Effect of dexmedetomidine on hemodynamic changes in children undergoing laparoscopic surgery

ABSTRACT

Stress response to surgery is modulated by numerous factors, including magnitude of the injury, type of procedure and anesthetic technique. Dexmedetomidine, a highly selective alpha[2]-adrenergic agonist, increases perioperative hemodynamic stability in healthy patients but decreases arterial blood pressure and heart rate. Purpose: This study was designed to assess the hemodynamic effects to nociceptive stimuli in children submitted to laparoscopic surgery under balanced anesthesia with sevoflurane and dexmedetomidine. Randomized, double-blind and placebo-controlled study including thirty children submitted to laparoscopic surgery. Patients were allocated to three equal groups [n=10] [1] Low-dose DEX group infusion of 0.5 micro g.kg[-1] over 10 minutes and maintenance dose of 0.5 beta g.kg.h[-1] [2] High-dose DEX group infusion of 1 micro g.kg[-1] over 10 minutes and maintenance dose of 0.5 micro g.kg.h[-1] as an adjuvant to inhaled sevoflurane anesthesia; [3] Placebo group normal saline infusion at a similar rate and volume of the dexmedetomidine infusion. Arterial blood pressure, heart rate, arterial oxygen saturation, end-tidal carbon dioxide tension as well as supplemental fentanyl requirement were observed. ANOVA, Chi-Square and kruskal-Wallis tests, with Bonferroni correction for inter-group comparison were used for statistical analysis. During the strongest nociceptive stimuli [airway access and abdominal catheter placement], children receiving high dose dexmedetomidine showed a remarkable reduction in all hemodynamic variables, and supplemental fentanyl doses [P<0.01]. Combined use of dexmedetomidine with inhaled sevoflurane in pediatric patients submitted to laparoscopic surgery, efficiently blocks the hemodynamic responses to nociceptive stimuli and surgical trauma due to suppression of sympathetic overactivity