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. 2016 May-Aug;10(2):284-90.
doi: 10.4103/0259-1162.172343.

Sevoflurane in low-flow anesthesia using "equilibration point"

Veena Chatrath  1 , Ranjana Khetarpal  1 , Divya Bansal  1 , Harjinder Kaur  1
Affiliations

Sevoflurane in low-flow anesthesia using "equilibration point"

Veena Chatrath et al. Anesth Essays Res. 2016 May-Aug.

Abstract

Context: While giving low-flow anesthesia, it is a routine practice to give fixed duration of initial high-flow. This study was conducted to show the use of equilibration point as changeover point from initial high-flow to low-flow.

Aims: It was to compare the use of equilibration point, hemodynamics, end-tidal agent concentration, recovery time, and recovery score between isoflurane and sevoflurane.

Settings and design: It was a prospective randomized study conducted on 100 patients who were admitted for elective surgery expected to be < 2 h duration.

Materials and methods: Patients were randomly assigned to one of the two groups of 50 each. Group I received isoflurane and Group S sevoflurane as an inhalational agent.

Statistical analysis: The observations obtained in both the groups were recorded and compared. Analysis was done using unpaired t-test and Chi-square test.

Results: Hemodynamic parameters were comparable in both the groups. The mean equilibration times obtained for sevoflurane and isoflurane were 8.22 ± 1.060 min and 17.24 ± 10.2 min, respectively. The drift in end-tidal agent concentration over time was less in sevoflurane group. Mean recovery time was 7.92 ± 1.56 min in the sevoflurane group and 12.89 ± 3.45 min in the isoflurane group (P = 0.001). There was no significant difference between intraoperative and postoperative complications.

Conclusion: Use of equilibration time of the volatile anesthetic agent as a changeover point, from high-flow to low-flow, can help us to use circle system with low-flow anesthesia in a more efficient way, especially with newer anesthetics such as sevoflurane.

Keywords: Equilibration time; low-flow; volatile anesthetic agent.

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Figures

Figure 1
Figure 1
Mean end-tidal concentration of volatile anesthetic agent at different time intervals in Group I and Group S
Figure 2
Figure 2
Mean bispectral index at different time intervals in Group I and Group S
Figure 3
Figure 3
Mean end-tidal concentration of N2 O at different time intervals in Group I and Group S
Figure 4
Figure 4
Mean inspired O2 concentration at different time intervals in Group I and Group S
See this image and copyright information in PMC

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