A randomized study of maternal serum cytokine levels following cesarean section under general or neuraxial anesthesia

ABSTRACT 

Background

Cytokines are significant mediators of the immune response to surgery and also play a role in parturition. The aim of the study was to investigate the impact of the anesthetic technique for cesarean section on plasma levels of cytokines IL-6 and TNF-α.

Methods

Thirty-five parturients scheduled for elective cesarean section were randomly assigned to general (n=18) or neuraxial (n=17) anesthesia. The general anesthesia group received thiopental 4mg/kg, succinylcholine 1–1.5mg/kg and 1% end-tidal concentration of sevoflurane in nitrous oxide and 50% oxygen. The neuraxial anesthesia group received intrathecal 0.5% levobupivacaine 1.8–2.2mL and epidural fentanyl 1μg/kg. Blood samples were taken for IL-6 and TNF-α immediately after positioning the parturient on the operating table, after uterine incision and before the umbilical cord clamping and 24h after surgery (T₁, T₂ and T₃ respectively).

Results

The two groups did not differ in IL-6 (P=0.15) or TNF-α (P=0.73) serum concentrations at any time point. In the general and neuraxial anesthesia groups, IL-6 serum concentrations were significantly higher in the third blood sample, T₃ (12.2±5.0 and 15.2±4.3 pg/mL), than in T₁ (0.41±0.38 and 0.29±0.10 pg/mL) and T₂ (0.37±0.47 and 0.24±0.05) respectively (P<0.001). Within each group, serum TNF-α concentrations did not differ significantly over time (P=0.44).

Conclusions

Under the present study design anesthetic technique did not affect IL-6 or TNF-α concentrations in parturients undergoing elective cesarean section. Serum IL-6 levels increased 24 h postoperatively independently of anesthetic technique.

Keywords: General anesthesia, Neuraxial anesthesia, Cesarean section, Cytokines, IL-6, TNF-α