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Effect of charcoal filter on the emergence from sevoflurane anesthesia in a semi-closed rebreathing circuit.

Chang DJ, Choi SH, Choi YS, Min KT - Yonsei Med. J. (2011)

Bottom Line: The elimination kinetics of sevoflurane from end-tidal concentration, Bispectral index and times of eye opening and extubation were obtained.The exponential time constant (τ) of alveolar sevoflurane concentration in the charcoal filter group was significantly shorter than that in the control group (1.7±0.5 vs. 2.5±1.1 min, p=0.008).The charcoal filter hastened rapid eye opening (11.1±3.8 vs. 14.8±3.0 min, p=0.007) and extubation (11.9±3.9 vs. 15.3±3.2 min, p=0.014), compared to the control group.

View Article: PubMed Central - PubMed

Affiliation: Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, 250 Seongsan-ro, Seodaemun-gu, Seoul 120-752, Korea.

ABSTRACT

Purpose: A charcoal filter attached within the anesthetic circuit has been shown to efficiently adsorb halothane or isoflurane, thus hastening anesthetic recovery in low or minimal flow system. This study was intended to demonstrate whether the charcoal filter enhances the recovery time from sevoflurane anesthesia using a semi-closed circuit system.

Materials and methods: Thirty healthy patients scheduled for elective surgery under sevoflurane anesthesia were randomly assigned to the charcoal filter or control group. Upon completion of surgery, the end-tidal concentration of sevoflurane was maintained at 2.0 vol%. A charcoal filter was attached to the expiratory limb of the breathing circuit of charcoal filter group subjects. After sevoflurane was discontinued, ventilation was controlled with the same minute volume as the intra-operative period at a fresh gas flow rate of 5 L·min⁻¹ with 100% O₂. The elimination kinetics of sevoflurane from end-tidal concentration, Bispectral index and times of eye opening and extubation were obtained.

Results: The exponential time constant (τ) of alveolar sevoflurane concentration in the charcoal filter group was significantly shorter than that in the control group (1.7±0.5 vs. 2.5±1.1 min, p=0.008). The charcoal filter hastened rapid eye opening (11.1±3.8 vs. 14.8±3.0 min, p=0.007) and extubation (11.9±3.9 vs. 15.3±3.2 min, p=0.014), compared to the control group.

Conclusion: A charcoal filter enhances the recovery from sevoflurane anesthesia with a semi-closed rebreathing circuit.

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Related in: MedlinePlus

FA·FA0-1 declined exponentially after sevoflurane anesthesia. A plot equation for exponential decay was derived using the least-squares fit for data from FA·FA0-1 (r2: control=0.885; charcoal filter=0.933). The exponential time constant (τ) of sevoflurane for the charcoal filter group was significantly shorter than that for the control group (1.7±0.5 vs. 2.5±1.1 min, P=0.008). FA·FA0-1, the decay rate of alveolar concentration (FA) during elimination of sevoflurane relative to the last alveolar concentration during administration of sevoflurane (FA0); exp, exponent.
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Figure 3: FA·FA0-1 declined exponentially after sevoflurane anesthesia. A plot equation for exponential decay was derived using the least-squares fit for data from FA·FA0-1 (r2: control=0.885; charcoal filter=0.933). The exponential time constant (τ) of sevoflurane for the charcoal filter group was significantly shorter than that for the control group (1.7±0.5 vs. 2.5±1.1 min, P=0.008). FA·FA0-1, the decay rate of alveolar concentration (FA) during elimination of sevoflurane relative to the last alveolar concentration during administration of sevoflurane (FA0); exp, exponent.

Mentions: The use of a charcoal filter resulted in significantly more rapid eye opening (25% shortening, p=0.007) and shorter extubation time (23% shortening, p=0.014) after sevoflurane anesthesia (Table 2). Elimination of sevoflurane (FA·FA0-1 ratio) was more rapid in the charcoal filter group, and the exponential time constant (τ) of the alveolar anesthetic concentration was significantly shorter in the charcoal filter group (30% shortening, p=0.008) (Table 2, Fig. 3). All the patients in the both groups recovered from anesthesia uneventfully.


Effect of charcoal filter on the emergence from sevoflurane anesthesia in a semi-closed rebreathing circuit.

Chang DJ, Choi SH, Choi YS, Min KT - Yonsei Med. J. (2011)

FA·FA0-1 declined exponentially after sevoflurane anesthesia. A plot equation for exponential decay was derived using the least-squares fit for data from FA·FA0-1 (r2: control=0.885; charcoal filter=0.933). The exponential time constant (τ) of sevoflurane for the charcoal filter group was significantly shorter than that for the control group (1.7±0.5 vs. 2.5±1.1 min, P=0.008). FA·FA0-1, the decay rate of alveolar concentration (FA) during elimination of sevoflurane relative to the last alveolar concentration during administration of sevoflurane (FA0); exp, exponent.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3104448&req=5

Figure 3: FA·FA0-1 declined exponentially after sevoflurane anesthesia. A plot equation for exponential decay was derived using the least-squares fit for data from FA·FA0-1 (r2: control=0.885; charcoal filter=0.933). The exponential time constant (τ) of sevoflurane for the charcoal filter group was significantly shorter than that for the control group (1.7±0.5 vs. 2.5±1.1 min, P=0.008). FA·FA0-1, the decay rate of alveolar concentration (FA) during elimination of sevoflurane relative to the last alveolar concentration during administration of sevoflurane (FA0); exp, exponent.
Mentions: The use of a charcoal filter resulted in significantly more rapid eye opening (25% shortening, p=0.007) and shorter extubation time (23% shortening, p=0.014) after sevoflurane anesthesia (Table 2). Elimination of sevoflurane (FA·FA0-1 ratio) was more rapid in the charcoal filter group, and the exponential time constant (τ) of the alveolar anesthetic concentration was significantly shorter in the charcoal filter group (30% shortening, p=0.008) (Table 2, Fig. 3). All the patients in the both groups recovered from anesthesia uneventfully.

Bottom Line: The elimination kinetics of sevoflurane from end-tidal concentration, Bispectral index and times of eye opening and extubation were obtained.The exponential time constant (τ) of alveolar sevoflurane concentration in the charcoal filter group was significantly shorter than that in the control group (1.7±0.5 vs. 2.5±1.1 min, p=0.008).The charcoal filter hastened rapid eye opening (11.1±3.8 vs. 14.8±3.0 min, p=0.007) and extubation (11.9±3.9 vs. 15.3±3.2 min, p=0.014), compared to the control group.

View Article: PubMed Central - PubMed

Affiliation: Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, 250 Seongsan-ro, Seodaemun-gu, Seoul 120-752, Korea.

ABSTRACT

Purpose: A charcoal filter attached within the anesthetic circuit has been shown to efficiently adsorb halothane or isoflurane, thus hastening anesthetic recovery in low or minimal flow system. This study was intended to demonstrate whether the charcoal filter enhances the recovery time from sevoflurane anesthesia using a semi-closed circuit system.

Materials and methods: Thirty healthy patients scheduled for elective surgery under sevoflurane anesthesia were randomly assigned to the charcoal filter or control group. Upon completion of surgery, the end-tidal concentration of sevoflurane was maintained at 2.0 vol%. A charcoal filter was attached to the expiratory limb of the breathing circuit of charcoal filter group subjects. After sevoflurane was discontinued, ventilation was controlled with the same minute volume as the intra-operative period at a fresh gas flow rate of 5 L·min⁻¹ with 100% O₂. The elimination kinetics of sevoflurane from end-tidal concentration, Bispectral index and times of eye opening and extubation were obtained.

Results: The exponential time constant (τ) of alveolar sevoflurane concentration in the charcoal filter group was significantly shorter than that in the control group (1.7±0.5 vs. 2.5±1.1 min, p=0.008). The charcoal filter hastened rapid eye opening (11.1±3.8 vs. 14.8±3.0 min, p=0.007) and extubation (11.9±3.9 vs. 15.3±3.2 min, p=0.014), compared to the control group.

Conclusion: A charcoal filter enhances the recovery from sevoflurane anesthesia with a semi-closed rebreathing circuit.

Show MeSH
Related in: MedlinePlus