and 17 had high-risk PE. 21 healthy subjects were also enrolled in this study. Ischemia-modified albumin (IMA), prooxidants-antioxidants balance (PAB), advanced protein oxidation products (AOPPs), and ferric reducing antioxidant power (FRAP) were measured as oxidative stress parameters to evaluate the role of oxidative stress.

Results: In the low-risk and moderate-risk APE groups, AOPPs and PAB levels were significantly higher and FRAP levels were significantly lower than those in the control group. AOPPs and IMA levels in the patients with high-risk PE were significantly higher than those in both the low-risk and moderate-risk APE patients. There was a significant correlation between levels of AOPPs and the levels of both IMA (r: 0.462, p < 0.001) and PAB (r:0.378, p < 0.005). Serum FRAP levels were negatively correlated with PAB (r:- 0.683, p < 0.001) and AOPPs levels (r:- 0,384, p < 0.001). There was also a significant positive correlation between the serum IMA and PAB levels.

Conclusions: We clearly demonstrated that reactive oxygen species formation is significantly enhanced in APE. IMA and AOPPs may be used as clinical markers in the evaluation of APE severity in clinical practice. However, further studies with larger patient populations and longer follow-up periods are required to confirm the mechanisms underlying these findings.