Effect of dexmedetomidine combined with erector spinae plane block on inflammatory responses and cellular immune function after thoracic interbody fusion

Abstract

Objective To evaluate the effect of dexmedetomidine combined with erector spinae plane block on inflammatory responses and cellular immune function after thoracic interbody fusion in patients. Methods Ninety American Society of Anesthesiologists physical status Ⅰ or Ⅱ patients of both sexes, aged 18-60 yr, with body mass index of 19-25 kg/m2, scheduled for elective thoracic interbody fusion with the vertebral segments involved in the operation <6, were divided into 3 groups(n=30 each)using a random number table method: general anesthesia group(group G), dexmedetomidine group(group D)and dexmedetomidine plus erector spinae plane block group(group DE). In group D and group DE, dexmedetomidine was intravenously infused over 10 min at a loading dose of 0.5 μg/kg starting from 30 min before anesthesia induction, followed by continuous infusion of 0.5 μg·kg-1·h-1 until 15 min before the end of operation. In group DE, bilateral erector spinae blocks were performed under ultrasound guidance at 20 min before anesthesia induction, and 0.25% ropivacaine 30 ml was injected into each side. Patients received patient-controlled analgesia(PCA)after operation. The consumption of propofol was recorded. The patients were followed up for 48 h after operation, and the pressing times of PCA and consumption of sufentanil were recorded. The emergence time, extubation time and volume of blood loss were also recorded. Blood samples were collected from the radial artery immediately before induction(T1), at 30 min of operation(T2), and at 1 h and 1, 3 and 5 days after operation(T3-6)for determination of plasma CD42+ , HLA-DR+ and CD14+ concentrations, white blood cell(WBC)count(by electrical impedance method)and plasma C-reactive protein(CRP)concentrations(by latex-enhanced scattering turbidimetry assay). CD42+ /CD14+ and HLA-DR+ /CD14+ ratios were calculated. Results Compared with group G, the pressing times of PCA and consumption of sufentanil were significantly decreased, CD42+ /CD14+ ratio was decreased, and HLA-DR+ /CD14+ ratio was increased at T3-6 in group D, and the emergence time, extubation time, pressing times of PCA and consumption of sufentanil and propofol were significantly decreased, CD42+ /CD14+ ratio was decreased, HLA-DR+ /CD14+ ratio was increased at T3-6, and the plasma CRP concentrations and WBC count were decreased at T2-6 in group DE (P<0.05). Compared with group D, the emergence time, extubation time, pressing times of PCA and consumption of sufentanil and propofol were significantly decreased, CD42+ /CD14+ ratio was decreased at T5, HLA-DR+ /CD14+ ratio was increased at T3, 4, and the plasma CRP concentrations and WBC count were decreased at T3-6 in group DE (P<0.05). Conclusion Dexmedetomidine combined with erector spinae plane block can reduce inflammatory responses and improve cellular immune function after thoracic interbody fusion in patients. Key words: Dexmedetomidine; Nerve block; Inflammation; Immunity, cellular