Neuraxial Versus General Anesthesia for Total Knee Replacement Surgery - Are There Different Effects on the Immune System?

Numerous of factors affect the immunological response during surgery. Despite intensive research, the impact of different anesthetic techniques on the immune system remains unclear.

Aim of this ex vivo / in vitro study was to determine the effects of general and neuraxial anesthesia on monocyte subset alteration and the release of prototypical pro- and anti-inflammatory cytokines. Twenty patients undergoing total knee replacement surgery were randomly assigned to receive either general anesthesia (ITN) or combined spinal/epidural anesthesia (CSE). Samples of venous blood were taken from the patients before and after induction of anesthesia, immediately, 6 hours, 24 hours, and 48 hours after surgery. All blood samples were incubated in presence or absence of LPS (lipopolysaccharide; 1 µg/ml) for 24 hours. CD14 and HLA-DR expression patterns on monocytes and intracellular TNF-alpha production were quantified via flow cytometry. TNF-α and IL-10 release were measured via enzyme linked immunosorbent assay (ELISA).