Abstract
The current study aimed to evaluate the impact of clinically relevant concentrations of dexmedetomidine on the deformability of erythrocytes in vitro and the effects of dexmedetomidine on the deformability of erythrocytes in patients undergoing laparoscopic cholecystectomy. Erythrocyte suspensions of different concentrations were divided into six groups: Control (group C); low, medium and high concentrations of dexmedetomidine (groups DL, DM and DH, respectively); yohimbine alone (group Y) and yohimbine mixed with dexmedetomidine (group YD). The suspensions were incubated in a thermostatic shaking incubator (50 rpm, 37°C) for 60 min. The nitric oxide (NO) concentrations and endothelial nitric oxide synthase (eNOS) activities of red blood cells and the erythrocyte deformability index (EI) were then measured. Patients (n=40) scheduled for laparoscopic cholecystectomy were randomly divided into a dexmedetomidine group (group A) and a control group (group B). The induction and maintenance of anesthesia in the two groups was identical. The EI and hematocrit (Hct) were assayed prior to anesthesia (T(0)) and following the surgery (T(1)). In the in vitro assay, the EI, the activity of eNOS and the NO concentration of the erythrocytes were significantly higher in groups DL, DM, DH and YD than in group C (P<0.05). In addition, the EI, the eNOS activity and NO concentration of the erythrocytes were higher in group DM than in group YD (P<0.05). In the patients, the EI value at T(1) (0.90±0.04) was higher than at T(0) (0.81±0.06) in group B (P<0.05). No statistically significant difference between the EI values at T(0) and T(1) was identified in group A (P>0.05). Dexmedetomidine treatment is able to improve the deformability of erythrocytes in vitro and in anesthesia. The improvement of erythrocyte deformability by dexmedetomidine may be partially associated with adrenergic receptors through activation of eNOS to enhance the concentration of NO in red blood cells.