title: Study of the optimal duration of preoxygenation in children.
abstract: OBJECTIVE
  To determine the optimal length of preoxygenation in children.
  
  
  METHODS
  Random design and comparison among groups.
  
  
  METHODS
  Operating room of a plastic surgery hospital of the Chinese Academy of Medical Sciences and the Peking Union Medical College.
  
  
  METHODS
  Forty healthy, ASA status 1 children (age 2 to 7 yrs), undergoing elective plastic surgery.
  
  
  METHODS
  Children in Group 1 breathed 100% oxygen (O2) for 1 minute. Group 2 children breathed 100% O2 for 2 minutes. Group 3 and Group 4 children breathed 100% O2 for 3 minutes. Anesthesia was induced with midazolam 0.3 mg/kg, fentanyl 5 micrograms/kg. Muscle relaxation was achieved with vecuronium 0.1 mg/kg (Groups 1, 2, and 3) or succinylcholine 1.5 mg/kg (Group 4).
  
  
  RESULTS
  Oxygen saturation (SpO2) was measured by pulse oximeter. The oximeter probe was applied to the right big toe. After preoxygenation, the times for SpO2 to decrease to 98% (T98), 95% (T95), and 90% (T90), respectively, were recorded during the apneic period. T98, T95, and T90 were significantly shorter in Group 1 than in Group 2 or Group 3. There was no statistically significant difference among Groups 2, 3, or 4 regarding T98, T95, and T90. The times for SpO2 to decrease from 95% to 90% were similar among the four groups.
  
  
  CONCLUSIONS
  2 minutes of preoxygenation in children can provide the maximum benefit of denitrogenation and achieve 2 minutes of safe apea. 95% and 99% confidence intervals were 69 to 100 and 59 to 100, respectively. Succinylcholine had only a slight effect on the safe apneic period.
authors.affiliation: Department of Anesthesia, Plastic Surgery Hospital, Chinese Academy of Medical Sciences, Beijing.
authors.forename: F S
authors.initials: FS
authors.lastname: Xue
authors.forename: S Y
authors.initials: SY
authors.lastname: Tong
authors.forename: X L
authors.initials: XL
authors.lastname: Wang
authors.forename: X M
authors.initials: XM
authors.lastname: Deng
authors.forename: G
authors.initials: G
authors.lastname: An
mesh_terms: D000758:Anesthesia; D002648:Child; D002675:Child, Preschool; D005283:Fentanyl; D006339:Heart Rate / Q000502:physiology; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D008874:Midazolam; D010092:Oximetry; D010100:Oxygen / Q000008:administration & dosage*; D013390:Succinylcholine; D013518:Surgery, Plastic; D013997:Time Factors; D014673:Vecuronium Bromide
chemical_list: D006454:Hemoglobins; D014673:Vecuronium Bromide; D013390:Succinylcholine; D008874:Midazolam; D010100:Oxygen; D005283:Fentanyl