title: The Cricoid Force Necessary to Occlude the Esophageal Entrance: Is There a Gender Difference?
abstract: We tested the hypothesis whether gender differences exist in the applied cricoid force necessary to prevent regurgitation. Real-time visual and dynamic means were used to assess the effectiveness of different applied cricoid forces in occluding the esophageal entrance in men (group 1) and in women (group 2).
  
  
  
  In anesthetized and paralyzed patients, the glottis and esophageal entrance were visualized with a Glidescope video laryngoscope. Trained operators performed cricoid pressure (CP) and gastric tube insertion trials. Successful gastric tube insertion in the presence of CP was considered ineffective CP, whereas unsuccessful insertion was considered effective CP. The applied cricoid forces were measured with a novel instrument, the cricometer. The first patient in each group received 20 N. The applied cricoid force in successive patients was determined by the response of the previous patient within the same group, using the up-and-down sequential allocation technique.
  
  
  
  In the 30 men and 30 women who qualified for the study, the median cricoid force (cricoid force = 50) that occluded the esophageal entrance was 30.8 N (95% confidence interval = 28.15-33.5) in men, and 18.7 N in women (95% confidence interval = 17.1-20.3; P < .0001). Patency of the esophageal entrance was observed when CP was not applied and when inadequate forces that allowed successful esophageal cannulation were used.
  
  
  
  The current study provides evidence that the median force necessary to occlude the esophageal entrance to prevent regurgitation is less in women compared with men. Applying the appropriate cricoid force in women should also decrease airway-related problems that tend to occur with the use of excessive forces. The findings of the current study may only be applicable to patients with normal body habitus.
authors.affiliation: From the *Department of Anesthesiology, Procare Riaya Hospital, Al-Khobar, Kingdom of Saudi Arabia; †Lebanese University, Beirut, Lebanon; ‡Department of Anesthesiology, Advocate Illinois Masonic Medical Center, Chicago, Illinois; §Department of Anesthesiology, University of Illinois College of Medicine, Chicago, Illinois; ‖Department of Anesthesiology, King Fahad Specialist Hospital, Dammam, Kingdom of Saudi Arabia; ¶Laboratoire d'anesthésie INSERM UMR788 Université Paris-Sud and Département d'Anesthésie-Réanimation, Hôpitaux Universitaires Paris-Sud, AP-HP Le Kremlin Bicêtre, France; #Al-Azhar University, Egypt; **Department of Internal Medicine, Procare Riaya Hospital, Al-Khobar, Kingdom of Saudi Arabia; and ††Department of Information Technology, Almutlaq Holding, Al-Khobar, Kingdom of Saudi Arabia.
authors.forename: Ahed M
authors.initials: AM
authors.lastname: Zeidan
authors.forename: M Ramez
authors.initials: MR
authors.lastname: Salem
authors.forename: Munir
authors.initials: M
authors.lastname: Bamadhaj
authors.forename: Jean-Xavier
authors.initials: JX
authors.lastname: Mazoit
authors.forename: Hussein
authors.initials: H
authors.lastname: Sadek
authors.forename: Hassan
authors.initials: H
authors.lastname: Houjairy
authors.forename: Kamal
authors.initials: K
authors.lastname: Abdulkhaleq
authors.forename: Nabil
authors.initials: N
authors.lastname: Bamadhaj
mesh_terms: D000328:Adult; D003413:Cricoid Cartilage / Q000033:anatomy & histology* / Q000502:physiology; D004947:Esophagus / Q000033:anatomy & histology* / Q000502:physiology; D005260:Female; D005931:Glottis / Q000033:anatomy & histology / Q000502:physiology; D006801:Humans; D007442:Intubation, Intratracheal; D057045:Laryngopharyngeal Reflux / Q000503:physiopathology / Q000517:prevention & control*; D020704:Laryngoscopes; D008297:Male; D008875:Middle Aged; D011312:Pressure; D012727:Sex Characteristics; D055815:Young Adult