Tracheal extubation in deeply anesthetized pediatric patients after tonsillectomy: a comparison of high-concentration sevoflurane alone and low-concentration sevoflurane in combination with dexmedetomidine pre-medication

BACKGROUND: Dexmedetomidine can facilitate a smooth extubation process and reduce the requirement of sevoflurane and emergence agitation when administrated perioperatively. We aimed to observe the extubation process and the recovery characteristics in pediatric patients undergoing tonsillectomy while anesthetized with either high-concentration sevoflurane alone or low-concentration sevoflurane combined with pre-medication of single dose of intravenous dexmedetomidine. METHODS: Seventy-five patients (ASA I or II, aged 3–7 years) undergoing tonsillectomy were randomized into three equal groups: to receive intravenous saline (Group D0), dexmedetomidine 1 μg/kg (Group D1), or dexmedetomidine 2 μg/kg (Group D2) approximately 10 min before anesthesia. Before the end of surgery, sevoflurane were adjusted to 1.5 times, 1.0 time and 0.8 times the minimal effective concentration in groups D(0), D(1) and D(2), respectively. The sevoflurane concentration for each group was maintained for at least 10 min before the tracheal deep-extubation was performed. The extubation event, recovery characteristics and post-op respiratory complications were recorded. RESULTS: All tracheal tubes in three groups were removed successfully during deep anesthesia. Nine patients in Group D(0), three patients in Group D(1), and two patients in Group D(2) required oral airway to maintain a patent airway after extubation. The frequency of oral airway usage in groups D(1) and D(2) were significantly lower than that in Group D(0). The percentages of patients with ED and the requirements of fentanyl in groups D(1) and D(2) were also significantly lower than those in Group D(0). The time from extubation to spontaneous eye opening in Group D(2) was longer than that in groups D(0) and D(1). The times of post-anesthesia care unit discharge in groups D(0) and D(2) were longer than that in Group D(1). No other respiratory complications and vomiting were observed. CONCLUSION: A single dose of intravenous dexmedetomidine as pre-medication in combination with low-concentration sevoflurane at the end of surgery provided safe and smooth deep extubation condition and it also lowered the emergence agitation in sevoflurane-anaesthetized children undergoing tonsillectomy. Preoperative dexmedetomidine at 1 μg/kg did not prolong postoperative recovery time. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR): ChiCTR-IOR-16008423, date of registration: 06 may 2016.