Effect of propofol combined with opioids on cough reflex suppression in gastroscopy: study protocol for a double-blind randomized controlled trial

IntroductionThe best methods for inducing analgesia and sedation for gastroscopy are still debated but finding an adequate regimen of sedation/analgesia is important. Stimulation of the larynx under sedation can cause reflex responses. Propofol with opioids has been recommended for gastroscopy sedation but the effects on cough reflex suppression remain unclear. This trial will evaluate the effects of propofol combined with small doses of dezocine, oxycodone, sufentanil or fentanyl for gastroscopy. We hypothesise that better performance may be obtained with a combination of propofol and oxycodone. We will observe the incidence and degree of reflex coughing and gagging under sedation when using propofol combined with one of the above drugs or propofol alone.Methods and analysisThis will be a prospective, randomised, double-blind, controlled trial. ASA I–II level patients aged 18–65 years and scheduled for gastroscopy will be included. It is planned that 500 subjects will be randomised to intravenously receive 2–2.2 mg/kg propofol plus 0.5–0.8 μg/kg fentanyl (fentanyl group), 2–2.2 mg/kg propofol plus 0.05–0.08 μg/kg sufentanil (sufentanil group), 2–2.2 mg/kg propofol plus 0.04–0.05 mg/kg dezocine (dezocine group), 2–2.2 mg/kg propofol plus 0.04–0.05 mg/kg oxycodone (oxycodone group), or 2.4–3 mg/kg propofol plus 2–2.5 mL saline (control group) for sedation. The primary endpoint is the incidence and degree of reflex coughing and gagging. The secondary endpoints include the occurrence of discomfort or side effects, the use of jaw thrust, assisted ventilation or additional propofol, recovery time, duration of procedure and Steward score.Ethics and disseminationThis study has been approved by the Institutional Ethics Committee for Clinical Research of Zhongda Hospital, Affiliated to Southeast University (No. 2015ZDSYLL033.0). The results of the trial will be published in an international peer-reviewed journal.Trial registrationThis study has been registered with the Chinese Clinical Trial Register (No. ChiCTR-ICR-15006952).Trial statusAt the time of manuscript submission, the study was in the recruitment phase.