To Compare the Consumption of Sevoflurane and Desflurane in Low Flow Anaesthesia

To Compare the Consumption of Sevoflurane and Desflurane in Low-flow Anesthesia Using the Recommendations of ASA (American Society of Anaesthesiologist Environmental Sustainability Committee

This prospective observational study aims to compare sevoflurane and Desflurane consumption in low-flow anaesthesia using the ASA (American Society of Anaesthesiology).

Environmental Sustainability Committee recommendations. The patients aged 20-65 years, ASA I and II undergoing surgery under general anaesthesia were included in the study.

Question: Can we reduce our carbon footprint of desflurane and sevoflurane using low-flow anaesthesia, according to the recommendations of the ASA Environment Sustainability Committee?

PRIMARY To compare the mac hour consumption of sevoflurane and desflurane anaesthetic agents under low flow (one litre/min) conditions To calculate the carbon footprint of sevoflurane and desflurane in the study cases.

SECONDARY To test whether a significant generation of carbon monoxide occurs due to the interaction of sevoflurane/desflurane with soda lime in the closed circuit Groups 1) low-flow sevoflurane (LFS)- 1 L/min gas flow 2) low- flow desflurane (LFD)- 1 L/min gas flow Anaesthesia will be administered according to the recommendations of the ASA Environment Sustainability Committee.

Three strategies to reduce the fresh gas flow and environmental contamination are

1. Induction: Set the Vaporizer to Deliver a Concentration Greater than Intended
2. Intubation: Turn Off the Fresh Gas Flow, Not the Vaporizer.
3. Maintenance: Minimize Fresh Gas Flow During Maintenance.

Study Overview

• Status: Completed
• Conditions: Sevoflurane; Desflurane
• Intervention / Treatment: Other: Low flow anaesthesia using ASA enviormental sustanibility commitee recomendation

Detailed Description

OBJECTIVES

PRIMARY To compare the mac hour consumption of sevoflurane and desflurane anaesthetic agents under low flow (one litre/min) conditions To calculate the carbon footprint of sevoflurane and desflurane in the low-flow anaesthesia being used in this study

SECONDARY To test whether a significant generation of carbon monoxide occurs due to the interaction of sevoflurane/desflurane with soda lime in the closed circuit.

Methodology Two groups: 1) low-flow sevoflurane (LFS) 2) low- flow desflurane (LFD) Anaesthesia will be administered according to the recommendations of the ASA Environment Sustainability Committee.

Three strategies to reduce the fresh gas flow and environmental contamination are

1. Induction: Set the Vaporizer to Deliver a Concentration Greater than Intended
2. Intubation: Turn Off the Fresh Gas Flow, Not the Vaporizer.
3. Maintenance: Minimize Fresh Gas Flow During Maintenance.

Five hundred sixty-four patients aged 20-65 and ASA status I-II scheduled for procedures longer than three hours duration at Rajiv Gandhi Cancer Institute & Research Center (RGCI&RC) from 2017-2018 will be included in this study.

Patients having severe cardiac and hepatic problems, renal dysfunction and chronic alcoholism are excluded from the study Computer-generated randomisation will be done to allocate the patients into two equal groups for low-flow sevoflurane and low-flow desflurane anaesthesia.

After the arrival of the patients, aVenous cannula will be inserted; midazolam 0.05 mg. kg-1 will be administered intravenously for anxiolysis. Noninvasive monitors, including electrocardiograms, non-invasive blood pressure monitoring, pulse oximetry, axillary temperature, and bispectral index (BIS), will be applied.

Anaesthesia will be induced with fentanyl (2µg.kg-1 ), propofol (2.5 mg. kg-1 ) and atracurium (0.5mg. kg -1 ) to facilitate endotracheal intubation.

All patients will be mechanically ventilated with a mixture of air-oxygen (50% oxygen + 50% air) in addition to the anaesthetic agent according to the study group using the anaesthesia workstation (Primus®, Dräger, Luebeck, Germany).

The tidal volume will be set at 8mL/kg, and the respiratory frequency will be to maintain an end-tidal CO 2 (Et CO2 ) between 30-35mmHg.

After intubation, anaesthesia will be maintained with the fresh gas flow (FRF) of 4 lit./min and 4% Vol sevoflurane or 6% Vol desflurane in the 50% oxygen/air mixture for 5 minutes.

The fresh gas flow will be decreased to 1 L min-1, and after that, dial concentration will be reduced by 0.5% every 2 minutes to maintain 1 MAC(minimum alveolar concentration).

The dial concentration after that will be adjusted to achieve a value of 1 MAC. An adequate neuromuscular blockade will be achieved by administering atracurium boluses of 0.1mg. kg-1 every 20min.

During skin closure, the anaesthetic will be discontinued, and the patient will receive 100% O 2.

At 25% recovery of the first response to train-of-four stimulation, the neuromuscular blockade will be reversed by neostigmine (4µg.kg-1 ) and atropine (15µg.kg-1 ). ABG( Arterial blood gas) were done baseline and post-procedure.

PARAMETERS TO BE RECORDED:

A. Carbon footprint calculation.

1. Consumption of the anaesthetic agent will be recorded from the logbook Draeger Primus™ on termination of anaesthesia
2. Consumed inhalational agent (ml) in 1 MAC hour. Consumption of the inhalational agent (ml) will be converted to MAC hour consumption by dividing it by the entire duration of 1.0 MAC anaesthesia.
3. Calculation of carbon dioxide equivalent. The consumed inhalational agent (ml) will be converted to tones by volume weight conversion formula (1.465 for Desflurane and 1.522 for Sevoflurane) and then multiplied by( Global warming potential) GWP100 (2540 for Desflurane and 130 for Sevoflurane) to get carbon dioxide equivalent.
4. Estimation of carboxy haemoglobin (CoHb) levels as read from ABG analysis on termination of anaesthesia.

• Study Type: Observational
• Enrollment (Actual): 564

Contacts and Locations

Study Locations

• India
  • Delhi, India, 110085
    • RGCI& RC

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Probability Sample

Study Population

564 patients aged 20-65 and ASA status I-II scheduled for procedures longer than three hours duration at RGCI&RC from 2017-2018 will be included in this study

Description

Inclusion Criteria:

1. Patients with American Society of Anesthesiologists grade (ASA) I & II.
2. Patients with age 20-65 years.

Exclusion Criteria:

1. Contraindications to inhalation agents.
2. Liver dysfunction.
3. Chronic alcoholism.
4. Chronic smokers.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
low-flow sevoflurane (LFS); Anaesthesia will be administered according to the recommendations of ASA Enviornment Sustainability Committee. Three strategies to reduce the fresh gas flow and enviornmental contamination are; Induction: Set the Vaporizer to Deliver a Concentration Greater than Intended; Intubation: Turn Off the Fresh Gas Flow, Not the Vaporizer.; Maintanance: Minimize Fresh Gas Flow During Maintenance.	Other: Low flow anaesthesia using ASA enviormental sustanibility commitee recomendation; Induction: Set the Vaporizer to Deliver a Concentration Greater than Intended; Intubation: Turn Off the Fresh Gas Flow, Not the Vaporizer.; Maintanance: Minimize Fresh Gas Flow During Maintenance.
low- flow desflurane (LFD); Anaesthesia will be administered according to the recommendations of ASA Enviornment Sustainability Committee. Three strategies to reduce the fresh gas flow and enviornmental contamination are; Induction: Set the Vaporizer to Deliver a Concentration Greater than Intended; Intubation: Turn Off the Fresh Gas Flow, Not the Vaporizer.; Maintanance: Minimize Fresh Gas Flow During Maintenance.	Other: Low flow anaesthesia using ASA enviormental sustanibility commitee recomendation; Induction: Set the Vaporizer to Deliver a Concentration Greater than Intended; Intubation: Turn Off the Fresh Gas Flow, Not the Vaporizer.; Maintanance: Minimize Fresh Gas Flow During Maintenance.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To compare the MAC hour consumption of sevoflurane under low flow conditions. To compare the mac hour consumption of sevoflurane and desflurane anasthetic agents under low flow (one litre/min) conditi	To compare the mac hour consumption of sevoflurane anasthetic agents under low flow (one litre/min) conditions To calculate the carbon foot print of sevoflurane and desflurane in the low flow anaesthesia being used in this study	Duration of surgery 4hours,4-6 hours, more than 6hours
To calculate the carbon foot print of sevoflurane and desflurane in low flow anaesthesia	Carbon foot print calculation according to the formula	Duration of surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To test whether significant generation of carbon monoxide occurs due to interaction of sevoflurane / desflurane with sodalime in the closed circuit.	To test whether significant generation of carbon monoxide occurs due to interaction of sevoflurane / desflurane with sodalime in the closed circuit.	end of surgery

Collaborators and Investigators

• Sponsor: Rajiv Gandhi Cancer Institute & Research Center, India

Study record dates

Study Major Dates

• Study Start (Actual): February 16, 2018
• Primary Completion (Actual): September 16, 2021
• Study Completion (Actual): December 1, 2021

Study Registration Dates

• First Submitted: September 19, 2021
• First Submitted That Met QC Criteria: September 17, 2024
• First Posted (Estimated): September 19, 2024

Study Record Updates

• Last Update Posted (Estimated): September 19, 2024
• Last Update Submitted That Met QC Criteria: September 17, 2024
• Last Verified: September 1, 2024

More Information

Terms related to this study

• Keywords: Low flow anesthesia; carbon footprint
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Central Nervous System Depressants; Anesthetics
• Other Study ID Numbers: Res/SCM/23/2017/53

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