Short-term Outcomes in Infants after General Anesthesia with Low-dose Sevoflurane/Dexmedetomidine/Remifentanil versus Standard-dose Sevoflurane (the TREX Trial)

Background: The Trial Remifentanil DEXmedetomidine (TREX) trial aimed to determine whether, in children less than 2 yr old, low-dose sevoflurane/dexmedetomidine/remifentanil anesthesia is superior to standard-dose sevoflurane anesthesia in terms of global cognitive function at 3 yr of age. The aim of the current secondary analyses was to compare incidence of intraoperative hypotension and bradycardia, postoperative pain, time to recovery, need for treatment of intraoperative hypotension and bradycardia, incidence of light anesthesia and need for treatment, need for postoperative pain medications, and morbidity and mortality outcomes at 5 days between the two arms. Methods: This phase III randomized active controlled, parallel group, assessor blinded, multicenter, superiority trial was performed in 20 centers in Australia, Italy, and the United States. A total of 455 infants less than 2 yr of age expected to undergo general anesthesia for at least 2 h were enrolled. They were randomized between low-dose sevoflurane/dexmedetomidine/remifentanil anesthesia and standard-dose sevoflurane. The short-term perioperative outcomes noted above were compared between these two groups. Results: There was less hypotension (risk difference, −11.6%; 95% CI, −18.9 to −4.3%) and more bradycardia (risk difference, 18.2%; 95% CI, 8.8 to 27.7%) in the low-dose sevoflurane/dexmedetomidine/remifentanil anesthesia compared to the standard-dose sevoflurane arm. There were more patients with episodes of light anesthesia (89 vs . 4), and protocol abandonments (1 vs . 0) in the low-dose sevoflurane/dexmedetomidine/remifentanil anesthesia arm. Time from eye opening to postanesthesia care unit discharge was similar in both arms, as were morbidity and mortality. One patient in each arm suffered a life-threatening event, but neither suffered long-term sequelae. Conclusions: These early postoperative results suggest that in children less than 2 yr of age receiving greater than 2 h of general anesthesia, the low-dose sevoflurane/dexmedetomidine/remifentanil anesthesia technique and the standard sevoflurane anesthesia technique are broadly clinically similar, with no clear evidence to support choosing one technique over the other.