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1-1-8 one-step sevoflurane wash-in scheme for low-flow anesthesia: simple, rapid, and predictable induction
Thepakorn Sathitkarnmanee
Khon Kaen University Faculty of Medicine
Corresponding Author
ORCiD: https://orcid.org/0000-0002-8401-1510
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View the published version at BMC Anesthesiology.
Background Sevoflurane is suitable for low-flow anesthesia (LFA). LFA needs a wash-in phase. The reported sevoflurane wash-in schemes lack simplicity, target coverage, and applicability. We proposed a one-step 1-1-8 wash-in scheme for sevoflurane LFA to be used with both N 2 O and Air. The objective of our study was to identify time for achieving each level of alveolar concentration of sevoflurane (F A S) from 1% to 3.5% in both contexts. Methods We recruited 199 adults requiring general anesthesia with endotracheal intubation and controlled ventilation—102 in group N 2 O and 97 in group Air. After induction and intubation, a wash-in was started using a fresh gas flow of O 2 :N 2 O or O 2 :Air at 1:1 L·min -1 plus sevoflurane 8%. The ventilation was controlled to maintain end-tidal CO 2 of 30-35 mmHg. Results The rising patterns of F A S and inspired concentration of sevoflurane (F I S) are similar, running parallel between the groups. The F A S/F I S ratio increased from 0.46 to 0.72 within 260 sec in group N 2 O and from 0.42 to 0.69 within 286 sec in group Air. The respective time to achieve an F A S of 1%, 1.5%, 2%, 2.5%, 3%, and 3.5% was 1, 1.5, 2, 3, 3.5, and 4.5 min in group N 2 O and 1, 1.5, 2, 3, 4, and 5 min in group Air. The heart rate and blood pressure of both groups significantly increased initially then gradually decreased as F A S increased. Conclusions The 1-1-8 wash-in scheme for sevoflurane LFA has many advantages, including simplicity, coverage, swiftness, safety, economy, and that it can be used with both N 2 O and Air. A respective F A S of 1%, 1.5%, 2%, 2.5%, 3%, and 3.5% when used with N 2 O and Air can be expected at 1, 1.5, 2, 3, 3.5, and 4.5 min and 1, 1.5, 2, 3, 4, and 5 min.
Keywords
Wash-in, Low flow anesthesia, Nitrous oxide, Air, Sevoflurane
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On 24 Jan, 2020
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On 14 Jan, 2020
Editorial decision: Accept
On 14 Jan, 2020
No comments provided
Editorial decision: Minor revision
On 10 Jan, 2020
Reviewer #1 agreed
On 23 Dec, 2019
Review #1 received
Received 23 Dec, 2019
Reviewers invited
Invitations sent on 17 Dec, 2019
Editor assigned
On 15 Dec, 2019
Submission checks complete
On 14 Dec, 2019
Editor invited
On 14 Dec, 2019
No comments provided
Editorial decision: Minor revision
On 12 Dec, 2019
Review #3 received
Received 10 Dec, 2019
Reviewer #3 agreed
On 24 Nov, 2019
Review #2 received
Received 12 Nov, 2019
Reviewer #2 agreed
On 06 Nov, 2019
Review #1 received
Received 23 Oct, 2019
Reviewer #1 agreed
On 10 Oct, 2019
Submission checks complete
On 07 Oct, 2019
Reviewers invited
Invitations sent on 07 Oct, 2019
Editor assigned
On 25 Sep, 2019
Editor invited
On 24 Sep, 2019
First submitted
On 23 Sep, 2019
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Subject Areas
Anesthesiology & Pain Medicine
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This preprint is under consideration at BMC Anesthesiology. A preprint is a preliminary version of a manuscript that has not completed peer review at a journal. Research Square does not conduct peer review prior to posting preprints. The posting of a preprint on this server should not be interpreted as an endorsement of its validity or suitability for dissemination as established information or for guiding clinical practice.
Learn more about In Review
Research article
1-1-8 one-step sevoflurane wash-in scheme for low-flow anesthesia: simple, rapid, and predictable induction
Thepakorn Sathitkarnmanee
Khon Kaen University Faculty of Medicine
Corresponding Author
ORCiD: https://orcid.org/0000-0002-8401-1510
Badges
Prescreen
This manuscript passed our Prescreen assessment
Complete author information
Appropriate declaration statements
Potential risks to human health
Prescreen
Peer Review Timeline
CURRENT STATUS: Published
Version 3
Posted 16 Jan, 2020
Published
On 24 Jan, 2020
No community comments so far
Submission checks complete
On 14 Jan, 2020
Editorial decision: Accept
On 14 Jan, 2020
No comments provided
Editorial decision: Minor revision
On 10 Jan, 2020
Reviewer #1 agreed
On 23 Dec, 2019
Review #1 received
Received 23 Dec, 2019
Reviewers invited
Invitations sent on 17 Dec, 2019
Editor assigned
On 15 Dec, 2019
Submission checks complete
On 14 Dec, 2019
Editor invited
On 14 Dec, 2019
No comments provided
Editorial decision: Minor revision
On 12 Dec, 2019
Review #3 received
Received 10 Dec, 2019
Reviewer #3 agreed
On 24 Nov, 2019
Review #2 received
Received 12 Nov, 2019
Reviewer #2 agreed
On 06 Nov, 2019
Review #1 received
Received 23 Oct, 2019
Reviewer #1 agreed
On 10 Oct, 2019
Submission checks complete
On 07 Oct, 2019
Reviewers invited
Invitations sent on 07 Oct, 2019
Editor assigned
On 25 Sep, 2019
Editor invited
On 24 Sep, 2019
First submitted
On 23 Sep, 2019
Metrics
Comments: 0
PDF Downloads: ...
HTML Views: ...
Subject Areas
Anesthesiology & Pain Medicine
License:
This work is licensed under a CC BY 4.0 License. Read Full License
View the published version at BMC Anesthesiology.
Background Sevoflurane is suitable for low-flow anesthesia (LFA). LFA needs a wash-in phase. The reported sevoflurane wash-in schemes lack simplicity, target coverage, and applicability. We proposed a one-step 1-1-8 wash-in scheme for sevoflurane LFA to be used with both N 2 O and Air. The objective of our study was to identify time for achieving each level of alveolar concentration of sevoflurane (F A S) from 1% to 3.5% in both contexts. Methods We recruited 199 adults requiring general anesthesia with endotracheal intubation and controlled ventilation—102 in group N 2 O and 97 in group Air. After induction and intubation, a wash-in was started using a fresh gas flow of O 2 :N 2 O or O 2 :Air at 1:1 L·min -1 plus sevoflurane 8%. The ventilation was controlled to maintain end-tidal CO 2 of 30-35 mmHg. Results The rising patterns of F A S and inspired concentration of sevoflurane (F I S) are similar, running parallel between the groups. The F A S/F I S ratio increased from 0.46 to 0.72 within 260 sec in group N 2 O and from 0.42 to 0.69 within 286 sec in group Air. The respective time to achieve an F A S of 1%, 1.5%, 2%, 2.5%, 3%, and 3.5% was 1, 1.5, 2, 3, 3.5, and 4.5 min in group N 2 O and 1, 1.5, 2, 3, 4, and 5 min in group Air. The heart rate and blood pressure of both groups significantly increased initially then gradually decreased as F A S increased. Conclusions The 1-1-8 wash-in scheme for sevoflurane LFA has many advantages, including simplicity, coverage, swiftness, safety, economy, and that it can be used with both N 2 O and Air. A respective F A S of 1%, 1.5%, 2%, 2.5%, 3%, and 3.5% when used with N 2 O and Air can be expected at 1, 1.5, 2, 3, 3.5, and 4.5 min and 1, 1.5, 2, 3, 4, and 5 min.
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