Application Of Ketamine Combined With Dexmedetomidine And Fentanyl In Awake Intubation

Part 1: Safety and efficacy of ketamine versus Ketamine-Fentanyl-Dexmedetomidine combination for sedation and analgesic in rats.Objective: To explore the sedative and analgesic effects and safety of ketamine(KTM)compound dexmedetomidine(DEX)and fentanyl(FEN).Methods: SD rats(5-6 w)were divided into 3 groups: control,KTM(KTM 50mg/kg),and KFD(KTM 25 mg/kg + FEN 0.005 mg/kg + DEX 0.05 mg/g).The sedative and analgesic effects were assessed by righting reflex,toe pinch,and EEG.Safety was assessed by histopathology and vital signs monitoring.Results: Compared with ketamine group,the KFD group provides similar onset time of sedation but longer duration,and better analgesic effect(P < 0.05).Compared with the the control and KET groups,the KFD group had higher power ratio of the δfrequency band(CON: 43.17 ± 1.04%;KET: 50.71 ± 0.78%;KFD: 62.95 ± 1.87%,P< 0.01).Furthermore,combination of FEN and DEX alleviated the liver toxicity of KTM,reduced the rapid heart rate caused by ketamine and increase the respiratory rat(P < 0.01).Conclusions: Compared with ketamine alone,the combination of KFD provides safer and more effective sedation and analgesia.Part 2: Application of ketamine combined with dexmedetomidine and fentanyl in awake fiberoptic bronchoscope intubation.Objective: The aim of this study was to evaluate the sedative and analgesic validity and administration routes of dexmedetomidine and fentanyl combined with ketamine in awake fiberoptic bronchoscope intubation(AFOBI).Methods: Patients undergoing head and neck surgery under general anesthesia with a predicted difficult airway were included.Participants were randomly assigned to 7different groups(n = 6): groups 1～3 were intravenous(IV),while groups 4～6 were intranasal(IN)(group 1: dexmedetomidine(DEX)1 μg/kg + fentanyl(FEN)1 μg/kg;groups 2～3: DEX 1 μg/kg + FEN 0.7 μg/kg + ketamine(KTM)0.1/0.2 mg/kg;group4: DEX 1.5 μg/kg + FEN 1.4 μg/kg;and groups 5～7: DEX 1 μg/kg + FEN 1 μg/kg +KTM 0.2/0.4/0.6 mg/kg).The visual analog scale(VAS)score during intubation,patient satisfaction rate,time required for the modified observer’s assessment of alertness/sedation scale(OAA/S)score to reach above 2 and for the bispectral index(BIS)to decrease to 80,motor activity assessment scale(MAAS)score,changes in vital signs like heart rate,adverse effects like coughing and concentration of anesthetics in plasma were recorded.Results: Among the IV groups,the VAS score of group 1(5.65 ± 2.11)was higher than those of group 2(1.89 ± 2.16,P < 0.05)and group 3(1.15 ± 0.98,P < 0.001).Among the IN groups,the VAS score was lower in group 6(0.86 ± 1.27)than in group 4(7.20± 2.70,P < 0.001)and group 5(3.93 ± 2.73,P < 0.05).Furthermore,patient satisfaction rate increased with the dose of ketamine.In the IN groups,the satisfaction rate was rising with the dosage of ketamine(P < 0.05).Participants in group 6 and group 7 were less likely to cough when intubated than those in group 4(P = 0.008),while the differences among IV groups were not significant(P ? 0.05).Liver and kidney functions of patients have changed after surgery in each group,such as AST,ALT and UA(P < 0.05).There were no significant differences in the other endpoints like time required for the modified OAA/S score to reach above 2 and for the BIS to decrease to80 or the MAAS score.Conclusions: The combination of sub-anaesthetic doses of ketamine can reduce the dose of fentanyl and dexmedetomidine used in AFOBI and provide better and safer sedative and analgesic effects.