Pain and Analgesic Doses <i>Versus</i> Free Interleukin 18 (IL-18F) Blood Levels Following Surgery: A Prospective Randomized Study of Patients With Minilaparotomy Cholecystectomy <i>Versus</i> Laparoscopic Cholecystectomy.

Abstract

Cytokines (CYT) are regulators of the acute phase immune response (APR) to inflammation and trauma. The purpose of this work was to assess blood level correlations of various CYTs; interleukin-18 (IL-18), IL-18 binding protein (IL-18BP), free interleukin 18 (IL-18F) <i>versus</i> numerical rating pain scale (NRS) and number of analgesic doses (NAD) following surgery in patients undergoing laparoscopic cholecystectomy (LC) or minilaparotomy cholecystectomy (MC). Blood levels of IL-18, IL-18BP, IL-18F and five CYTs were determined and the NRS pain surveys were performed preoperatively (PRE) and postoperatively (POP). The IL-18F blood levels correlated to IL-18 (<i>r</i>=0.92, <i>p</i>&lt;0.001), IL-18BP (r=-0.260, <i>p</i>&lt;0.001), Caspase-1 (r=0.64, <i>p</i>&lt;0.001), catalase (r=0.13, <i>p</i>&lt;0.04), and nitrotyrosine (<i>r</i>=-0.16, <i>p</i>=0.01) blood levels. The IL-18F blood levels increased at POP and the increase between PRE and POP2 blood levels (632 <i>versus</i> 739) was significant (<i>p</i>&lt;0.01). Moreover, the IL-18F and IL-18BP levels correlated significantly to NRS pain scales (r=-0.16, <i>p</i>=0.02 and r=0.17, <i>p</i>=0.02, respectively) and to the NAD levels (r=-0.20, <i>p</i>=0.016 and r=-0.16, <i>p</i>=0.05, respectively) in patients with cholecystectomy. This is the first report to demonstrate that postoperative IL-18F levels are significantly associated with NRS pain scores and the number of analgesic doses in patients undergoing cholecystectomy. These findings suggest that IL-18F and IL-18BP may contribute to the acute-phase immune response to surgical trauma and its relationship with postoperative pain and analgesic requirements.