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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

A hand-made charcoal filter [approximate dimension of the canister; volume of 100 mL, length of 17 cm, and diameter of 3 cm, filled with pallet typed charcoal granules, 4×(5-8) mm] attached into anesthetic circuit.
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Figure 1: A hand-made charcoal filter [approximate dimension of the canister; volume of 100 mL, length of 17 cm, and diameter of 3 cm, filled with pallet typed charcoal granules, 4×(5-8) mm] attached into anesthetic circuit.

Mentions: A hand-made charcoal filter, filled with pallet typed charcoal granules [diameter 4×(5-8) mm, 45 g; Shinki chemical, Seoul, Korea], consists of a canister (approximate dimension; volume of 100 mL, length of 17 cm and diameter of 3 cm), a bacterial filter and two 1×1 mm mesh sieves attached at each end (Fig. 1). In an in vitro pre-test, we measured the effects of charcoal filter on the adsorption of sevoflurane in a semiclosed circle system connected to an artificial lung. Prior to the study, the accuracy of the vaporizer was determined at incremental 1.0 vol% settings to be within ±5% of the dial setting for sevoflurane. An artificial lung (5 L) was connected to the breathing circuit of an anesthetic machine, and a charcoal filter was added to the expiratory limb of the circuit. The artificial lung was ventilated with 100% O2 at a fresh gas flow of 5 L·min-1 (tidal volume of 500 mL and respiratory rate of 12·min-1). Sevoflurane was administered at a vaporizer dial setting of 1.0 vol% for three minutes and the dial setting was then raised to 2.0 vol% and 4.0 vol% every three minutes. The end-tidal sevoflurane concentration (ET-sevo) was measured at the 'Y-piece' and recorded every 30 seconds with and without the charcoal filter using the Dräger Infinity Delta Monitor (Dräger Medical AG&CO, Lübeck, Germany). Charcoal granules were replaced in the device after five times of use to preserve adsorbent power in both in vitro and clinical study.7


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)

A hand-made charcoal filter [approximate dimension of the canister; volume of 100 mL, length of 17 cm, and diameter of 3 cm, filled with pallet typed charcoal granules, 4×(5-8) mm] attached into anesthetic circuit.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 1: A hand-made charcoal filter [approximate dimension of the canister; volume of 100 mL, length of 17 cm, and diameter of 3 cm, filled with pallet typed charcoal granules, 4×(5-8) mm] attached into anesthetic circuit.
Mentions: A hand-made charcoal filter, filled with pallet typed charcoal granules [diameter 4×(5-8) mm, 45 g; Shinki chemical, Seoul, Korea], consists of a canister (approximate dimension; volume of 100 mL, length of 17 cm and diameter of 3 cm), a bacterial filter and two 1×1 mm mesh sieves attached at each end (Fig. 1). In an in vitro pre-test, we measured the effects of charcoal filter on the adsorption of sevoflurane in a semiclosed circle system connected to an artificial lung. Prior to the study, the accuracy of the vaporizer was determined at incremental 1.0 vol% settings to be within ±5% of the dial setting for sevoflurane. An artificial lung (5 L) was connected to the breathing circuit of an anesthetic machine, and a charcoal filter was added to the expiratory limb of the circuit. The artificial lung was ventilated with 100% O2 at a fresh gas flow of 5 L·min-1 (tidal volume of 500 mL and respiratory rate of 12·min-1). Sevoflurane was administered at a vaporizer dial setting of 1.0 vol% for three minutes and the dial setting was then raised to 2.0 vol% and 4.0 vol% every three minutes. The end-tidal sevoflurane concentration (ET-sevo) was measured at the 'Y-piece' and recorded every 30 seconds with and without the charcoal filter using the Dräger Infinity Delta Monitor (Dräger Medical AG&CO, Lübeck, Germany). Charcoal granules were replaced in the device after five times of use to preserve adsorbent power in both in vitro and clinical study.7

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