OBJECTIVES: To evaluate the hemodynamic responses to nociceptive stimuli in children submitted to videolaparoscopic appendectomy under balanced anesthesia with isoflurane and dexmedetomidine. METHODS: Randomized, double-blind and placebo-controlled study involving 26 children submitted to videolaparoscopic appendectomy carried out at Hospital São Lucas (PUCRS) between May 2004 and February 2005. Patients were assigned to two groups: (a) Dexmedetomidine group (n=13): infusion of 1µg/kg over 10 minutes and maintenance dose of 0.5µg/kg/h) as an adjuvant to inhaled isoflurane anesthesia; (b) Control group (n=13): normal saline infusion at a similar rate and volume of the dexmedetomidine infusion. During the different surgical and anesthetic periods, groups were compared regarding heart rate, systolic and diastolic arterial blood pressures as well as need of supplemental fentanyl infusion. Student's t test, ANOVA, and Finner's procedure were used for statistical analysis. RESULTS: During the strongest nociceptive stimuli (airway access and abdominal catheter placement), the heart rate and systolic blood pressure increased significantly (p<0.001) in the control group compared to the dexmedetomidine group. Compared to baseline levels, the hemodynamic responses to nociceptive stimuli were more stable when dexmedetomidine was used in combination with inhaled isoflurane anesthesia. The need for supplemental doses of fentanyl and the hemodynamic parameters were similar for both groups. CONCLUSION: Dexmedetomidine combined with inhaled isoflurane for anesthesia of children submitted to videolaparoscopic appendectomy, efficiently blocks the hemodynamic responses to nociceptive stimuli. When compared to placebo, the use of dexmedetomidine did not change the need for supplemental doses of fentanyl for maintenance of hemodynamic parameters during the intraoperative period.
Dexmedetomidine; Alpha adrenoceptor agonist; Laparoscopy; Pediatric anesthesia; Appendectomy
