Single Breath Induction of Anaesthesia, Using a Vital Capacity Breath of Halothane, Nitrous Oxide, and Oxygen

Abstract

Inhalational induction of anaesthesia. using a single vital capacity breath of 4% halothane in 66% nitrous oxide and 33% oxygen was evaluated in 100 unpremedicated outpatients. The technique was found to be acceptable to most (91%) of the patients studied, with a mean (SD) induction time (measured from beginning of inspiration to loss of 'eyelash reflex? of 83(21) seconds. Relative cardiovascular stability was a notable jinding of the technique. with a slight decrease in the mean arterial pressure of only 10%. Anaesthetic induction time was unaffected by age, weight or smoking habits. The technique of single breath induction is therefore proposed as a safe and acceptable alternative to intravenous induction in cooperative adult patients.

Comparison between halothane and sevoflurane for adult vital capacity induction

“…The authors were surprised by the incidence of adverse events which was much higher than that in Wilton and Thomas's study. 5 The difference could be explained by deviation from the original description, 5 where halothane concentration was reduced from 4% to 3% after loss of eyelash and then to 2% after another 2 min. In our study we maintained halothane concentration at 4% because we wished to make a high concentration comparison with sevoflurane.…”

“…Concentrations of the volatile agents used in this study have been used previously for vital capacity induction: 4% for halothane [4][5][6] and 8% for sevoflurane. 9 These were dial settings and the measured concentrations delivered were: greater than 3.5% halothane (4.4 minimum alveolar concentration (MAC) equivalents), and greater than 7.5% sevoflurane (3.8 MAC equivalents).…”

“…[4][5][6] This study was undertaken in adults to compare the ventilatory characteristics during high concentration gaseous induction using sevoflurane and halothane.…”

Single‐breath inhalation induction of sevoflurane anaesthesia with and without nitrous oxide: a feasibility study in adults and comparison with an intravenous bolus of propofol

“…It was then used successfully for fit healthy unpremedicated adults [11] where the halothane was carried in nitrous oxide and oxygen. Nitrous oxide was used to reduce the induction time and minimise the cardiovascular depressant effect of halothane [12].…”

Recovery after single‐breath halothane induction of anaesthesia in daycase patients

“…is faster than conventional techniques of inhalational induction, because it produces a more rapid rise in alveolar halothane concentration.z The addition of nitrous oxide to the mixture further reduces induction time, by decreasing the alveolar concentration of halothane required to induce anae~thesia.~ and by means of the second gas This technique is a safe and practicable alternative to intravenous induction in cooperative a d u k 6 Thiopentone is almost completely metabolised by the liver: it has a long terminal half-lift' and is associatcd with a prolonged hangover effect. The avoidance of thiopentone may incrcase the speed of recovery from anaesthesia, which would be of particular benefit to daycase patients.…”