Damage to lymfocyte DNA during anaesthesia: a pilot study comparing general and subarachnoid anaesthesia

Objective: DNA damage due to general anesthesia (GA) has been described by various methods. Comparisons of different anesthesia techniques has not been found in the available literature. The primary aim of the study was to test the feasibility of the method. The secondary aim was to disprove the hypothesis that neuraxial anesthesia damages DNA just as much as GA in a pilot study. Design: Prospective, non-randomized. monocentric, observational pilot study. Setting: University Hospital. Materials and methods: Patients (n = 34) undergoing orthopedic/traumatological lower limb surgery were divided into two groups: general anesthesia (GA group) and subarachnoid anesthesia (SAB group). In all enrolled patients, after informed consent was obtained, blood was taken before surgery and within 24 hours after the surgery. Lymphocyte DNA damage was assessed by comet assay, which can quantitatively detect damage to nuclear DNA. Using specific enzymes, oxidative DNA damage can be detected. Comet assay results are evaluated semi-automatically by Lucia software (Laboratory Imaging, CZ) in fluorescence microscopy, which allows quantification of oxidized DNA bases and single stranded DNA breaks. The Wilcoxon test at the statistical significance level of p = 0.05 was used to compare the results between both groups. Results: The GA group consisted of 19 patients. the SAB group of 15 patients. There was a significantly higher DNA damage in the GA group compared to their preoperative values. Non-significant differences in DNA damage were observed in the SAB group. Conclusion: We proved the feasibility of the comet assay method in quantification of DNA damage in patients after anesthesia and surgery. The results point at the possible relationship between the anesthesia technique and DNA changes associated with surgery and/or anesthesia. The chosen method brings reproducible results with a potential for its use in the investigation of the effects of anesthesia on DNA, and opens the way for testing protective concepts aimed at minimizing DNA damage due to surgical trauma and anesthesia.