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Pre‐oxygenation enhances induction with sevoflurane as assessed using bispectral index monitoring
Author(s) -
Fassoulaki A.,
Petropoulos G.,
Kottis G.,
Sarantopoulos C.
Publication year - 2006
Publication title -
acta anaesthesiologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.738
H-Index - 107
eISSN - 1399-6576
pISSN - 0001-5172
DOI - 10.1111/j.1399-6576.2006.00981.x
Subject(s) - sevoflurane , bispectral index , medicine , anesthesia , oxygenation , tidal volume , heart rate , respiratory rate , oxygen , respiratory system , propofol , blood pressure , chemistry , organic chemistry
Background: Several methods may enhance the inhalational induction of anesthesia. In this randomized double‐blind study, we evaluated the speed of induction of anesthesia with sevoflurane with or without pre‐oxygenation. Methods: Fifty‐four patients scheduled for hysteroscopy received for 10 min air or 100% oxygen via a facemask followed by ≥ 7% sevoflurane in 100% oxygen. During the first 300 s of sevoflurane administration, bispectral index (BIS) values were recorded every 30 s in all patients. In 14 patients, seven in each group, BIS, endtidal CO 2 , tidal volume, respiratory rate, SpO 2 , and heart rate were recorded every minute during the pre‐induction period and every 30 s during the first 5 min of sevoflurane administration. Results: The BIS, endtidal CO 2 , tidal volume and respiratory rate did not differ between the oxygen or air breathing groups ( P = 0.696, P = 0.999, P = 0.388, and P = 0.875, respectively), though the oxygen group exhibited lower tidal volumes by 16–20%. The SpO 2 and heart rates were higher in the oxygen breathing group ( P < 0.001 and P = 0.042, respectively). During sevoflurane administration, BIS values were lower in the oxygen group vs. the group breathing air, in particular at 90, 120, 150, 180 and 210 s ( P = 0.001, P = 0.001, P = 0.001, P = 0.001 and P = 0.030, respectively). The endtidal CO 2 and the tidal volumes between the groups did not differ. The two groups differed in the SpO 2 and the heart rates during induction ( P = 0.004 and 0.003, respectively). Conclusions: Before sevoflurane administration, breathing 100% oxygen for 10 min enhances induction of anesthesia with sevoflurane.