PTH-054\u2005Feasibility of non-invasive nasal ventilation (THRIVE) for propofol-induced sedation in therapeutic upper gastrointestinal endoscopy

Abstract

Background Pharyngeal conditions such as Zenker’s Diverticulum (ZD) increase with age and may be amenable to endoscopic therapy. However, therapy is traditionally performed under general anaesthesia (GA) which requires ventilatory support and may preclude therapy in frailer patients. Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE) is a non-invasive nasal method of ventilation which obviates the need for tracheal intubation. However, evidence supporting the feasibility of THRIVE for in endoscopic procedures is lacking. This study aimed to assess the feasibility, efficacy and safety of THRIVE as an adjunct to deep sedation in endoscopic pharyngeal and upper oesophageal procedures. Methods In this prospective study, consecutive patients undergoing therapeutic endoscopy of the pharynx and upper oesophagus between June 2016 and March 2018 were included. All procedures were performed under deep sedation with propofol and/or remifentanil in endoscopy unit as a day case. For ZD, the pharyngeal pouch and the stomach were cleared of debris to reduce the risk of aspiration before sedation was up titrated to facilitate therapy. Sedation related adverse events and the total dose of sedative drugs used were recorded. Results A total of 50 patients were included for analysis, with a mean age of 71.1 (range 31–93) and male patients comprising 58%. 46% were categorized as ASA grades I-II, 48% Grade III and 6% as Grade IV. The median procedure time was 20 minutes. 83% of patients were sedated with both propofol (median dose 103 mg) and remifentanil (median dose 167 mcg) using a target controlled infusion under specialist anaesthetic supervision. THRIVE was commenced in all patients, with none requiring conversion to invasive ventilation. The commonest sedation related adverse event was transient hypotension (38%) followed by bradycardia (8%) and hypoxia (8%). No procedures were abandoned due to complications. Patients achieved full post-procedure recovery from sedation after a median of 5 minutes. Conclusions Deep sedation with THRIVE proved to be a useful and safe technique for advanced therapeutic upper GI endoscopy. The role of THRIVE may be generalisable to other invasive therapeutic modalities involving high-risk patients such as ERCP.