Comparison of induction time and characteristics between sevoflurane and sevoflurane / nitrous oxide

Abstract

A previous investigation using nitrous oxide with 5% enflurane (3.8 MAC) for single breath induction produced a stage of excitement which may be related to the difference in blood/gas coefficient solubility of these agents. The closer blood/gas solubility coefficient of sevoflurane and nitrous oxide may eliminate this phenomenon. We therefore evaluated 40 volunteers in a randomized study using 7.5% sevoflurane (3.7 MAC) in oxygen (n = 21) or sevoflurane with nitrous oxide (n = 19) using a single breath induction technique. Sevoflurane in nitrous oxide and oxygen reduced induction time by 15% compared to sevoflurane in oxygen alone (41 +/- 16 and 48 +/- 16 sec (s.d.), respectively). This was, however, not statistically significant. There were scarcely induction-related complications, such as coughing, laryngospasm, breath-holding, movements of a limb and excessive salivation, in either group. Thus, the addition of nitrous oxide neither increased the number of complications, nor the speed of induction.

Multiple-deep-breath inhalation induction with 5% sevoflurane and 67% nitrous oxide: comparison with intravenous injection of propofol

“…The incidence of PONV was slightly lower in the propofol group, but the difference was not statistically siginficant. Patient satisfaction with the anesthetic technique was at variance with that of previous investigations [1][2][3]6,7,[11][12][13][14], although no report showed that more patients preferred gaseous induction to intravenous induction. In our study fewer patients in the sevoflurane group were satisfied with the anesthetic method they had undergone, because of the smell of inhaled gas, nausea after anesthesia, etc.…”

“…In our study the times to loss of consciousness, loss of eyelash reflex, and insertion of the LMA in the sevoflurane group were greater than those in other trials of 7.5%-8% sevoflurane [1][2][3]5,7]. The time to insertion of the LMA was faster with propofol, although there were no significant differences in the time to loss of consciousness and eyelash reflex between the two groups in our study.…”

“…In Japan the sevoflurane vaporizer that allows the use of concentrations over 5% is not in common use, and therefore we undertook the present investigation inducing anesthesia with 5% sevoflurane. It has been demonstrated that nitrous oxide added to sevoflurane makes the induction time faster [1,[5][6][7]. We applied induction with sevoflurane carried in nitrous oxide and oxygen for the study group, whereas in the control group the patients were administered nitrous oxide and oxygen via the face mask during induction with intravenous propofol.…”

Nitrous Oxide Effects the Uptake of Sevoflurane to the Body During Induction

“…Muzi et al (8), in the study that they conducted in adults, found a similar result for ERDT. Yurino et al (9) determined that nitrous oxide had shortened the induction time by 15%; however, they were not able to prove this statistically.…”

“…Those who defend that it shortens the induction period have suggested that N 2 O accomplishes this by the second gas effect and the previously shown additive effects (11,18,19,30). The opponent group has advocated in their studies that N 2 O does not shorten the induction period and the addition of N 2 O during induction is unnecessary (9,10,22). However, in the studies representing both opinions, the excitatory and movement responses were determined to be less in the N 2 O added groups.…”