Pharyngeal airway protective reflexes are triggered before the maximum volume of fluid that the hypopharynx can safely hold is exceeded. Am J Physiol Gastrointest Liver Physiol 2011 Aug;301(2):G197-202
Date
05/14/2011Pubmed ID
21566013Pubmed Central ID
PMC3154610DOI
10.1152/ajpgi.00046.2011Scopus ID
2-s2.0-79960986585 (requires institutional sign-in at Scopus site) 28 CitationsAbstract
Aerodigestive reflexes triggered by pharyngeal stimulation can protect the airways by clearing fluid from the pharynx. The objective of this study was to determine the relationship between the maximum capacity of fluid that can safely dwell in the hypopharynx [hypopharyngeal safe volume (HPSV)] before spilling into the larynx and the threshold volumes required to trigger pharyngoglottal closure reflex (PGCR), pharyngo-upper esophageal sphincter contractile reflex (PUCR), and reflexive pharyngeal swallow (RPS). Twenty-five healthy volunteers (mean age 24 yr, 8 males) were studied in the semi-inclined supine position. PGCR, PUCR, and RPS were elicited using techniques of concurrent upper esophageal sphincter manometry and pharyngo-laryngoscopy. The hypopharynx was then anesthetized to abolish RPS. HPSV was determined by infusing water in the pharynx, and perfusion was stopped when the infusate reached the superior margin of the interarytenoid fold. The threshold volumes for triggering PGCR, PUCR, and RPS by slow and rapid injections before pharyngeal anesthesia were 0.18 ± 0.02 and 0.09 ± 0.02 ml; 0.20 ± 0.020 and 0.13 ± 0.04 ml; and 0.61 ± 0.04 and 0.4 ± 0.06 ml, respectively. All of the above volumes were significantly smaller than the HPSV (0.70 ± 0.06 ml, P < 0.01) except for the threshold volume to elicit RPS during slow perfusion, which was not significantly different (P = 0.23). We conclude that pharyngeal aerodigestive reflexes are triggered by both slow and rapid pharyngeal perfusion of water at significantly smaller volumes than the maximum capacity of the hypopharynx to safely hold contents without spilling into the airway. These reflexes thereby aid in prevention of aspiration.
Author List
Dua K, Surapaneni SN, Kuribayashi S, Hafeezullah M, Shaker RAuthors
Kulwinder S. Dua MD Professor in the Medicine department at Medical College of WisconsinReza Shaker MD Assoc Provost, Sr Assoc Dean, Ctr Dir, Chief, Prof in the Medicine department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
AdolescentAdult
Deglutition
Esophageal Sphincter, Upper
Female
Humans
Hypopharynx
Male
Manometry
Reflex
Respiratory Aspiration
Sensory Thresholds
Water
Young Adult
