The Effectiveness Of Dexmedetomidine Infusion In Blind Nasotracheal Intubation

Objective: To explore the effect of intravenous anaesthetics dexmedetomidine applied to the way of blind nasotracheal intubation that is used in the already predicted difficult airway.Methods: We studied 30 adult patients that already predicted difficult airway undergoing elective surgery having general Anaesthesia with tracheal intubation, 30 adult patients were randomly divided into two groups of 15. All patients were ASA physical status I or II,non—smokers,and free of cardiac,pulmonary,renal,neuromuscular and other vital organs disease. A1l patients received premeditation of Intra muscular Atropine(0.5mg)and Luminal(0.1 g) 30 minutes before anesthesia. After entering the operating theater, routine monitoring of all vitals are checked, oxygen was given for 5 minutes in advance to confirm endotracheal intubation. All important and necessary tools and drugs have been prepared wisely. Application of 1% tetracaine topically to the nasal cavity, tongue base and pharyngeal surface, and then with a cotton swab containing ephedrine for nasal preparation. Endotracheal tube of ID 6.5 mm coated with sterile paraffin oil on its opening end is then passed. In Dexmedetomidine given group, Dexmedetomidine had given to peripheral vein of lower extremity by slow injection with the dosage of 1μg/kg and infusion rate is set to 0.2 -0.7μg ? kg-1 ? h-1. In Control group, midazolam 0.05mg/kg, fentanyl 1μg/kg were given to peripheral vein of lower extremity by slow injection。Blind nasotracheal intubation was done after 5 minutes of intravenous drug administration and patients were determined asleep with disappeared eyelash reflex. While maintaining and performing the intubation , Drager Fabius 2604l00 rows intermittent positive pressure ventilation anesthesia machine (IPPV), tidal volume ventilation parameter is set to (VT) = 8ml/kg, respiratory frequency (f) = l0bpm, inspiratory to expiratory ratio (I: E ) = l: 2, inspired oxygen concentration (Fi02) = 1 00%, PEEP = 3. In two groups of patients, MAP,HR,SpO2, number of respiratory depression,VAS score were recorded before and 2 min later of the administration of intravenous anesthetics . The above vitals are checked too for blind nasotracheal intubation immediately after and 2 minutes later respectively.Results: The successful completion of tracheal intubation in both groups, Dexmedetomidine was compared with the control group and showed significantly reduced hemodynamic changes (P <0.05);SpO2 decreased significantly change (P <0.05), having no respiratory depression.The control groups contained 2 patients showed respiratory depression (P <0.05), VAS score less than the conventional group (P <0.05).Conclusions: The presence of difficult airway in patients with blind nasotracheal intubation, intravenous Dexmedetomidine performed superior than conventional applications. The effect of midazolam combined with fentanyl, Dexmedetomidine achieved better sedative effect, analgesic, stable hemodynamics, and in maintaining the role of spontaneous breathing, so patients feel more comfortable and improve the safety of surgery and shorten the preoperative time to reduce the risk of anesthesia.