title: The laryngeal mask airway in infants and children.
abstract: OBJECTIVE
  To compare the effectiveness of various laryngeal mask airway (LMA) sizes and their performance during positive pressure ventilation (PPV) in paralyzed pediatric patients.
  
  
  METHODS
  Pediatric patients (n = 158), < 30 kg, ASA 1 or 2 were studied. After paralysis, an LMA of the recommended size was inserted and connected to a volume ventilator. Fibreoptic bronchoscopy (FOB) was performed and graded: 1, larynx only seen; 2, larynx and epiglottis posterior surface seen; 3, larynx, and epiglottis tip or anterior surface seen--visual obstruction of epiglottis to larynx: < 50%; 4, epiglottis down-folded, and its anterior surface seen--visual obstruction of epiglottis to larynx: > 50%; 5, epiglottis down-folded and larynx not seen directly. Inspiratory and expiratory tidal volumes (V(T)), and airway pressure were measured by a pneumo-tachometer, and the fraction of leakage (F(L)) was calculated. In 79 cases, LMA was used for airway maintenance throughout surgery.
  
  
  RESULTS
  Successful LMA placement was achieved in 98% of cases: three failures were due to gastric insufflation. For LMA # 1, 1.5, 2, and 2.5, FOB grades [median (range)] were 3(1-5), 3(1-5), 1(1-5) and 1(1-3) respectively. In smaller LMAs, the cuff more frequently enclosed the epiglottis (P < .001). F(L) of LMA # 1 was higher than those of LMA # 1.5 and LMA # 2.5 (P < .05), and F(L) of LMA # 2 was higher than that of LMA # 2.5 (P < .05). In the 79 patients, the number of patients experiencing complications decreased as LMA size increased (P < .05).
  
  
  CONCLUSIONS
  Use of the LMA in smaller children results in more airway obstruction, higher ventilatory pressures, larger inspiratory leak, and more complications than in older children.
authors.affiliation: Department of Anesthesiology, National Cancer Center, Koyang, Kyunggi-do, Korea.
authors.forename: C
authors.initials: C
authors.lastname: Park
authors.forename: J H
authors.initials: JH
authors.lastname: Bahk
authors.forename: W S
authors.initials: WS
authors.lastname: Ahn
authors.forename: S H
authors.initials: SH
authors.lastname: Do
authors.forename: K H
authors.initials: KH
authors.lastname: Lee
mesh_terms: D002648:Child; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D017214:Laryngeal Masks; D011175:Positive-Pressure Respiration