Cardiopulmonary bypass (CPB) with extracorporeal circulation produces changes in the
immune system accompanied by an increase in proinflammatory cytokines and a decrease
in anti-inflammatory cytokines. We hypothesize that dexmedetomidine (DEX) as an
anesthetic adjuvant modulates the inflammatory response after coronary artery bypass
graft surgery with mini-CPB. In a prospective, randomized, blind study, 12 patients
(4 females and 8 males, age range 42-72) were assigned to DEX group and compared with
a conventional total intravenous anesthesia (TIVA) group of 11 patients (4 females
and 7 males). The endpoints used to assess inflammatory and biochemical responses to
mini-CPB were plasma interleukin (IL)-1, IL-6, IL-10, interferon (INF)-γ, tumor
necrosis factor (TNF)-α, C-reactive protein, creatine phosphokinase, creatine
phosphokinase-MB, cardiac troponin I, cortisol, and glucose levels. These variables
were determined before anesthesia, 90 min after beginning CPB, 5 h after beginning
CPB, and 24 h after the end of surgery. Endpoints of oxidative stress, including
thiobarbituric acid reactive species and delta-aminolevulinate dehydratase activity
in erythrocytes were also determined. DEX+TIVA use was associated with a significant
reduction in IL-1, IL-6, TNF-α, and INF-γ (P<0.0001) levels compared with TIVA
(two-way ANOVA). In contrast, the surgery-induced increase in thiobarbituric acid
reactive species was higher in the DEX+TIVA group than in the TIVA group (P<0.01;
two-way ANOVA). Delta-aminolevulinate dehydratase activity was decreased after CPB
(P<0.001), but there was no difference between the two groups. DEX as an adjuvant
in anesthesia reduced circulating IL-1, IL-6, TNF-α, and INF-γ levels after mini-CPB.
These findings indicate an interesting anti-inflammatory effect of DEX, which should
be studied in different types of surgical interventions.
