Plasma levels of IL-10 and nitric oxide under two different anaesthesia regimens

An alteration in production of both interleukin-10 (IL-10) and nitric oxide (NO) has been found following surgical/anaesthesia trauma. It is also suggested that IL-10 could be an important factor in regulating NO metabolism during the postoperative period. Furthermore, NO seems to play a crucial role in the anaesthetic state. The purpose of this study was to investigate plasma levels of IL-10 and NO following surgery, any possible correlation between these two variables and whether anaesthesia technique could influence NO and IL-10 circulating concentrations.

Thirty-two patients scheduled to undergo elective major surgery were enrolled in the study and allocated into two groups to receive two different techniques of anaesthesia, total intravenous (i.v.) anaesthesia (Group I) and inhalational anaesthesia (Group II). Blood samples were drawn before (t0), at the end (t1) of operation and after 24 h (t2). Plasma IL-10 and NO levels were measured by using an enzyme-linked-immunosorbent assay (ELISA) and a total NO assay kit, respectively.

In both patient groups there was a significant decrease of plasma NO levels at the end of surgery (30.35 +/- 2.70 mmol L(-1) at t0 to 13.76 +/- 1.51 mmol L(-1) at t1 in Group I, P < 0.0001; 28.23 +/- 2.50 mmol L(-1) at t0 to 11.38 +/- 0.95 mmol L(-1) at t1 in Group II, P < 0.0001). This reduction remained at 24 h postoperatively (14.33 +/- 1.52 mmol L(-1) in Group I, P < 0.0001; 12.52 +/- 1.11 mmol L(-1) in Group II, P < 0.0001, both vs. t0). There was an increase in IL-10 concentrations (26.35 +/- 3.42 pg mL(-1) and 75.39 +/- 8.33 pg mL(-1) at t1 and t2, respectively, vs. 4.93 +/- 0.31 pg mL(-1) at t0, P = 0.03 and P < 0.0001, respectively, in Group I; 26.18 +/- 3.22 pg mL(-1) and 69.91 +/- 7.33 pg mL(-1) at t1 and t2, respectively, vs. 5.50 +/- 0.33 pg mL(-1) at t0, P = 0.02 and P < 0.0001, respectively, in Group II). No relationship was found between circulating IL-10 and NO.

During the postoperative period, IL-10 overproduction does not correlate with the decrease in systemic NO concentration.