Anästhesie und klinische Forschung
Offener Zugang

Abstrakt

Effect of Multiple Doses of Dexmedetomidine for Moderate Sedation Facilitating Intubation during Nasotracheal Fiberoptic Laryngoscope in Awake Patients-A Randomized Prospective Study

Sherif Kamal Arafa, Amir Abozikry ElSayed

Background: Nasal fiberoptic intubation in fully conscious patients is the gold standard technique of choice in known difficult airway as cervical instability, limited mouth opening and any facial defects. The usage of an ideal sedation agent with a perfect dose or regimen securing stability of hemodynamic conditions and optimizing the intubating condition at the same time is an indispensable demand for awake fiberoptic intubation.

Aim: To detect variant efficiency of different doses of dexmedetomidine used for conscious sedation facilitating intubation by using nasotracheal fiberoptic laryngoscope in awake patients.

Methods: The study was performed in a prospective, blinded, randomized manner to compare the effect of different loading and maintenance doses of dexmedetomidine during awake fiberoptic intubation on 40 patients of both sexes aged between 20 and 60 years with ASA grade I or II enrolled for elective surgery. Patients randomly divided into two groups; 20 for each. All patients received 50 mcg Fentanyl and 2 mg Midazolam at premedication room, before transfer to operating room. Group I patients received I.V. Dexmedetomidine 1 mcg/kg as a bolus dose slowly over ten minutes then 0.7 mcg/kg/h as maintenance dose throughout the fiberoptic manipulation. Group II patients received I.V. Dexmedetomidine 0.7 mcg/kg as a bolus dose slowly over ten minutes then 0.2 mcg/kg/h as a maintenance dose throughout the technique. Primary outcomes were assessment of sedation level of each patient by Alertness and Sedation Scale (AA/S). Patient's reaction to insertion of tracheal tube that could be also assessed during Pre-oxygenation, both fiberscope placement and endotracheal placement (at 1, 2, 3, 4, 5 min interval) and if the patients were feeling comfort or distressing .This comfort scale for each patient was estimated by addition of seven comfort items at each time point, the total score was 35. Patient tolerance also was assessed on the basis of 5 point fiber optic index (FOI) score. Secondary outcomes were hemodynamic categories as heart rate, systolic blood pressure, diastolic blood pressure, mean blood pressure, oxygen saturation and end tidal capnography during Pre-oxygenation, both fiberoptic placement and endotracheal insertion ( at 1, 2, 3, 4, 5 min interval) and any side effects were also explored.

Results: All patients in both groups underwent fiberoptic intubation with no differences statistically among two groups demographically, heart rate, systolic, diastolic and mean blood pressure. There were statistically differences among two groups as regard to SPO₂, PACO₂ and OAA/S scale only at 3, 4 and 5 min during endotracheal tube placement. No side effects were observed.

Conclusion: We concluded that dexmedetomidine especially with loading 1 μg/kg and higher maintenance dose 0.7 μg/kg/h were more suitable for fiberoptic intubation with better patient tolerance, patient comfort, patient satisfaction, good sedation and preserved upper airway with spontaneous breathing.