The Rectus Sheath Block (RSB) Analgesia Following Laparotomy Could Affect Malonidialdehyde (MDA) Concentrations in Benign Disease and Cancer.

Background/aim: The aim of the study was to compare the MDA (malonidialdehyde) plasma concentrations versus CAT (catalase)/NT (nitrotyrosine) plasma concentrations, patient satisfaction and pain score at rest/pressure to the wound area in laparotomy patients with rectus sheath block (RSB) analgesia.

Patients And Methods: Initially, 56 patients were randomized to four groups; control group (n=12), single-dose (n=16), repeated-dose (n=12) and continuous infusion (n=16) RSB analgesia groups. The plasma concentrations of CAT, NT and MDA markers were measured just before, immediately after and 24 h after operation.

Results: The RSB analgesia enhanced significantly patient satisfaction (p=0.001). The plasma MDA decreased immediately after operation (POP1) and the postoperative decrease between the preoperative and the POP1 values in the MDA marker were statistically significant (p<0.001). In linear mixed model, the time effect in both the single group and in the benign group in plasma NT biomarker was statistically significant (p=0.001, p=0.013, respectively). The median plasma MDA concentrations (ng/ml) following surgery were significantly lower in patients with cancer versus patients with benign disease (589 vs. 852, p=0.021). Jitterplots of the individual plasma NT versus plasma MDA showed that there was significant correlation in benign and cancer patients (r=0.347, p<0.001).

Conclusion: Plasma MDA decreased significantly after operation in all patients and cancer patients had significantly lower MDA concentrations following surgery than patients with benign disease.