Dexmedetomidine premedication increases preoperative sedation and inhibits stress induced by tracheal intubation in adult: a prospective randomized double-blind clinical study
Authors: Xiong Jun , Gao Jie , Pang Yanan , Zhou Yafen , Sun Yongxing , Sun Yanyan 
Published: December 2022

Abstract
Objective
The aim of this prospective randomized double-blind study is to evaluate whether oral dexmedetomidine (DEX) premedication could increase sedation in order to reduce preoperative anxiety and inhibit stress response during general anesthesia tracheal intubation.

Materials
A total of 100 ASA I and II adult patients undergoing elective neurosurgery were randomly divided into the control group (C group, n = 50) and the oral DEX premedication (DEX group, n = 50). Patients were administrated 4 μg/kg dexmedetomidine orally pre-anesthesia 120 min. Hemodynamic variables were monitored and recorded from premedication to 10 min after tracheal intubation. The primary outcome, the sedation level of all participants, was evaluated by Richmond Agitation Sedation Scale (RASS), and Numerical Rating Scale was to measure their intensity of thirst and satisfaction of patients’ family members. During general anesthesia induction, the total dosage of induction anesthetics and complications relative to anesthesia induction were recorded. After tracheal intubation, blood sample was drain from radial atrial line to measure levels of adrenocorticotropic hormone (ACTH) and cortisol.

Results
RASS scores at 60 min after premedication and on arrival in the operating room were significantly reduced in the DEX group (P < 0.001). Oral DEX premedication not only increased the intensity of thirst but also the satisfaction of their family members (P < 0.001). The cortisol level after tracheal intubation was deduced by oral DEX premedication (P < 0.05). Oral DEX premedication reduced heart rate (HR) and mean arterial pressure (MAP) on arrival in the operating room, and HR when tracheal intubation (P < 0.05). During the whole process of anesthesia induction, although the lowest MAP in two groups were not significantly different, the lowest HR was significantly lower in the DEX group (P < 0.05). Oral DEX premedication might reduce HR from premedication to 10 min after tracheal intubation. However MAP was reduced just from premedication to on arrival in the operating room. Total induction dosages of propofol, midazolam, sulfentanil and rocuronium were similar in two groups (P > 0.05), as well as the complications relative to anesthesia induction and cases of rescue dopamine therapy were similar (P > 0.05).

Conclusion
Oral DEX 4 μg/kg premedication was an efficient intervention to increase preoperative sedation and reduce stress reaction induced by general anesthesia tracheal intubation, but also it was with the stable hemodynamic during the process of general anesthesia tracheal intubation, and improved the satisfaction of patients’ family members. In this study, the sparing-anesthetic effect of 4 μg/kg DEX oral premedication was not significant, and this would be needed to study in future.

Trial registration
This trail was registered at Chinese Clinical Trial Registry (https://www.chictr.org.cn, Jie Gao) on 15/04/2021, registration number was ChiCTR2100045458.