ObjectiveTo explore the efficacy and safety of different sedative and analgesic methods in emergent endotracheal intubations in RICU. Methods110 cases of tracheal intubation in critically ill patients were divided into 5 groups randomly: ① control group(given no sedative or analgesic drug before intubation); ② fentanyl group(given intravenous fentanyl 2 μg/kg before intubation,followed by fentanyl 2 μg·kg-1·h-1 maintenance); ③ dexmedetomidine hydrochloride+fentanyl group(given dexmedetomidine hydrochloride 1 μg/kg+fentanyl 2 μg/kg before intubation,followed by dexmedetomidine hydrochloride 0.5 μg·kg-1·h-1+fentanyl 2 μg·kg-1·h-1 maintenance); ④ midazolam+fentanyl group(given midazolam 0.05 mg/kg+fentanyl 2 μg/kg before intubation,followed by midazolam 0.05 mg·kg-1·h-1+fentanyl 2 μg·kg-1·h-1 maintenance); ⑤ Propofol+fentanyl group(given propofol 1 mg/kg+fentanyl 2 μg/kg before intubation,followed by propofol 0.4 mg·kg-1·h-1+fentanyl 2 μg·kg-1·h-1 maintenance).The mean arterial pressure(MAP),heart rate(HR),respiratory frequency(RR),PaO2/FiO2,Riker sedation score and agitation were monitored before,during and after intubations.The one-time success rate of intubation and severe arrhythmia (sinus bradycardia,frequent ventricular premature,ventricular fibrillation,and cardiac arrest) incidence rate were recorded. ResultsThe one-time success rates of intubations of the propofol+fentanyl group (95.4%) and the midazolam+fentanyl group (90.9%) were higher than that in the dexmedetomidine hydrochloride+fentanyl group (86.4%,P<0.05),while one-time intubation success rate of three groups were higher than that of the fentanyl group (45.4%) and the control group (31.8%,P<0.05).5 minutes after intubation,the PaO2/FiO2 index of 5 groups of patients were higher than those before intubation,but the PaO2/FiO2 index of the control group and the fentanyl group were lower than those in the other three groups(P<0.05).The occurrence of serious arrhythmia rate in the dexmedetomidine hydrochloride+fentanyl group (0%),the midazolam+fentanyl group (9%) and the propofol+fentanyl group (9%) were lower than that in the control group (13.6%) and the fentanyl group (18.2%).The MAP during intubation and 2 minutes after intubation of the propofol+fentanyl group and the midazolam+fentanyl group were lower than that in the other three groups(P<0.05).The proportion of patients with Riker sedation and agitation score≤4 at intubation in the dexmedetomidine hydrochloride+fentanyl group (68.2%) was lower than that in the propofol+fentanyl group(90.9%) and the midazolam+fentanyl group (86.4%,P<0.05),but higher than those in the fentanyl group(22.7%)and the control group(18.2%,P<0.05). ConclusionPropofol,midazolam or dexmedetomidine hydrochloride with fentanyl are all effective and safe methods of sedation and analgesia in emergent endotracheal intubation in RICU.Dexmedetomidine hydrochloride with fentanyl is an ideal sedative relatively with less influence on cardiovascular system and less myocardial oxygen consumption.