The Influence of Two Different CO2 Absorbers on Sevoflurane Consumption During Anaesthesia

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).

Study Overview

• Status: Completed
• Conditions: Anesthesia
• Intervention / Treatment: Other: Comparing two CO2 absorbers in the ventilator circuit

• Study Type: Observational
• Enrollment (Actual): 38

Contacts and Locations

Study Locations

• Netherlands
  • Noord-Holland
    • Amsterdam, Noord-Holland, Netherlands, 1105 AZ
      • Amsterdam UMC, location AMC

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 100 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Patients undergoing general anesthesia with sevoflurane for > 2 hours.

Description

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.

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Crossover
• Time Perspectives: Prospective

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

Study group; Patients undergoing surgery (>120 min) with the use of sevoflurane based general anaesthesia (in 1.0 MAC concentration).

Other: Comparing 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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Influence of CO2 filters on Sevoflurane consumption	Comparing Sevoflurane consumption between Amsorb Plus and sodalime CO2 absorbers	30 minutes per filter

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Influence of fresh gas flow on Sevoflurane consumption	Comparing Sevoflurane consumption between 0.5 and 2.0 liters per minute fresh gas flow	30 minutes per fresh gas flow setting

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Estimated CO2 footprint and environmental impact of general anaesthesia with two different CO2 filters	Estimate the CO2 footprint and environmental impact of general anaesthesia with sevoflurane comparing two different CO2 filters using life cycle analysis methods.	30 minutes
Estimated cost of general anaesthesia with two different CO2 filters	Estimate the total cost of general anaesthesia with sevoflurane comparing two different CO2 filters using life cycle analysis methods.	30 minutes
Estimated CO2 footprint and environmental impact of general anaesthesia with two fresh gas flow settings	Estimate the CO2 footprint of general anaesthesia with sevoflurane comparing two different fresh gas flow settings using life cycle analysis methods.	30 minutes
Estimated cost of general anaesthesia with two fresh gas flow settings	Estimate the total cost of general anaesthesia with sevoflurane comparing two different fresh gas flow settings.	30 minutes

Collaborators and Investigators

• Sponsor: Academisch Medisch Centrum - Universiteit van Amsterdam (AMC-UvA)

Study record dates

Study Major Dates

• Study Start (Actual): February 12, 2020
• Primary Completion (Actual): May 29, 2020
• Study Completion (Actual): May 29, 2020

Study Registration Dates

• First Submitted: February 13, 2020
• First Submitted That Met QC Criteria: February 14, 2020
• First Posted (Actual): February 17, 2020

Study Record Updates

• Last Update Posted (Actual): February 11, 2021
• Last Update Submitted That Met QC Criteria: February 10, 2021
• Last Verified: February 1, 2021

More Information

Terms related to this study

• Other Study ID Numbers: W20_025 # 20.051

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No