Duration of apnea in anesthetized infants and children required for desaturation of hemoglobin to 95%. The influence of upper respiratory infection.
Sixty-one patients ASA physical status 1-2 aged 1 month to 12 years undergoing elective surgery were included in the study. Anesthesia was induced via a mask with sevoflurane up to 5% and 66% nitrous oxide in oxygen. After paralysis with vecuronium (0.12 mg/kg iv), the trachea was intubated and the lungs were ventilated manually with 3% sevoflurane in oxygen until the end-tidal nitrous oxide decreased to less than 5%. Apnea was started by disconnecting the breathing circuit from the endotracheal tube. The time from the start of apnea to Spo2 of 95% was measured. Manual ventilation was reinstituted when Spo2 decreased to 95% and another set of vital signs was recorded. Twenty of 61 patients had symptoms of upper respiratory infection. The time to Spo2 of 95% correlated well with height, age, and body weight both by linear and non-linear regression analyses. The patients with symptomatic upper respiratory infection required less time for Spo2 to decrease to 95% compared to the asymptomatic children. We conclude that younger children require less time for Spo2 to decrease to 95%. The presence of upper respiratory infection is an additional factor increasing the susceptibility of small children to hypoxemia.
Kinouchi
K
K
Department of Anesthesiology, Osaka Medical Center, Japan.
Tanigami
H
H
Tashiro
C
C
Nishimura
M
M
Fukumitsu
K
K
Takauchi
Y
Y
D000769:Anesthesia, Inhalation; D002648:Child; D002675:Child, Preschool; D004987:Ethers; D006801:Humans; D007223:Infant; D008738:Methyl Ethers; D009609:Nitrous Oxide; D010100:Oxygen; D010108:Oxyhemoglobins / Q000378:metabolism*; D012119:Respiration / Q000502:physiology*; D012120:Respiration Disorders / Q000503:physiopathology*; D000077149:Sevoflurane; D013514:Surgical Procedures, Operative; D013997:Time Factors
D004987:Ethers; D008738:Methyl Ethers; D010108:Oxyhemoglobins; D000077149:Sevoflurane; D009609:Nitrous Oxide; D010100:Oxygen