Effect of dexmedetomidine combined with continuous positive airway pressure on oxidative stress and inflammatory responses during one-lung ventilation in elderly patients undergoing radical surgery for esophageal carcinoma

Abstract

Objective To evaluate the effect of dexmedetomidine combined with continuous positive airway pressure (CPAP) on the oxidative stress and inflammatory responses during one-lung ventilation (OLV) in the elderly patients undergoing radical surgery for esophageal carcinoma.Methods One hundred and twenty ASA physical status Ⅱ or Ⅲ patients,aged 65-80 yr,with body mass index 18-25 kg/m2,scheduled for radical surgery for esophageal carcinoma,were randomly divided into 4 groups (n =30 each) using a random number table:control group (group C),dexmedetomidine group (group D),CPAP group (group P) and dexmedetomidine combined with CPAP group (group DP).After induction of anesthesia,the patients were endotracheally intubated and then mechanically ventilated.At the beginning of skin incision,OLV was performed instead.In D and DP groups,a loading dose of dexmedetomidine 0.3 μg/kg was infused starting from 10 min before incision,followed by infusion at a rate of 0.3 μg·kg-1 ·h-1 untill the chest was closed.CPAP 2 cmH2O was used on the non-ventilated side during OLV in P and DP groups.Immediately before incision,at 90 min of OLV,at the end of operation and on 1 day after operation,venous blood samples were obtained for determination of the serum malondialdehyde (MDA),interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) concentrations.The development of complications was recorded at 1 and 7 days after operation.Results Compared with group C,the incidence of hyoxemia during operation and pulmonary atelectasis and infection after operation was significantly decreased in the other three groups,the incidence of hyoxemia and pulmonary atelectasis and infection after operation was decreased,and the serum concentrations of MDA,IL-6 and TNF-α were decreased in group DP (P ＜ 0.05).Compared with D and P groups,the serum concentrations of MDA,IL-6 and TNF-α were significantly decreased,and the incidence of pulmonary atelectasis and infection after operation was decreased in group DP (P ＜ 0.05).The incidence of hyoxemia during operation was significantly lower in group DP than in group D (P ＜ 0.05).Conclusion Dexmedetomidine combined with CPAP can alleviate the oxidative stress and inflammatory responses more effectively and is more helpful in improving prognosis than either alone during OLV in elderly patients. Key words: Dexmedetomidine ; Continuous positive airway pressure ; Respiration, artificial; Oxidative stress ; Inflammation ; Aged