Swallowing ability and intra-oral water-retaining ability during moderate propofol sedation in healthy human volunteers

Abstract

BACKGROUND The cough reflex or aspiration under monitored anaesthesia care might be associated with sedative-induced changes in swallowing and intra-oral water-retaining abilities. OBJECTIVES To investigate the effects of moderate propofol sedation on swallowing and intra-oral water-retaining ability. DESIGN Prospective observational study. SETTING Single tertiary care centre during 2017. PARTICIPANTS A total of 13 healthy adult volunteers. INTERVENTION Volunteers in the supine position were asked to retain 10 ml of orally injected water for 5 min. After 5 minutes or when the water was spontaneously swallowed, the retention time and residual intra-oral water volume were measured. Subjects then voluntarily swallowed a further 10 ml of injected water and the residual water volume was measured. This whole process was repeated under sedation with propofol at effect-site concentrations of 0.5, 1.0 and 1.5 μg ml−1. MAIN OUTCOME MEASURES The primary outcome was the estimated volume swallowed (swallowing volume); the secondary outcome was water retention time. RESULTS Median water retention time decreased from 300 to 11 s (P < 0.001), and greater spontaneous swallowing was induced with increased propofol effect-site concentrations measuring up to 1.5 μg ml−1 (P < 0.001). The median of the estimated swallowing volumes with voluntary swallowing while awake and with all three concentrations of propofol were 9.5, 9.6, 9.6 and 9.4 ml, respectively (P = 0.805); more water remained after spontaneous swallowing than after voluntary swallowing at all concentrations. Differences in mean estimated swallowing volumes between voluntary and spontaneous swallowing were 3.4 ml (95% CI, 0.9 to 6.0, P = 0.016) for 0.5 μg ml−1, 4.1 ml (95% CI, 1.8 to 6.3, P = 0.002) for 1.0 μg ml−1 and 5.1 ml (95% CI, 3.4 to 6.8, P < 0.001) for 1.5 μg ml−1. CONCLUSIONS Moderate propofol sedation decreases water-retaining ability but has no effect on voluntary swallowing. Ensuring that patients can respond under sedation may effectively prevent the unexpected cough reflex and aspiration by enabling occasional voluntary swallowing. TRIAL REGISTRATION UMIN Clinical Trials Registry identifier: UMIN000027517.

Effect of ciprofol- and propofol-induced sedation for gastrointestinal endoscopy on pharyngeal swallowing function: A prospective experimental study

“…The use of propofol for moderate and deep sedation could impair pharyngeal swallowing function and increase the risk of unintentional aspiration and cough. Additionally, it could lead to injection pain, marked depression of cardiovascular and respiratory parameters, and impaired protective re exes [2,3].…”

Remimazolam: Is the quest for the holy grail of sedation during diagnostic or endoscopic interventions over?

“…Propofol currently seems to be the gold standard, especially because it has a rapid onset and offset 3 . However, propofol sedation is associated with injection pain, hypotension, bradycardia, hypoxia, apnoea, reduced swallowing capability, and fatigue 4,5 . Any drug with a similar sedative profile or with a faster onset/offset than propofol which additionally is devoid of side effects would create a significant improvement in clinical sedation in the endoscopy suite.…”