title: Remifentanil alters sensory neuromodulation of swallowing in healthy volunteers: quantification by a novel pressure-impedance analysis.
abstract: Exposure to remifentanil contributes to an increased risk of pulmonary aspiration, likely through reduced pharyngeal contractile vigor and diminished bolus propulsion during swallowing. We employed a novel high-resolution pressure-flow analysis to quantify the biomechanical changes across the upper esophageal sphincter (UES). Eleven healthy young (23.3 ± 3.1 yr old) participants (7 men and 4 women) received remifentanil via intravenous target-controlled infusion with an effect-site concentration of 3 ng/ml. Before and 30 min following commencement of remifentanil administration, participants performed ten 10-ml saline swallows while pharyngoesophageal manometry and electrical impedance data were recorded using a 4.2-mm-diameter catheter housing 36 circumferential pressure sensors. Remifentanil significantly shortened the duration of UES opening (P < 0.001) and increased residual UES pressure (P = 0.003). At the level of the hypopharynx, remifentanil significantly shortened the latency from maximum bolus distension to peak contraction (P = 0.004) and significantly increased intrabolus distension pressure (P = 0.024). Novel mechanical states analysis revealed that the latencies between the different phases of the stereotypical UES relaxation sequence were shortened by remifentanil. Reduced duration of bolus flow during shortened UES opening, in concert with increased hypopharyngeal distension pressures, is mechanically consistent with increased flow resistance due to a more rapid bolus flow rate. These biomechanical changes are congruent with modification of the physiological neuroregulatory mechanism governing accommodation to bolus volume.
authors.affiliation: Speech Pathology and Audiology, School of Health Sciences, Flinders University, Adelaide, South Australia, Australia; sebastian.doeltgen@flinders.edu.au.
authors.forename: S H
authors.initials: SH
authors.lastname: Doeltgen
authors.affiliation: Human Physiology, Medical Science and Technology, School of Medicine, Flinders University, Adelaide, South Australia, Australia;
authors.forename: T I
authors.initials: TI
authors.lastname: Omari
authors.affiliation: Department of Anaesthesiology and Intensive Care, Örebro University Hospital, Örebro, Sweden; and School of Medical Sciences, Örebro University, Örebro, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: Savilampi
mesh_terms: D000328:Adult; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000009:adverse effects* / Q000494:pharmacology; D001696:Biomechanical Phenomena; D003679:Deglutition / Q000187:drug effects*; D017097:Electric Impedance; D049631:Esophageal Sphincter, Upper / Q000187:drug effects / Q000502:physiology; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D010880:Piperidines / Q000008:administration & dosage / Q000009:adverse effects* / Q000494:pharmacology; D000077208:Remifentanil
chemical_list: D000701:Analgesics, Opioid; D010880:Piperidines; D000077208:Remifentanil
keywords: high-resolution manometry; remifentanil; swallowing; upper esophageal sphincter; μ-opioid receptor