Data management and analysis were performed using SPSS statistics software version 22 (Armonk, NY: IBM Corp, for Windows). Numerical data were summarized using the mean and standard deviation (SD) while categorical data were summarized as numbers and percentages. The latter data were assessed using the chi-square χ2 test to compare between the two groups. The t test or paired t test was used to compare means of continuous data as appropriate. P values <.05 were considered significant.
The sample size was calculated according to the oxidative stress marker MDA.13 (link) Depending on a previous study performed on patients undergoing major abdominal surgery, it was found that MDA was 0.4 (0.03) and 0.37 (0.03) (μmol/L) in the control and NAC groups, respectively.13 (link) Assuming the statistical power is 90% and α was set to .05, and by using PASS 11th release NCSS, LLC. Kaysville, Utah, USA,14 we recruited 30 cases into each group.
The sample size was calculated according to the oxidative stress marker MDA.13 (link) Depending on a previous study performed on patients undergoing major abdominal surgery, it was found that MDA was 0.4 (0.03) and 0.37 (0.03) (μmol/L) in the control and NAC groups, respectively.13 (link) Assuming the statistical power is 90% and α was set to .05, and by using PASS 11th release NCSS, LLC. Kaysville, Utah, USA,14 we recruited 30 cases into each group.
