title: Sex-based ProSeal laryngeal mask airway size selection: a randomized crossover study of anesthetized, paralyzed male and female adult patients.
abstract: We compared the Size 4 and 5 ProSeal laryngeal mask airway (PLMA) in men and the Size 3 and 4, and 4 and 5 PLMA in women in terms of 1) ease of insertion, 2) oropharyngeal leak pressure (OLP), 3) ease of ventilation at a tidal volume of 10 mL/kg, 4) gas exchange, 5) location of gas leak, 6) anatomic position of the airway and drain tube, and 7) mucosal injury. Thirty male and 60 female (ASA physical status I-II; 18-80 yr old) anesthetized, paralyzed patients were studied in a crossover fashion in three equal-sized groups. PLMA insertion was performed by a single experienced operator by using digital manipulation. In male patients comparing the Size 4 and 5, OLP was higher (P = 0.0002) and leak fraction lower (P = 0.03) for the Size 5, but the number of insertion attempts, insertion time, mucosal injury, anatomic position, gas exchange, and location of gas leak were similar. In female patients comparing the Size 4 and 5 PLMA, OLP was higher for the Size 5 (P < 0.0001), but the number of insertion attempts was fewer (P = 0.02), insertion time was quicker (P = 0.02), and there was less mucosal injury (P = 0.01) with the Size 4. There were no differences in anatomic position, gas exchange, or location of gas leak. In female patients comparing the Size 3 and 4 PLMA, OLP was higher (P = 0.0005) and leak fraction was lower (P = 0.03) for the Size 4, but the number of insertion attempts, insertion time, mucosal injury, anatomic position, gas exchange, and location of gas leak were similar. There were no episodes of failed oxygenation, failed ventilation, or gastric insufflation. We conclude that if size is selected by sex, the Size 4 PLMA is preferable for women and the Size 5 PLMA for men.
  
  
  CONCLUSIONS
  When sex is used to select the appropriate size of the ProSeal laryngeal mask airway, the Size 4 ProSeal is preferable for women and the Size 5 ProSeal for men.
authors.affiliation: Department of Anaesthesia, Pain Clinic, Ibaraki, Japan.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Kihara
authors.forename: Joseph
authors.initials: J
authors.lastname: Brimacombe
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000758:Anesthesia; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D017214:Laryngeal Masks; D008297:Male; D008875:Middle Aged; D009092:Mucous Membrane / Q000293:injuries; D010243:Paralysis / Q000139:chemically induced; D011175:Positive-Pressure Respiration; D012121:Respiration, Artificial; D015656:Respiratory Mechanics / Q000502:physiology; D012737:Sex Factors; D013990:Tidal Volume / Q000502:physiology; D014132:Trachea / Q000033:anatomy & histology*