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Duration of apnoea in anaesthetized children required for desaturation of haemoglobin to 95%: comparison of three different breathing gases
Author(s) -
KINOUCHI KEIKO,
FUKUMITSU KAZUO,
TASHIRO CHIKARA,
TAKAUCHI YUJI,
OHASHI YOKO,
NISHIDA TOMOYO
Publication year - 1995
Publication title -
pediatric anesthesia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.704
H-Index - 82
eISSN - 1460-9592
pISSN - 1155-5645
DOI - 10.1111/j.1460-9592.1995.tb00255.x
Subject(s) - medicine , anesthesia , sevoflurane , tracheal tube , breathing , oxygen , breathing gas , apnea , intubation , ventilation (architecture) , general anaesthesia , tracheal intubation , room air distribution , chemistry , mechanical engineering , organic chemistry , engineering , physics , thermodynamics
Summary In this study, we compared three gas compositions to determine if the duration of apnoea for S po 2 to decrease is proportionate to the oxygen fraction of the gas prior to apnoea. Twenty‐five patients ASA physical status 1–2 aged two months to 12 years were included in the study. Anaesthesia was induced via a mask with 5% sevoflurane and 66% N 2 O in oxygen. After paralysis with vecuronium (0.12 mg·kg −1 , i.v.) the trachea was intubated and anaesthesia was maintained with sevoflurane and N 2 O in oxygen. When cardiovascular stability was obtained, the patient was randomly set to breathe one of three gas compositions: 1. oxygen ( F io 2 1.0), 2. N 2 O/O 2 ( F io 2 0.4), and 3. air/O 2 ( F io 2 0.4). All three gas compositions included 2–4% of sevoflurane to maintain anaesthesia. After more than eight min of each gas breathing, apnoea was begun by disconnecting the breathing circuit from the tracheal tube. The time from the start of apnoea ( S po 2 100%) to S po 2 of 95% (T 95 ) was measured. T 95 measured after breathing N 2 O/O 2 and air/O 2 were 34.6 ± 5.7 and 28.8 ± 4.7% of that measured after oxygen breathing ( P < 0.001 vs oxygen breathing, P < 0.001 vs oxygen and N 2 O/O 2 breathing), respectively. Preoxygenation before intubation was validated to delay the haemoglobin desaturation brought about by apnoea. An induction technique using a low F io 2 will allow rapid haemoglobin desaturation.