Methodology :
A retrospective study was conducted by reviewing the endoscopy record of patients receiving Dexmedetomidine-based conscious sedation regime for gastrointestinal endoscopy in Tuen Mun Hospital from July 2019 to June 2021. All procedures were performed in endoscopy room and titration of sedative agents was determined by in-charge endoscopists. Dexmedetomidine was administered as loading intravenous (IV) infusion (0.5-1mcg/kg) over 10 minutes followed by maintenance IV infusion (0.2-0.8mcg/kg/hour). Fentanyl was also prescribed as IV infusion or IV bolus for analgesic effect. Bolus IV Midazolam may be given if necessary to achieve desirable level of sedation. Blood pressure was recorded at least every 5 minutes while continuous cardiac, oximeter and capnography monitoring were applied to all patients.
Result & Outcome :
141 patients (80 males & 61 females), with mean age of 59.6 +/- 19 years old (range 16-93), were included in this analysis. 160 endoscopic procedures were performed, including 57 cases (35.6%) of double-balloon enteroscopy (DBE), 29 cases (18.1%) of DBE-assisted endoscopic retrograde cholangiopancreatography (ERCP), 22 cases (13.8%) of motorized spiral enteroscopy and 52 cases (32.5%) of endoscopic submucosal dissection. Mean procedure time was 153.8 +/- 84.7 minutes (range 33-347). Mean dosage of Dexmedetomidine was 102 +/- 35mcg and mean dosage of Fentanyl was 141.5 +/- 58.6mcg. Midazolam was prescribed in 122 procedures (76.3%) with a mean dosage of 4 +/- 2.1mg. Hemodynamic instability (defined as systolic blood pressure <90mmHg and/ or heart rate <50bpm) happened in 75 procedures (47%): hypotension alone (24.4%, n=39), bradycardia alone (16.3%, n=26), both hypotension and bradycardia (6.3%, n=10). All hemodyanmic instability cases were reversed readily by the following methods: IV fluid challenge and/or reducing Dexmedetomidine infusion rate (88%, n=66), IV Ephedrine (9.3%, n=7) and IV Atropine (2.7%, n=2). Oxygen desaturation (SpO2 85-90%) occurred in 4 cases (2.5%), all of which were corrected successfully by supplementary oxygen. No early termination of procedure due to struggle or sedation-related adverse event was reported. In multivariate analysis, age >65 years old is significantly associated with hemodynamic instability (OR 1.83, 95% CI 1.05-4.46, p=0.036).
Conclusions: Dexmedetomidine-based conscious sedation regime is a reasonably safe option for lengthy endoscopic procedure. Cautious use is recommended in the elderly.
