Influence of adding detomidine to a lidocaine paravertebral anaesthesia on cytokines and chemokines in cows undergoing laparotomy.

This study investigated the effects of perineural detomidine on inflammatory mediators in cows undergoing laparotomy for left abomasal displacement (LAD) or right abomasal displacement (RAD) and explored the associations with pain scores. Thirty-nine cows were randomised to receive a proximal paravertebral nerve block with lidocaine (LIDO, n = 20) or lidocaine-detomidine (LIDO-DETO, n = 19). Citrate blood samples were collected before (T0) and at T2, T12, and T24 hours postoperatively. Plasma was analysed using a multiplex assay based on the Luminex technology (IL-1α, IL-1β, IL-2, IL-4, IL-10, IL-17A, TNF-α, IFN-γ, CXCL10, CCL2, CCL3) and ELISA (IL-6, IL-8). Pain scores were assessed at T2, T12 and T24. Following a logarithmic transformation, linear mixed models were used to investigate the effects of time point, group, surgery duration, surgeon's experience, and R-/LAD on cytokines and chemokines. The relationship between pain scores and inflammatory mediators was analysed using Spearman's rho correlation (p < 0.05). Significant temporal changes in inflammatory mediators were observed. LIDO-DETO was associated with higher IL-6, IFN-γ, CXCL10, and CCL2. Also, R-/LAD and surgery duration had an influence on certain inflammatory mediators. Experience of the surgeon had minimal influence, and cytokine concentrations showed no correlation with postoperative pain scores, except for a weak negative association with IL-1α. Inflammatory mediators exhibited time-dependent postoperative changes, partly modulated by perineural detomidine. Notably, the increase in IL-6 and IFN-γ under LIDO-DETO occurred despite reduced postoperative pain scores, underscoring the dissociation between systemic inflammatory markers and clinical pain and highlighting the multifactorial nature of postoperative immune responses.