The role of N-acetylcysteine in lower extremity ischemia/reperfusions

To evaluate the efficacy of N-acetyl cysteine (NAC) in lower extremity ischemia/reperfusion.

A total of 23 patients who underwent surgical intervention due to acute femoral artery occlusion were assigned into 2 groups: control group (group 1, n=12); and NAC group (group 2, n=11). Patients in NAC group received NAC before reperfusion, and 8 and 16 h after reperfusion (3x300 mg), while patients in control group received only NaCl 0.9% (3x100 mL). Catalase, malondialdehyde (MDA) and thiol concentrations were determined in femoral vein samples collected at 6 different time points: before reperfusion (t1), and 30 min (t2), 2 h (t3), 6 h (t4), 12 h (t5) and 24 h (t6) after reperfusion. Alveolar-arterial oxygen gradient (A-aO2) was calculated in radial artery blood samples simultaneously collected at the same time points.

No significant differences between the two groups with regard to age (control group 61+/-13 and NAC group 64+/-11 years), gender (control group M/F: 7/5, NAC 6/5) and the average time from onset of symptoms (control group 9.6+/-3.5 h, and NAC group 10.2+/-3.1 h) were present. Catalase enzyme activity increased with reperfusion in both groups and there were no differences between the two groups. MDA levels did not change significantly with reperfusion in NAC group, whereas they were significantly higher in control group at t2 and t3 compared to NAC group (P<0.05). Thiol concentrations decreased with reperfusion in control group, and in NAC group increases that started with reperfusion returned back to baseline levels after 24 hours. Although the A-aO2 gradient increased in both groups with the beginning of reperfusion, the most prominent increase occurred in control group (P<0.05).

In control group, the significant increase in MDA levels and A-aO2 gradient in reperfusion phase were considered a sign of local and end organ injury. We did not observe these changes in NAC performed group thus showing the efficacy of NAC.