Effects of fresh gas flow, tidal volume, and charcoal filters on the washout of sevoflurane from the Datex Ohmeda (GE) Aisys, Aestiva/5, and Excel 210 SE Anesthesia Workstations.
Can J Anaesth
; 61(10): 935-42, 2014 Oct.
Article
em En
| MEDLINE
| ID: mdl-25069780
ABSTRACT
PURPOSE:
We investigated the effects of tidal volume (VT), fresh gas flow (FGF), and a charcoal filter in the inspiratory limb on the washout of sevoflurane from the following Datex Ohmeda (GE) Anesthesia Workstations (AWSs) Aisys, Aestiva/5, and Excel 210SE.METHODS:
After equilibrating the AWSs with 2% sevoflurane, the anesthetic was discontinued, and the absorbent anesthesia breathing circuit (ABC), reservoir bag, and test lung were changed. The lung was ventilated with 350 or 200 mL·breath(-1), 15 breaths·min(-1), and a FGF of 10 L·min(-1) while the washout of sevoflurane was performed in triplicate using a calibrated Datex Ohmeda Capnomac Ultima™ and a calibrated MIRAN SapphIRe XL ambient air analyzer until the concentration was ≤ 10 parts per million (ppm). The effects of decreasing the FGF to 5 and 2 L·min(-1) after the initial washout and of a charcoal filter in the ABC were recorded separately.RESULTS:
The median washout times with the Aisys AWS (14 min, P < 0.01) and the Aestiva/5 (17 min, P < 0.001) with VT 350 mL·breath(-1) were significantly less than that with the Excel 210SE (32 min). The mean (95% confidence interval) washout time with the Aisys increased to 23.5 (21.5 to 25.5) min with VT 200 mL·breath(-1) (P < 0.01). Decreasing the FGF from 10 to 5 and 2 L·min(-1) with the Aisys caused a rebound in sevoflurane concentration to ≥ 50 ppm. Placement of a charcoal filter in the inspiratory limb reduced the sevoflurane concentration to < 2 ppm in the Aisys and Aestiva/5 AWSs within two minutes.CONCLUSION:
The GE AWSs should be purged with large FGFs and VTs ~350 mL·breath(-1) for ~25 min to achieve 10 ppm sevoflurane. The FGF should be maintained to avoid a rebound in anesthetic concentration. Charcoal filters rapidly decrease the anesthetic concentration to < 2 ppm.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Anestésicos Inalatórios
/
Anestesiologia
/
Éteres Metílicos
Limite:
Humans
Idioma:
En
Revista:
Can J Anaesth
Assunto da revista:
ANESTESIOLOGIA
Ano de publicação:
2014
Tipo de documento:
Article
País de afiliação:
Estados Unidos