Anesthesia
Conditions
Brief summary
Traditional sodalime CO2 absorbers are known to not only react with CO2 but also with sevoflurane. Therewith, a potentially harmful compound (compound A) is formed that can be nephrotoxic. In the United States, the sevoflurane manufacturer therefore recommends keeping the FGF (FGF) at \>2.0 L min-1 if a sodalime CO2 absorbent is used. Amsorb Plus® (Datex-Ohmeda Inc., Madison, WI, USA), is a novel type of CO2 absorbent that does not react with sevoflurane. This allows the FGF to be reduced to 0.5 L min-1. This has two important advantages: (i) less fresh sevoflurane is added to the circle system, and (ii) the sevoflurane that is in the system does not react with the CO2 absorber. Sevoflurane is a potent greenhouse gas with a 100 year CO2-equivalents of 120. Measures that can reduce the consumption of volatile anaesthetics could make a significant contribution to reducing the carbon footprint of the operative process. Additionally, Amsorb Plus® canisters seem to have a longer life span than sodalime canisters and do not need to be disposed of via toxic waste stream, but via domestic waste. In this study, we were interested if (i) the use of Amsorb Plus leads to a reduction in sevoflurane usage and therefore contribute to a reduction in the CO2 footprint of general anaesthesia with sevoflurane, (ii) Does the use of Amsorb Plus® lead to a reduction in the amount of (toxic) waste produced by operating theatres? Comparator: a traditional sodalime CO2 absorber (Medisorb™ Multi-Absorber Original, CareFusion, Helsinki, Finland).
Interventions
OTHERComparing two CO2 absorbers in the ventilator circuit
General anaesthesia will be induced with a standardised regimen (propofol 0.8-2.5 mg·kg-1, sufentanil 0.2 - 0.5 µg·kg-1 and rocuronium 0.5 - 1 mg·kg-1). After tracheal intubation, anaesthesia will be maintained with sevoflurane targeted at 1 MAC end tidal concentration (corrected for age using the formula by Mapleson) in 40% O2. Different ventilator settings will be compared for 30 minutes (in randomised order): I. Sodalime, FGF 2.0 L min-1. II. Amsorb Plus®, FGF 2.0 L min-1. III. Soda lime, FGF, 0.5 L min-1. IV. Amsorb Plus®, FGF 0.5 L min-1. FGF=fresh gas flow.
Sponsors
Academisch Medisch Centrum - Universiteit van Amsterdam (AMC-UvA)
Study design
Observational model
CASE_CROSSOVER
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to 100 Years
Healthy volunteers
No
Inclusion criteria
* Adult patient * non-pregnant * ASA-I to ASA-III * undergoing Sevoflurane based general anaesthesia (in a therapeutic concentration of 1.0 MAC) * Elective surgery * Scheduled operating time \>2 hours.
Exclusion criteria
* Unable/ unwilling to participate * ASA-IV or higher * Age \< 18 years * Known pregnancy * Contra-indications for sevoflurane anaesthesia * Emergency surgery * Scheduled operating time \<2 hours.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Influence of CO2 filters on Sevoflurane consumption | 30 minutes per filter | Comparing Sevoflurane consumption between Amsorb Plus and sodalime CO2 absorbers |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Influence of fresh gas flow on Sevoflurane consumption | 30 minutes per fresh gas flow setting | Comparing Sevoflurane consumption between 0.5 and 2.0 liters per minute fresh gas flow |
Other
| Measure | Time frame | Description |
|---|---|---|
| Estimated CO2 footprint and environmental impact of general anaesthesia with two different CO2 filters | 30 minutes | Estimate the CO2 footprint and environmental impact of general anaesthesia with sevoflurane comparing two different CO2 filters using life cycle analysis methods. |
| Estimated cost of general anaesthesia with two different CO2 filters | 30 minutes | Estimate the total cost of general anaesthesia with sevoflurane comparing two different CO2 filters using life cycle analysis methods. |
| Estimated CO2 footprint and environmental impact of general anaesthesia with two fresh gas flow settings | 30 minutes | Estimate the CO2 footprint of general anaesthesia with sevoflurane comparing two different fresh gas flow settings using life cycle analysis methods. |
| Estimated cost of general anaesthesia with two fresh gas flow settings | 30 minutes | Estimate the total cost of general anaesthesia with sevoflurane comparing two different fresh gas flow settings. |
Countries
Netherlands
Outcome results
None listed